Histatin 5-Inspired Short-Chain Peptides Selectively Combating Pathogenic Fungi with Multifaceted Mechanisms

Short-chain antifungal peptides (AFPs) inspired by histatin 5 have been designed to address the problem of antifungal drug resistance. These AFPs demonstrate remarkable antifungal activity, with a minimal inhibitory concentration as low as 2 µg mL-1 . Notably, these AFPs display a strong preference for targeting fungi rather than bacteria and mammalian cells. This is achieved by binding the histidine-rich domains of the AFPs to the Ssa1/2 proteins in the fungal cell wall, as well as the reduced membrane-disrupting activity due to their low amphiphilicity. These peptides disrupt the nucleus and mitochondria once inside the cells, leading to reactive oxygen species production and cell damage. In a mouse model of vulvovaginal candidiasis, the AFPs demonstrate not only antifungal activity, but also promote the growth of beneficial Lactobacillus spp. This research provides valuable insights for the development of fungus-specific AFPs and offers a promising strategy for the treatment of fungal infectious diseases.

Using CT imaging features to predict visceral pleural invasion of non-small-cell lung cancer

AIM

To examine the diagnostic performance of different models based on computed tomography (CT) imaging features in differentiating the invasiveness of non-small-cell lung cancer (NSCLC) with multiple pleural contact types.

MATERIALS AND METHODS

A total of 1,573 patients with NSCLC (tumour size ≤3 cm) were included retrospectively. The clinical and pathological data and preoperative imaging features of these patients were investigated and their relationships with visceral pleural invasion (VPI) were compared statistically. Multivariate logistic regression was used to eliminate confounding factors and establish different predictive models.

RESULTS

By univariate analysis and multivariable adjustment, surgical history, tumour marker (TM), number of pleural tags, length of solid contact and obstructive inflammation were identified as independent risk predictors of pleural invasiveness (p=0.014, 0.003, <0.001, <0.001, and 0.017, respectively). In the training group, comparison of the diagnostic efficacy between the combined model including these five independent predictors and the image feature model involving the latter three imaging predictors were as follows: sensitivity of 88.9% versus 77% and specificity of 73.5% versus 84.1%, with AUC of 0.868 (95% CI: 0.848-0.886) versus 0.862 (95% CI: 0.842-0.880; p=0.377). In the validation group, the sensitivity and specificity of these two models were as follow: the combined model, 93.5% and 74.3%, the imaging feature model, 77.4% and 81.3%, and their areas under the curve (AUCs) were both 0.884 (95% CI: 0.842-0.919). The best cut-off value of length of solid contact was 7.5 mm (sensitivity 68.9%, specificity 75.5%).

CONCLUSIONS

The image feature model showed great potential in predicting pleural invasiveness, and had comparable diagnostic efficacy compared with the combined model containing clinical data.

Guanidinylated/PEGylated chitosan in the bioink promotes the formation of multi-layered keratinocytes in a human skin equivalent

The biological differences of skin between rodent and human beings and the strong appeal to replace the experimental animals have led to the development of alternative models with structures similar to the real human skin. Keratinocytes cultured in vitro on conventional dermal scaffolds tend to form monolayer rather than multi-layer epithelial tissue architectures. How to construct human skin or epidermal equivalents with multi-layered keratinocytes similar to real human epidermis remains one of the greatest challenges. Herein, a human skin equivalent with multi-layered keratinocytes was constructed by 3D bioprinting fibroblasts and subsequent culturing epidermal keratinocytes. Biocompatible guanidinylated/PEGylated chitosan (GPCS) was used as the main component of bioink to 3D bioprint tissue-engineered dermis. The function of GPCS to promote HaCat cell proliferation and connection was confirmed at the genetic, cellular, and histological levels. Compared with the skin tissues with mono-layered keratinocytes engineered with collagen and gelatin, adding GPCS in the bioink generated tissue-engineered human skin equivalents with multi-layered keratinocytes. Such human skin equivalents could be alternative models for biomedical, toxicological, and pharmaceutical research.

One-Dimensional Rod-like Tobacco Mosaic Virus Promotes Macrophage Polarization for a Tumor-Suppressive Microenvironment

The phenotype of tumor-associated macrophages plays an important role in their function of regulating the tumor immune microenvironment. The M1-phenotype macrophages display tumor-killing and immune activating functions. Here we show that the tobacco mosaic virus (TMV), a rod-like plant virus, can polarize macrophages to an M1 phenotype and shape a tumor-suppressive microenvironment. RAW 264.7 cells and bone marrow derived-macrophages (BMDMs) can recognize TMV via Toll-like receptor-4, and then the MAPK and NF-κB signaling pathways are activated, leading to the production of pro-inflammatory factors. Furthermore, the in vivo assessments on a subcutaneous co-injection tumor model show that the TMV-polarized BMDMs shape a tumor-suppressive microenvironment, resulting in remarkable delay of 4T1 tumor growth. Another in vivo assessment on an established tumor model indicates the high tumor-metastasis-inhibiting capacity of TMV-polarized BMDMs. This work suggests a role for this plant virus in macrophage-mediated therapeutic approaches and provides a strategy for tumor immunotherapy.

