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Many prokaryotic viruses are temperate and their reactivation is tightly regulated. However, except for a few bacterial model systems, the regulatory circuits underlying the exit from lysogeny are poorly understood, especially in archaea. Here, we report a three-gene module which regulates the switch between lysogeny and replicative cycle in a haloarchaeal virus SNJ2 (family Pleolipoviridae). The SNJ2 orf4 encodes a winged helix-turn-helix DNA binding protein which maintains lysogeny through repressing the expression of the viral integrase gene intSNJ2. To switch to the induced state, two other SNJ2-encoded proteins, Orf7 and Orf8, are required. Orf8 is a homolog of cellular AAA+ ATPase Orc1/Cdc6, which is activated upon mitomycin C-induced DNA damage, possibly through posttranslational modification. Activated Orf8 initiates the expression of Orf7 which, in turn, antagonizes the function of Orf4, leading to the transcription of intSNJ2, thereby switching SNJ2 to the induced state. Comparative genomics analysis revealed that the SNJ2-like Orc1/Cdc6-centered three-gene module is common in haloarchaeal genomes, always present in the context of integrated proviruses. Collectively, our results uncover the first DNA damage signaling pathway encoded by a temperate archaeal virus and reveal an unexpected role of the widely distributed virus-encoded Orc1/Cdc6 homologs.

Sensitivity analysis about small watershed is an important way to objectively understand the development characteristics of debris flow ditches. With the support of Remote Sensing and Geographic Information System technologies, Dongchuan County with frequent debris flow development in Kunming, Yunnan Province, southwest China was selected as the research object, the Landsat image and Digital Elevation Model were used to interpret the small watersheds on both sides of the Xiaojiang River. By selecting four indicators of fault zone, slope, gully density and land use as the impact factors, the sensitivity coefficients were quantitatively calculated. The following research results were obtained: The distribution feature of debris flow small watersheds was that, the Dongchuan fault zone was the axis which small watersheds were symmetrically distributed on; the sensitivity of the Dongchuan fault zone was the highest in the buffer distance of 5-10 km, which was prone to debris flow disasters; the debris flow was most sensitive in the slope range of 40°-50°; the debris flow was most sensitive to the gully density of 0.6-0.9 km/km2 with broken surface; three types of land use such as bare land, water and construction land had high sensitivity coefficient and were easy to cause mountain disasters. According to the sensitivity coefficients of the above impact factors, the stacking method superposition analysis was carried out to obtain the sensitivity distribution of debris flow disasters in Dongchuan County. The medium sensitive area accounted for 53.84% of the total area, and the high sensitive area accounted for 27.02% of the total area. The medium sensitive area and the high sensitive area were the main areas where debris flow occurred. This study has certain reference significance for disaster prevention, soil and water conservation by quantitative calculation and comparison of debris flow disaster sensitivity.

The fibrillization and deposition of the human islet amyloid polypeptide (hIAPP) are the pathological hallmark of type 2 diabetes mellitus (T2DM), and these insoluble fibrotic depositions of hIAPP are considered to strongly affect insulin secretion by inducing toxicity toward pancreatic islet β-cells. The current strategy of preventing amyloid aggregation by nanoparticle-assisted inhibitors can only disassemble fibrotic amyloids into more toxic oligomers and/or protofibrils. Herein, for the first time, we propose a type of cysteine-derived chiral carbon quantum dot (CQD) that targets plasmin, a core natural fibrinolytic protease in humans. These CQDs can serve as fibrinolytic activity regulators for plasmin to cleave hIAPP into nontoxic polypeptides or into even smaller amino acid fragments, thus alleviating hIAPP's fibrotic amyloid-induced cytotoxicity. Our experiments indicate that chiral CQDs have opposing effects on plasmin activity. The l-CQDs promote the cleavage of hIAPP by enhancing plasmin activity at a promotion ratio of 23.2%, thus protecting β-cells from amyloid-induced toxicity. In contrast, the resultant d-CQDs significantly inhibit proteolysis, decreasing plasmin activity by 31.5% under the same reaction conditions. Second harmonic generation (SHG) microscopic imaging is initially used to dynamically characterize hIAPP before and after proteolysis. The l-CQD promotion of plasmin activity thus provides a promising avenue for the hIAPP-targeted treatment of T2DM to treat low fibrinolytic activity, while the d-CQDs, as inhibitors of plasmin activity, may improve patient survival for hyperfibrinolytic conditions, such as those existing during surgeries and traumas.

