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Introduction/Aims: Line blot (LB) is in widespread use for myositis antibody detection. Yet, studies of its positive predictive value (PPV) in patients with suspected idiopathic inflammatory myopathy (IIM), which would be of particular relevance to neuromuscular clinicians, are lacking. We aimed to determine the PPV of myositis antibody LB testing in patients with suspected IIM, and examine whether PPV was significantly impacted by intensity of antibody positivity. Methods: This was a retrospective study of patients who underwent myositis antibody LB testing for suspected IIM between March 2019 and August 2022. Results: Of 70 patients who underwent testing for suspected IIM and had positive myositis antibody LB results, 43 (61%) were female and the median age was 61 years (range: 10–83 years). Forty‐four were classified as true‐positives, yielding a PPV of 63%. The PPV of patients with weak‐positive myositis antibody results (14/30, 47%) was significantly lower than the PPV of patients with moderate‐positive or strong‐positive myositis antibody results (30/40, 75%) (p =.02). Discussion: Our study found that myositis antibody LB testing in patients with suspected IIM had a modest PPV, underscoring the need for antibody interpretation in the context of all available clinical and ancillary test data to avoid misdiagnosis. The significantly lower PPV in patients with weak‐positive results emphasizes the particular importance of clinical correlation in such patients. Further study into the diagnostic performance of various LBs for myositis antibody detection is needed to inform their interpretation in clinical practice. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO)-mediated vasodilatation is a fundamental response of vasculature, however, regulation of NO signaling pathway on resistance vessels in the older adult with hypertension is still unclear. The 16-week-spontaneously hypertensive rats (SHR), the 18-month-SHR (OldSHR), and the age-matched Wistar-Kyoto rats were used to study the changes of mesenteric resistance artery dilatation caused by sodium nitroprusside (SNP). After pre-vasoconstriction by norepinephrine (NE), the response of endothelium-denuded mesenteric artery ring to SNP was observed, and the changes in vascular response after pharmacological interventions of key nodes in the NO/sGC/cGMP/PKG1α signaling pathway were observed as well. RNA sequencing and functional enrichment analyses were used to provide information for conducting validation experiments. Vasodilation of NO in OldSHR was decreased, which significantly correlated with the reduction of PKG-mediated effect. Functional enrichment analysis of RNA sequencing showed that genes encoding important proteins such as sGC and MYPT1 (protein phosphatase 1 regulatory subunit 12A) were downregulated in OldSHR. Molecular biology validation results showed that mRNA expression of both α and β subunits of sGC were reduced, while mRNA and protein expression of PKG1α were reduced in OldSHR. More importantly, the expression of MYPT1 and pS668-MYPT1 was significantly reduced in OldSHR, even under the treatment of SNP. The experiment also revealed an enhanced cAMP system in vasodilation in hypertension, while this function was completely lost in the OldSHR. Therefore, an NO-mediated decrease in vascular smooth muscle relaxation was found in the OldSHR. The dysfunction in cGMP-PKG signaling, in particular, decreased pS668-MYPT1 was mechanistically involved. [ABSTRACT FROM AUTHOR]

This paper reviews the functions of dielectrophoresis (DEP) that have been applied to biosensor and biochip platforms for bacteria detection, including concentration of bacterial cells from continuous flows, separation of target bacterial cells from non-target cells, as well as the enhancement of antibody capture efficiency on biosensor and biochip surfaces. DEP could provide effective concentration and separation simultaneously in well-designed microfluidic biosensor and biochip systems. The integration of DEP with a detection system allows the integration of sample preparation and enrichment steps with detection, which has the potential to eliminate the traditionally used time-consuming culture-based enrichment steps and other multiple off-chip sample preparation steps. DEP is also useful in biosensor and biochips platforms for enhancing antibody capture efficiency in both flow-through and non-flow-through microdevices. The enhanced antibody capture efficiency could allow the sensor capture more cells and to be detected by the sensor, particularly in dealing with low number of cells. The integration of multifunctions of DEP into biosensor and biochip platform has the potential to improve the detection of bacterial cells. [ABSTRACT FROM AUTHOR]

Abstract: This study integrated dielectrophoresis (DEP) with non-flow through biochips to enhance the immuno-capture and detection of foodborne pathogenic bacteria. It demonstrated two major functions provided by DEP to improve the chip performance: (i) concentrating bacterial cells from the suspension to different locations on the chip surface by positive and negative DEP; (ii) making the cells in close contact with the immobilized antibodies on the chip surface so that immuno-capture efficiency can be dramatically enhanced. The microchip achieved the immuno-capture efficiencies of ∼56.0% and ∼64.0% to Salmonella cells with 15 and 30min DEP, respectively, which were considerably higher than those of ∼10.4% and ∼17.6% for 15 and 30min immuno-capture without DEP. The immuno-captured bacterial cells were detected by the sandwich format ELISA on the chips. The final absorbance signals were enhanced by DEP assisted immuno-capture by 64.7–105.2% for the samples containing 103–106 cells/20μl. The integration of DEP with the biochips has the potential to advance the chip-based immunoassay methods for microbial detection. [Copyright &y& Elsevier]

Abstract: The realization of rapid, sensitive, and specific methods to detect foodborne pathogenic bacteria is central to implementing effective practice to ensure food safety and security. As a principle of transduction, the impedance technique has been applied in the field of microbiology as a means to detect and/or quantify foodborne pathogenic bacteria. The integration of impedance with biological recognition technology for detection of bacteria has led to the development of impedance biosensors that are finding wide-spread use in the recent years. This paper reviews the progress and applications of impedance microbiology for foodborne pathogenic bacteria detection, particularly the new aspects that have been added to this subject in the past few years, including the use of interdigitated microelectrodes, the development of chip-based impedance microbiology, and the use of equivalent circuits for analysis of the impedance systems. This paper also reviews the significant developments of impedance biosensors for bacteria detection in the past 5 years, focusing on microfabricated microelectrodes-based and microfluidic-based Faradaic electrochemical impedance biosensors, non-Faradaic impedance biosensors, and the integration of impedance biosensors with other techniques such as dielectrophoresis and electropermeabilization. [Copyright &y& Elsevier]

