Dual-Emissive Carbon Dots: Exploring Their Fluorescence Properties for Sensitive Turn-Off-On Recognition of Ferric and Pyrophosphate Ions and Its Application in Fluorometric Detection of the Loop-Mediated Isothermal Amplification Reaction.

In this study, dual-emissive carbon dots (CDs) were prepared using p-phenylenediamine (pPDA) and phytic acid (PA) precursors via a one-pot-hydrothermal method. The photophysical, morphological, and structural characterization of CDs was carried out using absorption, fluorescence, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and high-resolution transmission electron microscopy (HR-TEM) analysis. The as-prepared CDs displayed dual-fluorescence peaks at 525 and 620 nm upon excitation at 450 nm. The CDs showed good photostability and exhibited solvent-dependent fluorescence properties. The solvatochromic behavior of CDs was utilized to detect water content in organic solvents. Furthermore, the dual-emissive property of CDs was utilized for the sequential detection of ferric (Fe3+) and pyrophosphate ions (PPi) by a fluorescence turn-off-on mechanism. The proposed assay showed appreciable fluorescence response toward Fe3+ and PPi with high selectivity and good tolerance for common interfering ions. The potential practical application of the CD probe was ascertained by carrying out the fluorometric detection of PPi to affirm the loop-mediated isothermal amplification (LAMP) reaction specific for Mycobacterium tuberculosis (negative and positive clinical samples).

αA and αB peptides from human cataractous lenses show antichaperone activity and enhance aggregation of lens proteins.

Purpose: To identify and characterize properties of αA- and αB-crystallins' low molecular weight peptides (molecular weight [Mr] < 5 kDa) that were present in a 62-year-old human nuclear cataract, but not in normal 62-year-old human lenses. Methods: Low molecular weight peptides (< 5 kDa) were isolated with a trichloroacetic acid (TCA) solubilization method from water-soluble (WS) and water-insoluble (WI) proteins of nuclear cataractous lenses of a 62-year-old donor and normal human lenses from an age-matched donor. Five commercially synthesized peptides (found only in cataractous lenses and not in normal lenses) were used to determine their chaperone and antichaperone activity and aggregation properties. Results: Mass spectrometric analysis showed 28 peptides of αA-crystallin and 38 peptides of αB-crystallin were present in the cataractous lenses but not in the normal lenses. Two αA peptides (named αAP1 and αAP2; both derived from the αA N-terminal domain (NTD) region) and three αB peptides (named αBP3, αBP4, and αBP5, derived from the αB NTD-, core domain (CD), and C-terminal extension (CTE) regions, respectively) were commercially synthesized. αAP1 inhibited the chaperone activity of αA- and αB-crystallins, but the other four peptides (αAP2, αBP3, αBP4, and αBP5) exhibited mixed effects on chaperone activity. Upon incubation with human WS proteins and peptides in vitro, the αBP4 peptide showed higher aggregation properties relative to the αAP1 peptide. During in vivo experiments, the cell-penetrating polyarginine-labeled αAP1 and αBP4 peptides showed 57% and 85% aggregates, respectively, around the nuclei of cultured human lens epithelial cells compared to only 35% by a scrambled peptide. Conclusions: The antichaperone activity of the αAP1 peptide and the aggregation property of the αBP4 peptide with lens proteins could play a potential role during the development of lens opacity.

Achieving a "step change" in the tuberculosis epidemic through comprehensive community-wide intervention: a model-based analysis.