Purpose: To describe the longitudinal track of sexual activity in patients with breast cancer during treatment and its influencing factors. Methods: A prospective longitudinal study was conducted to investigate 225 patients who were first diagnosed with breast cancer in A tumor specialty three-class hospital in Southwest China. 225 patients were evaluated for sexual activity at the time of admission and diagnosis (T0) and one month (T1), three months (T2), six months (T3), and nine months (T4) after diagnosis. A trajectory analysis model (GBTM) was used to explore the changes in sexual activity in breast cancer patients. Logistic regression analysis was used to analyse the factors that affected the classification of sexual activity trajectories. Results: The ratio of sexual activity abruptly declined from 100% at baseline to 39.1% at T1. The percentage of sexual activity was improved, from 51.4% at T2 to 63.1% at T4. The optimal model was a 2-group trajectory of sexual activity in breast cancer patients,36.6% in the "low activity group" and 63.4% in the "high activity group." The factors influencing the grouping of sexual activity trajectories were aging (β=0.751, P=0.004), sexual desire at baseline (β=0.724, P=0.003), and vaginal lubrication (β=1.177, PConclusions: Research has demonstrated that the sexual activity level of breast cancer patients decreases in early stage and increases over time. Moreover, we observed that breast cancer patients had better libido and vaginal lubrication before the disease, especially those older than 50. At the same time, we suggest that the level of sexual activity in young breast cancer patients is a tremendous worthy concern during clinical work. Efficient interventions of sexual activity in advance of treatment may help to improve the sexual health of these patient populations. Implications for cancer survivors：There is a need to re-examine the evaluation steps of sexual function in breast cancer patients and provide targeted intervention services for patients.

Neuroinflammation can cause cognitive deficits, and preexisting neuroinflammation is observed frequently in the clinic after trauma, surgery, and infection. Patients with preexisting neuroinflammation often need further medical treatment under general anesthesia. However, the effects of postconditioning with general anesthetics on preexisting neuroinflammation have not been determined. In this study, adult rats were posttreated with sevoflurane or propofol after intracerebroventricular administration of lipopolysaccharide. The effects of sevoflurane or propofol postconditioning on neuroinflammation-induced recognition memory deficits were detected. Our results found that postconditioning with sevoflurane but not propofol reversed the selective spatial recognition memory impairment induced by neuroinflammation, and these differential effects did not appear to be associated with the similar anti-neuroinflammatory responses of general anesthetics. However, postconditioning with propofol induced a selective long-lasting upregulation of extrasynaptic NR2B-containing N-methyl-D-aspartate receptors in the dorsal hippocampus, which downregulated the cAMP response element-binding signaling pathway and impaired spatial recognition memory. Additionally, the NR2B antagonists memantine and Ro25-6981 reversed this neurotoxicity induced by propofol postconditioning. Taken together, these results indicate that under preexisting neuroinflammation, postconditioning with sevoflurane can provide reliable neuroprotection by attenuating lipopolysaccharide-induced neuroinflammation, apoptosis, and neuronal loss and eventually improving spatial recognition deficits. However, although posttreatment with propofol also has the same anti-neuroinflammatory effects, the neurotoxicity caused by propofol postconditioning following neuroinflammation warrants further consideration.

Language anxiety is one of the important emotional factors affecting learning effect, especially in listening activities. Listening anxiety is common among English learners and can affect their academic performance. Rational use of listening learning strategies can reduce the negative impact of anxiety on English learning. This paper conducts a qualitative research on the status and causes of non-English major postgraduates’ listening anxiety through interviews, and puts forward targeted countermeasures to overcome the listening anxiety.

