Incidental finding of a retained intracorneal wooden foreign body.

We present a case of an intracorneal wooden foreign body that remained undetected for 15 years following an ocular injury sustained during gardening. The patient presented with stable visual acuity despite the long-standing presence of a wooden splinter embedded in the cornea. Interestingly, Pentacam corneal tomography did not show any abnormalities despite the foreign body piercing through the corneal stroma and endothelium. This case may serve as an opportunity to re-examine the approach to managing chronic and stable intracorneal wooden foreign bodies and explore the implications of continued observation rather than surgical management.

A novel bivalent interaction mode underlies a non-catalytic mechanism for Pin1-mediated Protein Kinase C regulation.

Regulated hydrolysis of the phosphoinositide phosphatidylinositol(4,5)-bis-phosphate to diacylglycerol and inositol-1,4,5-P3 defines a major eukaryotic pathway for translation of extracellular cues to intracellular signaling circuits. Members of the lipid-activated protein kinase C isoenzyme family (PKCs) play central roles in this signaling circuit. One of the regulatory mechanisms employed to downregulate stimulated PKC activity is via a proteasome-dependent degradation pathway that is potentiated by peptidyl-prolyl isomerase Pin1. Here, we show that contrary to prevailing models, Pin1 does not regulate conventional PKC isoforms α and ßII via a canonical cis-trans isomerization of the peptidyl-prolyl bond. Rather, Pin1 acts as a PKC binding partner that controls PKC activity via sequestration of the C-terminal tail of the kinase. The high-resolution structure of Pin1 complexed to the C-terminal tail of PKCßII reveals that a novel bivalent interaction mode underlies the non-catalytic mode of Pin1 action. Specifically, Pin1 adopts a compact conformation in which it engages two conserved phosphorylated PKC motifs, the turn motif and hydrophobic motif, the latter being a non-canonical Pin1-interacting element. The structural information, combined with the results of extensive binding studies and in vivo experiments suggest that non-catalytic mechanisms represent unappreciated modes of Pin1-mediated regulation of AGC kinases and other key enzymes/substrates.

Reversible and irreversible inhibitors of coronavirus Nsp15 endoribonuclease.

The emergence of severe acute respiratory syndrome coronavirus 2, the causative agent of coronavirus disease 2019, has resulted in the largest pandemic in recent history. Current therapeutic strategies to mitigate this disease have focused on the development of vaccines and on drugs that inhibit the viral 3CL protease or RNA-dependent RNA polymerase enzymes. A less-explored and potentially complementary drug target is Nsp15, a uracil-specific RNA endonuclease that shields coronaviruses and other nidoviruses from mammalian innate immune defenses. Here, we perform a high-throughput screen of over 100,000 small molecules to identify Nsp15 inhibitors. We characterize the potency, mechanism, selectivity, and predicted binding mode of five lead compounds. We show that one of these, IPA-3, is an irreversible inhibitor that might act via covalent modification of Cys residues within Nsp15. Moreover, we demonstrate that three of these inhibitors (hexachlorophene, IPA-3, and CID5675221) block severe acute respiratory syndrome coronavirus 2 replication in cells at subtoxic doses. This study provides a pipeline for the identification of Nsp15 inhibitors and pinpoints lead compounds for further development against coronavirus disease 2019 and related coronavirus infections.

Restoration of PITPNA in Type 2 diabetic human islets reverses pancreatic beta-cell dysfunction.

Defects in insulin processing and granule maturation are linked to pancreatic beta-cell failure during type 2 diabetes (T2D). Phosphatidylinositol transfer protein alpha (PITPNA) stimulates activity of phosphatidylinositol (PtdIns) 4-OH kinase to produce sufficient PtdIns-4-phosphate (PtdIns-4-P) in the trans-Golgi network to promote insulin granule maturation. PITPNA in beta-cells of T2D human subjects is markedly reduced suggesting its depletion accompanies beta-cell dysfunction. Conditional deletion of Pitpna in the beta-cells of Ins-Cre, Pitpnaflox/flox mice leads to hyperglycemia resulting from decreasing glucose-stimulated insulin secretion (GSIS) and reducing pancreatic beta-cell mass. Furthermore, PITPNA silencing in human islets confirms its role in PtdIns-4-P synthesis and leads to impaired insulin granule maturation and docking, GSIS, and proinsulin processing with evidence of ER stress. Restoration of PITPNA in islets of T2D human subjects reverses these beta-cell defects and identify PITPNA as a critical target linked to beta-cell failure in T2D.

Towards better understanding the stiffness of nanocomposites via parametric study of an analytical model modeling parameters and experiments.

