Applying artificial intelligence and computational modeling to nanomedicine.

Achieving specific and targeted delivery of nanomedicines to diseased tissues is a major challenge. This is because the process of designing, formulating, testing, and selecting a nanoparticle delivery vehicle for a specific disease target is governed by complex multivariate interactions. Computational modeling and artificial intelligence are well-suited for analyzing and modeling large multivariate datasets in short periods of time. Computational approaches can be applied to help design nanomedicine formulations, interpret nanoparticle-biological interactions, and create models from high-throughput screening techniques to improve the selection of the ideal nanoparticle carrier. In the future, many steps in the nanomedicine development process will be done computationally, reducing the number of experiments and time needed to select the ideal nanomedicine formulation.

Enhancement of dielectrophoresis-based particle collection from high conducting fluids due to partial electrode insulation.

Dielectrophoresis (DEP) is a successful method to recover nanoparticles from different types of fluid. The DEP force acting on these particles is created by an electrode microarray that produces a nonuniform electric field. To apply DEP to a highly conducting biological fluid, a protective hydrogel coating over the metal electrodes is required to create a barrier between the electrode and the fluid. This protects the electrodes, reduces the electrolysis of water, and allows the electric field to penetrate into the fluid sample. We observed that the protective hydrogel layer can separate from the electrode and form a closed domed structure and that collection of 100 nm polystyrene beads increased when this occurred. To better understand this collection increase, we used COMSOL Multiphysics software to model the electric field in the presence of the dome filled with different materials ranging from low-conducting gas to high conducting phosphate-buffered saline fluids. The results suggest that as the electrical conductivity of the material inside the dome is reduced, the whole dome acts as an insulator which increases electric field intensity at the electrode edge. This increased intensity widens the high-intensity electric field factor zone resulting in increased collection. This informs how dome formation results in increased particle collection and provides insight into how the electric field can be intensified to the increase collection of particles. These results have important applications for increasing the recovery of biologically-derived nanoparticles from undiluted physiological fluids that have high conductance, including the collection of cancer-derived extracellular vesicles from plasma for liquid biopsy applications.

On-chip dielectrophoretic recovery and detection of a lactate sensing probiotic from model human saliva.

Early detection has led to increased survival for multiple cancers; however, the 5-year survival rate of oral carcinoma (OC) has remained at 40% for the last several decades. Screening for OC is routinely done via visual examinations, followed by tissue biopsy and laboratory testing. Point-of-care testing would be a more convenient and widely available alternative for at-risk individuals. Increased lactate production is a hallmark of many head-and-neck tumors, due to the Warburg Effect, where tumor cells favor glycolysis in the place of oxidative phosphorylation. To detect excess lactate, we have modified the commensal bacterium Escherichia coli Nissle 1917 to express fluorescent reporter genes in response to extracellular lactate. Administering this commensal as a mouth wash and subsequently collecting saliva for the detection of the reporter may allow for noninvasive, early detection of cancerous lesions in at-risk individuals. Furthermore, we demonstrate a new on-chip electrokinetic technique to recover these probiotic probes from model saliva fluid to improve the detection of reporter gene activation.

Turning antibodies off and on again using a covalently tethered blocking peptide.

In their natural form, antibodies are always in an "on-state" and are capable of binding to their targets. This leads to undesirable interactions in a wide range of therapeutic, analytical, and synthetic applications. Modulating binding kinetics of antibodies to turn them from an "off-state" to an "on-state" with temporal and spatial control can address this. Here we demonstrate a method to modulate binding activity of antibodies in a predictable and reproducible way. We designed a blocking construct that uses both covalent and non-covalent interactions with the antibody. The construct consisted of a Protein L protein attached to a flexible linker ending in a blocking-peptide designed to interact with the antibody binding site. A mutant Protein L was developed to enable photo-triggered covalent crosslinking to the antibody at a specific location. The covalent bond anchored the linker and blocking peptide to the antibody light chain keeping the blocking peptide close to the antibody binding site. This effectively put the antibody into an "off-state". We demonstrate that protease-cleavable and photocleavable moieties in the tether enable controlled antibody activation to the "on-state" for anti-FLAG and cetuximab antibodies. Protein L can bind a range of antibodies used therapeutically and in research for wide applicability.