Background Stem cell therapies have gained great attention for providing novel solutions for treatment of various injuries and diseases due to stem cells’ self-renewal, ability to differentiate into various cell types, and favorite paracrine function. Nevertheless, the low retention of transplanted stem cell still limits their clinical applications such as in wound healing in view of an induced harsh microenvironment rich in reactive oxygen species (ROS) during inflammatory reactions. Methods Herein, a novel chitosan/acellular dermal matrix (CHS/ADM) stem cell delivery system is developed, which is of great ROS scavenging activity and significantly attenuates inflammatory response. Result Under ROS microenvironment, this stem cell delivery system acts as a barrier, effectively scavenging an amount of ROS and protecting mesenchymal stem cells (MSCs) from the oxidative stress. It notably regulates intracellular ROS level in MSCs and reduces ROS-induced cellular death. Most importantly, such MSCs delivery system significantly enhances in vivo transplanted stem cell retention, promotes the vessel growth, and accelerates wound healing. Conclusions This novel delivery system, which overcomes the limitations of conventional plain collagen-based delivery system in lacking of ROS-environmental responsive mechanisms, demonstrates a great potential use in stem cell therapies in wound healing.

It is well known that tumors have an acidic pH microenvironment and contain a high content of hydrogen peroxide (H2O2). These features of the tumor microenvironment may provide physiochemical condi...

Neuroinflammation can cause cognitive deficits, and pre-existing neuroinflammation is very common in the clinic after trauma, surgery, and infection. Patients with pre-existing neuroinflammation often need further medical treatment under general anesthesia. However, it is still unknown the effects of postconditioning with general anesthetics on the pre-existing neuroinflammation. In this study, adult rats were post-treated with sevoflurane or propofol after intracerebroventricular administration of lipopolysaccharide. The effects of sevoflurane or propofol postconditioning on neuroinflammation-induced recognition memory deficit were detected. Our results found that postconditioning with sevoflurane, but not propofol reversed the selective spatial recognition memory impairment induced by neuroinflammation, and these differential effects did not appear to be associated with the similar anti-neuroinflammatory response of general anesthetics. However, postconditioning with propofol induced a selective long-lasting upregulation of extrasynaptic NR2B-containing NMDARs in the dorsal hippocampus, which down-regulated the CREB signaling pathway, and impaired spatial recognition memory. Additionally, the NR2B antagonists, memantine and Ro2506981, reversed this neurotoxicity induced by propofol postconditioning. Altogether, these results indicate that under the pre-existing neuroinflammation, postconditioning with sevoflurane can provide reliable neuroprotection through attenuating LPS-induced neuroinflammation, apoptosis, neuronal loss, and eventually improving spatial recognition deficit. However, although posttreatment with propofol also have the same anti-neuroinflammatory effects, the neurotoxicity caused by propofol postconditioning following neuroinflammation deserves to be continuously concerned.

Nanoscale delivery based on polyethylene glycol (PEG)ylated graphene oxide (GO-PEG) merits attention for biomedical applications owing to its functional surface modification, superior solubility/biocompatibility and controllable drug release capability. However, impaired skin regeneration in applications of these fascinating nanomaterials in diabetes is still limited, and critical issues need to be addressed regarding insufficient collagen hyperplasia and inadequate blood supply. Therefore, a high-performance tissue engineering scaffold with biocompatible and biodegradable properties is essential for diabetic wound healing. Natural and artificial acellular dermal matrix (ADM) scaffolds with spatially organized collagen fibers can provide a suitable architecture and environment for cell attachment and proliferation. Here, a novel collagen-nanomaterial-drug hybrid scaffold was constructed from GO-PEG-mediated quercetin (GO-PEG/Que)-modified ADM (ADM-GO-PEG/Que). The resulting unique and versatile hybrid scaffold exhibited multiple advantages, including the following: a biocompatible, cell-adhesive surface for accelerating mesenchymal stem cell (MSC) attachment and proliferation; superior stability and adjustability of the conduction potential of quercetin for inducing the differentiation of MSCs into adipocytes and osteoblasts; and a biodegradable nanofiber interface for promoting collagen deposition and angiogenesis in diabetic wound repair. This study provides new prospects for the design of innovative GO-PEG-based collagen hybrid scaffolds for application in efficient therapeutic drug delivery, stem cell-based therapies, tissue engineering and regenerative medicine.

