Multiplex Detection of Foodborne Pathogens using 3D Nanostructure Swab and Deep Learning-Based Classification of Raman Spectra

Proactive management of foodborne illness requires routine surveillance of foodborne pathogens, which requires developing simple, rapid, and sensitive detection methods. Here, a strategy is presented that enables the detection of multiple foodborne bacteria using a 3D nanostructure swab and deep learning-based Raman signal classification. The nanostructure swab efficiently captures foodborne pathogens, and the portable Raman instrument directly collects the Raman signals of captured bacteria. a deep learning algorithm has been demonstrated, 1D convolutional neural network with binary labeling, achieves superior performance in classifying individual bacterial species. This methodology has been extended to mixed bacterial populations, maintaining accuracy close to 100%. In addition, the gradient-weighted class activation mapping method is used to provide an investigation of the Raman bands for foodborne pathogens. For practical application, blind tests are conducted on contaminated kitchen utensils and foods. The proposed technique is validated by the successful detection of bacterial species from the contaminated surfaces. The use of a 3D nanostructure swab, portable Raman device, and deep learning-based classification provides a powerful tool for rapid identification (≈5 min) of foodborne bacterial species. The detection strategy shows significant potential for reliable food safety monitoring, making a meaningful contribution to public health and the food industry.

Multivariable model of postoperative delirium in cardiac surgery patients: proteomic and demographic contributions

Background

Delirium following cardiac surgery is common, morbid, and costly, but may be prevented with risk stratification and targeted intervention. Preoperative protein signatures may identify patients at increased risk for worse postoperative outcomes, including delirium. In this study, we aimed to identify plasma protein biomarkers and develop a predictive model for postoperative delirium in older patients undergoing cardiac surgery, while also uncovering possible pathophysiological mechanisms.

Methods

SOMAscan analysis of 1,305 proteins in the plasma from 57 older adults undergoing cardiac surgery requiring cardiopulmonary bypass was conducted to define delirium-specific protein signatures at baseline (PREOP) and postoperative day 2 (POD2). Selected proteins were validated in 115 patients using the ELLA multiplex immunoassay platform. Proteins were combined with clinical and demographic variables to build multivariable models that estimate the risk of postoperative delirium and bring light to the underlying pathophysiology.

Results

A total of 115 and 85 proteins from SOMAscan analyses were found altered in delirious patients at PREOP and POD2, respectively (p<0.05). Using four criteria including associations with surgery, delirium, and biological plausibility, 12 biomarker candidates (Tukey's fold change (|tFC|)>1.4, Benjamini-Hochberg (BH)-p<0.01) were selected for ELLA multiplex validation. Eight proteins were significantly altered at PREOP, and seven proteins at POD2 (p<0.05), in patients who developed postoperative delirium compared to non-delirious patients. Statistical analyses of model fit resulted in the selection of a combination of age, sex, and three proteins (angiopoietin-2 (ANGPT2); C-C motif chemokine 5 (CCL5); and metalloproteinase inhibitor 1 (TIMP1); AUC=0.829) as the best performing predictive model for delirium at PREOP. The delirium-associated proteins identified as biomarker candidates are involved with inflammation, glial dysfunction, vascularization, and hemostasis, highlighting the multifactorial pathophysiology of delirium.

Conclusion

Our study proposes a model of postoperative delirium that includes a combination of older age, female sex, and altered levels of three proteins. Our results support the identification of patients at higher risk of developing postoperative delirium after cardiac surgery and provide insights on the underlying pathophysiology. ClinicalTrials.gov ( NCT02546765 ).

Development of reference material for quality control of uranium analysis in marine sediments

Environmental radioactivity monitoring is strengthening due to public concerns over radioactive contamination since the Fukushima nuclear power plant accident. Therefore, various research laboratories, institutes, and universities have been conducting environmental radioactivity surveys around nuclear power plants (NPPs). However, the reliability of the results continues to trigger controversy in society. This study was conducted to develop reference material (RM) for the quality control of 238U and 234U analyses in marine sediments. The RM was prepared according to ISO Guides 31, 34, and 35. A homogeneity test of the marine sediment RM was implemented by analyzing two batch samples from ten bottles using multiple acid digestion and alkali fusion, respectively. We found that the 238U and 234U reference values of the RM were 43.0 ± 1.7 Bq kg-1(k=1) and 41.5 ± 1.9 Bq kg-1(k=1), respectively. This marine sediment RM will be useful for the quality control of analytical methods for similar samples and proficiency tests.