Abstract: In this study, we present a new, simple and rapid impedance method to detect bacterial cells by making use of the impedance properties of bacterial cell suspensions using interdigitated microelectrodes. It was found that bacterial cell suspensions in deionized (DI) water with different cell concentrations could generate different electrical impedance spectral responses, whereas cell suspensions in phosphate buffered saline (PBS) solution could not produce any significant differences in impedance spectra in response to different cell concentrations. In DI water suspensions, impedance at 1kHz decreased with the increasing cell concentrations in the suspensions. The impedance of cell suspensions in DI water was discussed and found that it was resulted from the cell wall charges and the release of ions or other osmolytes from the cells. A linear relationship between the impedance and the logarithmic value of the cell concentration was found in the cell concentration range from 106 to 1010 cfu/ml, which can be expressed by a regression equation of Z (kΩ)=−2.06log C (cells/20μl)+5.23 with R 2 =0.98. The detection limit was calculated to be 3.45×106 cfu/ml, which is comparable with many label-free immunosensors for detection of pathogenic bacteria reported in the literature. To achieve the selectivity of this method, we also demonstrated the feasibility of integrating magnetic separation to this impedance method. This study has demonstrated that bacterial cell concentration can be inferred by measuring the impedance of cell suspensions in DI water. This new detection mechanism could be an alternative to current impedance methods that have been reported for the detection of bacterial cells, e.g. impedance microbiology and electrical/electrochemical impedance biosensors. [Copyright &y& Elsevier]

Abstract: Bone markers are specific bone-derived molecules that reflect bone remodeling activity and can be classified into two categories: bone formation and bone resorption markers. Children have significantly elevated bone marker levels due to high skeletal growth velocity and rapid bone turnover during childhood growth. Many physiological and pathological processes may influence bone metabolism and bone marker concentrations during childhood growth. Measurements of bone markers may be useful in investigating skeletal diseases in children and monitoring the response to treatment. This review documents recent advances in analytical methods, preanalytical considerations related to each marker and particularly highlights the most valuable bone formation markers, bone alkaline phosphatase and osteocalcin, and bone resorption markers, pyridinium cross-links and cross-linked telopeptides. Age- and sex-specific pediatric reference intervals and their limitations in clinical application are also discussed. [Copyright &y& Elsevier]

Abstract: A quartz crystal microbalance (QCM) DNA sensor, based on the nanoparticle amplification method, was developed for detection of Escherichia coli O157:H7. A thiolated single-stranded DNA (ssDNA) probe specific to E. coli O157:H7 eaeA gene was immobilized onto the QCM sensor surface through self-assembly. The hybridization was induced by exposing the ssDNA probe to the complementary target DNA, and resulted in the mass change and therefore frequency change of the QCM. Streptavidin conjugated Fe3O4 nanoparticles (average diameter=145nm) were used as “mass enhancers” to amplify the frequency change. Synthesized biotinylated oligonucleotides as well as E. coli O157:H7 eaeA gene fragments (151 bases) amplified using asymmetric PCR with biotin labeled primers were tested. As low as 10−12 M synthesized oligonucleotides and 2.67×102 colony forming unit (CFU)/ml E. coli O157:H7 cells can be detected by the sensor. Linear correlation between frequency change and logarithmic number of bacterial cell concentration was found for E. coli O157:H7 from 2.67×102 to 2.67×106 CFU/ml. [Copyright &y& Elsevier]

Abstract: In this study, we demonstrated the use of a general medium—brain heart infusion (BHI) broth that is not specifically formulated for impedance measurement, to achieve detectable impedance signals by using an interdigitated microelectrode (IME) with capacitance measurement at low frequencies. Anti-Salmonella antibody coated immunomagnetic beads were used to separate S. typhimurium from samples to provide the selectivity to this method. From analysis based on the equivalent circuit of the IME system, we found that the impedance change in BHI broth resulting from the growth of Salmonella was indeed the change in the double layer capacitance and could be monitored at 10 Hz using the IME. The results indicated that medium modification to improve impedance signal is not necessary with this IME system. However, effective immunological separation for the target organism is required for the selectivity when non-selective media are used. This finding provides a more flexible option of medium in impedance methods, which may provide opportunities to test those species of bacteria that have no suitable conductance growth medium. The detection time, t d, was obtained from the impedance growth curve (impedance against bacterial growth time) at 10 Hz at the point where the impedance started to change. A linear relationship between the detection time and the logarithmic value of the initial cell number (N) was found in the Salmonella cell number ranging from 101 to 106 cfu/ml. The regression equation was t d =−1.22Log N +8.90, with R 2 =0.95. The detection times for the initial cell number of 101 CFU/ml and 106 CFU/ml are 8 h and 1.5 h, respectively. This method is more sensitive than impedance methods using conventional electrodes. [Copyright &y& Elsevier]

Fibrocytes are a unique leukocyte subpopulation implicated in wound healing. They are derived from peripheral blood mononuclear cells, display fibroblast-like properties, and synthesize extracellular matrix macromolecules. This study investigated whether fibrocytes are present in healing burn wounds and whether the number of fibrocytes in tissue correlates with the degree of burn injury and the development of hypertrophic scar. Proteins extracted from cultured fibrocytes and nonadherent lymphocytes were found to be similar using two-dimensional gel electrophoresis and quite distinct from those obtained from fibroblasts. However, one protein, identified as leukocyte-specific protein 1 using mass spectrometric peptide mapping, was found in significantly larger amounts in fibrocytes than in lymphocytes but was undetectable in fibroblasts. Double immunostaining with antibodies to leukocyte-specific protein-1 and to the N-terminal propeptide of type I collagen was performed on cryosections of hypertrophic scar, mature scar, and normal skin. Fibrocytes were seen in scar tissue as dual-labeled spindle-shaped cells but were absent from normal skin. Moreover, the number of fibrocytes was higher in hypertrophic than in mature scar tissue. We conclude that fibrocytes, which have been reported to be antigen-presenting cells, are recruited to wounds following extensive burn injury and could potentially upregulate the inflammatory response and synthesize collagen and other matrix macromolecules, thus contributing to the development of hypertrophic scarring. [ABSTRACT FROM AUTHOR]