C-X-C chemokine receptor type 4 (CXCR4) is an alpha-chemokine receptor specific for stromal cell-derived factor 1 (SDF-1 also called CXCL12). The antagonist of CXCR4 can mobilize CD34+ cells and hematopoietic stem cells from bone marrow within several hours, and it has an efficacy on diabetes ulcer through acting on the SDF-1/CXCR4 axis. In this study, we investigated for the first time whether the antagonist of CXCR4 (Plerixafor/AMD3100) delivered on acellular dermal matrix (ADM) may accelerate diabetes-impaired wound healing. ADM scaffolds were fabricated from nondiabetic mouse skin through decellularization processing and incorporated with AMD3100 to construct ADM-AMD3100 scaffold. Full-thickness cutaneous wound in streptozotocin (STZ)-induced diabetic mice were treated with ADM, AMD3100, or ADM-AMD3100. 21 days after treatment, wound closure in ADM-AMD3100-treated mice was more complete than ADM group and AMD3100 group, and it was accompanied by thicker collagen formation. Correspondingly, diabetic mice treated with ADM-AMD3100 demonstrated prominent neovascularization (higher capillary density and vascular smooth muscle actin), which were accompanied by up-regulated mRNA levels of SDF-1 and enhanced migration of CXCR4 in the granulation tissue. Our results demonstrate that ADM scaffold provide perfect niche for loading AMD3100 and ADM-AMD3100 is a promising method for diabetic wound healing mainly by increasing expression of SDF-1 and enhancing migration of CXCR4-positive cells.

Convenient methods for rapidly evaluating wound healing could help clinicians to select effective treatment measures for patients within an appropriate time frame. In this study, we explored the use of second-harmonic generation (SHG) combined with optical coherence tomography (OCT) to monitor the healing state of wounds, including the macro-morphology and optical signal characteristics of regenerated tissue. Wounds were imaged and monitored using OCT and SHG on healing days 3, 5, 7, 14, 21, and 28. The accumulation and maturation of newly formed collagen during the healing process was detected using SHG in real time. Additionally, changes in the OCT signal and attenuation coefficient in wounds before and after trauma were measured using the single-scattering OCT model. The wound closure percentage, the SHG intensity of collagen, and the attenuation coefficient of the wounds were analyzed using correlation analysis, which produced correlation coefficients of R12 = 0.944, R22 = 0.9776, and R32 = 0.9354, respectively. In theory, it is feasible to replace the wound closure percentage with the SHG intensity of collagen and the attenuation coefficient to evaluate wound healing. The OCT and SHG combination could be used to diagnose wound healing in real time.

Background/Aims: Bone marrow Mesenchymal stem cells (MSCs) are promising for promoting cutaneous wound healing through reinforcing cellular processes. We evaluated the effect of GFP-tagged MSCs transplantation on skin regeneration in excisional wounds in mice. Methods: MSCs from GFP-labeled transgenic mice were co-cultured with acellular dermal matrix (ADM) scaffolds, and MSC-ADM scaffolds were transplanted into surgical skin wounds of BALB/c mice. After implantation, the survival and behavior of MSCs were examined by second harmonic generation and two-photon excitation fluorescence imaging, western blotting and DNA amplification and sequencing. Results: GFP-tagged MSCs were retained inside the regenerating skin until day 14 post-transplantation. Alpha-smooth muscle actin (α-SMA) and vimentin (VIM) were detected at 3, 5, 7, and 14 days post-transplantation by immunofluorescence double labeling. Although the GFP+/α-SMA+- and GFP+/VIM+-cell numbers decreased gradually with healing time, α-SMA+- and VIM+-cell numbers significantly increased, most of them were endogenous functional cells which were related to angiogenesis and collagen fiber structural remodeling. Conclusion: Therefore, in the initial stage of wound healing, transplanted MSCs differentiated into functional cells and played paracrine roles to recruit more endogenous cells for tissue remodeling. With the disappearance of exogenous cells, endogenous cells were responsible for the latter stage of cutaneous wound healing.