Overcoming the Stromal Barrier of the Cornea with a Peptide Conjugate Nano-Assembly to Combat Fungal Keratitis

Fungal hyphae deeply invade the cornea in fungal keratitis. The corneal stroma hinders the infiltration of antifungal drugs and reduces their bioavailability. Here, this work reports a peptide conjugate nano-assembly that permeates the stroma and kills the pathogen without irritating the ocular cornea. The hydrophilic surface of the nano-assembly ensures deep permeation into the stroma. When encountering a fungal hyphal cell, the nano-assembly disassembles and exposes the α-helical peptide to destroy the fungal membrane, thus inactivating the pathogen. In a rabbit model of fungal keratitis, the nano-assembly exhibits a better therapeutic effect than commercially available natamycin ophthalmic suspension. Peptide conjugates with a nano-assembled structure and assembly-disassembly behavior could serve as the foundation of a new therapy for fungal keratitis.

[Effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice]

Objective: To explore the effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice. Methods: The experimental research method was adopted. The control hydrogel composed of polyvinyl alcohol and gelatin, and the water-soluble chitosan hydrogel composed of the aforementioned two materials and water-soluble chitosan were prepared by the cyclic freeze-thaw method. The fluidity of the two dressings in test tube before and after the first freeze-thawing was generally observed, and the difference in appearance of the final state of two dressings in 12-well plates were compared. According to random number table (the same grouping method below), the cell strains of L929 and HaCaT were both divided into water-soluble chitosan hydrogel group and control hydrogel group, respectively. After adding corresponding dressings and culturing for 24 h, the cell proliferation activity was measured using cell counting kit 8. Rabbit blood erythrocyte suspensions were divided into normal saline group, polyethylene glycol octyl phenyl ether (Triton X-100) group, water-soluble chitosan hydrogel group, and control hydrogel group, which were treated accordingly and incubated for 1 hour, and then the hemolysis degree of erythrocyte was detected by a microplate reader. Twenty-four female db/db mice aged 11-14 weeks were selected, and full-thickness skin defect wounds on their backs were inflicted and inoculated with the methicillin-resistant Staphylococcus aureus (MRSA), 72 h later, the mice were divided into blank control group, sulfadiazine silver hydrogel group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. On post injury day (PID) 0 (immediately), 7, 14, and 21, the healing of the wound was observed. On PID 14 and 21, the wound healing rate was calculated. On PID 14, MRSA concentration in wounds was determined. On PID 21, the wounds were histologically analyzed by hematoxylin and eosin staining; the expression of CD31 in the wounds was detected by immunofluorescence method, and its positive percentage was calculated. Raw264.7 cells were taken and divided into interleukin-4 (IL-4) group, blank control group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. At 48 h of culture, the percentages of CD206 positive cells were detected by flow cytometry. The number of samples was all 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Dunnett T3 test. Results: Two dressings in test tube had certain fluidity before freeze-thawing and formed semi-solid gels after freeze-thawing for once. The final forms of two dressings in 12-well plates were basically stable and translucent sheets, with little difference in transparency. At 24 h of culture, the cell proliferation activities of L929 and HaCaT in water-soluble chitosan hydrogel group were significantly higher than those in control hydrogel group (with t values of 6.37 and 7.50, respectively, P<0.01). At 1 h of incubation, the hemolysis degree of erythrocyte in water-soluble chitosan hydrogel group was significantly lower than that in Triton X-100 group (P<0.01), but similar to that in normal saline group and control hydrogel group (P>0.05). On PID 0, the traumatic conditions of mice in the 4 groups were similar. On PID 7, more yellowish exudates were observed inside the wound in blank control group and control hydrogel group, while a small amount of exudates were observed in the wound in sulfadiazine silver hydrogel group and water-soluble chitosan hydrogel group. On PID 14, the wounds in blank control group and control hydrogel group were dry and crusted without obvious epithelial coverage; in sulfadiazine silver hydrogel group, the scabs fell off and purulent exudate was visible on the wound; in water-soluble chitosan hydrogel group, the base of wound was light red and obvious epithelial coverage could be observed on the wound. On PID 14, the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 21, the wound in water-soluble chitosan hydrogel group was completely closed, while the wounds in the other 3 groups were not completely healed; the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 14, the concentration of MRSA in the wound in water-soluble chitosan hydrogel group was significantly lower than that in blank control group (P<0.01), but similar to that in control hydrogel group and sulfadiazine silver hydrogel group (P>0.05). On PID 21, the new epidermis was severely damaged in blank control group; the epidermis on the wound in control hydrogel group also had a large area of defect; complete new epidermis had not yet being formed on the wound in sulfadiazine silver hydrogel group; the wound in water-soluble chitosan hydrogel group was not only completely covered by the new epidermis, the basal cells of the new epidermis were also regularly aligned. On PID 21, the percentage of CD31 positivity in the wound in water-soluble chitosan hydrogel group was (2.19±0.35)%, which was significantly higher than (0.18±0.05)% in blank control group, (0.23±0.06)% in control hydrogel group, and (0.62±0.25)% in sulfadiazine silver hydrogel group, all P<0.01. At 48 h of culture, the percentage of CD206 positive Raw264.7 cells in water-soluble chitosan hydrogel group was lower than that in IL-4 group (P>0.01) but significantly higher than that in blank control group and control hydrogel group (P<0.05 or P<0.01). Conclusions: The water-soluble chitosan hydrogel has good biosafety and can induce higher level of macrophage M2 polarization than control hydrogel without water-soluble chitosan, so it can enhance the repair effect of MRSA-infected full-thickness skin defect wounds in diabetic mice and promote rapid wound healing.