The microscopic surface molecular structures and macroscopic electrochemical impedance properties of the epoxysilane monolayer and anti-Escherichia coli antibody layer on an indium–tin oxide (ITO) electrode surface were studied in this paper. Characterization of stepwise changes in microscopic features of the surfaces and electrochemical properties upon the formation of each layer were carried out using both atomic force microscopy (AFM) and electrochemical impedance spectroscopy in the presence of [Fe(CN)6]3-/4- as a redox couple. AFM images of the self-assembled monolayer (SAM) evidenced the dense, complete, and homogeneous morphology of the epoxysilane monolayer on the ITO surface. The uniformity of the epoxysilane SAM allowed antibodies to attach to the epoxy surface groups of the silanes in a similarly uniform fashion. The effects of epoxysilane monolayer and the antibody layer on the electrochemical properties of the electrode were quantitatively analyzed in terms of double layer capacitance, electron transfer resistance, Warburg impedance and solution resistance using Randles model as the equivalent circuit. It was demonstrated that the epoxysilane monolayer and the antibody layer act as barriers for the electron transfer between the electrode surface and the redox species in the solution, resulting in most significant increases in the electron transfer resistance compared to all the electric elements. Immunoreaction with E. coli O157:H7 cells demonstrated specific recognition of the immobilized anti-E. coli antibodies as evidenced by AFM imaging and impedance spectroscopy. It was found that the binding of E. coli cells mainly affected the electron transfer resistance and Warburg impedance. [Copyright &y& Elsevier]

Interdigitated microelectrodes (IMEs) were used as impedance sensors for rapid detection of viable Salmonella typhimurium in a selective medium and milk samples. The impedance growth curves, impedance against bacterial growth time, were recorded at four frequencies (10 Hz, 100 Hz, 1 kHz, and 10 kHz) during the growth of S. typhimurium. The impedance did not change until the cell number reached 105−106 CFU ml−1. The greatest change in impedance was observed at 10 Hz. To better understand the mechanism of the IME impedance sensor, an equivalent electrical circuit, consisting of double layer capacitors, a dielectric capacitor, and a medium resistor, was introduced and used for interpreting the change in impedance during bacterial growth. Bacterial attachment to the electrode surface was observed with scanning electron microscopy, and it had effect on the impedance measurement.The detection time, tD, defined as the time for the impedance to start change, was obtained from the impedance growth curve at 10 Hz and had a linear relationship with the logarithmic value of the initial cell number of S. typhimurium in the medium and milk samples. The regression equations for the cell numbers between 4.8 and 5.4×105 CFU ml−1 were tD=−1.38 log N+10.18 with R2=0.99 in the pure medium and tD=−1.54 log N+11.33 with R2=0.98 in milk samples, respectively. The detection times for 4.8 and 5.4×105 CFU ml−1 initial cell numbers were 9.3 and 2.2 h, respectively, and the detection limit could be as low as 1 cell in a sample. [Copyright &y& Elsevier]

Three-electrode electrochemical impedance technique was investigated for detection of Salmonella typhimurium by monitoring the growth of bacteria in selenite cystine (SC) broth supplemented with trimethylamine oxide hydrochloride (TMAO·HCl) and mannitol (M). The change in the system impedance during the growth of bacteria was studied using frequency spectral scanning. It was found that the impedance at low frequencies (<10 kHz) mainly came from the double-charged layer capacitance, reflecting the changes at the electrode interface and the adsorption on the electrode surface. While at high frequencies (>10 kHz), the system impedance mainly depended on the medium resistance. The adsorption of bacteria on the electrode surface was detected by measuring low frequency impedance, and verified with Faradic impedance spectroscopy. Enumeration of S. typhimurium using a low frequency (1 Hz) capacitance measurement and a high frequency (1 MHz) resistance measurement were compared. The detection times were determined for quantitative analysis based on the growth curves of bacteria referring to either the medium resistance or electrode capacitance. The regression equations for the detection times (td, h) and the initial cell number (N, cells·ml−1) were td=−1.24 log N+13.4 with R2=0.98 and td=−1.40 log N+14.46 with R2=0.97 for the medium resistance and electrode capacitance methods, respectively. [Copyright &y& Elsevier]

A new method for in situ monitoring Salmonella typhimurium in a selective medium was developed by measuring the cathodic peak current of oxygen in cyclic voltammograms during bacterial proliferation with an electrochemical voltammetric analyzer. The rapid oxygen consumption at a time during the growth of bacteria resulted in a sharp decline of the curves. The detection times (threshold values) obtained from the oxygen consumption curve were inversely related to the concentrations of S. typhimurium in the medium. This method for detection of S. typhimurium is more sensitive than nucleic acid-based polymerase chain reaction (PCR) methods and any of the antibody-based methods such as enzyme-linked immunosorbent assay (ELISA) technology, electrochemical immunoassays, immunosensors, and it has a sensitivity similar to conventional culture methods and impedimetric methods but is more rapid than either of them. A calibration curve was obtained by plotting initial cell concentrations (CFU ml−1) determined by conventional plate counting, as a function of the detection time. A linear response was found on the calibration curve for S. typhimurium between 1–2×100 and 1–2×106 cells per ml. The detection time for 1–2×100 and 1–2×106 cells per ml of viable S. typhimurium in the medium was 10 and 2.1 h, respectively. [Copyright &y& Elsevier]