Full-thickness cutaneous wound repair in adults usually leads to non-regenerative healing, which produces disorganized and non-functional fibrotic tissues. Mesenchymal stem cells (MSCs) on acellular dermal matrix (ADM) scaffolds are currently believed to be a promising strategy for wound healing improvement. Extracellular matrix (ECM) is aware of playing a pivotal role in wound healing, and changing the properties of the ECM is therefore expected to alter repair outcomes. Inspired by the analogous regeneration process in foetal skin with minimal or no scar tissue formation, in this study, ADM scaffold sourced from 1 day old mouse skin is introduced. Its influence on collagen reconstruction of granulation tissue during adult full-thickness wound healing is revealed and is compared to that from 20 week old mouse skin. Advanced nonlinear optical two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging were used to intravitally and three-dimensionally monitor the activities of MSCs and formation of granulation tissue. Dynamic changes of collagen content in granulation tissue were analyzed from aspects of synthesis and degradation. The associated collagen proteins, type I and type III collagen (Col-I and Col-III) and matrix matalloproteinase-13 (Mmp-13) were assessed at the transcriptional, translational and deposition levels. The results showed that there were significant differences in remodelling characteristics as a consequence of ADM properties. One-day old ADM + MSC treatment induced up-regulation of Col-III expression, down-regulation of Col-I and also down-regulation of Mmp-13. Accordingly, 1 day ADM + MSC treatment caused higher type III collagen deposition and a higher ratio of Col-III/Col-I in the granulation tissue. ADM derived from 1 day old skin ECM was superior to ADM derived from 20 week old skin ECM, caused enhanced angiogenesis, down regulation of TGF-β1 and promoted re-epithelization and faster, more constructive, and compositionally appropriate formation of granulation tissue. These results suggest that ADM derived from 1 day old skin ECM is a favourable biomaterial for adult wound healing.

According to the current legal metrological regulation of diaphragm gas meter, domestic gas meters in China are required to pass mandatory initial verification at 20°C, and then a 10 years' legal duration is allowed without any subsequent or in-service verifications. Here, experimental study has been implemented to investigate the metrological performance and temperature adaptability of old diaphragm gas meters with different use age. Through the introduction of weighting factors, weighted mean errors are calculated to analyse the correlation between the indication errors of gas meters and their use age, as well as the relationship between the indication errors and test temperatures. Experimental results indicate that the use age of gas meters has negligible influence on their metrological performance during the 10 years' legal duration. However, the indication errors worsen as temperature varies.

Ketamine can induce neurotoxicity after exposures to the developing brain. To investigate whether ketamine at subanesthetic dosage or its environmental condition can cause long-term cognitive dysfunction after multiple exposures in male or female neonatal rats, postnatal day 5 (P5)-day-old Sprague-Dawley rats were randomized into three groups: ketamine group, vehicle group, and control group (no disturbance). Learning and memory abilities from P60 to P65 and immunofluorescence tests for myelin basic protein (MBP) in gray matter on P65 were conducted. The results showed that in female rats, the path length on day 1 in ketamine group and on days 1 and 2 in vehicle group was longer than that in control (P0.05). The mean density of MBP in the medial prefrontal cortex (mPFC) was significantly increased in vehicle and ketamine groups compared with that in control (P0.05). In male rats, there were no significant differences in path length among the groups, and the density of MBP in the mPFC and hippocampus in vehicle or ketamine group was not different from that in control (P>0.05). Pearson’s correlation analysis showed that there was a positive correlation between MBP density in the mPFC and path length in adult female rats (r=0.753, P

It is well known that tumors have an acidic pH microenvironment and contain a high content of hydrogen peroxide (H

Nanozymes are emerging as a promising strategy for the treatment of tumors. Herein, to cope with the tumor microenvironment (TME), weak acidity (pH 5.6 to 6.8) and trace amounts of overexpressed hydrogen peroxide (H2O2) (100 µM–1 mM), we report nitrogen-doped graphene nanomaterials (N-GNMs), which act as highly efficient catalytic peroxidase (POD)-mimicking nanozymes in the TME for tumor-specific treatment. N-GNMs exhibit POD catalytic properties triggered by a weakly acidic TME and convert H2O2 into highly toxic hydroxyl radicals (•OH) thus causing the death of tumor cells while in the neutral pH surroundings of normal tissues, such catalysis is restrained and leaves normal cells undamaged thereby achieving a tumor-specific treatment. N-GNMs also display a high catalytic activity and can respond to the trace endogenous H2O2 in the TME resulting in a high efficiency of tumor therapy. Our in vitro chemical and cell experiments illustrated the POD-like activity of N-GNMs and in vivo tumor model experiments confirmed the significant inhibitory effect of N-GNMs on tumor growth.

