Determining the precise course of bacterial infection requires abundant in vivo real-time data. Synchronous monitoring of the bacterial load, temperature, and immune response can satisfy the shortage of real-time in vivo data. Here, we conducted a study in the joint-infected mouse model to synchronously monitor the bacterial load, temperature, and immune response using the second near-infrared (NIR-II) fluorescence imaging, infrared thermography, and immune response analysis for 2 weeks. Staphylococcus aureus (S. aureus) was proved successfully labeled with glucose-conjugated quantum dots in vitro and in subcutaneous-infected model. The bacterial load indicated by NIR-II fluorescence imaging underwent a sharp drop at 1 day postinfection. At the same time, the temperature gap detected through infrared thermography synchronously brought by infection reached lowest value. Meanwhile, the flow cytometry analysis demonstrated that immune response including macrophage, neutrophil, B lymphocyte, and T lymphocyte increased to the peak at 1 day postinfection. Moreover, both M1 macrophage and M2 macrophage in the blood have an obvious change at ~ 1 day postinfection, and the change was opposite. In summary, this study not only obtained real-time and long-time in vivo data on the bacterial load, temperature gap, and immune response in the mice model of S. aureus infection, but also found that 1 day postinfection was the key time point during immune response against S. aureus infection. Our study will contribute to synchronously and precisely studying the complicated complex dynamic relationship after bacterial infection at the animal level.

This study aimed to identify novel umami peptides in Agaricus bisporus and investigate their umami enhancing effect. We virtually screened 155 potential umami peptides from the ultrasound-assisted A. bisporus hydrolysate according to Q values, iUmami-SCM, Umami_YYDS, and Tastepeptides_DM models, and molecular docking. Five peptides (AGKNTNGSQF, DEAVARGATF, REESDFQSSF, SEETTTGVHH, and WNNDAFQSSTN) were synthesized for sensory evaluation and kinetic analysis. The result showed that the umami thresholds of the five peptides were in the range of 0.21-0.40 mmol/L. Notably, REESDFQSSF, SEETTTGVHH, and WNNDAFQSSTN had low dissociation constant (KD) values and high affinity for the T1R1-VFT receptor. The enhancing effect of the three peptides with MSG or IMP was investigated by sensory evaluation, kinetic analysis, and molecular dynamics simulations. In stable complexes, ARG_277 in T1R1 played a major role in umami peptide binding to T1R1-VFT. These results provide a theoretical basis for future screening of umami peptides and improving the umami taste of food containing mushrooms.

The administration time is a critical but long-neglected point in cell therapy based on macrophages because the incorrect time of macrophage administration could result in diverse outcomes regarding the same macrophage therapy. In this work, the second near-infrared (NIR-II) fluorescence imaging in vivo tracking of M2 macrophages during a pro-healing therapy in the mice model of rotator cuff injury revealed that the behavior of administrated macrophages was influenced by the timing of their administration. The delayed cell therapy (DCT) group had a longer retention time of injected M2 macrophages in the repairing tissue than that in the immediate cell therapy (ICT) group. Both Keller–Segel model and histological analysis further demonstrated that DCT altered the chemotaxis of M2 macrophages and improved the healing outcome of the repaired structure in comparison with ICT. Our results offer a possible explanation of previous conflicting results on reparative cell therapy and provoke reconsideration of the timing of these therapies.

课程思政教育是将思想政治教育渗透到专业课程教学过程中,注重在价值传播中凝聚知识底蕴,在知识传播中强调价值引领,因此在高校思想政治工作中发挥了重要作用[1].解剖学课程因蕴含丰富的思政元素,成为培育医学生人文素养、科学精神和医者仁心的重要而独特的学科.现有解剖学课程思政教育内容充实、形式丰富,但更多的是以教师为主体对学生进行教育和输出,但课程思政教育对学生的影响,即学生对课程思政教育的获得感与满意度,尚欠缺有效的评价与探讨[2-4].

Advancements in lymphography technology are essential for comprehensive investigation of the lymphatic system and its function. Here, a shortwave infrared (SWIR) luminescence imaging of lymphatic vessels is proposed in both normal and lymphatic dysfunction in rat models with PbS quantum dots (PbS Qdots). The lymphography with PbS Qdots can clearly and rapidly demonstrate the normal lymphatic morphology in both the tail and hind limb. More importantly, compared to ICG, SWIR luminescence imaging with PbS Qdots can easily identify the dominant lymphatic vessel and node with higher luminescence signal in rats. Moreover, lymphatic pump is identified as segment contracting sections with a size of ≈1 cm in rat by in vivo SWIR lymphograhy, which propose a direct feature for precise evaluation of lymphatic function. Notably, in vivo SWIR luminescence imaging with PbS Qdots also clearly deciphers the in vivo pattern of morphological and function recovery from lymphatic system in rat model. In summary, SWIR luminescence imaging with PbS Qdots can improve the lymphography and thus deepen the understanding of the morphology and structure of the lymphatic system as well as lymphatic function such as lymphatic pump, which will facilitate the diagnosis of lymphatic dysfunction in the future.