Open Speech Platform: Democratizing Hearing Aid Research.

Hearing aids help overcome the challenges associated with hearing loss, and thus greatly benefit and improve the lives of those living with hearing-impairment. Unfortunately, there is a lack of adoption of hearing aids among those that can benefit from hearing aids. Hearing researchers and audiologists are trying to address this problem through their research. However, the current proprietary hearing aid market makes it difficult for academic researchers to translate their findings into commercial use. In order to abridge this gap and accelerate research in hearing health care, we present the design and implementation of the Open Speech Platform (OSP), which consists of a co-design of open-source hardware and software. The hardware meets the industry standards and enables researchers to conduct experiments in the field. The software is designed with a systematic and modular approach to standardize algorithm implementation and simplify user interface development. We evaluate the performance of OSP regarding both its hardware and software, as well as demonstrate its usefulness via a self-fitting study involving human participants.

A Wearable, Extensible, Open-Source Platform for Hearing Healthcare Research.

Hearing loss is one of the most common conditions affecting older adults worldwide. Frequent complaints from the users of modern hearing aids include poor speech intelligibility in noisy environments and high cost, among other issues. However, the signal processing and audiological research needed to address these problems has long been hampered by proprietary development systems, underpowered embedded processors, and the difficulty of performing tests in real-world acoustical environments. To facilitate existing research in hearing healthcare and enable new investigations beyond what is currently possible, we have developed a modern, open-source hearing research platform, Open Speech Platform (OSP). This paper presents the system design of the complete OSP wearable platform, from hardware through firmware and software to user applications. The platform provides a complete suite of basic and advanced hearing aid features which can be adapted by researchers. It serves web apps directly from a hotspot on the wearable hardware, enabling users and researchers to control the system in real time. In addition, it can simultaneously acquire high-quality electroencephalography (EEG) or other electrophysiological signals closely synchronized to the audio. All of these features are provided in a wearable form factor with enough battery life for hours of operation in the field.

Feasibility of Measurement and Adherence to System Performance Measures for Rheumatoid Arthritis in 5 Models of Care.

OBJECTIVE: To test the feasibility of reporting on 4 national performance measures for patients with rheumatoid arthritis (RA) in 5 different models of care. METHODS: The following performance measures were evaluated in 5 models of care: waiting time (WT) to rheumatologist consultation, percentage of patients seen in yearly followup (FU), percentage taking disease-modifying antirheumatic drugs (DMARD), and time to starting DMARD. All models aimed to improve early access and care for patients with RA. RESULTS: A number of feasibility issues were encountered in performance measure evaluation because of differences in site data collection and/or the duration of the model of care. For example, while 4/5 programs maintained clinical or research databases, chart reviews were still required to report on WT. Median WT for care in 2015 varied by site between 21 and 75 days. Yearly FU rates could only be calculated in 2 sites (combined owing to small numbers) and varied between 83% and 100%. Percentage of patients taking a DMARD and time to DMARD could be calculated in 3 models, and rates of DMARD use were between 90% and 100%, with median time to DMARD of 0 days in each. CONCLUSION: Our review has shown that even in models of care designed to improve access to care and early treatment, data to document improvements are often lacking. Where data were available for measuring, deficits in WT performance were noted for some centers. Our results highlight a need to improve reporting processes to drive quality improvement.

A Wearable Platform for Research in Augmented Hearing.

We have previously reported a realtime, open-source speech-processing platform (OSP) for hearing aids (HAs) research. In this contribution, we describe a wearable version of this platform to facilitate audiological studies in the lab and in the field. The system is based on smartphone chipsets to leverage power efficiency in terms of FLOPS/watt and economies of scale. We present the system architecture and discuss salient design elements in support of HA research. The ear-level assemblies support up to 4 microphones on each ear, with 96 kHz, 24 bit codecs. The wearable unit runs OSP Release 2018c on top of 64-bit Debian Linux for binaural HA with an overall latency of 5.6 ms. The wearable unit also hosts an embedded web server (EWS) to monitor and control the HA state in realtime. We describe three example web apps in support of typical audiological studies they enable. Finally, we describe a baseline speech enhancement module included with Release 2018c, and describe extensions to the algorithms as future work.