BACKGROUND: Global progress towards reducing tuberculosis (TB) incidence and mortality has consistently lagged behind the World Health Organization targets leading to a perception that large reductions in TB burden cannot be achieved. However, several recent and historical trials suggest that intervention efforts that are comprehensive and intensive can have a substantial epidemiological impact. We aimed to quantify the potential epidemiological impact of an intensive but realistic, community-wide campaign utilizing existing tools and designed to achieve a "step change" in the TB burden. METHODS: We developed a compartmental model that resembled TB transmission and epidemiology of a mid-sized city in India, the country with the greatest absolute TB burden worldwide. We modeled the impact of a one-time, community-wide screening campaign, with treatment for TB disease and preventive therapy for latent TB infection (LTBI). This one-time intervention was followed by the strengthening of the tuberculosis-related health system, potentially facilitated by leveraging the one-time campaign. We estimated the tuberculosis cases and deaths that could be averted over 10 years using this comprehensive approach and assessed the contributions of individual components of the intervention. RESULTS: A campaign that successfully screened 70% of the adult population for active and latent tuberculosis and subsequently reduced diagnostic and treatment delays and unsuccessful treatment outcomes by 50% was projected to avert 7800 (95% range 5450-10,200) cases and 1710 (1290-2180) tuberculosis-related deaths per 1 million population over 10 years. Of the total averted deaths, 33.5% (28.2-38.3) were attributable to the inclusion of preventive therapy and 52.9% (48.4-56.9) to health system strengthening. CONCLUSIONS: A one-time, community-wide mass campaign, comprehensively designed to detect, treat, and prevent tuberculosis with currently existing tools can have a meaningful and long-lasting epidemiological impact. Successful treatment of LTBI is critical to achieving this result. Health system strengthening is essential to any effort to transform the TB response.

Increased Association of Deamidated αA-N101D with Lens membrane of transgenic αAN101D vs. wild type αA mice: potential effects on intracellular ionic imbalance and membrane disorganization.

We have generated two mouse models, in one by inserting the human lens αAN101D transgene in CRYαAN101D mice, and in the other by inserting human wild-type αA-transgene in CRYαAWT mice. The CRYαAN101D mice developed cortical cataract at about 7-months of age relative to CRYαAWT mice. The objective of the study was to determine the following relative changes in the lenses of CRYαAN101D- vs. CRYαAWT mice: age-related changes with specific emphasis on protein insolubilization, relative membrane-association of αAN101D vs. WTαA proteins, and changes in intracellular ionic imbalance and membrane organization. METHODS: Lenses of varying ages from CRYαAWT and CRYαAN101D mice were compared for an age-related protein insolubilization. The relative lens membrane-association of the αAN101D- and WTαA proteins in the two types of mice was determined by immunohistochemical-, immunogold-labeling-, and western blot analyses. The relative levels of membrane-binding of recombinant αAN101D- and WTαA proteins was determined by an in vitro assay, and the levels of intracellular Ca2+ uptake and Na, K-ATPase mRNA were determined in the cultured epithelial cells from lenses of the two types of mice. RESULTS: Compared to the lenses of CRYαAWT, the lenses of CRYαAN101D mice exhibited: (A) An increase in age-related protein insolubilization beginning at about 4-months of age. (B) A greater lens membrane-association of αAN101D- relative to WTαA protein during immunogold-labeling- and western blot analyses, including relatively a greater membrane swelling in the CRYαAN101D lenses. (C) During in vitro assay, the greater levels of binding αAN101D- relative to WTαA protein to membranes was observed. (D) The 75% lower level of Na, K-ATPase mRNA but 1.5X greater Ca2+ uptake were observed in cultured lens epithelial cells of CRYαAN101D- than those of CRYαAWT mice. CONCLUSIONS: The results show that an increased lens membrane association of αAN101D--relative WTαA protein in CRYαAN101D mice than CRYαAWT mice occurs, which causes intracellular ionic imbalance, and in turn, membrane swelling that potentially leads to cortical opacity.

A professionalism program in medical education and training - From broad values to specific applications: YLL School of Medicine, Singapore.

The process for introducing and developing a program for teaching medical professionalism at the National University of Singapore, School of Medicine is outlined. Professionalism was recognised as embracing 'honesty and integrity,' 'responsibility and participation,' 'respect and sensitivity,' and 'compassion and empathy.' Those broad values are expressed as specific attitudes and behaviours that are taught and assessed throughout the course. Honesty and integrity, for example, are demonstrated by 'presenting original, authentic assignments' (in medical education); and 'accepting personal mistakes and honestly acknowledging them' (in clinical training and practice). Values and items of behaviour were drawn from the literature, and reviewed and refined to address needs identified within the Medical School. A broad spectrum of pre-clinical and clinical teachers contributed to this development. The program was reassessed to determine the extent to which it has been implemented and has evolved following its adoption. The results are confirming in that: the majority of recommendations have been implemented; the program has developed further; and is supported by ancillary student enrichment activities. Medical professionalism has been given prominence through all phases of the course. Nevertheless, challenges remain and particularly in the extent to which medical professionalism is taught and assessed in various clinical postings.