Development of metal radioactive liquid reference material for proficiency test

This study developed liquid reference materials containing various metals, to be used for quality assurance of radiation measurements of the most common metallic wastes generated during the operation or decommissioning of nuclear power plants. The liquid reference materials were prepared by assuming the dissolution of stainless-steel using acid and melting of the major metals present in the stainless steel, namely Fe, Ni, Cr, and Mn, along with the standard sources (134Cs, 137Cs, 60Co, 90Sr). The theoretical massic activity of the standard sources added to the samples and the measured reference values of the gamma and beta emitters in the samples were compared, and they showed good agreement within a one-sigma confidence interval (k = 1). Using the developed reference materials, a proficiency test was conducted on three domestic labs, and the results were evaluated using Z-score. While the evaluation results showed good agreement between the reference values and the reported values for 137Cs and 60Co, all participating labs reported lower values than the reference value for 134Cs. For 90Sr, two out of the three labs reported significantly higher values than the reference value. Based on the results of this study, the developed metal radioactive liquid reference material is expected to be registered as certified reference material (CRM) in the future. They will be used as the CRM for measuring and ensuring the quality of radioactive metal waste.

Elution-free DNA detection using CRISPR/Cas9-mediated light-up aptamer transcription: Toward all-in-one DNA purification and detection tube

Accurate and efficient detection of DNA is crucial for disease diagnosis and health monitoring. The traditional methods for DNA analysis involve multiple steps, including sample preparation, lysis, extraction, amplification, and detection. In this study, we present a one-step elution-free DNA analysis method based on the combination of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated light-up aptamer transcription (CLAT) assay and a DNA-capturing poly(2-dimethylaminomethyl styrene) (pDMAMS)-coated tube. The sample solution and lysis buffer are added to the pDMAMS-coated tube, and the DNA is efficiently captured on the surface via electrostatic interaction and directly detected by CLAT assay. The ability of the CRISPR/Cas9 system to specifically recognize DNA enables direct detection of DNA captured on the pDMAMS-coated tube. The combination of CLAT assay and pDMAMS-coated tube simplifies DNA detection in a single tube without the need for complicated extraction steps, improving sensitivity. Our platform demonstrated attomolar sensitivity in the detection of target DNA in cell lysate (0.92 aM), urine (7.7 aM), and plasma (94.6 aM) samples within 1 h. The practical applicability of this method was further demonstrated in experiments with tumor-bearing mice. We believe that this approach brings us closer to an all-in-one DNA purification and detection tube system and has potential applications in tissue and liquid biopsies, as well as various other DNA sensing applications.

High order assembly of multiple protein cages with homogeneous sizes and shapes via limited cage surface engineering

Protein cages are attractive building blocks to build high order materials such as 3D cage lattices, which offer accurately ordered bio-templates. However, controlling the size or valency of these cage-to-cage assemblies is extremely difficult due to highly multivalent and symmetric cage structures. Here, various high order cage assemblies with homogeneous sizes and geometries are constructed by developing an anisotropic ferritin cage with limitedly exposed binding modules, leucine zipper. The anisotropic ferritin is produced as expressed in cells without the need of complex in vitro cage fabrication by careful subunit manipulation. Ferritin cages with limitedly exposed zippers are assembled around a core ferritin with fully exposed opposing zippers, generating homogeneous high order structures, whereas two fully exposed ferritins are assembled into heterogeneous cage aggregates. Diverse fully exposed core cages are prepared by varying the zipper-ferritin fusion geometries and even by using larger cage structures. With these core cages and the anisotropic ferritin, a range of high order cage assemblies with diverse ferritin valencies (3 to over 12) and sizes (over 40 nm) are created. Cell surface binding and internalization of cage structures are greatly varied by assembly sizes, where high order ferritins are clearly more effective than monomeric ferritin.

Development of concrete reference material for quality assurance/quality control of gamma radioactivity measurement for nuclear power plant decommissioning waste

The Korea Research Institute of Standards and Science has developed a new concrete reference material (RM) for measuring gamma-emitting radionuclides, such as 134Cs, 137Cs, 65Zn, 241Am, and 60Co, to improve and maintain the quality assurance and quality control of the radioactivity measurement in radioactive waste generated during the decommissioning of nuclear power plants. In this study, cement, SiO2, and bentonite, which are the main components of concrete, were mixed in an appropriate ratio with radionuclides. For certification and homogeneity assessment, 10 bottles were randomly selected, two sub-samples were collected from each bottle, and radionuclides were measured via HPGe gamma spectrometry. The results of the homogeneity tests using a one-way analysis of variance on 241Am, 134Cs, 137Cs, 65Zn, and 60Co in the concrete RM fulfilled the requirements of ISO Guide 35. Coincidence summing and self-absorption correction were performed on measurement results by introducing the Monte Carlo efficiency transfer code and Monte Carlo N-Particle transport code. The reference values for five radionuclides (60Co, 65Zn, 241Am, 134Cs, and 137Cs) in the RM were in the range of 15-40 Bq/kg, and the expanded uncertainty was within 10% (k = 2). To the best of our knowledge, this was the first study to develop concrete RM for measuring gamma-emitting radionuclides.