Extracellular vesicles (EVs) show potential as a therapeutic tool for peripheral nerve injury (PNI), promoting neurological regeneration. However, there are limited data on the in vivo spatio-temporal trafficking and biodistribution of EVs. In this study, we introduce a new non-invasive near-infrared fluorescence imaging strategy based on glucose-conjugated quantum dot (QDs-Glu) labeling to target and track EVs in a sciatic nerve injury rat model in real-time. Our results demonstrate that the injected EVs migrated from the uninjured site to the injured site of the nerve, with an increase in fluorescence signals detected from 4 to 7 days post-injection, indicating the release of contents from the EVs with therapeutic effects. Immunofluorescence and behavioral tests revealed that the EV therapy promoted nerve regeneration and functional recovery at 28 days post-injection. We also found a relationship between functional recovery and the NIR-II fluorescence intensity change pattern, providing novel evidence for the therapeutic effects of EV therapy using real-time NIR-II imaging at the live animal level. This approach initiates a new path for monitoring EVs in treating PNI under in vivo NIR-II imaging, enhancing our understanding of the efficacy of EV therapy on peripheral nerve regeneration and its mechanisms.

The degradation of collagen in different body parts is a critical point for designing collagen-based biomedical products. Here, three kinds of collagens labeled by second near-infrared (NIR-II) quantum dots (QDs), including collagen with low crosslinking degree (LC), middle crosslinking degree (MC) and high crosslinking degree (HC), were injected into the subcutaneous tissue, muscle and joints of the mouse model, respectively, in order to investigate the in vivo degradation pattern of collagen by NIR-II live imaging. The results of NIR-II imaging indicated that all tested collagens could be fully degraded after 35 days in the subcutaneous tissue, muscle and joints of the mouse model. However, the average degradation rate of subcutaneous tissue (k = 0.13) and muscle (k = 0.23) was slower than that of the joints (shoulder: k = 0.42, knee: k = 0.55). Specifically, the degradation rate of HC (k = 0.13) was slower than LC (k = 0.30) in muscle, while HC showed the fastest degradation rate in the shoulder and knee joints. In summary, NIR-II imaging could precisely identify the in vivo degradation rate of collagen. Moreover, the degradation rate of collagen was more closely related to the implanted body parts rather than the crosslinking degree of collagen, which was slower in the subcutaneous tissue and muscle compared to the joints in the mouse model.

Abstract Purpose: This study aimed to explore the performance of whole-tumour histogram analysis of diffusion kurtosis imaging (DKI) in the characterization of rectal cancer.Methods: Forty-two rectal cancer patients were retrospectively enrolled. Histogram analysis of D, K and the conventional apparent diffusion coefficient (ADC) were calculated. Student’s t test or the Mann–Whitney U test and receiver operating characteristic (ROC) curves were used for statistical analysis.Results: The ADCSD and ADCkurtosis were significantly higher in N (+) patients than in N0 patients (p<0.05). The ADCSD, DSD and Kkurtosis were significantly higher in PNI-positive patients than in PNI-negative patients (p<0.05). Dskewness was significantly higher in KRAS mutation-type patients than in KRAS wild-type patients (p<0.05). The area under the curve (AUC) of the multiparametric ADCSD and ADCkurtosis values for the detection of metastatic lymph nodes was 0.816 (p<0.001); the sensitivity and specificity were 81.0% and 76.2%, respectively. The AUC of the multiparametric ADCSD, DSD, and Kkurtosis values for the detection of PNI was 0.830 (p<0.001); the sensitivity and specificity were 80% and 88.9%, respectively. Dskewness can be used to determine the KRAS status; the cut-off value, AUC, sensitivity and specificity were 0.465, 0.732 (p=0.010), 78.3%, and 73.7%, respectively. Conclusion: Whole-tumour histogram analysis of DKI could be used to identify both pathological and genetic characteristics of rectal cancer.

Here, fluorescent carbon nanodots (CNDs) were generated using water extract of tomato leaves. Sphere nanodots were formed within 30 min by a one-step microwave heating. An ultraviolet 360 nm photoluminescence (PL) peak was found upon high-energy excitation. This peak showed excitation-independent property, and might belong to some solely-emitting fluorescent moieties attaching to the CNDs. The biomolecules with complex chemical structure in the plant leaves were responsible for the unique spectral property of the CNDs. Taking advantage of their special property, the CNDs were applied as an fluorescent probe for spectral-matching sensing of chromium(VI) [Cr(VI)] in the aqueous solution. The detection limit was as low as 79 nM, and the CNDs probe showed good selectivity towards other metal ions. Real sample tests using the tap water were also carried out, showing potential of the CNDs in the practical applications.