The transcription factor SOX6 contributes to the developmental origins of obesity by promoting adipogenesis.

An association between impaired fetal growth and the postnatal development of obesity has been established. Here, by comparing adipocytes differentiated from mesenchymal stem cells (MSCs) taken from the umbilical cord and derived from normal and growth-restricted neonates, we identified the transcription factor SOX6 as highly expressed only in growth-restricted individuals. We found that SOX6 regulates adipogenesis in vertebrate species by activating adipogenic regulators including PPARγ, C/EBPα and MEST. We further show that SOX6 interacts with ß-catenin in adipocytes, suggesting an inhibition of WNT/ß-catenin signaling, thereby promoting adipogenesis. The upstream regulatory region of the MEST gene in MSCs from growth-restricted subjects harbors hypomethylated CpGs next to SOX6 binding motifs, and we found that SOX6 binding is impaired by adjacent CpG methylation. In summary, we report that SOX6 is a novel regulator of adipogenesis synergizing with epigenetic mechanisms.

Preclinical evaluation of hydrogel sealed fluropassivated indigenous vascular prosthesis.

Background & objectives: Polyethylene terephthalate (PET) graft, designed and developed at our institute for vascular reconstruction, is porous to promote optimal incorporation and neointima formation, requiring pre-clotting or biomodification by sealing the pores before implantation. The objective of this study was to characterize, test and perform preclinical evaluation of hydrogel (alginate dialdehyde cross-linked gelatin) sealed fluoropassivated PET vascular prosthesis in pig model, so as to avoid pre-clotting, for its safety and efficacy before employing the indigenous and less expensive graft for clinical use. Methods: Hydrogel sealed, fluoropassivated PET vascular prosthesis were tested for haemocompatibility and toxicity followed by small animal toxicology tests and in vivo experiments in pigs receiving implantation at thoracic aorta. All 33 animals received test as well as control grafts with a plan for phased explantation at 2, 12 and 26 weeks. All animals underwent completion angiogram at the end of procedure as well as before graft explantation. Results: Haemocompatibility tests for haemolysis and toxicity tests showed no adverse events in tested mice and rabbits. Completion angiogram showed intact anastamosis and patent graft in each animal in post-operative period and at explantation. Gross and histopathological examination showed well-encapsulated grafts, clean glistening neointima and no evidence of thrombus in both test and control grafts. Interpretation & conclusions: Hydrogel sealed, fluoropassivated PET vascular prosthesis was found non-toxic, haemocompatible and remained patent in in vivo studies at planned intervals.

An oestrogen-receptor-alpha-bound human chromatin interactome.

Genomes are organized into high-level three-dimensional structures, and DNA elements separated by long genomic distances can in principle interact functionally. Many transcription factors bind to regulatory DNA elements distant from gene promoters. Although distal binding sites have been shown to regulate transcription by long-range chromatin interactions at a few loci, chromatin interactions and their impact on transcription regulation have not been investigated in a genome-wide manner. Here we describe the development of a new strategy, chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) for the de novo detection of global chromatin interactions, with which we have comprehensively mapped the chromatin interaction network bound by oestrogen receptor alpha (ER-alpha) in the human genome. We found that most high-confidence remote ER-alpha-binding sites are anchored at gene promoters through long-range chromatin interactions, suggesting that ER-alpha functions by extensive chromatin looping to bring genes together for coordinated transcriptional regulation. We propose that chromatin interactions constitute a primary mechanism for regulating transcription in mammalian genomes.

Alterations to DNA methylation and expression of CXCL14 are associated with suboptimal birth outcomes.