[Analysis of the application of radiotherapy facility construction project evaluation standard in health management institutions]

Objective: To investigate the application of GBZ/T 220.2-2009 "The Specification of Radiological Protection Assessment for Occupational Hazard in Construction Project-Part 2: Radiotherapy Facility" in health management institutions, and to understand the scientificity, practicability and problems existing in the implementation of the standard. Methods: The method of multistage stratified sampling and questionnaire survey were used to collect the standard application status among 96 radiological health managers who had participated in the evaluation of radiotherapy facility construction projects in 6 provinces and cities from November 2020 to April 2021. A descriptive statistical analysis method was used to analyze the basic information of the survey object, the knowledge of the standard, the publicity and implementation of the standard. Results: The radiological health management personnel mainly came from health supervision agencies (62.5%, 60/96) , and 86.5% (83/96) were engaged in the pre-evaluation of radiotherapy device construction project and the approval and supervision of control effect evaluation. The awareness rate and training rate of radiological health managers on GBZ/T 220.2-2009 were 88.5% (85/96) and 31.3% (30/96) , respectively. 89.6% (86/96) managers thought it could meet the needs of radiotherapy facility construction project approval or supervision. 49.0% (47/96) of managers believed that the standard needed to be revised. Conclusion: The content of GBZ/T 220.2-2009 is basically scientific and reasonable, but the publicity, implementation and training of radiological health administrator still need to be strengthened. It is suggested to revise some clauses in the standard that do not meet the requirements.

A Methodology for Reconstructing Source Properties of a Conical Piezoelectric Actuator Using Array-Based Methods

We investigated the force produced by a conical piezoelectric (PZT, lead zirconate titanate) transducer actuated by high voltage pulses (HVP) in contact with a steel transfer plate. Using elastic wave propagation theory in a semi-infinite plate, we aimed to quantify the magnitude and estimate the shape of the force-time function via the body waves produced in the transfer plate using the displacement field recorded on an array of 20 absolutely calibrated PZT receivers. We first calibrated the receiver array using glass capillary fracture. We proceeded to use a conical PZT transducer to actively produce a source at the origin, allowing us to study the displacement field produced on the now calibrated PZT receiver array. We studied two types of HVP: An impulsive and step source. The calibrated receiver array was used to estimate the general shape of the force-time functions for each type of HVP. From our hypothesized force-time functions we were able to estimate the peak force produced by the PZT actuator: The impulsive source generated a force of f peak = 2.90 ± 0.42 N and the step source generated f peak = 1.79 ± 0.30 N, respectively, for a peak applied voltage of 273 V. This translates to an applied force of ∼ 0.011 N/V and 0.007 N/V for the impulse and step force-time functions, respectively, which is similar to estimates found in the literature for other conical transducers in contact with metallic transfer media. This measurement was verified directly by independent measurements of the peak force f peak using a dynamic force transducer. We found that our methodology correctly estimated the magnitude of the force but is limited to transducers with incident angles θ < 53 ∘ . Beyond this angle, overestimates of the force were observed due to the lack of body wave energy produced by the source. These results allow us to quantitatively determine the forces produced by active PZT techniques using only the measurement of the displacement field captured on a calibrated conical PZT array. Quantitative understanding of active PZT sources additionally constrains the transfer functions approach, which is commonly used in the non-destructive testing of materials and in other fields, such as rock physics and laboratory seismology.

Amino Acid Dependent Performance of Modified Chitosan Against Bacteria and Red Blood Cell

In order to combat antibiotic resistance, the development of new antibacterial agents is essential. In this study, we prepared four types of amino acid modified chitosan (CS-AA). Compared with chitosan modified with hydrophobic amino acids, the chitosan modified with positively charged amino acids showed higher antibacterial efficiency against Escherichia coli (E. coli) under similar grafting rate. CS-AA achieves antibacterial properties mainly by destroying the integrity of bacterial cell membranes. All the four types of CS-AA show low toxicity towards red blood cells. This work indicates that positively charged groups are more important than hydrophobic groups in the design of chitosan-based antibacterial agents, and provides helpful information for the molecular design of effective antibacterial agents.

A single-arm pilot of a web-based intervention to improve itch-related quality of life

BACKGROUND

Many patients with chronic itch and atopic dermatitis (AD) or psoriasis do not receive/use available medical and psychosocial treatments properly due to system, provider and/or patient factors.

OBJECTIVE

An educational website (ITCH-RELIEF) to improve itch-related quality of life (QoL) for adults with AD or psoriasis and chronic itch was developed and assessed. ITCH RELIEF stands for Interactive Toolbox of Comprehensive Health Resources to Enhance Living with Itch - Educational Facilitation (for Adults).