This study was conducted to further explore the mechanism of transforming growth factor β1 (TGF-β1) activation, which plays a critical role in many physiological and pathological conditions. We have previously shown that the large (270 kDa), but not small (40 kDa), mannose 6-phosphate receptors facilitate the cellular response to latent TGF-β1 released from genetically modified cells. In this study, we explored the role of cell membrane associated transglutaminase and plasmin in mannose 6-phosphate receptor induced latent TGF-β activation using MS and MS-9 cells bearing either no receptors or the 270 kDa mannose 6-phosphate/insulin-like growth factor II receptors, respectively. As a source of latent TGF-β1, PA317 cells were transfected with either pLin-TGF-β1 vector or pLin retroviral vector with no TGF-β1 insert using calcium phosphate precipitation. The latency and bioactivity of TGF-β1 in conditioned medium derived from transfected PA317 cells were evaluated by enzyme-linked immunosorbent assay and mink lung epithelial cell growth inhibition assay, respectively. The level of latent TGF-β1 was 13-fold higher (20.1 ± 0.4 vs. 1.5 ± 0.03 ng/ml) in conditioned medium from pLin-TGF-β1 transfected cells than that of control. The latency and bioactivity of TGF-β1 released from pLin-TGF-β1 transfected cells were confirmed by evaluation of 3H-thymidine incorporation in Mv1Lu epithelial cells treated with non- and heat-activated 10% conditioned medium. The results showed a significantly lower 3H-thymidine incorporation in Mv1Lu epithelial cells treated with heat-activated PA317 conditioned medium (4% of control) relative to those treated with either control or nonheated conditioned medium. This inhibition was abrogated by addition of 40 μg/ml of TGF-β1 neutralizing antibody. The level of 3H-thymidine incorporation was then evaluated in MS-9 cells receiving Dulbecco's modified Eagle medium containing either 0% 10%, 30% or 50% volumes of nonactivated PA317 conditioned medium for 24 hours. The results showed a markedly lower proliferation in response to 30% and 50% conditioned medium used in MS-9 cells. Under similar experimental conditions, addition of only mannose 6-phosphate, but not fructose 6-phosphate or mannose 1-phosphate, at 1 mM concentration restored the MS-9 cell proliferative response to latent TGF-β1. The inhibitory effects of latent TGF-β1 on MS-9 cell proliferation were restored by addition of either TGF-β1 neutralizing antibody or cystamine, a transglutaminase inhibitor. In contrast, addition of aprotinin, a plasmin inhibitor, had a marginal influence on inhibitory effects of latent TGF-β1 on MS-9 cell proliferation. Interestingly, a mixture of latent TGF-β1 + MS-9 cell membranes, but not MS cell membranes, also inhibited the mink lung epithelial cell proliferation (34% of control). These findings indicate that mannose 6-phosphate/insulin-like growth factor II receptors are involved in latent TGF-β activation and that is at least partly dependent on cell membrane associated transglutaminase, but not on plasmin. [ABSTRACT FROM AUTHOR]

Background: Manganese (Mn) and Selenium (Se) deficiencies are noted in adult patients with chronic kidney disease (CKD). However, levels of these trace elements have not been well studied in the paediatric CKD population. We determined the Mn and Se levels in a single-institution cohort of paediatric patients with CKD. Methods: Ancillary cross-sectional study to a prospective longitudinal randomized control trial on zinc supplementation, which included 42 children and adolescents aged 0 to 19 years with CKD stages I to IV not on dialysis, who had 1–6 trace element measurements. Cystatin C estimated glomerular filtration rate (eGFR) was calculated using the Filler formula. Plasma Mn and Se levels were measured, and anthropomorphic data/blood parameters were collected from electronic health records. The trial was registered on clinicaltrials.gov, NCT02126293. Results: There were 96 Mn and Se levels in 42 patients (age 12.5 ± 4.6 years). The median Mn concentration was 12.61 nmol/L [10.08, 16.42] with a trend towards lower values with lower eGFR (p = 0.0367 one-sided). Mn z-scores were significantly lower than the general paediatric reference population. The mean Se level was 1.661 ± 0.3399 µmol/L with a significant positive correlation with eGFR (p = 0.0159, r = 0.366). However, only 4 patients with low eGFR had abnormally low Se levels. Conclusions: This single-institution study of children with CKD demonstrates a significant decrease in Se levels with decreasing eGFR, but no significant difference between mean Se z-scores of our cohort and the reference population. There was no significant relationship between Mn levels and eGFR however the mean Mn z-score was significantly lower than the theoretical mean. Trial registration: clinicaltrials.gov, NCT02126293, https://clinicaltrials.gov/ct2/show/NCT02126293. Date: April 30, 2014. [ABSTRACT FROM AUTHOR]

The present work highlights the synthesis of graphene oxide (GO) modified polythiophene (PTh) for its application as an antibacterial agent as well as a visible light active photocatalyst. PTh was synthesized via the interfacial polymerization method using FeCl3 as initiator and then formulated as nanohybrids by mixing it in different weight ratios with graphene oxide (GO) i.e., 1 wt.%,3 wt.% and 5 wt. %. PTh and GO/PTh nanohybrids were characterized using FTIR, UV-visible, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) techniques. The polymerization of PTh as well as modification of PTh with GO was confirmed by IR studies, while the shifting of electronic transitions of PTH upon modification with GO were confirmed by the UV-visible studies. The degradation of dyes, Alizarin Yellow (AY), Basic Blue (BB) and Congo Red (CR) was carried out via sonophotocatalysis under visible light using PTh and GO/PTh as catalysts for a period of 60 min. The GO/PTh revealed higher degradation efficiency as compared to PTh. To evaluate its effectiveness as an antibacterial agent against Bacillus subtilis, disk diffusion inhibitory assay was carried out under dark and light conditions. The results showed that PTh and GO/PTh nanohybrids had bactericidal properties, regardless of light exposure. The results of the minimal inhibitory concentration (MIC) assay indicated the nanohybrid of 3-GO/PTh had the lowest MIC, followed by 1-GO/PTh and 5-GO/PTh. [ABSTRACT FROM AUTHOR]