CXCL14 is a chemokine that has previously been implicated in insulin resistance in mice. In humans, the role of CXCL14 in metabolic processes is not well established, and we sought to determine whether CXCL14 is a risk susceptibility gene important in fetal programming of metabolic disease. For this purpose, we investigated whether CXCL14 is differentially regulated in human umbilical cords of infants with varying birth weights. We found an elevated expression of CXCL14 in human low birth weight (LBW) cords, as well as in cords from nutritionally restricted Macaca fascicularis macaques. To further analyze the regulatory mechanisms underlying the expression of CXCL14, we examined CXCL14 in umbilical cord-derived mesenchymal stem cells (MSCs) that provide an in vitro cell-based system amenable to experimental manipulation. Using both whole frozen cords and MSCs, we determined that site-specific CpG methylation in the CXCL14 promoter is associated with altered expression, and that changes in methylation are evident in LBW infant-derived umbilical cords that may indicate future metabolic compromise through CXCL14.

Molecular pathways reflecting poor intrauterine growth are found in Wharton's jelly-derived mesenchymal stem cells.

STUDY QUESTION: Are molecular pathways reflecting the biology of small for gestational age (SGA) neonates preserved in umbilical cord-derived mesenchymal stem cells (MSCs)? SUMMARY ANSWER: MSCs from SGA newborns were found to express an altered EGR-1-dependent gene network involved in the regulation of cell proliferation and oxidative stress. WHAT IS KNOWN ALREADY: Individuals with suboptimal intrauterine development are at greater risk of metabolic diseases such as type II diabetes, obesity and cardiovascular disease. STUDY DESIGN, SIZE, DURATION: Umbilical cords (n = 283) from the GUSTO (growing up in Singapore towards healthy outcomes) birth cohort study, and primary MSC isolates established from SGA and matched control cases (n = 6 per group), were subjected to gene expression analysis and candidate genes were studied for functional validation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Umbilical cord specimens were derived from babies born at the National University Hospital (NUH) in Singapore. Local ethical approval was obtained. MSC isolates were established in Wharton's jelly and molecular analysis was conducted by gene expression microarrays and RT-PCR. Cells from SGA and control groups were compared in the presence and absence of insulin and candidate gene function was studied via siRNA-mediated gene knockdown and over-expression experiments in MSCs. MAIN RESULTS AND THE ROLE OF CHANCE: Using repeated measure ANOVAs, proliferation rates of MSCs isolated from SGA neonates were found to be significantly increased (P < 0.01). In the absence of insulin, EGR-1 levels were found to be significantly reduced in the group of SGA-derived MSCs, whereas EGR-1 expression was found to be up-regulated in the same group in the presence of insulin (P < 0.01). EGR-1 was found to induce expression of COX-2 in the SGA group (P < 0.01) and both, EGR-1 and COX-2 stimulated glucose uptake in MSCs (P < 0.01). EGR-1 and COX-2 levels were associated in whole umbilical cords (n = 283, P < 0.01) and EGR-1 positively correlated with abdominal circumference and birthweight (n = 91, P < 0.01 and n = 91, P < 0.01). LIMITATIONS, REASONS FOR CAUTION: Cell models may not entirely reflect the physiology of the host and patient follow-up studies will be necessary for further clinical validation. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that Wharton's jelly-derived MSCs are useful in identifying pathways specific for fetal growth restriction. STUDY FUNDING/COMPETING INTERESTS: This work is supported by the Translational Clinical Research (TCR) Flagship Program on Developmental Pathways to Metabolic Disease funded by the National Research Foundation (NRF) and administered by the National Medical Research Council (NMRC), Singapore- NMRC/TCR/004-NUS/2008'. SICS Investigators are supported through the Agency for Science Technology and Research (A*STAR) funding. No potential conflicts of interest relevant to this article were reported.

Dysregulation of Autophagy Occurs During Congenital Cataract Development in ßA3ΔG91 Mice.