METHODS

Single-arm pre- and post-test design with 1-month follow-up (N = 137 at baseline).

RESULTS

There was statistically and clinically significant improvement in the primary outcome of itch-related QoL impairment as assessed by the ItchyQoL from baseline [M = 78.9, 95% confidence interval (CI) = 75.9, 81.9] to follow up (M = 75.4, CI = 72.4, 78.5), P = 0.007, as well as statistically significant improvement in several itch-related secondary outcomes (all Ps < 0.05).

CONCLUSIONS

This study demonstrated initial effectiveness of an online intervention to improve itch-related QoL among individuals with AD or psoriasis and chronic itch. Future studies should address limitations by randomizing more heterogeneous participants, utilizing a longer follow-up and assessing medication use.

Psychosocial adjustment mediates impacts of playmate positive support on body mass index and overweight risk in adolescents

OBJECTIVES

We examined the mediation effects of psychosocial adjustment on the impact of playmate positive support throughout childhood and early adolescence (from age 54 months to 11 years) on later body mass index (BMI) and overweight risk in middle adolescence (age 15 years).

STUDY DESIGN

This was a prospective cohort study.

METHODS

Among 844 children and their families, positive support between child-playmate dyads was repeatedly assessed from child's age 54 months to Grade 5. Long-term positive support between child-playmate dyads throughout childhood and early adolescence was prospectively linked to child's BMI and overweight/obesity status at age 15 years. The average scores of repeated assessments of internalizing and externalizing behavior problems from Grades 3 to 6 were used as mediators.

RESULTS

Significant mediations of internalizing and externalizing behavior problems were observed on pathways from positive support between child-playmate dyads to later BMI and overweight/obesity status at age 15 years. The observed mediations were mainly sustained with pronounced magnitudes in girls, but not in boys.

CONCLUSIONS

Our findings demonstrated a significant mediating role of psychosocial adjustment. Future research efforts are highly encouraged to replicate our findings and further explore this underlying mediation mechanism.

Conjugating Peptides onto 1D Rodlike Bionanoparticles for Enhanced Activity against Gram-Negative Bacteria

Gram-negative bacteria, which possess an impermeable outer membrane, are responsible for many untreatable infections. The lack of development of new relevant antibiotics for over 50 years has increased threats. Peptides are regarded as the most promising alternatives to antibiotics. However, since the activities of existing peptides are not yet comparable to those of current antibiotics, there is an urgent need to improve their antibacterial efficiencies. Herein, we conjugate peptides onto one-dimensional rod-like tobacco mosaic virus (TMV). The peptides on the obtained nanoparticles (peptide-TMV) are hundreds of times superior to free peptides in combating Gram-negative bacteria. Through morphology and gene detection of Escherichia coli, it was revealed that following peptide-TMV application, the high osmotic pressure related to membrane damage and the generated reactive oxygen species cause Escherichia coli's death. In addition, peptide-TMV causes a downregulation of biofilm-related genes, inhibiting biofilm formation. This work paves the way to combat Gram-negative bacteria-related infection.

Diagnostic efficacy of contrast-enhanced ultrasound versus MRI Liver Imaging Reporting and Data System (LI-RADS) for categorising hepatic observations in patients at risk of hepatocellular carcinoma

AIM

To investigate the diagnostic efficacy of the contrast-enhanced ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) for categorising hepatic observations in patients at risk of hepatocellular carcinoma (HCC) compared with magnetic resonance imaging (MRI) LI-RADS.

MATERIALS AND METHODS

CEUS and MRI data were analysed retrospectively according to the LI-RADS scheme. Follow-up results and pathological findings served as the reference standard. Receiver operating characteristic (ROC) curve analysis was used to reveal the area under the curve (AUC). The sensitivity, specificity, accuracy, and positive (PPV) and negative predictive values (NPV) of LR-5 for determining HCC were calculated. The intra-observer agreement of CEUS LI-RADS was also evaluated.

RESULTS

Eighty-four patients with 86 liver observations were enrolled. Forty-two observations were classified as LR-5 by CEUS and MRI, respectively. Based on the reference standard, 53 nodules were HCC. The AUCs were 0.876 for CEUS and 0.873 for MRI, without a significant difference (Z=0.050, p=0.960). The sensitivity, specificity, PPV, NPV, and accuracy of LR-5 was 75.47%, 93.94%, 95.24%, 70.45%, 82.56% with CEUS and 73.58%, 90.9%, 92.86%, 68.18%, 80.23% with MRI, respectively. There was a significant difference in specificity between CEUS and MRI (p=0.006). There was almost perfect agreement for arterial phase hyperenhancement (k=0.870), substantial agreement for washout (k=0.765) and CEUS LI-RADS category (k=0.787).

CONCLUSION

The CEUS LI-RADS scheme is an effective diagnostic tool for HCC with substantial intra-observer reliability. The diagnostic performance of CEUS LI-RADS for determining HCC was comparable to MRI LI-RADS, and the specificity of CEUS LR-5 was significantly higher.