Propofol can induce acute neuronal apoptosis, neuronal loss or long-term cognitive impairment when exposed in neonatal rodents, but the mechanisms by which propofol induces developmental neurotoxicity are unclear. Recent studies have demonstrated that propofol can increase the TNF-α level in the developing brain, but there is a lack of direct evidence to show whether TNF-α is partially or fully involved in propofol-induced neurotoxicity. The present study shows that propofol exposure in neonatal rats induces an increase of TNF-α in the cerebral spinal fluid, hippocampus and prefrontal cortex (PFC). Etanercept, a TNF-α inhibitor, prevents propofol-induced short- or long-term neuronal apoptosis, neuronal loss, synaptic loss and long-term cognitive impairment. Furthermore, mTNF-α (precursor of TNF-α) expression in microglia cells is increased after propofol anaesthesia in either the hippocampus or PFC, but mTNF-α expression in neurons is only increased in the PFC. These findings suggest that TNF-α may mediate propofol-induced developmental neurotoxicity, and etanercept can provide neural protection. Microglia are the main cellular source of TNF-α after propofol exposure, while the synthesis of TNF-α in neurons is brain-region selective.

Hyperthermia cancer treatment is an adjunctive therapy that aims at killing the tumor cells with excessive heat that is usually generated by metal contrasts exposed to alternating magnetic field. The efficacy of hyperthermia is often limited by the heat damage to normal tissue due to indiscriminate distribution of the metal contrasts within the body. Tumor-targeting metal contrasts may reduce the toxicity of hyperthermia and improve the efficacy of thermotherapy against cancer. MUC1 is a glycoprotein over expressed in most adenocarcinomas, and represents an attractive therapeutic target. In this study, a MUC1 aptamer is conjugated with iron nanoparticles to construct adenocarcinoma-targeting metal contrasts. DNA hybridization studies confirmed that the aptamers were conjugated to the iron nanoparticles. Importantly, more aptamer-modified nanoparticles attached to the MUC1-positive cancer cells compared with the unmodified nanoparticles. Moreover, aptamer-modified nanoparticles significantly enhanced the targeted hyperthermia damage to MUC1-positive cancer cells in vitro (p < 0.05). The results suggest that MUC1 aptamer-modified metal particles may have potential in development of targeted hyperthermia therapy against adenocarcinomas.

In fetal skin, there is a process of scarless repair that does not exist in adults. The characteristics of the fetal skin extracellular matrix (ECM) are presumed to play a pivotal role for this scarless wound healing. The use of an acellular dermal matrix (ADM) with certain specific characteristics of the skin ECM thus is implied to have impact on skin repair and regeneration and the alteration of ADM properties may allow for the development of an effective intervention for scarless wound healing. In this study, two types of ADM from skin ECM were adopted to explore the potential to achieve scarless wound healing in adult mice. We transplanted this matrix onto the 10-week-old full-thickness cutaneous wound mice model. The ADM derived from the ECM of 1-day-old mouse skin (ADM-1D) was chosen to approximate certain characteristics of fetal skin while the ADM from the ECM of 20-week-old mouse skin (ADM-20W) provided a control with characteristics of mature skin. Second-harmonic generation (SHG) microscopic imaging was performed to dynamically demonstrate the collagen reconstruction process in the new born dermis during primary wound healing. The outcome of healing on day 21 was evaluated. Compared to ADM-20W, ADM-1D provided a more favorable influence on the re-establishment of the epidermis as well as collagen density, orientation and stiffness in the new born dermis, to a degree approaching normal uninjured adult dermal tissue. A remarkable difference in biomechanical stiffness is present between ADM-1D and ADM-20W, which might be one of the crucial determinants for potential adult scarless wound healing.