Purpose: To examine lens phenotypic characteristics in ßA3ΔG91 mice and determine if ßA3ΔG91 affects autophagy in the lens. Methods: We generated a ßA3ΔG91 mouse model using CRISPR/Cas9 methodology. Comparative phenotypic and biochemical characterizations of lenses from postnatal day 0 (P0), P15, and 1-month-old ßA3ΔG91 and wild-type (WT) mice were performed. The methodologies used included non-invasive slit-lamp examination, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot, and immunohistochemical (IHC) analyses to determine the levels of autophagy-related genes and proteins. Transmission electron microscopy (TEM) analysis of lenses was performed to assess organelle degradation and the presence of autophagic vesicles. TUNEL staining was used to determine apoptosis in the lens. Results: Relative to WT lenses, 1-month-old ßA3ΔG91 mice developed congenital nuclear cataract and microphthalmia and showed an early loss of endoplasmic reticulum (ER) in the cortex and attenuation of nuclei degradation. This observation was confirmed by TEM analysis, as was the presence of autophagic vesicles in ßA3ΔG91 lenses. Comparative IHC and RT-qPCR analyses showed relatively higher levels of autophagy markers (ubiquitinated proteins and p62, LC3, and LAMP2 proteins) in ßA3ΔG91 lenses compared to WT lenses. Additionally, ßA3ΔG91 lenses showed relatively greater numbers of apoptotic cells and higher levels of cleaved caspase-3 and caspase-9. Conclusions: The deletion of G91 in ßA3ΔG91 mice leads to higher levels of expression of autophagy-related proteins and their transcripts relative to WT lenses. Taken together, G91 deletion in ßA3/A1-crystallin is associated with autophagy disruption, attenuation of nuclei degradation, and cellular apoptosis in the lens, which might be congenital cataract causative factors.

A Review on Implantable Neuroelectrodes.

The efficacy of every neuromodulation modality depends upon the characteristics of the electrodes used to stimulate the chosen target. The geometrical, chemical, mechanical and physical configuration of electrodes used in neurostimulation affects several performance attributes like stimulation efficiency, selectivity, tissue response, etc. The efficiency of stimulation in relation to electrode impedance is influenced by the electrode material and/or its geometry. The nature of the electrode material determines the charge transfer across the electrode-tissue interface, which also relates to neuronal tissue damage. Electrode morphology or configuration pattern can facilitate the modulation of extracellular electric field (field shaping). This enables selective activation of neurons and minimizes side effects. Biocompatibility and biostability of the electrode materials or electrode coating have a role in glial formation and tissue damage. Mechanical and electrochemical stability (corrosion resistance) determines the long-term efficacy of any neuromodulation technique. Here, a review of electrodes typically used for implantable neuromodulation is discussed. Factors affecting the performance of electrodes like stimulation efficiency, selectivity and tissue responses to the electrode-tissue interface are discussed. Technological advancements to improve electrode characteristics are also included.

Gemma: a resource for the reuse, sharing and meta-analysis of expression profiling data.

UNLABELLED: Gemma is a database, analysis software system and web site for genomics data re-use and meta-analysis. Currently, Gemma contains analyzed data from over 3300 expression profiling studies, yielding hundreds of millions of differential expression results and coexpression patterns (correlated expression) for retrieval and visualization. With optional registration users can save their own data and securely share it with other users. Web services and integration with third-party resources further increase the scope of the tools, which include a Cytoscape plugin. AVAILABILITY: http://chibi.ubc.ca/Gemma, Apache 2.0 license.

Phenotypic modulation of cell types around implanted polyethylene terephthalate fabric in rabbit muscle.