3D-printable supramolecular hydrogels with shear-thinning property: fabricating strength tunable bioink via dual crosslinking

3-dimensional (3D) bioprinting technology provides promising strategy in the fabrication of artificial tissues and organs. As the fundamental element in bioprinting process, preparation of bioink with ideal mechanical properties without sacrifice of biocompatibility is a great challenge. In this study, a supramolecular hydrogel-based bioink is prepared by polyethylene glycol (PEG) grafted chitosan, α-cyclodextrin (α-CD) and gelatin. It has a primary crosslinking structure through the aggregation of the pseudo-polyrotaxane-like side chains, which are formed from the host-guest interactions between α-CD and PEG side chain. Apparent viscosity measurement shows the shear-shinning property of this bioink, which might be due to the reversibility of the physical crosslinking. Moreover, with β-glycerophosphate at different concentrations as the secondary crosslinking agent, the printed constructs demonstrate different Young's modulus (p < 0.001). They could also maintain the Young's modulus in cell culture condition for at least 21 days (p < 0.05). By co-culturing each component with fibroblasts, CCK-8 assay demonstrate cellular viability is higher than 80%. After bioprinting and culturing, immunofluorescence staining with quantification indicate the expression of Ki-67, Paxillin, and N-cadherin is higher in day 14 than those in day 3 (p < 0.05). Oil red O and Nissl body specific staining reflect strength tunable bioink may have impact on the cell fate of mesenchymal stem cells (p < 0.05). This work might provide new idea for advanced bioink in the application of re-establishing complicated tissues and organs.

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Supramolecular bioink demonstrates good shear-shinning property.

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Dual crosslinking provides the bioink with tunable strength.

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Tunable strength facilitates stem cells lineage differentiation.

Combating Pseudomonas aeruginosa Biofilms by a Chitosan-PEG-Peptide Conjugate via Changes in Assembled Structure

Pseudomonas aeruginosa (P. aeruginosa) biofilms are associated with a wide range of infections, from chronic tissue diseases to implanted medical devices. In a biofilm, the extracellular polymeric substance (EPS) causes an inhibited penetration of antibacterial agents, leading to a 100-1000 times tolerance of the bacteria. In view of the water-filled channels in biofilms and the highly negative charge of EPS, we design a chitosan-polyethylene glycol-peptide conjugate (CS-PEG-LK₁₃) in this study. The CS-PEG-LK₁₃ prefers a neutrally charged assembly at a size of ∼100 nm in aqueous environment, while undergoes disassembly to expose the α-helical peptide at the bacterial cell membrane. This behavior provides CS-PEG-LK₁₃ superiorities in both penetrating the biofilms and inactivating the bacteria. At a concentration of 8 times the minimum inhibitory concentration, CS-PEG-LK₁₃ has a much higher antibacterial efficiency (72.70%) than LK₁₃ peptide (15.24%) and tobramycin (33.57%) in an in vitro P. aeruginosa biofilm. Moreover, CS-PEG-LK₁₃ behaves comparable capability of combating an implanted P. aeruginosa biofilm to highly excess tobramycin. This work has implications for the design of new antibacterial agents in biofilm combating.

Phenotype Regulation of Smooth Muscle Cells Through Facial Crystallization of Poly(ɛ-Caprolactone)

Phenotype conversion of smooth muscle cells (SMCs) plays a key role in the formation of atherosclerosis. Understanding how SMCs respond to a micro/nano-topology and elucidating the cellular mechanism of phenotype conversion is critical to the atherosclerosis treatment. Herein, we prepared poly(ɛ-caprolactone) (PCL) spherulites with a radius more than 350 μm for the studying of radial microstructure influence on SMCs behaviors. We found that on the PCL spherulitic films, SMCs grew aligning the radial direction of PCL spherulites, overexpressed α-SMA gene than OPN gene, and preferred contractile phenotype. FAK signaling pathway and ROCK1 signaling pathway both contributed to the contractile phenotype maintenance of SMCs. This work illustrated the feasibility of spherulites in regulating SMCs behaviors, and elucidated the mechanism how SMCs respond to a radial micro/nano-topology. This research may provide theoretical basis for the atherosclerosis formation and treatment.

[An analysis of medical X-ray examination frequency in ten hospitals in Tianjin, China]

Objective: To investigate the usage frequency of radiological diagnosis devices in ten hospitals in Tianjin, China, and to provide a basis for the survey of medical radiation frequency in Tianjin. Methods: Ten hospitals from the ten districts in Tianjin were enrolled as subjects by a convenient sampling method. A survey was conducted to assess the general information and radiological diagnosis device information and usage frequency in those hospitals in 2016. The radiological examination frequency in Tianjin was estimated. Results: A total of 610 458 patients received radiological examinations in the sampled hospitals in 2016. In those patients, 371 882 received X-ray examinations for imaging and 238 576 for computed tomography (CT) ; there were slightly more female patients than male patients, suggesting a relatively equal gender distribution; patients older than 40 years accounted for 65.53%, which was the highest among all the age groups. Different types of radiological diagnosis devices were mostly used in tertiary and secondary hospitals. In Tianjin, the estimated frequency of X-ray examination for imaging and CT scanning was 451 and 188 per thousand people, respectively, in 2016. Conclusion: The frequency of radiological diagnosis is relatively high in the ten hospitals in Tianjin. The investigation of medical radiation in Tianjin needs to be improved.