Protein Cages Engineered for Interaction-Driven Selective Encapsulation of Biomolecules

Hollow protein cages have become attractive drug delivery vehicles with high biocompatibility and precise functional/structural manipulability. However, difficulties in effective cargo loading inside the cages have been limiting further development of protein cage-based drug carriers. Here, we developed a specific interaction-driven encapsulation and cellular delivery strategy for various biomolecules by engineering a porous protein cage. The computationally designed hyperstable mi3 protein cage was circularly permuted to fuse the cancer targeting RGD tripeptide to the cage surface and SpyTag (ST), which forms a covalent bond with SpyCatcher (SC), to the cage inner cavity. SC-fused proteins with different sizes and charges could be stably and actively encapsulated in the engineered nanocage via the ST/SC reaction. Cargo protein encapsulation inside the cage was directly confirmed by cryo-electron microscopy (EM) structure determination. In addition, SC-fused monomeric avidin was added to the nanocage to encapsulate various biotinylated (nonprotein) cargos such as oligonucleotides and the anticancer drug doxorubicin. All cargo molecules loaded onto the engineered mi3 were effectively delivered to cells. This work introduces a highly versatile cargo loading/delivery strategy, where loading/delivery interactions, cargo molecules, and cell targeting moieties can be further varied for optimal cellular drug delivery.

Bactericidal Effect of Cecropin A Fused Endolysin on Drug-Resistant Gram-Negative Pathogens

The rapid spread of superbugs leads to the escalation of infectious diseases, which threatens public health. Endolysins derived from bacteriophages are spotlighted as promising alternative antibiotics against multi-drug resistant bacteria. In this study, we isolated and characterized the novel Salmonella typhimurium phage PBST08. Bioinformatics analysis of the PBST08 genome revealed putative endolysin ST01 with a lysozyme-like domain. Since the lytic activity of the purified ST01 was minor, probably owing to the outer membrane, which blocks accessibility to peptidoglycan, antimicrobial peptide cecropin A (CecA) was fused to the N-terminus of ST01 to disrupt the outer membrane. The resulting CecA::ST01 has been shown to have increased bactericidal activity against gram-negative pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Enterobacter cloacae and the most affected target was A. baumannii. In the presence of 0.25 μM CecA::ST01, A. baumannii ATCC 17978 strain was completely killed and CCARM 12026 strain was wiped out by 0.5 μM CecA::ST01, which is a clinical isolate of A. baumannii and resistant to multiple drugs including carbapenem. Moreover, the larvae of Galleria mellonella could be rescued up to 58% or 49% by the administration of CecA::ST01 upon infection by A. baumannii 17978 or CCARM 12026 strain. Finally, the antibacterial activity of CecA::ST01 was verified using 31 strains of five gram-negative pathogens by evaluation of minimal inhibitory concentration. Thus, the results indicate that a fusion of antimicrobial peptide to endolysin can enhance antibacterial activity and the spectrum of endolysin where multi-drug resistant gram-negative pathogens can be efficiently controlled.

POS1060 CHANGES IN DISEASE ACTIVITY AND PATIENT-REPORTED OUTCOMES IN PSORIATIC ARTHRITIS PATIENTS TREATED WITH IXEKIZUMAB IN A REAL-WORLD US COHORT

Background

Ixekizumab (IXE), an IL-17A inhibitor, has demonstrated efficacy in clinical trials1-3 but real-world effectiveness (RWE) data are limited.4

Objectives

To describe changes in disease activity and patient-reported outcomes (PROs) at 6 and 12 months follow-up among psoriatic arthritis (PsA) patients initiating IXE in a routine clinical setting.

Methods

This retrospective cohort study included patients from the OM1 PsA Registry (OM1, Boston, MA), a linked electronic medical record and administrative claims dataset with over 50,000 patients. Eligible patients had ≥1 prescription for IXE (first = index), were ≥18 years old at index, had ≥1 diagnosis code for PsA in the 12 months before or on index, and had ≥12 months of baseline and ≥6 months of follow-up data as of June 2021. For patients with baseline and follow-up measures available, changes in Clinical Disease Activity Index (CDAI), PROs, and other clinical outcomes from baseline to 6 and 12 months were described. For patients on IXE monotherapy, change in CDAI score from baseline to 6 and 12 months was assessed using mixed effects linear models adjusted for age, sex, and baseline CDAI score.