Ganglioside antibodies can help diagnose distinct acute and chronic inflammatory neuropathies including axonal variants of Guillain-Barre syndrome, Miller-Fisher syndrome (MFS), multifocal motor neuropathy, and chronic sensory ataxic neuropathies. Because ganglioside antibody testing may be routinely ordered in patients with suspected inflammatory neuropathy, we sought to evaluate its yield and utilization in clinical practice. We performed a retrospective chart review of all patients at London Health Sciences Centre who underwent ganglioside antibody testing between April 2019 and August 2023. The disease phenotype was determined for each patient, and the proportion of all tests that yielded a true-positive result was calculated. Ganglioside antibody positivity was classified as a true-positive result if the disease phenotype was robustly associated with the detected ganglioside antibody and there was no other more likely diagnosis. We identified 92 patients who underwent ganglioside antibody testing. One patient (1%) was classified as having a true-positive result; this patient had GQ1b-IgG positivity with MFS. Among 92 patients tested, 20 patients (22%) had a disease phenotype that was considered to be robustly associated with ganglioside antibody positivity. The yield of ganglioside antibody testing in clinical practice is low. We found that this testing is frequently ordered in patients with disease phenotypes that are not robustly associated with ganglioside antibody positivity, indicating that suboptimal test utilization is a primary contributor to its low yield. Restricting ganglioside antibody testing to patients with characteristic disease phenotypes would be valuable to improving yield and utilization of this testing. • We found the yield of ganglioside antibody testing at our centre to be low at 1%. • We identified the potential for clinically irrelevant positive antibody results. • Testing was frequent among patients without characteristic disease phenotypes. • Inappropriate patient selection was likely a primary contributor to low test yield. • Restricting testing to those with characteristic disease phenotypes is warranted. [ABSTRACT FROM AUTHOR]

Carbon–semiconductor hybrid quantum dots are classical carbon dots with core carbon nanoparticles doped with a selected nanoscale semiconductor. Specifically, on those with the nanoscale TiO2 doping, denoted as CTiO2-Dots, their synthesis and thorough characterization were reported previously. In this work, the CTiO2-Dots were evaluated for their visible light-activated antibacterial function, with the results showing the effective killing of not only Gram-positive but also the generally more resistant Gram-negative bacteria. The hybrid dots are clearly more potent antibacterial agents than their neat carbon dot counterparts. Mechanistically, the higher antibacterial performance of the CTiO2-Dots is attributed to their superior photoexcited state properties, which are reflected by the observed much brighter fluorescence emissions. Also considered and discussed is the possibility of additional contributions to the antibacterial activities due to the photosensitization of the nanoscale TiO2 by its doped core carbon nanoparticles. [ABSTRACT FROM AUTHOR]

This study investigated the effects of matrix on the behaviors of 3D-cultured cells of two prostate cancer cell lines, LNCaP and DU145. Two biologically-derived matrices, Matrigel and Cultrex BME, and one synthetic matrix, the Alvetex scaffold, were used to culture the cells. The cell proliferation rate, cellular response to anti-cancer drugs, and expression levels of proteins associated with drug sensitivity/resistance were examined and compared amongst the 3D-cultured cells on the three matrices and 2D-cultured cells. The cellular responses upon treatment with two common anti-cancer drugs, Docetaxel and Rapamycin, were examined. The expressions of epidermal growth factor receptor (EGFR) and β-III tubulin in DU145 cells and p53 in LNCaP cells were examined. The results showed that the proliferation rates of cells cultured on the three matrices varied, especially between the synthetic matrix and the biologically-derived matrices. The drug responses and the expressions of drug sensitivity-associated proteins differed between cells on various matrices as well. Among the 3D cultures on the three matrices, increased expression of β-III tubulin in DU145 cells was correlated with increased resistance to Docetaxel, and decreased expression of EGFR in DU145 cells was correlated with increased sensitivity to Rapamycin. Increased expression of a p53 dimer in 3D-cultured LNCaP cells was correlated with increased resistance to Docetaxel. Collectively, the results showed that the matrix of 3D cell culture models strongly influences cellular behaviors, which highlights the imperative need to achieve standardization of 3D cell culture technology in order to be used in drug screening and cell biology studies. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the electric cell-substrate impedance sensing (ECIS) system was used to study the cellular activities of oral squamous cell carcinoma (OSCC) cells in a real-time and label-free manner. Various cellular activities, including cell adhesion, spreading, proliferation, and drug-induced apoptosis and inhibition of apoptosis, were monitored. A linear relationship was found between the impedance-based cell index and the cell number in the range of 3500 to 35,000 cells/well. Anti-cancer drug-cisplatin-induced OSCC cell apoptosis at the minimal concentration of 5μM after 20h of treatment and followed a linear dose-dependent manner in the concentration range from 10μM to 25μM. The inhibition of cisplatin-induced apoptosis by the carcinogen, nicotine, at concentrations from 0.1μM to 10μM was monitored. The most significant inhibitory effect of nicotine on cisplatin-induced apoptosis was observed at concentrations of 0.5–1μM. The results obtained with impedance method correlated well with microscopic imaging analysis of cellular morphology and cell viability analysis. This study demonstrated that the impedance-based method can provide real-time information about the cellular activity of viable cells and detect drug-induced cellular activities much earlier than commonly used cell-based image analysis. This impedance-based method has the potential to provide a useful analytical approach for cancer research. [Copyright &y& Elsevier]

Abstract: The performance of a low conductive growth medium (LCGM) (conductivity of <1300 μS) was evaluated for its ability to support growth of food borne bacterial pathogens including Listeria monocytogenes and to determine the expression of the two key virulence proteins in L. monocytogenes for possible applications in an impedance-based microfluidic biochip detection platform. Growth of Listeria was monitored spectrophotometrically and the lag phase, generation time, growth rate and maximum population density were determined using the Gompertz equation. LCGM had a lag phase of 2.3 h and showed a higher cell density compared to Luria Bertini (LB) broth. Length of lag phase was highly dependent on initial inoculum concentrations. The changes in conductivity with respect to growth in the low conductive medium were monitored using a conductivity probe. L. monocytogenes growth could be detected within 2 h (0.1 mS) in LCGM and within 6 h in LB. The performance of the media was also evaluated for the recovery of Listeria cells exposed to various stresses as 42 °C for 1, 2 or 6 h, an osmotic stress in 10.5% NaCl, an acidic stress at pH 2, 3 or 5 and a combined stress of 10.5% NaCl, pH 5 and 1 h exposure at 42 °C. The recovery rate was comparable with that of Tryptic soy broth containing yeast extract (TSBYE). L. monocytogenes in LCGM supported the expression of two key virulence markers, actin polymerization protein (ActA) and internalin B (InlB), which could be detected using specific antibodies. In general LCGM also supported the growth of several other bacterial species suggesting its implication in microbial quality monitoring of products. In conclusion, LCGM is a sensitive low conductive medium that supports the growth as well as the expression of virulence markers for potential applications in sensitive detection of L. monocytogenes or other food borne pathogens in impedance-based sensor platform. [Copyright &y& Elsevier]