Whereas the nature of healing reaction in skeletal muscle following implantation of biomaterial has been extensively studied, the extent of variation in cell phenotypes is poorly known. Here, we studied the phenotypic alteration of cell types following injury in skeletal muscle of rabbits implanted with a commonly used biomaterial, polyethylene terephthalate (PET) fabric. Following implantation, histomorphological features were studied after 1, 4, and 12 weeks. Routine objective histomorphological evaluation was supplemented with histochemistry for collagen and immunohistochemistry for proliferating cell nuclear antigen (PCNA), CD34, vimentin, and alpha smooth muscle actin (α-SMA). The extent of reaction was quantified. The foreign body giant cells were found to comprise subpopulations, based on the variation in vimentin detectability or the presence of differentially capable proliferating nuclei (PCNA positive). Many rhabdomyocytes adjacent to the implant were PCNA-positive and some of them showed CD34 positivity. Often, the rhabdomyocytes very near to implanted PET fabric assumed a myofibroblast phenotype as evidenced by vimentin and/or α-SMA positivity at immunohistochemistry. Overall, the results suggested a phenotypic alteration of native cell types following implantation of PET fabric in rabbit skeletal muscle. Quantification of such cell types at the tissue-material interphase in relation to the deposition of collagen may be desirable during safety evaluation of biomaterials by histomorphology.

Ascorbic acid-loaded gellan-g-poly(ethylene glycol) methacrylate matrix as a wound-healing material.

Ascorbic acid (AA) is one of the important biomolecules involved in all phases of wound healing. The aim of this study was to develop a new hydrogel system that offers topical delivery of ascorbic acid to wounds during wound care management. In this work, we grafted poly (ethylene glycol) methacrylate onto a renewable biopolymer gellan, and the graft copolymer (GPMA) formed was crosslinked covalently and ionically, and used as a matrix for delivering AA to the wounds. By the processes of grafting and crosslinking, the mechanical properties of the gellan increased several fold compared to mechanically weak native gellan. In vitro cytotoxicity evaluation showed that GPMA was non-cytotoxic to fibroblast cells. GPMA hydrogel matrix allowed the sustained release of AA. When AA was incorporated in GPMA, a significant improvement in wound closure was observed in scratch wound assay performed with keratinocytes. Since AA acts as a cofactor in collagen synthesis, the controlled delivery of AA to the wound microenvironment favors the up-regulation of colα1 gene expression. This study revealed that ascorbic acid, at a concentration of 150 µM, has a favorable impact on wound healing when tested in vitro. Overall results indicate that the GPMA matrix could be a promising material for wound healing applications.

Lens-specific ßA3/A1-conditional knockout mice: Phenotypic characteristics and calpain activation causing protein degradation and insolubilization.

ßA3/A1-crystallin is a lens structural protein that plays an important role in maintaining lens transparency via interactions with other crystallins. While the function of ßA3/A1-crystallin in the retina is well studied, its functions in the lens, other than as a structural protein, remain unclear. In the current study, we generated the lens-specific ßA3/A1-crystallin conditional knockout mouse (named ßA3/A1ckO) and explored phenotypic changes and the function of the crystallin in the lens. The ßA3/A1ckO mice showed congenital cataract at birth and exhibited truncation of lens proteins. Several truncated protein fragments were recovered as a pellet during a low-speed centrifugation (800 rpm, 70 x g) followed by a relatively higher speed centrifugation (5000 rpm, 2744 x g). Mass spectrometric analysis of pellets recovered following the two centrifugations showed that among the fragments with Mr < 20 kDa, the majority of these were from ß-tubulin, and some from phakinin, αA-crystallin, and calpain-3. Further, we observed that in vitro activation of calpain-3 by calcium treatment of the wild-type-lens homogenate resulted in the degradation of calpain-3, αA-crystallin and ß-tubulin and insolubilization of these proteins. Based on these results, it was concluded that the activation of calpain 3 resulted in proteolysis of ß-tubulin, which disrupted cellular microtubular structure, and caused proteolysis of other lens proteins (αA-crystallin and phakinin). These proteolyzed protein fragments become insoluble, and together with the disruption of microtubular structure, and could be the causative factors in the development of congenital nuclear cataract in ßA3/A1cKO mice.

Role of Fibroblast Growth Factor Receptor 2 (FGFR2) in Corneal Stromal Thinning.