The stiffness of polymeric materials can be improved dramatically with the addition of nanoparticles. In theory, as the nanoparticle loading in the polymer increases, the nanocomposite becomes stiffer; however, experiments suggest that little or no stiffness improvement is observed beyond an optimal nanoparticle loading. The mismatch between the theoretical and experimental findings, particularly at high particle loadings, needs to be understood for the effective use of nanoparticles. In this respect, we have recently developed an analytical model to close the gap in the literature and predict elastic modulus of nanocomposites. The model is based on a three-phase Mori-Tanaka model coupled with the Monte-Carlo method, and satisfactorily captures the experimental results, even at high nanoparticle loadings. The developed model can also be used to study the effects of agglomeration in nanocomposites. In this paper, we use this model to study the effects of agglomeration and related model parameters on the stiffness of nanocomposites. In particular, the effects of particle orientation, critical distance, dispersion state and agglomerate property, and particle aspect ratio are investigated to demonstrate capabilities of the model and to observe how optimal particle loading changes with respect these parameters. The study shows that the critical distance defining agglomerates and the properties of agglomerates are the key design parameters at high particle loadings. These two parameters rule the optimal elastic modulus with respect to particle loading. The findings will allow researchers to form design curves and successfully predict the elastic moduli of nanocomposites without the exhaustive experimental undertakings.

Nanoparticle-based surface enhanced Raman spectroscopic imaging of biological arrays.

Surfaces serve as the communication link between the adsorbate and the substrate. Hence, a thorough understanding of the surface chemistries directly interfacing with biological molecules and other adsorbates would provide insight into the fabrication approach as well as the adsorption characteristics of biomolecules adsorbed on the surface. This paper presents a surface-enhanced Raman spectroscopy (SERS) method for high-sensitivity detection and reading of protein microarrays based on gold nanoparticle labels. The reagent employed was 30 nm gold nanoparticles modified with a bifunctional Raman reporter molecule, 5,5'-dithiobis(succinimidyl-2-nitrobenzoate) (DSNB), to integrate anti-bovine IgG for an antigen response in the immunoassay and generate an intense SERS signal. The signal from the DSNB reporter molecule, particularly the strong symmetric nitro stretch was used for the detection of antigen-antibody interactions. Issues related to the sensitivity and selectivity of the assay were also addressed. This work provides useful insights into SERS-based immunoassays and serves as the basis for an eventful adventure into interfacial biomolecular interactions.

A predictive model towards understanding the effect of reinforcement agglomeration on the stiffness of nanocomposites.

Nanocomposite technologies can be significantly enhanced through a careful exploration of the effects of agglomerates on mechanical properties. Existing models are either overly simplified (e.g., neglect agglomeration effects) or often require a significant amount of computational resources. In this study, a novel continuum-based model with a statistical approach was developed. The model is based on a modified three-phase Mori-Tanaka model, which accounts for the filler, agglomerate, and matrix regions. Fillers are randomly dispersed in a defined space to predict agglomeration tendency. The proposed model demonstrates good agreement with the experimentally measured elastic moduli of spin-coated cellulose nanocrystal reinforced polyamide-6 films. The techniques and methodologies presented in the study are sufficiently general in that they can be extended to the analyses of various types of polymeric nanocomposite systems.

Application of Surface-Enhanced Raman Spectroscopy to Guide Therapy for Advanced Prostate Cancer Patients.

A critical unmet need for advanced prostate cancer (PCa) patients is optimizing systemic treatments to maximize the benefit for individuals. The response of patients with metastatic castration-resistant prostate cancer (mCRPC) to androgen receptor (AR)-directed hormonal treatments (i.e., enzalutamide and abiraterone) is mediated by the expression of a molecular variant of the androgen receptor called androgen receptor variant 7 (AR-V7). Detection and measurement of AR-V7 in mCRPC patients will lead to more informed PCa treatment. Herein, we demonstrate a quantitative nanoparticle-enhanced sandwich antibody assay for the successful ex vivo measurement of AR-V7 protein in serum from mCRPC patients. The nanoparticles are constructed as extrinsic Raman spectroscopy labels (ERLs), and surface-enhanced Raman spectroscopy (SERS) is used for assay readout. Our approach does not require specialized specimen collection materials, circulating tumor cell enrichment, or pretreatment of serum. Calibration of our assay is accomplished by expressing AR-V7 in an appropriate cell line as AR-V7 is not commercially available. We demonstrate a linear calibration curve from cell lysate and correlate lysate protein with mRNA from cultured prostate cancer cells. Finally, we demonstrate a novel pilot-scale application for clinical use by quantitatively measuring AR-V7 in serum of seven advanced PCa patients. Distinct separation of PCa patients by AR-V7 status (positive or negative) was observed. Together, the presence and amount of AR-V7 in serum offer predictive and prognostic value to inform selection between two classes of systemic treatments (i.e., hormones or taxanes). Triaging patients that are AR-V7-positive to other systemic treatments (e.g., taxane-based chemotherapy) can improve progression-free survival and overall survival.