Remdesivir, an antiviral agent for the treatment of coronavirus disease 2019 (COVID‐19), is metabolized intracellularly, with these metabolites eliminated predominantly in urine. Because of a lack of safety and pharmacokinetic (PK) data, remdesivir is not currently recommended for patients with estimated glomerular filtration rate less than 30 ml/min/1.73 m2 and those on hemodialysis. This study evaluated the PKs of remdesivir and its metabolite, GS‐441524, in patients with COVID‐19 who were and were not receiving renal replacement therapy (RRT). This study enrolled two patients with normal renal function, two with impaired renal function not receiving RRT, two receiving continuous RRT (CRRT), and three undergoing intermittent hemodialysis (IHD). Patients were administered 200 mg remdesivir on the first day, followed by 100 mg/day for 5–10 days. Serial blood samples were collected for PK analysis, and PK parameters were assessed by a noncompartmental method. Systemic exposure to remdesivir was higher in patients with impaired renal function and those receiving CRRT than in patients with normal renal function, but was similar in patients undergoing IHD and those with normal renal function. By contrast, systemic exposure to GS‐441524 was highest in patients undergoing IHD, followed by patients with impaired renal function and those receiving CRRT, and lowest in patients with normal renal function. The PK profiles of remdesivir and GS‐441524 varied according to renal function and RRT. The impact of PK changes of remdesivir and its metabolite on safety and efficacy should be considered when administering remdesivir to patients with COVID‐19 with renal impairment. [ABSTRACT FROM AUTHOR]

Carbon dots (CDots) are strongly absorptive over the visible spectrum, with the effective photon-harvesting driving rich excited state processes and properties. In this work, spectroscopic probing of these processes and properties is coupled with the evaluation of the photoinduced bactericidal function of CDots, aimed toward making correlations among the findings from the former and those from the latter on the inactivation of bacterial pathogens. Within the general mechanistic framework for CDots, the observed effective and efficient antibacterial activities of the CDots under visible light are attributed to major contributions by the initially photo-generated electrons and holes that are trapped at passivated surface defect sites of the dots, in addition to the traditional reactive oxygen species (ROS) produced in the emissive excited states from the recombination of the redox pairs. Such major contributions to the inactivation of the bacteria by the separated redox species in CDots can not be quenched by ROS scavengers commonly used in the study of photodynamic effects with classical molecular photosensitizers, thus making light-activated CDots uniquely potent antimicrobial agents. The characteristic features of photoexcited CDots and their related mechanistic implications are discussed in reference to the similar behaviors and mechanistic model of conventional semiconductor quantum dots. Image 1 [ABSTRACT FROM AUTHOR]

In this study, essential oils (EO)-incorporated multi-walled carbon nanotubes (MWCNTs) filters were developed for achieving dual functions in effective removing bacteria from aqueous solutions and inactivating bacteria cells captured on the filters. Tea tree essential oil (TTO), lemon essential oil (LEO), and TTO-LEO-mixture were coated on MWCNTs filters with different MWCNTs loadings ranging from 3 mg to 6 mg. MWCNTs filters with 6.0 mg MWCNTs showed complete removal (100%) of E. coli cells from PBS buffer with 6.35 log10 decrease of cell numbers. TTO, LEO, and TTO/LEO Mix (1:1) coatings at the volume of 50 μL on MWCNTs filters achieved bacterial removal rates of >98%, and highly effective inactivation efficiency. TTO coatings had the highest antimicrobial efficacies than LEO and Mix coatings, MWCNTs filters with 50 μL TTO coating showed 100% inhibitory rate of the captured bacteria on the filter surfaces. Those captured but survived cells on filters with less TTO coating (20μL) significantly reduced their salt tolerances to 30 and 40 g/L NaCl in LB agar, and became less salt tolerance with longer incubation time on the filters. The developed TTO-MWCNTs filters had much higher antimicrobial efficacies than the filters with dual functions developed previously. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon dots (CDots) exploit unique properties of small carbon nanoparticles; • CDots with N -ethylcarbazole (NEC) functionalization are very stable; • NEC-CDots are excellently compatible with poly(N -vinylcarbazole) (PVK); • Optical properties of NEC-CDots in PVK matrix are no different from those in solution; • PVK/NEC-CDots nanocomposites are valuable to electronic/optoelectronic applications. The adducts of N -ethylcarbazole (NEC) to small carbon nanoparticles prepared by microwave-assisted thermal processing are carbon dots (CDots) with NEC for the dot surface functionalization, thus NEC-CDots, which were shown previously for their high stability in the dot structure and properties. In this study, the optical absorptions and photoexcited state properties of NEC-CDots in solution and in poly(N -vinylcarbazole) (PVK) film matrix were evaluated by using optical spectroscopy methods, including those for fluorescence decays and lifetimes. The results suggest that the properties are largely unchanged from solution phase to the polymer matrix environment, very positive to their expected optoelectronic applications. [ABSTRACT FROM AUTHOR]

Background: Cell-based analysis may have the potential for using patient-derived tissues/cells as a basis for a more direct prediction of therapeutic outcomes.Methods: This study focused on the application of the Real Time Cell Electronic Sensing (RT-CES) system for screening effective anticancer drugs to different types of prostate cancers. The goal was to demonstrate the potential application of such technology toward the suitability in selection of personalized medicine. Three prostate cancer cell lines, DU145, LNCaP, and PC-3, and a normal prostate cell line were used. Docetaxel, Carboplatin, Abiraterone Acetate, Mitoxantrone, Sunitinib Malate were used as testing drugs.Results: Cellular adhesion, proliferation and drug induced cellular responses were monitored by the RTCES system, and the results were correlated to the well-established cell viability tests. Identification of an effective drug from a panel of available anticancer drugs to a specific cancer cell line, or testing the effectiveness of a certain drug to a panel of prostate cancer cell lines was demonstrated. Cellular resistance to a drug at single dose and multiple dose challenges was monitored by RT-CES measurement, while such resistance was not detectable by endpoint cell viability assays.Conclusions: The results of this study highlighted the advantages of such real-time impedance-based sensing system for applications in chemotherapy reagent selection. [ABSTRACT FROM AUTHOR]