Results

The study population included 1,812 patients with a mean age of 53.7 years (Table 1). Psoriasis was present in 82% and enthesitis in 28%. Over 60% of patients were obese, and the mean Charlson Comorbidity Index was 1.3. Most patients (84%) had prior treatment with a biologic disease-modifying antirheumatic drug (bDMARD) and 40% with a targeted synthetic DMARD (tsDMARD). The mean number of bDMARDs and tsDMARDs used during all available prior history was 2.3 and 1.1, respectively. The most common prior bDMARDs were secukinumab (n=428, 24%) and adalimumab (n=245, 14%).

Table 1.

Demographic and Clinical Characteristics by Therapy Status

All Patients(N=1,812)Monotherapy(N=1,485)Combination Therapy(N=327)Age (years)Mean (s.d.)53.7 (12.2)53.9 (12.3)52.9 (11.7)Median (Q1-Q3)55 (46-62)55 (46-62)54 (45-61)SexFemale1,108 (61.1%)909 (61.2%)199 (60.9%)Male704 (38.9%)576 (38.8%)128 (39.1%)Charlson Comorbidity IndexMean (s.d.)1.3 (1.6)1.3 (1.6)1.5 (1.7)Median (Q1-Q3)1 (0-2)1 (0-2)1 (0-2)BMIUnderweight: <18.510 (0.6%)10 (0.7%)0 (0.0%)Normal weight: 18.5-24.9210 (12.2%)172 (12.2%)38 (12.1%)Overweight: 25-29.9455 (26.5%)379 (27.0%)76 (24.2%)Obese: >= 301,045 (60.8%)845 (60.1%)200 (63.7%)Missing927913Domains of PsA: PsoriasisYes1,490 (82.2%)1,222 (82.3%)268 (82.0%)No322 (17.8%)263 (17.7%)59 (18.0%)Domains of PsA: EnthesitisYes510 (28.1%)409 (27.5%)101 (30.9%)No1,302 (71.9%)1,076 (72.5%)226 (69.1%)

Of patients with a baseline CDAI score, 61% had moderate or severe disease activity. For all patients, CDAI scores improved (decreased) by an average of 3.4 and 3.7 points at 6 and 12 months, respectively, from a baseline mean of 15.4. All disease activity measures and PROs improved from baseline to 6 and 12 months (Figure 1). In patients persistent with IXE, 35.3% and 33.7% were in CDAI remission or low disease activity at 6 and 12 months after initiation, respectively. For IXE monotherapy users (82% of patients), at baseline, patients had a mean CDAI of 14.3 (n=131) and 15.1 (n=105) for the 6 and 12 month analyses, respectively. Adjusted mean changes in CDAI from baseline to 6 months (-3.6 points, p < 0.0001) and 12 months (-4.9 points, p < 0.0001) were statistically significant.

Conclusion

In this cohort of PsA patients with multiple prior b/tsDMARD failures, improvements in disease activity and PROs were observed at 6 and 12 months after initiating treatment with IXE. Improvements were observed in patients overall and in the monotherapy subgroup. More real-world research on IXE and other bDMARDs are important to understand the effect of treatment choices on clinical and PROs in both bDMARD-naive and experienced PsA patients.

References

[1]Mease PJ. Ann. Rheum. Dis. 2017;76(1):79-87

[2]Nash P. Lancet. 2017;389(10086):2317-2327

[3]Mease PJ. Ann. Rheum. Dis. 2020;79(1):123-131

[4]Berman J. Biologics. 2021 Nov 18;15:463-470

Disclosure of Interests

Julie Birt Shareholder of: Shareholder of Eli Lilly and Company, Employee of: Employee of Eli Lilly and Company, William Tillett Speakers bureau: Abbvie, Amgen, Celgene, Eli-Lilly, Janssen, MSD, Novartis,, Pfizer, UCB, Consultant of: Abbvie, Amgen, Celgene, Eli-Lilly, Janssen, MSD, Novartis, Pfizer, UCB, Grant/research support from: Abbvie, Amgen, Celgene, Eli-Lilly, Janssen, UCB, Cristi Cavanaugh: None declared, Yoojin Jung: None declared, Aisha Vadhariya Shareholder of: Shareholder of Eli Lilly and Company, Employee of: Employee of Eli Lilly and Company, Sarah Ross Shareholder of: Shareholder of Eli Lilly and Company, Employee of: Employee of Eli Lilly and Company, Jess Paulus: None declared, Aubrey Trevelin Sprabery Shareholder of: Shareholder of Eli Lilly and Company, Employee of: Employee of Eli Lilly and Company, Ennio Lubrano: None declared

Valence-controlled protein conjugation on nanoparticles via re-arrangeable multivalent interactions of tandem repeat protein chains

Tandem repeat protein chains were wrapped around nanoparticles via re-arrangeable multivalent interactions for valence controlled protein conjugation.