BACKGROUND:Peripheral nerve regeneration is a coordinated process of Schwann cell (SC) reprogramming and intrinsic neuronal growth program activation. Panaxydol (PND) is a strong biologically active traditional Chinese medicine monomer extracted from Panax notoginseng rhizomes. In vitro, PND protects neurons and SCs from injury and stimulates the expression and secretion of neurotrophic factors (NTFs) by SCs. We hypothesized that PND may also promote peripheral nerve regeneration in adult animals.METHODS:PND (10 mg/kg body weight) was injected intraperitoneally into the Sprague-Dawley (SD) rats for two consecutive weeks after sciatic nerve transection. The morphology of the repaired sciatic nerve was evaluated after 16 weeks, and sensory and motor function recovery was evaluated using functional and behavioral techniques.RESULTS:PND was biologically safe at an injection dose of 10 mg/kg/day. After 14 days, it significantly increased the myelination of regenerated nerve fibers, and promoted sensory and motor function recovery. In the early stage of injury, PND significantly upregulated the mRNA expression of brain-derived neurotrophic factor (BDNF) and its receptors in distal injured nerves, which may represent a possible mechanism by which PND promotes nerve regeneration in vivo.CONCLUSIONS:Our study demonstrated that PND leads to sensory and motor recovery in a sciatic nerve transection model rat. Furthermore, we showed that BDNF mRNA level was significantly increased in the injured distal nerve, potentially contributing to the functional recovery. Further research is warrantied to examine whether direct injection is a more efficient method to increase BDNF expression compared to an exogenous BDNF administration.

Proteins and enzymes with potential therapeutic function have been widely used in drug delivery. Meanwhile, nanocrystals (NCs) have showed their advantage as in vivo fluorescent indicators. Combining of these two kinds of materials can result in multifunctional composites. Here, a one-step synthesis of protein–NCs nanocomposites with near infrared (NIR) fluorescence and efficient therapeutic function was developed. Ag NCs were formed using ribonucleases A (RNase A) enzyme as a stabilizer. Meanwhile, the RNase A with long chain rapped around Ag NCs and formed RNase A–Ag nanocomposites. The nanocomposites remained both the NIR fluorescence of Ag NCs and antitumor activity of RNase A. The inhibition of the growth of tumor cells by the nanocomposites was confirmed. This study developed an efficient drug delivery system through combination of the protein and nanoparticles, which had potential clinical application in the future.

Here, we present a novel nerve specific imaging agent for preventing intraoperative nerve injuries based on SWIR QD-based in vivo imaging, which not only provides real-time and long-time SWIR images to intraoperatively identify nerves but can also markedly minimize the risk of iatrogenic nerve injuries during surgeries.

INTRODUCTION:This study was designed to investigate the potential function of the activating protein 2α (AP-2α) gene in controlling the proliferation and apoptosis of gastric cancer.MATERIAL AND METHODS:Gastric cancer cell line MCG-803 cells and normal cell line GES-1 cells were selected to transfect pcDNA3.1(+)-AP-2α and pcDNA3.1(+) plasmids, respectively. Both mRNA and protein levels of AP-2α in each group transfected with the pcDNA3.1(+)-AP-2α plasmids were up-regulated after 48 h by real-time PCR and Western blotting analysis, leading to marked proliferation inhibition and significant cell cycle arrest.RESULTS:pcDNA3.1(+)-AP-2α reduced tumor tissue growth in a subcutaneous tumor gastric carcinoma nude mouse model. Protein over-expression of AP-2α in the nude mouse model was accompanied by down-regulation of Blc-2 and ErbB2, resulting in the up-regulation of caspase-3, -8, and -9, ERα and p21WAF1/CIP1.CONCLUSIONS:The reintroduction of the AP-2α gene by pcDNA3.1 could inhibit gastric tumor growth in vitro and in vivo, which may be an alternative future therapeutic molecular target for human gastric cancer.

Gastric cancer, a high-risk malignancy, is a genetic disease developing from a cooperation of multiple gene mutations and a multistep process. Gene therapy is a novel treatment method for treating gastric cancer. Here, we developed a novel Arg-Gly-Asp (RGD) peptides conjugated copolymers nanoparticles-based gene delivery system in order to actively targeting inhibit the growth of gastric cancer cells. These transcription factor (AP-2α) expression plasmids were also encapsulated into pluronic triblock copolymers nanoparticles which was constituted of poly(ethylene glycol)-block-poly(propylene glycol)- block-poly(ethylene glycol) (PEO-block-PPO-block-PEO, P123). The size, morphology and composition of prepared nanocomposites were further characterized by nuclear magnetic resonance (NMR), transmission electron microscopy (TEM) and dynamic light scattering (DLS). In MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide) analysis, these nanocomposites have minor effects on the proliferation of GES-1 cells but significantly decreased the viability of MGC-803, suggesting they own low cytotoxicity but good antitumor activity. The following in vivo evaluation experiments confirmed that these nanocomposites could prevent the growth of gastric cancer cells in the tumor xenograft mice model. In conclusion, these unique RGD peptides conjugated P123 encapsulated AP-2α nanocomposites could selectively and continually kill gastric cancer cells by over-expression of AP-2α in vitro and in vivo; this exhibits huge promising applications in clinical gastric cancer therapy.