Carbon-based hybrid nanostructures, especially carbon hybrid dots with metal oxides, are important to both fundamental studies and technological applications. In this work, carbon–TiO2 hybrid dots in two different structural configurations were prepared and investigated comparatively for their optical properties and photoinduced redox characteristics, and the results suggested major differences. In the configuration of small carbon nanoparticles each coated/doped with only a small amount of TiO2, the TiO2 played the role of enhancing the surface passivation effect in conjunction with organic surface functionalization agents for the hybrid dots to exhibit a much improved performance over that of their corresponding neat carbon dots. In the other configuration, however, the hybrid dots of TiO2 nanocrystals each composited with nanoscale carbon domains were apparently similar to dye-sensitized TiO2 nanoparticle systems, with the carbon domains providing the dye function for the harvesting of visible photons. While combining nanoscale carbon and TiO2 for various applications has been a popular topic in the recent literature, the results reported here provide new insights into the different structural configurations or arrangements between the carbon and TiO2 and their associated effects on the optical and photoinduced redox properties of the hybrid nanostructures. Significant implications of the results on an understanding of the mechanistic relationships between the hybrid nano-structures/configurations and optical/redox properties are highlighted, and opportunities in the further exploration of carbon–metal oxide hybrid dots and their applications are discussed. [ABSTRACT FROM AUTHOR]

A simple yet consequential modification was made to the popular carbonization processing of citric acid - polyethylenimine precursor mixtures to produce carbon dots (CDots). The modification was primarily on pushing the carbonization processing a little harder at a higher temperature, such as the hydrothermal processing condition of around 330 °C for 6 h. The CDots thus produced are comparable in spectroscopic and other properties to those obtained in other more controlled syntheses including the deliberate chemical functionalization of pre-processed and selected small carbon nanoparticles, demonstrating the consistency in CDots and reaffirming their general definition as carbon nanoparticles with surface passivation by organic or other species. Equally significant is the finding that the modified processing of citric acid - polyethylenimine precursor mixtures could yield CDots of record-setting fluorescence performance, approaching the upper limit of being quantitatively fluorescent. Thus, the reported work serves as a demonstration on not only the need in selecting the right processing conditions and its associated opportunities in one-pot syntheses of CDots, but also the feasibility in pursuing the preparation of quantitatively fluorescent CDots, which represents an important milestone in the development and understanding of these fluorescent carbon nanomaterials. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the antimicrobial effects of CDots in combination with other antimicrobial reagents, including H2O2, Na2CO3, and AcOH (acetic acid). CDots were synthesized and passivated with 2,2’-(ethylenedioxy)bis(ethylamine) (EDA). The minimal inhibitory concentration (MIC) of CDots was 64 μg/mL on both Gram negative bacteria E.coli cells and Gram positive bacteria Bacillus subtilis cells. When CDots were combined with H2O2, antibacterial synergistic effects were observed based on the fractional inhibitory concentration (FIC) index, and further confirmed by an isobologram analysis and viable cell number counting methods. With the combination treatment of 10 μg/mL CDots with 8.82 mM H2O2, the viable E.coli cell numbers decreased 2.46 log, which was significant lower than the log reduction from 8.82 mM H2O2 (1.57 log) or 10 μg/mL CDots (0.14 log) treatment alone. However, the combination of CDots with Na2CO3 or AcOH did not show synergistic effects, instead, exhibiting indifference effects according to the FIC index. This study indicated that the combination of CDots with their synergistic antimicrobial reagents, such as H2O2, could reach the goal of inhibiting bacteria growth by using lower concentration of each individual chemical in the combination than using one chemical treatment alone, reduce the risks imposed on environmental health and the possibilities of the development of microbial resistances. [ABSTRACT FROM AUTHOR]

Human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. Methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (NPs) is a more universal and attractive alternative to other physical and chemical approaches. Using norovirus GI.1 (Norwalk) virus-like particles (VLPs) as a model viral system, this study characterized the antiviral activity of Au/CuS core/shell nanoparticles (NPs) against GI.1 VLPs for the rapid inactivation of HuNoV. Inactivation of VLPs (GI.1) by Au/CuS NPs evaluated using an absorbance-based ELISA indicated that treatment with 0.083 μM NPs for 10 min inactivated ~50% VLPs in a 0.37 μg/ml VLP solution and 0.83 μM NPs for 10 min completely inactivated the VLPs. Increasing nanoparticle concentration and/or VLP-NP contact time significantly increased the virucidal efficacy of Au/CuS NPs. Changes to the VLP particle morphology, size, and capsid protein were characterized using dynamic light scattering, transmission electron microscopy, and Western blot analysis. The strategy reported here provides the first reported proof-of-concept Au/CuS NPs-based virucide for rapidly inactivating human norovirus. [ABSTRACT FROM AUTHOR]

Inactivation of pathogens from environment and inhibition of biofilm formation on various surfaces are important for biosafety, biosecurity and public health. Carbon nanotubes (CNTs) possess antimicrobial effects in addition to their unique optical, electrical, mechanical and thermal properties. This review summarizes the antimicrobial effects of single walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) in suspensions and on CNT contained surfaces. To increase antimicrobial effects, CNT composites containing other antimicrobial reagents are introduced. Also described are the possible antimicrobial mechanisms of CNTs. [ABSTRACT FROM AUTHOR]