Accurate and rapid assessment of the healing status of a wound in a simple manner would enable clinicians to diagnose wounds in time and promptly adopt appropriate treatments for nonhealing wounds. Traditional histologic and biochemical characterization of biopsied wound tissue is complicated to operate, slow and complex to interpret. Here we applied three testing methods and drew a conclusion that Raman microspectroscopy combined with SHG is a comprehensive way to trace the regeneration status of collagen during wound repair from both aspects of quantity and morphology. Four slices of one sample at different locations were made and three spots of each slice were detected. The average was used as the last spectrum. Spectra of wound samples at different time points show an obvious increase in the special Raman region of collagen fingerprints (1672, 1641, 1274, 1244, and 1180 cm−1) and C–C\C–H vibration of total proteins (1445, 941 cm−1) as the time duration for healing was prolonged. Besides, we used two analytical methods to analyze Raman spectra: the 1665/1445 cm−1 band area ratio and principal component analysis, respectively. The former reflects collagen accumulation during wound healing, while the latter shows a successful cluster of samples at different healing status. Our results demonstrate that Raman spectroscopy combined with SHG may be used as a complementary tool for in situ biochemical characterization in wound healing studies and clinical diagnosis.

Direct intra-skin injection of mesenchymal stem cells (MSCs) and the use of biomaterial scaffolds for grafts are both promising approaches of skin wound repair, however they still cannot generate skin that completely resembles the natural skin structures. In this study, we combined these two approaches by using acellular dermal matrix (ADM) recellularized with MSCs to repair cutaneous wounds in a murine model and two-photon fluorescence (TPF) microscopy and second-harmonic generation (SHG) microscopy to assess the effects of this therapy on wound healing. Bone marrow-derived mesenchymal stem cells (BM-MSCs) were tagged with GFP and seeded into ADM (ADM-MSC) via MSC and ADM co-culture. ADM-MSC, ADM or saline was applied to murine excisional skin wounds and wound-healing was evaluated by histological examination on days 7, 14, 21 and TFP microscopy on days 1, 3, 5 and 21 post-treatment. ADM-MSC promoted healing significantly more than treatment with ADM or saline alone, as it led to substantial neovascularization and complete skin appendage regeneration. Furthermore, the SHG microscopic imaging technique proved to be a useful tool for monitoring changes in the collagen network at the wound site during the healing process and assessing the effects of different therapies.

Background Adult full-thickness cutaneous wound repair suffers from an imbalanced immune response, leading to nonfunctional reconstructed tissue and fibrosis. Although various treatments have been reported, the immune-mediated tissue regeneration driven by biomaterial offers an attractive regenerative strategy for damaged tissue repair. Methods In this research, we investigated a specific bone marrow-derived mesenchymal stem cell (BMSC) sheet that was induced by the Traditional Chinese Medicine curcumin (CS-C) and its immunomodulatory effects on wound repair. Comparisons were made with the BMSC sheet induced without curcumin (CS-N) and control (saline). Results In vitro cultured BMSC sheets (CS-C) showed that curcumin promoted the proliferation of BMSCs and modified the features of produced extracellular matrix (ECM) secreted by BMSCs, especially the contents of ECM structural proteins such as fibronectin (FN) and collagen I and III, as well as the ratio of collagen III/I. Two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging of mouse implantation revealed superior engraftment of BMSCs, maintained for 35 days in the CS-C group. Most importantly, CS-C created a favorable immune microenvironment. The chemokine stromal cell-derived factor 1 (SDF1) was abundantly produced by CS-C, thus facilitating a mass migration of leukocytes from which significantly increased expression of signature TH1 cells (interferon gamma) and M1 macrophages (tumor necrosis factor alpha) genes were confirmed at 7 days post-operation. The number of TH1 cells and associated pro-inflammatory M1 macrophages subsequently decreased sharply after 14 days post-operation, suggesting a rapid type I immune regression. Furthermore, the CS-C group showed an increased trend towards M2 macrophage polarization in the early phase. CS-C led to an epidermal thickness and collagen deposition that was closer to that of normal skin. Conclusions Curcumin has a good regulatory effect on BMSCs and this promising CS-C biomaterial creates a pro-regenerative immune microenvironment for cutaneous wound healing.