A Realtime, Open-Source Speech-Processing Platform for Research in Hearing Loss Compensation.

We are developing a realtime, wearable, open-source speech-processing platform (OSP) that can be configured at compile and run times by audiologists and hearing aid (HA) researchers to investigate advanced HA algorithms in lab and field studies. The goals of this contribution are to present the current system and propose areas for enhancements and extensions. We identify (i) basic and (ii) advanced features in commercial HAs and describe current signal processing libraries and reference designs to build a functional HA. We present performance of this system and compare with commercial HAs using "Specification of Hearing Aid Characteristics," the ANSI 3.22 standard. We then describe a wireless protocol stack for remote control of the HA parameters and uploading media and HA status for offline research. The proposed architecture enables advanced research to compensate for hearing loss by offloading processing from ear-level-assemblies, thereby eliminating the bottlenecks of CPU and communication between left and right HAs.

Drug-induced lupus erythematosus presenting with cardiac tamponade: a case report and literature review.

The presentation of drug-induced lupus erythematosus (DILE) is typically mild, with a significantly lower incidence of life-threatening end-organ dysfunction relative to idiopathic systemic lupus erythematosus. DILE is an uncommon cause of cardiac tamponade but has been reported in patients treated with procainamide, isoniazid, hydralazine, sulfasalazine, and carbamazepine. We present a case of DILE presenting with cardiac tamponade associated with infliximab use that resolved with discontinuation of the medication and administration of high-dose steroids. In conclusion, DILE should be considered in the differential diagnosis in cases of pericarditis with cardiac tamponade without a clear cause.

UGT2B17 copy number gain in a large ankylosing spondylitis multiplex family.

BACKGROUND: The primary objective of this study is to identify novel copy number variations (CNVs) associated with familial ankylosing spondylitis (AS). A customized genome-wide microarray was designed to detect CNVs and applied to a multiplex AS family with six (6) affected family members. CNVs were detected using the built-in DNA analytics aberration detection method-2 (ADM-2) algorithm. Gene enrichment analysis was performed to observe the segregation. Subsequent validation was performed using real time quantitative fluorescence polymerase reaction (QF-PCR). The frequency of copy number variation for the UGT2B17 gene was then performed on two well-defined AS cohorts. Fisher exact test was performed to quantify the association. RESULTS: Our family-based analysis revealed ten gene-enriched CNVs that segregate with all six family members affected with AS. Based on the proposed function and the polymorphic nature of the UGT2B17 gene, the UGT2B17 gene CNV was selected for validation using real time QF-PCR with full concordance. The frequency of two copies of the UGT2B17 gene CNV was 0.41 in the Newfoundland AS cases and 0.35 in the Newfoundland controls (OR = 1.26(0.99-1.59); p < 0.05)), whereas the frequency of two (2) copies of the UGT2B17 gene CNV was 0.40 in the Alberta AS cases and 0.39 in the Alberta controls (OR = 1.05(95% CI: 0.83-1.33); p < 0.71)). CONCLUSIONS: A genome-wide microarray interrogation of a large multiplex AS family revealed segregation of the UGT2B17 gene CNV among all affected family members. The association of the UGT2B17 CNV with AS is particularly interesting given the recent association of this CNV with osteoporosis and the proposed function as it encodes a key enzyme that inhibits androgens. However, two copies of the UGT2B17 gene CNV were only marginally significant in a uniplex AS cohort from Newfoundland but not in a uniplex AS cohort from Alberta.

Novel mechanism of inhibition of rat kidney-type glutaminase by bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide (BPTES).