Purpose: To determine the role of fibroblast growth factor receptor 2 (FGFR2)-mediated signaling in keratocytes during corneal development, a keratocyte-specific FGFR2-knockout (named FGFR2cKO) mouse model was generated, and its phenotypic characteristics were determined. Methods: A FGFR2cKO mouse model was generated by the following method: FGFR2 flox mice were crossed with the inducible keratocyte specific-Cre mice (Kera-rtTA/tet-O-Cre). Both male and female FGFR2cKO- and control mice (1 to 3-months-old) were analyzed for changes in corneal topography and pachymetry maps using the optical coherence tomography (OCT) method. The comparative TUNEL assay and immunohistochemical analyses were performed using corneas of FGFR2cKO and control mice to determine apoptotic cells, and expression of collagen-1 and fibronectin. Transmission electron microscopic analysis was conducted to determine collagen structures and their diameters in corneas of FGFR2cKO and control mice. Results: OCT-analyses of corneas of FGFR2cKO mice (n = 24) showed localized central thinning and an increased corneal steepness compared to control mice (n = 23). FGFR2cKO mice further showed a decreased expression in collagen-1, decreased collagen diameters, acute corneal hydrops, an increased fibronectin expression, and an increased number of TUNEL-positive cells suggesting altered collagen structures and keratocytes' apoptosis in the corneas of FGFR2cKO mice compared to control mice. Conclusions: The FGFR2cKO mice showed several corneal phenotypes (as described above in the results) that are also exhibited by the human keratoconus corneas. The results suggested that the FGFR2cKO mouse model serves to elucidate not only the yet unknown role of FGFR2-mediated signaling in corneal physiology but also serves as a model to determine molecular mechanism of human keratoconus development.

Neural Tissue Engineering with Rat Adipose-Derived Mesenchymal Stem Cells: The Role of an Injectable, Resorbable Hydrogel Scaffold Derived from Oxidized Alginate and Gelatin.

The central nervous system has limited regeneration potential. The multipotency of adipose-derived mesenchymal stem cells (ADMSC) makes them an ideal autologous cell source for the regeneration of neural tissues. However, the likelihood of their differentiation into unwanted cell lineages when transplanted into a hostile injury environment is a serious disadvantage. Transplanting predifferentiated cells via an injectable carrier may aid in site-specific delivery for better survival of cells. Here, we focus on identifying an appropriate injectable hydrogel system that favors stem/progenitor cell attachment and differentiation for neural tissue engineering. An injectable composition of the hydrogel, derived from alginate dialdehyde (ADA) and gelatin, was formulated for this purpose. This hydrogel promoted proliferation/differentiation of ADMSCs to neural progenitors, visualized from the generation of prominent neurospheres and stage-specific expression of a neural progenitor marker (nestin, day 4), an intermittent neuronal marker (ß-III tub, day 5), and a mature neuronal marker (MAP-2, day 8) with neural branching and networking (>85%). The differentiated cells also expressed the functional marker synaptophysin. There was no negative impact on stem/progenitor cell survival (>95%) or differentiation (∼90%) as compared to two-dimensional (2D) culture. Addition of appropriate quantities of asiatic acid specific for neural niche supported cell growth and differentiation without affecting cell survival (>90%) and improved neural branching and elongation. Optimized interconnected porous hydrogel niche exhibited rapid gelation (3 min) and self-healing properties mimicking native neural tissue. Both ADA-gelatin hydrogel by itself and that incorporated with asiatic acid were found to support stem/neural progenitor cell growth and differentiation and have potential applications as antioxidants and growth promoters upon release at the cell transplantation site. In short, the matrix itself or incorporated with phytomoieties could serve as a potential minimally invasive injectable cell delivery vehicle for cell-based therapies of neural diseases.

Development of a COVID-19-Related Anti-Asian Tweet Data Set: Quantitative Study.