Investigating the effect of inquiry-based stress reduction on mortality awareness and interpersonal problems among intensive care unit nurses.

INTRODUCTION: Caring for dying patients is one of the job stressors. Nurses in intensive care units are among the medical staff who have a close interaction with dying patients. Studies have shown that psychological interventions are very helpful in improving thinking about death and its problems. Therefore, this study was conducted to investigate the effect of Inquiry-Based Stress Reduction on mortality awareness and interpersonal problems among intensive care unit nurses in southeastern Iran. MATERIALS AND METHODS: This was a Quasi-experimental study with a pretest-posttest design in southeast of Iran in 2021. Nurses were selected using the convenience sampling method and divided into intervention (n = 32) and control (n = 35) groups using the block randomization method. The intervention group received a two-hour Inquiry-Based Stress Reduction counseling session every week for 6 weeks. Data were gathered using Multidimensional Mortality Awareness Measure and Inventory of Interpersonal Problems before, immediately after, and 6 weeks after the intervention. IBM SPSS Statistics software version 25 was used for data analysis. RESULTS: In the intervention group, the mean scores of Mortality Awareness before, immediately after, and 6 weeks after the intervention were 130.41 ± 5.91, 164.47 ± 8.66, and 163.91 ± 9.29, respectively. Therefore, in the intervention group, the increase of Mortality Awareness mean score was statistically significant (P < 0.001). In the control group, the mean scores of Mortality Awareness before, immediately after, and 6 weeks after intervention were 129.63 ± 5.59, 135.26 ± 11.14, and 132.66 ± 5.62, respectively. Difference between the two groups was significant (P < 0.001). The results also showed that in the intervention group the mean scores of Interpersonal Problems immediately after and 6 weeks after the intervention were lower than before the intervention (P < 0.001). In the control group, Interpersonal Problems increased over time (P < 0.001). Accordingly, the difference between the two groups in terms of Interpersonal Problems during the study was statistically significant (P < 0.001). CONCLUSION: The study results suggest that the Inquiry-Based Stress Reduction is an appropriate intervention method to improve mortality awareness and reduce interpersonal problems in intensive care unit nurses.

Psychological Predictors of Mortality Awareness: Time Perspective, Contentment With Age and Paternal Antipathy and Neglect.

Much research has focused upon the association between mortality awareness and mental ill-health. In this study we attempt to explore positive as well as negative psychological concomitants of mortality awareness. 170 participants were recruited in an online questionnaire study, measuring seven independent variables - marginalisation, childhood adversity, rebelliousness, time perspective, attitudes toward age and stage of life, health attitudes and demographics - and five dependent variables, specifically mortality legacy, mortality fearfulness, mortality acceptance, mortality disempowerment and mortality disengagement. Several significant bivariate associations were found. Follow-up regression analysis observed combined effects of variables accounting for 28% of variance in mortality legacy, 27% for mortality fearfulness, 13% for mortality acceptance, 42% for mortality disempowerment and 25% for mortality disengagement. Time perspective, contentment with age, and paternal antipathy and neglect were the most notable independent predictors. It was concluded that attitudes towards health, stage of life and childhood experiences significantly predict mortality awareness.

Lipid transfer proteins and instructive regulation of lipid kinase activities: Implications for inositol lipid signaling and disease.

Cellular membranes are critical platforms for intracellular signaling that involve complex interfaces between lipids and proteins, and a web of interactions between a multitude of lipid metabolic pathways. Membrane lipids impart structural and functional information in this regulatory circuit that encompass biophysical parameters such as membrane thickness and fluidity, as well as chaperoning the interactions of protein binding partners. Phosphatidylinositol and its phosphorylated derivatives, the phosphoinositides, play key roles in intracellular membrane signaling, and these involvements are translated into an impressively diverse set of biological outcomes. The phosphatidylinositol transfer proteins (PITPs) are key regulators of phosphoinositide signaling. Found in a diverse array of organisms from plants, yeast and apicomplexan parasites to mammals, PITPs were initially proposed to be simple transporters of lipids between intracellular membranes. It now appears increasingly unlikely that the soluble versions of these proteins perform such functions within the cell. Rather, these serve to facilitate the activity of intrinsically biologically insufficient inositol lipid kinases and, in so doing, promote diversification of the biological outcomes of phosphoinositide signaling. The central engine for execution of such functions is the lipid exchange cycle that is a fundamental property of PITPs. How PITPs execute lipid exchange remains very poorly understood. Molecular dynamics simulation approaches are now providing the first atomistic insights into how PITPs, and potentially other lipid-exchange/transfer proteins, operate.