Lipid coated protein condensates as stable protocells with selective uptake abilities for biomolecules

To create cell-like synthetic systems, spatial confinement that is stable against environmental changes and selective uptake of diverse biomolecules into these compartments are key initial conditions. However, fabrication of protocells with these two features has been extremely difficult. Here, we used fully protein-based liquid condensates and a lipid coating on these condensates to construct highly stable protocells with an uptake ability for outside biomolecules. Condensates with an extremely high density of 6His-tagged proteins were coated with Ni(ii)-NTA(nitrilotriacetic acid)-modified lipids. High condensate rigidity and specific 6His-Ni-NTA interactions enabled the formation of lipid–protein protocells, which are stable even after centrifugations. In addition, immobile lipid coatings on condensates were permeable to outside biomolecules. When binding modules were fused into condensate-forming proteins, the resulting functionalized condensate-protocells could strongly and selectively uptake various outside proteins through specific protein interactions.

Lipid-coated protein condensates, which are formed via specific protein–lipid interactions, were stable against centrifugation but selectively permeable to external biomolecules.

Determinants for intrinsically disordered protein recruitment into phase-separated protein condensates

Multivalent interactions between amino acid residues of intrinsically disordered proteins (IDPs) drive phase separation of these proteins into liquid condensates, forming various membrane-less organelles in cells. These interactions between often biased residues of IDPs are also likely involved in selective recruitment of many other IDPs into condensates. However, determining factors for this IDP recruitment into protein condensates are not understood yet. Here, we quantitatively examined recruitment tendencies of various IDPs with different sequence compositions into IDP-clustered condensates both in vitro as well as in cells. Condensate-forming IDP scaffolds, recruited IDP clients, and phase separation conditions were carefully varied to find key factors for selective IDP partitioning in protein condensates. Regardless of scaffold sequences, charged residues in client IDPs assured potent IDP recruitment, likely via strong electrostatic interactions, where positive residues could further enhance recruitment, possibly with cation–pi interactions. Notably, poly-ethylene glycol, a widely used crowding reagent for in vitro phase separation, abnormally increased IDP recruitment, indicating the need for careful use of crowding conditions. Tyrosines of IDP clients also strongly participated in recruitment both in vitro and in cells. Lastly, we measured recruitment degrees by more conventional interactions between folded proteins instead of disordered proteins. Surprisingly, recruitment forces by an even moderate protein interaction (K_d ∼ 5 μM) were substantially stronger than those by natural IDP–IDP interactions. The present data offer valuable information on how cells might organize protein partitioning on various protein condensates.

Diverse interactions between folded and disordered proteins collectively dictate selective protein recruitment into bimolecular condensates.

High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

Risk factors for the delayed diagnosis of extrapulmonary TB

BACKGROUND: Extrapulmonary TB (EPTB) is more difficult to diagnose than pulmonary TB. The delayed management of EPTB can lead to complications and increase the socio-economic burden.METHODS: Patients newly diagnosed with EPTB were retrospectively enrolled from 11 general hospitals in South Korea from January 2017 to December 2018. The basic characteristics of patients were described. Univariable and multivariable analyses were performed between early and delayed diagnosis groups to identify risk factors for delayed diagnosis and treatment in EPTB.RESULTS: In total, 594 patients were enrolled. Lymph node TB (28.3%) was the predominant form, followed by abdominal (18.4%) and disseminated TB (14.5%). Concurrent lung involvement was 17.8%. The positivity of diagnostic tests showed no significant difference between the two groups. Acute clinical manifestations in disseminated, pericardial and meningeal TB, and immunosuppression were associated with early diagnosis. Delayed diagnosis was associated with outpatient clinic visits, delayed sample acquisition and diagnostic departments other than infection or pulmonology.CONCLUSION: The delay in diagnosis and treatment of EPTB was not related to differences in microbiological characteristics of Mycobacterium tuberculosis itself; rather, it was due to the indolent clinical manifestations that cause referral to non-TB-specialised departments in the outpatient clinic and delay the suspicion of TB and diagnostic testing.