Integration of Cell-Penetrating Peptides with Rod-like Bionanoparticles: Virus-Inspired Gene-Silencing Technology

Inspired by the high gene transfer efficiency of viral vectors and to avoid side effects, we present here a 1D rod-like gene-silencing vector based on a plant virus. By decorating the transacting activator of transduction (TAT) peptide on the exterior surface, the TAT-modified tobacco mosaic virus (TMV) achieves a tunable isoelectric point (from ∼3.5 to ∼9.6) depending on the TAT dose. In addition to enhanced cell internalization, this plant virus-based vector (TMV-TAT) acquired endo/lysosomal escape capacity without inducing lysosomal damage, resulting in both high efficiency and low cytotoxicity. By loading silencer green fluorescent protein (GFP) siRNA onto the TMV-TAT vector (siRNA@TMV-TAT) and interfering with GFP-expressing mouse epidermal stem cells (ESCs/GFP) in vitro, the proportion of GFP-positive cells could be knocked down to levels even lower than 15% at a concentration of ∼100% cell viability. Moreover, by interfering with GFP-expressing highly metastatic hepatocellular carcinoma (MHCC97-H/GFP) tumors in vivo, treatment with siRNA@TMV-TAT complexes for 10 days achieved a GFP-negative rate as high as 80.8%. This work combines the high efficiency of viral vectors and the safety of nonviral vectors and may provide a promising strategy for gene-silencing technology.

Fluorous interaction induced self-assembly of tobacco mosaic virus coat protein for cisplatin delivery

Tobacco mosaic virus coat protein was modified with a small molecular fluorous ponytail at specific sites, and self-assembled into spherical nanoparticles through fluorous interaction induced self-assembly. By loading the anti-cancer drug cisplatin through metal-ligand coordination, this spherical assembly with high stability has potential as a drug carrier.

Studies of Adsorbents for Hemoperfusion in Artificial Liver Support. I. Preparation and in Vitro Studies of Cross-Linked Agarose Beads Entrapped Activated Charcoal (CAAC)

A new method for the preparation of the cross-linked agarose beads entrapped activated charcoal (CAAC) is reported. Since the agarose-encapsulated adsorbents reported elsewhere cannot stand high temperature for sterilization, the CAAC has the advantage of thermal stability to withstand autoclave at 121°C. for ½ hour without breaking up or melting. A further advantage of CAAC is that the adsorbent has a much better consistency with good mechanical strength and elasticity, so that it can be formed into beads of a diameter less than 1 mm. This will not only give a better adsorption capacity than larger beads, but can also assure a better blood flow than soft beads which usually interfere in hemoperfusion due to compacting and sludging. Preliminary investigations indicate that the CAAC is relatively hemocompatible.

Balancing antimicrobial activity with biological safety: bifunctional chitosan derivative for the repair of wounds with Gram-positive bacterial infections

Because of the balance between antimicrobial activity and biological safety, the bifunctional chitosan derivative could control infections and promote healing simultaneously.

Rhabdomyolysis and fluctuating asymptomatic hyperCKemia associated with CACNA1S variant

BACKGROUND AND PURPOSE

CACNA1S encodes Ca_v 1.1, a voltage sensor for muscle excitation-contraction coupling, which activates the ryanodine receptor 1 (RYR1) leading to calcium release from the sarcoplasmic reticulum. CACNA1S mutations cause hypokalemic periodic paralysis, malignant hyperthermia and congenital myopathy. RYR1 mutations result in congenital myopathy, malignant hyperthermia and rhabdomyolysis.

METHODS

The aim was to describe a novel phenotype associated with a CACNA1S variant at a site previously linked to hypokalemic periodic paralysis.

RESULTS

The patient presented with fluctuating asymptomatic creatine kinase elevation after an episode of rhabdomyolysis but has no history of periodic paralysis. His muscle biopsy showed core-like structures occurring mainly in type 2 fibers. He carries a novel Ca_v 1.1 variant (p.Arg528Leu) affecting a highly conserved amino acid. Different mutations at the same location cause hypokalemic periodic paralysis.

CONCLUSION

This case underscores the similarity between the phenotypes caused by mutations in two functionally linked proteins, RYR1 and Ca_v 1.1.

Mussel-Inspired Polydopamine Coating on Tobacco Mosaic Virus: One-Dimensional Hybrid Nanofibers for Gold Nanoparticle Growth

One-dimensional (1D) hybrid nanofibers with surface-deposited gold nanoparticles (AuNPs) have been fabricated by self-assembly of rod-like tobacco mosaic virus (TMV) with mussel-inspired polymerization of dopamine and in situ reduction of gold ion, providing a method for sensing the endocytic pathway of nanomaterial.