Evaluation of the electroanalytical performance of carbon-on-gold films prepared by electron-beam evaporation.

Carbon film electrodes can often be used without pretreatment, and their fabrication allows for flexibility in size and shape and for mass production. In this work, we are exploring layered structures comprised of thin films of carbon on gold (eC/Au) prepared by electron-beam evaporation. These extremely flat films are not pyrolyzed and are comprised of mainly amorphous carbon but still exhibit reasonable conductivity due to the underlying gold layer. eC/Au electrodes, without any pretreatment, yield similar heterogeneous electron-transfer rates for benchmark redox systems and significantly lower background current in comparison with polished glassy carbon. Interestingly, they show insignificant adsorption of quinones, which is uncommon for most carbon electrode materials. However, eC/Au is still prone to adsorption of airborne hydrocarbons when exposed to ambient air like most graphitic materials. With reproducibly fast electron transfer kinetics, low background current, negligible adsorption, and ultraflat surface, eC/Au films are a promising candidate for electrochemical and sensor applications.

Gold nanostars as a colloidal substrate for in-solution SERS measurements using a handheld Raman spectrometer.

The evolution of Raman spectroscopy into a useful analytical technique has been due, in part, to the development of inexpensive, compact instrumentation and advancements in methodologies that enhance Raman intensities. Surface enhanced Raman scattering (SERS) is a primary methodology for quantitative and low detection limit measurements. While a broad array of applications using solid SERS substrates have been demonstrated, in-solution SERS measurements are not as widely pursued. This work seeks to optimize the synthesis of gold nanostars (AuNS) as a colloidal SERS substrate for in-solution measurements using handheld instrumentation. The types and concentrations of two buffers typically used for AuNS synthesis are examined to optimize the SERS intensity of a chemisorbed Raman probe. The observed SERS intensity primarily depends on conditions that allow higher surface coverage of the probe. Conditions that result in AuNS aggregates are found to be most optimal for SERS, similar to other nanoparticle shapes. A method to quantitate methimazole, an anti-hormone pharmaceutical, in urine is developed and reported. The primary impact of this work is the demonstration of the combination of water dispersible substrates and handheld instrumentation for rapid and sensitive analytical measurements.

Stretchable, tough, self-recoverable, and cytocompatible chitosan/cellulose nanocrystals/polyacrylamide hybrid hydrogels.

As medical practitioners' interest in hydrogels continues to grow, their new expectations in terms of mechanical properties, biocompatibility and durability are changed. Here, we demonstrated a new strategy to improve both mechanical properties and self-recovery of double network (DN) hydrogels by introducing a self-healing network, consisting of carboxymethyl chitosan (CMC) and dialdehyde cellulose nanocrystals (DACNC). Notably, the hydrogel could be repeatedly stretched to 4 times its initial length and has tensile strength of 244 kPa, and completely recovered its shape when compressed by 90% and had the compressive strength up to 8 MPa. In addition, the deformed hydrogel recovered 81.3% of its dissipated energy at room temperature without any external stimuli. The hydrogel also exhibited good biocompatibility. We have developed a new method to fabricate stretchable and tough hydrogels that could spontaneously self-repair following mechanical deformation. They are promising for controlled drug release and dye adsorption.

Factors Associated with the Development of Posterior Capsule Opacification Requiring Yttrium Aluminum Garnet Capsulotomy.