MULTIPHYSICS MODELING OF PRECURSORS IN MOLTEN SALT FAST REACTORS USING PROTEUS AND Nek5000

The goal of this work was to calculate the impact of the delayed neutron precursor drift in fast spectrum Molten Salt Reactors (MSRs) using coupled solutions from the neutronics code PROTEUS and the computational fluid dynamics code Nek5000. Specifically, using a multiphysics approach to solve the effective delayed neutron fraction (βeff) or delayed neutron precursor distribution for reactors with flowing fuel salts would provide valuable information for transient simulations and safety assessments. Given the multiple options for the flux solution and geometric resolution/fidelity in PROTEUS, two approaches were developed and applied to various test cases: PROTEUS-NODAL/Nek5000 and PROTEUS-SN/Nek5000. For the former, the precursors are tracked in the built-in precursor drift model in PROTEUS-NODAL, whereas in the latter, Nek5000 directly tracks the precursors. Both approaches were used to solve a single test channel problem and showed excellent agreement in the calculated βeff. Separately, a 3D hourglass-shaped core was modeled using the PROTEUS-SN/Nek5000 approach. This problem was designed to demonstrate the capability of the discrete ordinates (SN) solver and Nek5000 to model complex core designs with axially varying geometries and the ability for Nek5000 to track the precursors and calculate the resulting βeff. In addition, the Nek5000 calculations revealed the presence of recirculation zones in the hourglass design, which could lead to significant temperatures in the fuel salt and surrounding materials. These first coupled solutions show why these approaches may be necessary for not only predicting the precursor drift effect in fast MSRs but also for reactor design and performance assessments.

Advances in Mechanical Thrombectomy for Acute Ischemic Stroke Due to Large Vessel Occlusion

Acute ischemic stroke (AIS) is a significant cause of global morbidity and mortality, with functional implications for quality of life and long-term disability. The limitations of intravenous thrombolytic therapy for the treatment of AIS, especially for emergent large vessel occlusion (ELVO), have paved the way for alternative therapies and the rapidly evolving landscape of endovascular therapy (EVT). Here, we summarize the major landmark trials that have advanced the field largely due to ongoing biomedical engineering device development that have translated into significantly improved clinical outcomes. Our review describes the clinical success of EVT, and current and future trends.

Oxytocin receptor expression in stallion testes and epididymides

Endocrine, paracrine, and autocrine factors orchestrate the development and physiology of the stallion reproductive system. Oxytocin (OXT) is one of the critical endocrine, paracrine, and autocrine factors for the male reproductive system. Previous studies have investigated OXT receptor (OXTR) expression in testes and epididymides, including humans, marmosets, macaques, swine, and sheep. This study aimed to explore (1) OXTR localization in the testes and epididymides and (2) the seasonal modification of OXTR expression in the testes. Adult stallion testis and epididymis samples were prepared using routine castration procedures. Reverse-transcription PCR was performed to detect the presence of OXTR messenger RNA (mRNA) in the testes. Western blot procedure was performed to confirm the cross-reactivity of OXTR antibody to horse OXTR. Immunohistochemistry was performed to detect OXTR protein expression in the testes and epididymides. Oxytocin receptor mRNA was detected in the stallion testes. The OXTR protein band was observed at 55 kDa. Interestingly, the relative intensity of the OXTR protein band varied between nonbreeding and breeding season. The OXTR protein level in the testes collected during the breeding season was higher than that during the nonbreeding season. Oxytocin receptor localization was observed in the cytoplasm of Type A spermatogonia and spermatid. Oxytocin receptor protein expression was also observed in the cytoplasmic area of Leydig cells and the membrane of the seminiferous tubules. The cytoplasm of principal and basal cells in the caput, corpus, and cauda was also immunolabeled with OXTR antibody. In conclusion, based on the expression of OXTR in tissues of testes and epididymides, OXT-OXTR system may be a critical factor for stallion testicular and epididymal function. In addition, according to the seasonal alteration of intensity, the OXT-OXTR system may be associated with seasonal changes in the reproductive system in stallions.

Multivalent-Interaction-Driven Assembly of Discrete, Flexible, and Asymmetric Supramolecular Protein Nano-Prisms

Current approaches to design monodisperse protein assemblies require rigid, tight, and symmetric interactions between oligomeric protein units. Herein, we introduce a new multivalent-interaction-driven assembly strategy that allows flexible, spaced, and asymmetric assembly between protein oligomers. We discovered that two polygonal protein oligomers (ranging from triangle to hexagon) dominantly form a discrete and stable two-layered protein prism nanostructure via multivalent interactions between fused binding pairs. We demonstrated that protein nano-prisms with long flexible peptide linkers (over 80 amino acids) between protein oligomer layers could be discretely formed. Oligomers with different structures could also be monodispersely assembled into two-layered but asymmetric protein nano-prisms. Furthermore, producing higher-order architectures with multiple oligomer layers, for example, 3-layered nano-prisms or nanotubes, was also feasible.