Background: After parents raised concerns about potential lead (Pb) contamination of calcium carbonate for treatment of hyperphosphatemia in chronic kidney disease (CKD), we measured blood Pb using high-resolution sector field inductively coupled mass spectrometry in a quality-assurance investigation of ten pediatric dialysis patients (nine on hemodialysis) and six patients before dialysis. Methods: We assessed the kidney function as cystatin C estimated glomerular filtration rate (eGFR), blood Pb levels, calcium carbonate dose, and standard laboratory parameters, as well as Pb levels in the dialysis feed water. Results: Mean blood Pb concentration in the 16 pediatric CKD patients was 21.1 ± 15.8 µg/l with a maximum of 58 µg/l, which was significantly higher than that of 467 apparently healthy controls (median 6.35 µg/l, interquartile range 4.47, 8.71) and comparable to that of ten adult peritoneal dialysis (PD) patients. Lead levels correlated with red blood cell distribution width, eGFR, and calcium carbonate dose. Pb in dialysate feed water was always <0.00018 mg/l, which is below the accepted limit for water for dialysis of 0.005 mg/l. Conclusions: We found a high prevalence of elevated Pb levels in pediatric CKD patients that correlated with the calcium carbonate dose and GFR. Lead levels should be monitored in these patients. [ABSTRACT FROM AUTHOR]

Transforming growth factor-β (TGF-β) is known to affect nearly every aspect of wound repair. Many of the effects have been extensively investigated; however, the primary effect of endogenously derived TGF-β on wound reepithelialization is still not completely understood. To examine this, two types of wounds were made on a transgenic mouse over-expressing TGF-β1. Full-thickness back wounds were made to compare the wound healing process in the presence of compensatory healing mechanisms. Superficial partial-thickness ear wounds involving only the epidermis were made to determine the effect of TGF-β on reepithelialization. In the partial-thickness ear wounds, at later time points, the transgenic group had smaller epithelial gaps than the wild-type mice. A greater number of actively proliferating cells, as determined by bromodeoxyuridine incorporation, was also found in the transgenic mice at post-injury day 8. These results show that TGF-β1 stimulates the rate of reepithelialization at later time points in partial-thickness wounds. However, in the full-thickness back wounds, the transgenic animals exhibited a slower reepithelialization rate at all time points and the number of bromodeoxyuridine-positive cells was fewer. Our findings would suggest that the overexpression of TGF-β1 speeds the rate of wound closure in partial-thickness wounds by promoting keratinocyte migration. In full-thickness wounds, however, the overexpression of TGF-β1 slows the rate of wound reepithelialization. [ABSTRACT FROM AUTHOR]

Smad signaling mediates the cellular response to transforming growth factor-β (TGF-β). We hypothesize that variations in Smad signaling modify the response to TGF-β signaling in the lung after injury. C57BLKS/J mice were subjected to an 18% surface area burn injury, sacrificed at specific time points and their lung tissue was harvested. Lung TGF-β1 expression, as determined by RT-PCR, ELISA and PAI/Luciferase assay, was not affected by injury. Western blots for Smad2/3 and Smad4 on nuclear fractions revealed decreased Smad2, Smad3, and Smad4 protein levels at 3 h, while their total cellular levels did not differ from control mice. Smad7 protein increased transiently at 3 h. Correlating with Smad inhibition, transcription in type I alpha-2 collagen was also transiently depressed. By RT-PCR, Smad3 and Smad7 mRNAs decreased at 3 h, while Smad2 and Smad4 mRNA levels remained constitutive. Burn injury did not alter lung TGF-β1 expression but caused Smad inhibition through decreased nuclear translocation of Smad2, Smad3, and Smad4, and upregulated Smad7. Transcription was not the key regulatory step in Smad protein expression, as transient decreases in Smad3 and Smad7 mRNA did not correlate with protein levels. It appears that Smad activity may in part attenuate TGF-β activity after burn injury. [Copyright &y& Elsevier]

Transforming growth factor-β1 is a fibrogenic cytokine that is important in the development of fibroproliferative disorders of the skin after injury. To investigate the role of transforming growth factor-β1 produced by keratinocytes during wound healing, a plasmid with the human transforming growth factor-β1 gene coupled with the keratin 14 promoter (pG3Z: K14-TGF-β1) was constructed. The construct was tested successfully in vitro before being used to generate transgenic animals, which were subsequently bred into homozygous and heterozygous lines. Genotype screening of founders and progeny was performed by Southern blotting and targeting of the transgene to the epidermis by the keratin 14 promoter was shown by reverse transcription polymerase chain reaction. The major phenotypic change observed in the transgenic animals was “scruffiness” of the fur attributed to transgene expression in the skin, seen primarily in the homozygous line. A significant reduction in the rate of reepithelialization of full-thickness excisional wounds of dorsal skin was seen in homozygous animals compared with normal litter-mate controls at day 7 (p < 0.05, Fisher's Exact test) and day 9 (p < 0.01) postwounding. Wounds in heterozygous animals also healed more slowly at day 9 (p < 0.01). Northern analysis of mRNA extracted from the wounds showed increased human transforming growth factor-β1 message levels in homozygous and heterozygous animals, maximal at day 5. Significant increases in transforming growth factor-β1 activity in healing wounds measured using the plasminogen activator inhibitor-1/luciferase assay were found in the transgenic strains at day 9 postinjury as compared with the normal litter-mate control mice (p < 0.001, ANOVA). Type I procollagen mRNA expression was higher in the homozygous and heterozygous animals, with the highest levels reached at day 9. By day 5 postwounding, biopsies of both homozygous and... [ABSTRACT FROM AUTHOR]

• Carbon dots (CDots) exploit unique properties of small carbon nanoparticles; • Carbon/semiconductor hybrid dots substantially expand the CDots platform; • Carbon/TiO 2 dots in different compositions/configurations can be designed and prepared; • The hybrid dots can be explored for different photoexcited state properties; • The hybrid dots can serve as effective photodynamic antibacterial agents. Carbon/TiO 2 hybrid dots with the general configuration of nanoscale carbon domains incorporated with TiO 2 nanoparticles of different sizes (8 and 25 nm in diameter) were prepared and characterized, and their optical and photodynamic properties were studied. The properties were found to be affected dramatically by the relative sizes and configurations of the nanoscale carbon domains and TiO 2 nanoparticles in the hybrid dots, as reflected by the observed major difference in their photodynamic inactivation of bacteria under visible light. Mechanistic implications of the results are discussed. [ABSTRACT FROM AUTHOR]