The release of GA (mitochondrial glutaminase) from neurons following acute ischaemia or during chronic neurodegenerative diseases may contribute to the propagation of glutamate excitotoxicity. Thus an inhibitor that selectively inactivates the released GA may limit the accumulation of excess glutamate and minimize the loss of neurological function that accompanies brain injury. The present study examines the mechanism of inactivation of rat KGA (kidney GA isoform) by the small-molecule inhibitor BPTES [bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide]. BPTES is a potent inhibitor of KGA, but not of the liver GA isoform, glutamate dehydrogenase or gamma-glutamyl transpeptidase. Kinetic studies indicate that, with respect to glutamine, BPTES has a K(i) of approx. 3 microM. Moreover, these studies suggest that BPTES inhibits the allosteric activation caused by phosphate binding and promotes the formation of an inactive complex. Gel-filtration chromatography and sedimentation-velocity analysis were used to examine the effect of BPTES on the phosphate-dependent oligomerization of KGA. This established that BPTES prevents the formation of large phosphate-induced oligomers and instead promotes the formation of a single oligomeric species with distinct physical properties. Sedimentation-equilibrium studies determined that the oligomer produced by BPTES is a stable tetramer. Taken together, the present work indicates that BPTES is a unique and potent inhibitor of rat KGA and elucidates a novel mechanism of inactivation.

Association of toll-like receptor 4 variants and ankylosing spondylitis: a case-control study.

OBJECTIVE: Functional single nucleotide polymorphisms within the ectoplasmic domain of the Toll-like receptor 4 (TLR4) gene have been shown to result in an endotoxin-hyporesponsive phenotype and aberrant signal transduction for bacterial agonists. TLR4 is in proximity to a genome-wide linkage peak in 9q32-33. Given the proposed function and location of TLR4, we examined the association of 2 functional variants of TLR4 in patients with ankylosing spondylitis (AS) in Newfoundland. METHODS: In total, 101 AS patients and 100 ethnically matched controls were genotyped, using the Sequenom MassArray platform, for 2 functional variants in the TLR4 gene: Asp299Gly (A/G polymorphism) and Thr399Ile (C/T polymorphism). RESULTS: The minor allele frequency for the Asp299Gly variant (G) was significantly higher in AS cases compared to controls (7.5% vs 2.6%, respectively; OR 3.10, p = 0.037). The minor allele frequency for the Thr399Ile variant (T) for cases and controls was 7.4% vs 3.0% (OR 2.59, p = 0.071). Haplotype analysis using Haploview noted a higher proportion of GT in the cases (for GT, chi-squared p = 0.023). CONCLUSION: Given the functional role of TLR4 variants in the innate immune system, larger studies are now warranted to elucidate the association of TLR4 variants in AS.

Association of functional variants of PTPN22 and tp53 in psoriatic arthritis: a case-control study.

Recent studies have implicated PTPN22 and tp53 in susceptibility to several autoimmune diseases, including rheumatoid arthritis, suggesting that these genes are important in maintaining immune homeostasis. Because autoimmune diseases may share similar susceptibility loci, investigation of these genes in psoriatic arthritis (PsA) is of potential relevance. As a result we investigated known coding polymorphisms in PTPN22 and tp53 in a homogenous Caucasian PsA cohort from Newfoundland, Canada and an admixed Caucasian PsA cohort from Toronto, Canada. We observed a moderate association of the R620W variant of PTPN22 with PsA in the Toronto population only. Because of the conflicting findings reported regarding the association of PTPN22 with PsA, further studies in other PsA populations are warranted.

Association of nuclear factor-kappaB in psoriatic arthritis.

OBJECTIVE: To examine the association of single nucleotide polymorphisms (SNP) in the NFKB1 gene, as well as 2 genes in the nuclear factor (NF)-kappaB functional complex (RelA and NFKBIA), in patients with psoriatic arthritis (PsA) from Newfoundland. METHODS: Patients with PsA and controls were genotyped for one 4-base insertion/deletion and 5 SNP in NFKB1, 4 SNP in RelA, and 7 SNP in NFKBIA by time-of-flight mass spectrometry, using the Sequenom platform. Chi-square analysis was used to test the single locus associations between SNP in the NF-kappaB complex and PsA. Associations between multi-locus haplotypes and case or control status were tested using the software PHASE. RESULTS: Two hundred and twenty-four patients with PsA (52% male) and 88 ethnically matched controls (64% male) were genotyped. No association was noted with any of the SNP tested for the single locus associations in NFKB1, RelA, and NFKBIA or with multi-locus haplotypes. In particular, the allele frequency for the NFKB1 -94delATTG was 41.7% in cases and 41.6% in the controls (p = 0.97). CONCLUSION: No association between the NFKB1 -94 ins/delATTG promoter polymorphism or with other NF-kappaB complex SNP in patients with PsA from Newfoundland was observed.