Programming Self-Assembly of Tobacco Mosaic Virus Coat Proteins at Pickering Emulsion Interfaces for Nanorod-Constructed Capsules

Pickering emulsion constructions on nanorods with high aspect ratio are a great challenge because of the geometry restrictions. On the basis of the theory that the stability of Pickering emulsion is highly dependent on the size and amphiphilicity of the nanoparticle at fluid interfaces, we report a novel strategy to fabricate long-time stable Pickering emulsion consisting of tobacco mosaic virus (TMV)-like nanorods through the programming self-assembly of TMV coat protein (TMVCP). The first step is the self-assembly of amphiphilic TMVCP at Pickering emulsion interfaces, and the second step is the in situ interfacial self-assembly of TMVCP into nanorods with increased particle size. The robust capsules can be further fabricated through cross-linking of the proteins. By taking advantage of both the amphiphilicity of TMVCP and the subsequent size growth induced by TMVCP self-assembly, this work provides a powerful strategy for constructing robust capsules consisting of nanorods with high aspect ratio, which may show potential applications for drug delivery and virus recognition.

MiR-216b increases cisplatin sensitivity in ovarian cancer cells by targeting PARP1

Cisplatin resistance hinders the efficacy of chemotherapy in ovarian cancer. MicroRNAs (miRs) have been implicated in drug resistance in anti-cancer chemotherapy. We compared the expression profiles of miRs between cisplatin-resistant and cisplatin-sensitive ovarian cancer cells, and found that miR-216b was significantly downregulated in cisplatin-resistant ovarian cancer cells. To investigate its molecular mechanism, we performed cell viability and apoptosis assays in cisplatin-resistant ovarian cells, and found that miR-216b reduced cell viability and promoted apoptosis. Although 4 potential targets were obtained through bioinformatics, only the mRNA level of poly(ADP-ribose) polymerase (PARP)-1 was significantly regulated by miR-216b. Disruption of the complementary binding sequence of miR-216b on the 3'-untranslated region (3'-UTR) of the PARP1 led to the loss of miR-216b targeting. Spearman's correlation coefficient of the levels of miR-216b and PARP1 mRNA from 51 human ovarian cancer specimens also showed a significantly negative correlation between them. Importantly, the improved cisplatin sensitivity induced by miR-216b was markedly reversed by PARP1 overexpression. Tumor formation assay in nude mice further provided an evidence on the suppressive role of miR-216b in tumor growth. Taken together, this study demonstrated that a new miRNA, miR-216b, was involved in cisplatin resistance in ovarian cancer, which could be regarded as a potential sensitizer in cisplatin chemotherapy.

Glyco-decorated tobacco mosaic virus as a vector for cisplatin delivery

Plant viruses have been applied broadly in nanomedical applications profiting from their monodisperse structure, biocompatibility, easy modification, and non-pathogenicity in animals. Here we report a tobacco mosaic virus (TMV) based drug delivery system bearing carbohydrates as targeting ligands. Mannose (Man) and lactose (Lac) moieties were separately conjugated to the exterior surface of TMV (TMV-Man and TMV-Lac) through an efficient copper(i)-catalyzed azide-alkyne cycloaddition. Cisplatin (CDDP), an anticancer drug, was directly loaded into the TMV cavity (CDDP@TMV, CDDP@TMV-Man and CDDP@TMV-Lac) via a metal coordination bond. Through the specific recognition between carbohydrates and glycoproteins in cell membranes, these TMV based vectors show specificity in different cell lines: in the galectin-rich MCF-7 cell line, CDDP@TMV-Man shows enhanced endocytosis and apoptosis efficiency; in the asialoglycoprotein receptor (ASGPR)-overexpressing HepG2 cell line, CDDP@TMV-Lac shows superiority in endocytosis and apoptosis. This research provides a new strategy for tumor-targeted cisplatin delivery.

High Free Fatty Acid Levels Are Associated with Stroke Recurrence and Poor Functional Outcome in Chinese Patients with Ischemic Stroke

BACKGROUND

The aim of this study is to investigate whether serum and cerebrospinal fluid (CSF) free fatty acid (FFA) levels are associated with outcome and recurrence in a cohort of patients with an acute ischemic stroke (AIS).

METHODS

From December 2013 to May 2015, patients with first-ever AIS were included. FFA level and NIH stroke scale (NIHSS) were measured at the time of admission. Logistic regression analysis was used to evaluate the stroke outcome and recurrence according to FFA level. Clinical follow-up was performed at 6 month.

RESULTS

In our study, we studied 296 patients (52.7% male). We have found a positive correlation between serum and CSF levels of FFA. Patients with a poor outcome and recurrence had significantly increased FFA serum and CSF levels on admission (all p<0.0001). Multivariate logistic regression analysis adjusted for common risk factors showed that FFA was an independent predictor of poor functional outcome and recurrence. Odds ratios (OR) values were more significant for the higher levels of FFA.

CONCLUSION

In summary, baseline serum and CSF FFA level were associated with stroke poor function outcome and recurrence, suggesting an effect of FFA on disease course in AIS.

Roles of Hippo signaling in lung cancer

Lung cancer is the leading cause of cancer-related mortality in the world, with more than 1 million deaths/year. Over the past years, lung cancer treatment has been based on cytotoxic agents and an improvement in the outcome and quality of life for patients has been observed. However, it has become clear that additional therapeutic strategies are urgently required to provide an improved survival benefit for patients. A major intracellular signaling pathway, the Hippo signaling pathways have been extensively studied in neoplasia, including lung cancer. Furthermore, the study of constitutively activated receptor and their downstream signaling mediators has become a promising new field of investigation for lung cancer treatment. Nevertheless for lung cancer, this approach has not been successful yet. Here, we will review the molecular basis of Hippo signaling in lung cancer and further discuss the therapeutic potential of multi-targeted strategies involving Yes-associated protein inhibitors.