Client proximity enhancement inside cellular membrane-less compartments governed by client-compartment interactions

Membrane-less organelles or compartments are considered to be dynamic reaction centers for spatiotemporal control of diverse cellular processes in eukaryotic cells. Although their formation mechanisms have been steadily elucidated via the classical concept of liquid-liquid phase separation, biomolecular behaviors such as protein interactions inside these liquid compartments have been largely unexplored. Here we report quantitative measurements of changes in protein interactions for the proteins recruited into membrane-less compartments (termed client proteins) in living cells. Under a wide range of phase separation conditions, protein interaction signals were vastly increased only inside compartments, indicating greatly enhanced proximity between recruited client proteins. By employing an in vitro phase separation model, we discovered that the operational proximity of clients (measured from client-client interactions) could be over 16 times higher than the expected proximity from actual client concentrations inside compartments. We propose that two aspects should be considered when explaining client proximity enhancement by phase separation compartmentalization: (1) clients are selectively recruited into compartments, leading to concentration enrichment, and more importantly, (2) recruited clients are further localized around compartment-forming scaffold protein networks, which results in even higher client proximity.

Interplay between intrinsically disordered proteins inside membraneless protein liquid droplets

Intrinsically disordered proteins (IDPs) in cells phase separate to form diverse membraneless organelles, which have condensed liquid droplet-like properties and often contain multiple IDPs. However, how potential interactions between different IDPs affect the dynamic behavior of these protein droplets is largely unknown. Here, we develop a rapid IDP clustering system to generate protein droplets with varied residue compositions and examine diverse interacting IDPs inside droplets. Three different IDP droplets actively recruited other diverse IDPs inside droplets with extremely varied enrichment (inside/outside) degrees (over 100-fold variation) under highly crowded conditions. The recruited IDPs were mostly mobile even inside highly immobile droplets. Among the five tested IDPs, the disordered region of Ddx4 helicase with its unique multiple charged residue blocks was noticeably influenced by droplet mobility. We also discovered that droplets of different IDPs could rapidly fuse to each other. Interestingly, some droplets were heterogeneously fused with segregated subcompartments, and this segregation was enhanced by droplet maturation and was more apparent for specific IDP pairs, in which the polar and charged residue compositions are highly different. The present study not only reports multiple peculiar behaviors of interacting IDP pairs inside droplets but also provides valuable information on generating membraneless organelle models with controllable droplet properties.

Membraneless droplets of intrinsically disordered proteins (IDPs) with varied residue compositions uniquely interact with each other as droplets and clients.

Fabrication of rigidity and space variable protein oligomers with two peptide linkers

Supramolecular protein assemblies have garnered considerable interest due to their potential in diverse fields with unrivaled attainable functionalities and structural accuracy. Despite significant advances in protein assembly strategies, inserting long linkers with varied lengths and rigidity between assembling protein building blocks remains extremely difficult. Here we report a series of green fluorescent protein (GFP) oligomers, where protein building blocks were linked via two independent peptide strands. Assembling protein units for this two-peptide assembly were designed by flopped fusion of three self-assembling GFP fragments with two peptide linkers. Diverse flexible and rigid peptide linkers were successfully inserted into high-valent GFP oligomers. In addition, oligomers with one flexible linker and one rigid linker could also be fabricated, allowing more versatile linker rigidity control. Linker length could be varied from 10 amino acids (aa) even up to 76 aa, which is the longest among reported protein assembling peptide linkers. Discrete GFP oligomers containing diverse linkers with valencies between monomers to decamers were monodispersely purified by gel elution. Furthermore, various functional proteins could be multivalently fused to the present GFP oligomers. Binding assays, size exclusion chromatography, dynamic light scattering, circular dichroism, differential scanning calorimetry, and transmission electron microscopy suggested circular geometries of the GFP oligomers and showed distinct characteristics of GFP oligomers with length/rigidity varied linkers. Lastly, a surface binding study indicated that more spaced oligomeric binding modules offered more effective multivalent interactions than less spaced modules.

Cerebral Ketones Detected by 3T MR Spectroscopy in Patients with High-Grade Glioma on an Atkins-Based Diet

BACKGROUND AND PURPOSE

Ketogenic diets are being explored as a possible treatment for several neurological diseases, but the physiologic impact on the brain is unknown. The objective of this study was to evaluate the feasibility of 3T MR spectroscopy to monitor brain ketone levels in patients with high-grade gliomas who were on a ketogenic diet (a modified Atkins diet) for 8 weeks.

MATERIALS AND METHODS

Paired pre- and post-ketogenic diet MR spectroscopy data from both the lesion and contralateral hemisphere were analyzed using LCModel software in 10 patients.