SIGNIFICANCE: Determining risk factors for posterior capsule opacification will allow for further interventions to reduce the risk of development and thus additional procedures. PURPOSE: The purpose of this study was to investigate risk factors associated with development of clinically significant posterior capsule opacification requiring yttrium aluminum garnet (YAG) capsulotomy. METHODS: Medical records of patients (≥18 years) who underwent cataract surgery between January 1, 2011, and March 31, 2014, at Kresge Eye Institute were reviewed. Three hundred eyes requiring YAG capsulotomy up to 3 years after cataract surgery were included in the YAG capsulotomy group. Three hundred eyes not requiring YAG capsulotomy up to 3 years after cataract surgery were selected via age-matched simple randomization (control group). RESULTS: The YAG capsulotomy group included patients with younger age (65.8 ± 11.3 vs. 70.1 ± 10.6 years, P < .001), more men (42.67 vs. 34.67%, P = .04), fewer patients with hypertension (73.00 vs. 83.00%, P < .001), and more patients with hydrophilic intraocular lenses (74.67 vs. 47.00%, P < .001). Logistic regression analysis demonstrated a negative association between YAG capsulotomy and age (coefficient, -0.04; 95% confidence interval [CI], 0.95 to 0.98; P < .001) and hydrophobic intraocular lenses (coefficient, -1.50; 95% CI, 0.15 to 0.33; P < .001), and a positive association with presence of glaucoma (coefficient, 0.88; 95% CI, 1.39 to 4.17; P = .002). Elapsed time to YAG capsulotomy was sooner in patients with a history of uveitis (95% CI, 5.10 to 9.70 months; P = .02) and insertion of hydrophilic intraocular lenses (95% CI, 18.67 to 21.57 months; P < .001). CONCLUSIONS: Results of this study suggest that development of visually significant posterior capsule opacification is associated with younger age, glaucoma, and hydrophilic intraocular lenses, and it occurs earlier among those with hydrophilic intraocular lenses and a history of uveitis.

The interface between phosphatidylinositol transfer protein function and phosphoinositide signaling in higher eukaryotes.

Phosphoinositides are key regulators of a large number of diverse cellular processes that include membrane trafficking, plasma membrane receptor signaling, cell proliferation, and transcription. How a small number of chemically distinct phosphoinositide signals are functionally amplified to exert specific control over such a diverse set of biological outcomes remains incompletely understood. To this end, a novel mechanism is now taking shape, and it involves phosphatidylinositol (PtdIns) transfer proteins (PITPs). The concept that PITPs exert instructive regulation of PtdIns 4-OH kinase activities and thereby channel phosphoinositide production to specific biological outcomes, identifies PITPs as central factors in the diversification of phosphoinositide signaling. There are two evolutionarily distinct families of PITPs: the Sec14-like and the StAR-related lipid transfer domain (START)-like families. Of these two families, the START-like PITPs are the least understood. Herein, we review recent insights into the biochemical, cellular, and physiological function of both PITP families with greater emphasis on the START-like PITPs, and we discuss the underlying mechanisms through which these proteins regulate phosphoinositide signaling and how these actions translate to human health and disease.

Immuno-impedimetric Biosensor for Onsite Monitoring of Ascospores and Forecasting of Sclerotinia Stem Rot of Canola.

Sclerotinia stem rot, caused by the fungal pathogen Sclerotinia sclerotiorum, is a destructive disease of canola and many other broadleaf crops. The primary inoculum responsible for initiating Sclerotinia epidemics is airborne ascospores released from the apothecia of sclerotia. Timely detection of the presence of airborne ascospores can serve as an early-warning system for forecasting and management of the disease. A major challenge is to develop a portable and automated device which can be deployed onsite to detect and quantify the presence of minute quantities of ascospores in the air and serves as a unit in a network of systems for forecasting of the epidemic. In this communication, we present the development of an impedimetric non-Faradaic biosensor based on anti-S. sclerotiorum polyclonal antibodies as probes to selectively capture the ascospores and sense their binding by an impedance based interdigitated electrode which was found to directly and unambiguously correlate the number of ascospores on sensor surface with the impedance response.

A surface plasmon resonance based inhibition immunoassay for measurement of steroid hormones.

Quantitative measurement of small-molecule metabolites is now emerging as an effective way to link the metabolite profile to disease state. Surface plasmon resonance (SPR) is a sensing platform that has demonstrated applicability for a large range of biomolecules. However, direct detection of small molecules with SPR challenges the refractive index based detection mechanism. Herein, we utilized an indirect detection format and developed an inhibition immunoassay for the quantitative measurement of 17ß-estradiol (E2) using SPR. One competitor, BSA-E2 conjugate, was immobilized to the SPR chip via the reaction between the primary amino group of the conjugate and the succinimide group (NHS) introduced by the formation of a thiol-NHS monolayer on gold surface. Free E2 molecules compete with BSA-E2 on chip surface for binding sites provided by a monoclonal anti-E2 antibody. It was found the binding affinity of the antibody to BSA-E2 conjugate increases with decreasing surface coverage of BSA-E2 conjugate. Under optimal conditions, a sigmoidal calibration curve with a negative slope and a dynamic range from 10 pM to 2 nM was generated. The detection limit of the immunoassay is estimated to be 0.3 pM. Moreover, the immunoassay exhibits high specificity for E2 detection using estrone (E1) as a potential interference.