BACKGROUND: Since the advent of the COVID-19 pandemic, individuals of Asian descent (colloquial usage prevalent in North America, where "Asian" is used to refer to people from East Asia, particularly China) have been the subject of stigma and hate speech in both offline and online communities. One of the major venues for encountering such unfair attacks is social networks, such as Twitter. As the research community seeks to understand, analyze, and implement detection techniques, high-quality data sets are becoming immensely important. OBJECTIVE: In this study, we introduce a manually labeled data set of tweets containing anti-Asian stigmatizing content. METHODS: We sampled over 668 million tweets posted on Twitter from January to July 2020 and used an iterative data construction approach that included 3 different stages of algorithm-driven data selection. Finally, we found volunteers who manually annotated the tweets by hand to arrive at a high-quality data set of tweets and a second, more sampled data set with higher-quality labels from multiple annotators. We presented this final high-quality Twitter data set on stigma toward Chinese people during the COVID-19 pandemic. The data set and instructions for labeling can be viewed in the Github repository. Furthermore, we implemented some state-of-the-art models to detect stigmatizing tweets to set initial benchmarks for our data set. RESULTS: Our primary contributions are labeled data sets. Data Set v3.0 contained 11,263 tweets with primary labels (unknown/irrelevant, not-stigmatizing, stigmatizing-low, stigmatizing-medium, stigmatizing-high) and tweet subtopics (eg, wet market and eating habits, COVID-19 cases, bioweapon). Data Set v3.1 contained 4998 (44.4%) tweets randomly sampled from Data Set v3.0, where a second annotator labeled them only on the primary labels and then a third annotator resolved conflicts between the first and second annotators. To demonstrate the usefulness of our data set, preliminary experiments on the data set showed that the Bidirectional Encoder Representations from Transformers (BERT) model achieved the highest accuracy of 79% when detecting stigma on unseen data with traditional models, such as a support vector machine (SVM) performing at 73% accuracy. CONCLUSIONS: Our data set can be used as a benchmark for further qualitative and quantitative research and analysis around the issue. It first reaffirms the existence and significance of widespread discrimination and stigma toward the Asian population worldwide. Moreover, our data set and subsequent arguments should assist other researchers from various domains, including psychologists, public policy authorities, and sociologists, to analyze the complex economic, political, historical, and cultural underlying roots of anti-Asian stigmatization and hateful behaviors. A manually annotated data set is of paramount importance for developing algorithms that can be used to detect stigma or problematic text, particularly on social media. We believe this contribution will help predict and subsequently design interventions that will significantly help reduce stigma, hate, and discrimination against marginalized populations during future crises like COVID-19.

Gallium-Curcumin Nanoparticle Conjugates as an Antibacterial Agent against Pseudomonas aeruginosa: Synthesis and Characterization.

Combating antibiotic resistance has found great interest in the current clinical scenario. Pseudomonas aeruginosa, an opportunistic multidrug-resistant pathogen, is well known for its deadly role in hospital-acquired infections. Infections by P. aeruginosa are among the toughest to treat because of its intrinsic and acquired resistance to antibiotics. In this study, we project gallium-curcumin nanoparticle (GaCurNP) conjugates as a prospective candidate to fight against P. aeruginosa. The synthesized GaCurNPs were spherical with an average size ranging from 25-35 nm. Analysis by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy deduced the nature of interaction between gallium and curcumin. Conjugate formation with gallium was found to improve the stability of curcumin at the physiological pH. When tested after 24 h of contact, at the physiological pH and 37 °C, the degradation of curcumin bound in the GaCurNPs was 26%, while that of native curcumin was 95%. The minimum inhibitory concentration (MIC) of GaCurNPs was found to be 82.75 µg/mL for P. aeruginosa (ATCC 27853). GaCurNPs also showed excellent biofilm inhibition at 4MIC concentration. Raman spectroscopic analysis showed that GaCurNPs are capable of disrupting the cells of P. aeruginosa within 3 h of contact. Live/dead imaging also confirmed the compromised membrane integrity in cells treated with GaCurNPs. Scanning electron microscopy analysis showed membrane lysis and cell structure damage. The AlamarBlue assay showed that when L929 cell lines were treated with GaCurNPs with concentrations as high as 350 µg/mL, the cell viability elicited by the nanoparticles was 70.89%, indicating its noncytotoxic nature. In short, GaCurNPs appear to be a promising antibacterial agent capable of fighting a clinically significant pathogen, P. aeruginosa.