Microwave-assisted synthesis of N,N'-diaryl cyanoguanidines.

[reaction: see text] A mild, efficient, and high-yielding method for the synthesis of N,N'-diaryl cyanoguanidines from their corresponding thioureas under microwave-assisted conditions is described. A series of cyanoguanidines were synthesized containing both electron-donating and electron-withdrawing substituents. The reactions were facilitated by the use of polar solvents along with moderate temperatures.

The effect of ingestion of ferrous sulfate on the absorption of oral methotrexate in patients with rheumatoid arthritis.

OBJECTIVE: To investigate if ingestion of ferrous sulfate, 300 mg twice daily, will reduce the urinary excretion of unmetabolized methotrexate (MTX) in patients with rheumatoid arthritis (RA) who ingest 2 drugs concurrently, and determine if ferrous sulfate interferes with the absorption of oral MTX. METHODS: In this randomized double-blind placebo controlled crossover study, we compared the urinary excretion of unmetabolized MTX in 10 patients with RA who ingested 7.5 mg MTX as their weekly dose and took either ferrous sulfate 300 mg twice daily or placebo. RESULTS: Ten patients with RA taking 7.5 mg MTX orally once weekly had an average 24 h urine excretion of MTX (while taking 300 mg ferrous sulfate twice daily for one week) of 8.44 micromoles compared to 7.65 micromoles for patients taking placebo. The difference was not statistically significant (p = 0.50). CONCLUSION: Our results showed no less absorption of MTX for the placebo group compared to the group that took ferrous sulfate. These results do not support the hypothesis that ferrous sulfate interferes with the absorption of oral MTX.

Elevated serum nitric oxide levels in patients with inflammatory arthritis associated with co-expression of inducible nitric oxide synthase and protein kinase C-eta in peripheral blood monocyte-derived macrophages.

OBJECTIVE: To quantify circulating nitric oxide (NO) levels and inducible NO synthase (iNOS) expression in peripheral blood monocyte-derived macrophages (PB-MDM) from patients with inflammatory arthritis (IA) as a measure of disease activity, and to determine if there is a correlation between expression of iNOS and protein kinase C-eta (PKC-eta). METHODS: PB-MDM were isolated from whole blood of 20 patients with IA (14 rheumatoid arthritis and 6 peripheral spondyloarthropathies). Thirteen patients with osteoarthritis (OA) and 9 healthy individuals were controls. Serum NO levels were measured by indirect determination of nitrite and nitrate. Expression of PKC-eta and iNOS was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. RESULTS: Serum NO (189.9 +/- 49.7 microM) was significantly higher (p < 0.0028) in IA patients than in controls (131.1 +/- 18.5 microM) or patients with OA (126.9 +/- 37.1 microM). IA patients with severe inflammation had highest levels of NO, while those with mild inflammation had normal levels of NO. RT-PCR showed that PB-MDM from IA patients with active disease co-expressed iNOS and PKC-eta. This was observed in 15 out of 16 cases. All other groups with normal plasma NO expressed neither gene. CONCLUSION: Our findings show that elevated plasma NO levels were only present in IA patients with severe disease activity. We show for the first time a positive correlation between PKC-eta and iNOS expression in arthritis, supporting our earlier in vitro findings that PKC-eta expression was essential for lipopolysaccharide-mediated iNOS induction and NO production in human monocytes. PKC-eta may be important for the development of IA-induced iNOS positive phenotype in human PB-MDM.

Direct synthesis of guanidines using di(imidazole-1-yl)methanimine.

A direct synthetic approach to guanidine compounds is reported here using di(imidazole-1-yl)methanimine and di(imidazole-1-yl)cyanomethanimine as guanylating reagents.