RESULTS

At baseline, the ketone bodies acetone and β-hydroxybutyrate were nearly undetectable, but by week 8, they increased in the lesion for both acetone (0.06 ± 0.03 ≥ 0.27 ± 0.06 IU, P = .005) and β-hydroxybutyrate (0.07 ± 0.07 ≥ 0.79 ± 0.32 IU, P = .046). In the contralateral brain, acetone was also significantly increased (0.041 ± 0.01 ≥ 0.16 ± 0.04 IU, P = .004), but not β-hydroxybutyrate. Acetone was detected in 9/10 patients at week 8, and β-hydroxybutyrate, in 5/10. Acetone concentrations in the contralateral brain correlated strongly with higher urine ketones (r = 0.87, P = .001) and lower fasting glucose (r = -0.67, P = .03). Acetoacetate was largely undetectable. Small-but-statistically significant decreases in NAA were also observed in the contralateral hemisphere at 8 weeks.

CONCLUSIONS

This study suggests that 3T MR spectroscopy is feasible for detecting small cerebral metabolic changes associated with a ketogenic diet, provided that appropriate methodology is used.

Monomeric Covalent-Avidin for Rapid and Covalent Labeling of Quantum Dots to Cell Surface Proteins

With high brightness and photostability, quantum dots (QDs) are potent probes for long-term imaging of dynamic cell surface proteins, but practical methods to covalently label QDs to target proteins for stable imaging are largely lacking. Here, a small covalent-bond forming protein (Covalent-avidin)/peptide pair is introduced, which provides a recombinant protein-based rapid and covalent QD labeling strategy. Covalent-avidin is constructed by optimized fusion of circular permuted monomeric avidin to SpyCatcher, which forms an isopeptide bond with the SpyTag peptide. Covalent-avidin-conjugated QDs allow for strong and irreversible QD labeling to the biotinylated SpyTag-fused adrenergic receptor on live cells in 2 min. In addition, QDs with only a minimum number of conjugated Covalent-avidin show more stable receptor labeling than commercially available streptavidin-conjugated QDs, also with minimal unwanted clustering of labeled receptors. Monomeric Covalent-avidin will be a valuable protein linker for diverse other nanolabeling structures with beneficial properties such as covalent linkages and facile valency control.

Homo-molecular Fluorescence Complementation for Direct Visualization of Receptor Oligomerization in Living Cells

Cell surface receptor oligomerization is an attractive target process for drug screening. However, simple but reliable (and thus high-throughput) visualization methods for receptor oligomerization are still lacking. Herein, we report on a new single-construct homo-molecular fluorescence complementation (Homo-FC) probe, which shows strong fluorescence signals by oligomerization of fused receptors in living cells with unexpectedly low background signals. Importantly, this high signal-to-noise ratio was not affected by expression level variations of fused receptors. The Homo-FC probe was developed by optimized flopped fusion of split fragments of superfolder green fluorescence protein and subsequent surface charge engineering. Homo-FC reliably visualized the oligomerization of diverse natural receptors such as GPCR, EGFR, and even cytosolic DAI.

CXCR3 ligands in pleural fluid as markers for the diagnosis of tuberculous pleural effusion

SETTING

A tertiary care academic medical centre.

OBJECTIVE

To evaluate the clinical usefulness of C-X-C motif chemokine receptor 3 (CXCR3) ligands in tuberculous pleural effusion (TPE).

DESIGN

We recruited 336 patients with pleural effusion due to various causes. Concentrations of interferon-gamma (IFN-γ) and the CXCR3 ligands CXCL9 and CXCL11 were determined using enzyme immunoassays; adenosine deaminase (ADA) activity was measured in pleural fluid and serum.

RESULTS

TPE was diagnosed in 106 patients. Non-TB conditions included lung cancer (n = 95), para-pneumonic effusion (n = 52), non-lung malignancy (n = 30), other exudate (n = 24) and transudate (n = 29) disorders. All marker levels in serum samples and pleural fluid were significantly higher in the TPE group. Analyses of receiver operating characteristic curves for differentiating TPE from non-TB effusions produced the following results for the area under the curve (AUC) for CXCL9, CXCL11, IFN-γ and ADA, respectively: 0.982, 0.952, 0.982, and 0.952. Marker AUCs in lymphocytic exudates were also high. Combining the levels of CXCL9, IFN-γ and ADA in pleural fluid improved the diagnostic performance. Serum levels of CXCL9 had the highest AUC (0.848) for diagnosing TPE.

CONCLUSION

Levels of CXR3 ligands in pleural effusion are useful for diagnosing TPE.

Discovery of fluorescent 3-heteroarylcoumarin derivatives as novel inhibitors of anaplastic lymphoma kinase

Coumarin-based ALK inhibitors were identified as a new template for the development of novel fluorescent ALK inhibitors, which can be tracked using microscopy techniques.