Integrating a DNA Strand Displacement Reaction with a Whispering Gallery Mode Sensor for Label-Free Mercury (II) Ion Detection

Mercury is an extremely toxic chemical pollutant of our environment. It has attracted the world’s attention due to its high mobility and the ease with which it accumulates in organisms. Sensitive devices and methods specific for detecting mercury ions are, hence, in great need. Here, we have integrated a DNA strand displacement reaction with a whispering gallery mode (WGM) sensor for demonstrating the detection of Hg²⁺ ions. Our approach relies on the displacement of a DNA hairpin structure, which forms after the binding of mercury ions to an aptamer DNA sequence. The strand displacement reaction of the DNA aptamer provides highly specific and quantitative means for determining the mercury ion concentration on a label-free WGM sensor platform. Our approach also shows the possibility for manipulating the kinetics of a strand displacement reaction with specific ionic species.

Tobacco Mosaic Virus-Based 1D Nanorod-Drug Carrier via the Integrin-Mediated Endocytosis Pathway

For cancer therapy, viruses have been utilized as excellent delivery vehicles because of their facile transfection efficiency in their host cells. However, their inherent immunogenicity has become the major obstacle for their translation into approved pharmaceuticals. Herein, we utilized rodlike plant virus, tobacco mosaic virus (TMV), which is nontoxic to mammals and mainly infects tobacco species, as anticancer nanorod-drug vector for cancer therapy study. Doxorubicin (DOX) was installed in the inner cavity of TMV by hydrazone bond, which enabled the pH-sensitive drug release property. Conjugation of cyclic Arg-Gly-Asp (cRGD) on the surface of TMV can enhance HeLa cell uptake of the carrier via the integrin-mediated endocytosis pathway. Comparing with free DOX, the cRGD-TMV-hydra-DOX vector had similar cell growth inhibition and much higher apoptosis efficiency on HeLa cells. Moreover, the in vivo assay assumed that cRGD-TMV-hydra-DOX behaved similar antitumor efficiency but much lower side effect on HeLa bearing Balb/c-nu mice. Our work provides novel insights into potentially cancer therapy based on rodlike plant viral nanocarriers.

Size Dependent Cellular Uptake of Rod-like Bionanoparticles with Different Aspect Ratios

Understanding the cellular internalization mechanism of nanoparticles is essential to study their biological fate. Especially, due to the anisotropic properties, rod-like nanoparticles have attracted growing interest for the enhanced internalization efficiency with respect to spherical nanoparticles. Here, to elucidate the effect of aspect ratio of rod-like nanoparticles on cellular uptake, tobacco mosaic virus (TMV), a typical rod-like bionanoparticle, is developed as a model. Nanorods with different aspect ratios can be obtained by ultrasound treatment and sucrose density gradient centrifugation. By incubating with epithelial and endothelial cells, we found that the rod-like bionanoparticles with various aspect ratios had different internalization pathways in different cell lines: microtubules transport in HeLa and clathrin-mediated uptake in HUVEC for TMV₄ and TMV₈; caveolae-mediated pathway and microtubules transport in HeLa and HUVEC for TMV₁₇. Differently from most nanoparticles, for all the three TMV nano-rods with different aspect ratios, macropinocytosis takes no effect on the internalization in both cell types. This work provides a fundamental understanding of the influence of aspect ratio on cellular uptake decoupled from charge and material composition.

Into the polymer brush regime through the "grafting-to" method: densely polymer-grafted rodlike viruses with an unusual nematic liquid crystal behavior

The current work reports an intriguing discovery of how the force exerted on protein complexes like filamentous viruses by the strong interchain repulsion of polymer brushes can induce subtle changes of the constituent subunits at the molecular scale. Such changes transform into the macroscopic rearrangement of the chiral ordering of the rodlike virus in three dimensions. For this, a straightforward "grafting-to" PEGylation method has been developed to densely graft a filamentous virus with poly(ethylene glycol) (PEG). The grafting density is so high that PEG is in the polymer brush regime, resulting in straight and thick rodlike particles with a thin viral backbone. Scission of the densely PEGylated viruses into fragments was observed due to the steric repulsion of the PEG brush, as facilitated by adsorption onto a mica surface. The high grafting density of PEG endows the virus with an isotropic-nematic (I-N) liquid crystal (LC) phase transition that is independent of the ionic strength and the densely PEGylated viruses enter into the nematic LC phase at much lower virus concentrations. Most importantly, while the intact virus and the one grafted with PEG of low grafting density can form a chiral nematic LC phase, the densely PEGylated viruses only form a pure nematic LC phase. This can be traced back to the secondary to tertiary structural change of the major coat protein of the virus, driven by the steric repulsion of the PEG brush. Quantitative parameters characterising the conformation of the grafted PEG derived from the grafting density or the I-N LC transition are elegantly consistent with the theoretical prediction.