Propofol can cause developing neuronal apoptosis in both in vivo and in vitro studies, and the mechanism is unclear till now. Our previous study has demonstrated that propofol can increase the TNF-α expression in the prefrontal cortex in rat developing brain, the TNF-α antagonist, etanercept, can inhibit propofol-induced neuronal apoptosis, but little is known about how TNF-α mediates that process. This study reveals that propofol at clinically relevant concentrations increases the TNF-α synthesis and release in neurons, and induces neuronal apoptosis; etanercept significantly reduces neuronal apoptosis, the elevation of cleaved caspase-8 and cleaved caspase-9, or the Akt phosphorylation induced by propofol, while the selective PI3K antagonist blocks the neuroprotection of etanercept. Propofol does not change the expression of P2X7 receptor in neurons, and the P2X7 receptor antagonist cannot affect the TNF-α synthesis or release after propofol treatment. These results suggest that propofol can increase the synthesis and release of TNF-α in the primary cultured prefrontal cortical neurons, TNF-α contributes to the intrinsic and extrinsic pathway in propofol-induced neuronal apoptosis via PI3K/Akt signaling pathway, and P2X7R is not involved in the synthesis and release of TNF-α induced by propofol.

We report our preliminary results on quantification of glucose and dimethyl sulfoxide (DMSO) diffusion in normal and cancerous human bladder tissues in vitro by using a spectral domain optical coherence tomography (SD-OCT). The permeability coefficients (PCs) of a 30% aqueous solution of glucose are found to be (7.92 ± 0.81) × 10-6 cm s-1 and (1.19 ± 0.13) × 10-5 cm s-1 in normal and cancerous bladder tissues, respectively. The PCs of 50% DMSO are calculated to be (8.99 ± 0.93) × 10-6 cm s-1 and (1.43 ± 0.17) × 10-5 cm s-1 in normal and cancerous bladder tissues, respectively. The obtained results show a statistically significant difference in permeability of normal and cancerous tissue and indicate that the PC of 50% DMSO is about 1.13-and 1.21-fold higher than that of 30% glucose in normal bladder and cancerous bladder tissues, respectively. Thus, the quantitative measurements with the help of PCs from OCT images can be a potentially powerful method for bladder cancer detection.

C-X-C chemokine receptor type 4 (CXCR4) is an alpha-chemokine receptor specific for stromal cell-derived factor 1 (SDF-1 also called CXCL12). The antagonist of CXCR4 can mobilize CD34+ cells and hematopoietic stem cells from bone marrow within several hours, and it has an efficacy on diabetes ulcer through acting on the SDF-1/CXCR4 axis. In this study, we investigated for the first time whether the antagonist of CXCR4 (Plerixafor/AMD3100) delivered on acellular dermal matrix (ADM) may accelerate diabetes-impaired wound healing. ADM scaffolds were fabricated from nondiabetic mouse skin through decellularization processing and incorporated with AMD3100 to construct ADM-AMD3100 scaffold. Full-thickness cutaneous wound in streptozotocin (STZ)-induced diabetic mice were treated with ADM, AMD3100, or ADM-AMD3100. 21 days after treatment, wound closure in ADM-AMD3100-treated mice was more complete than ADM group and AMD3100 group, and it was accompanied by thicker collagen formation. Correspondingly, diabetic mice treated with ADM-AMD3100 demonstrated prominent neovascularization (higher capillary density and vascular smooth muscle actin), which were accompanied by up-regulated mRNA levels of SDF-1 and enhanced migration of CXCR4 in the granulation tissue. Our results demonstrate that ADM scaffold provide perfect niche for loading AMD3100 and ADM-AMD3100 is a promising method for diabetic wound healing mainly by increasing expression of SDF-1 and enhancing migration of CXCR4-positive cells.

Mesenchymal stem cells (MSCs) had been reported as a novel therapeutic strategy for non-healing diabetic cutaneous wound mainly by promoting the formation of extracellular matrix (ECM) and neovasculature. Collagen regeneration is one of the key processes of ECM remodeling in wound healing. Accordingly, rapid assessment of the collagen content in a noninvasive manner can promptly provide objective evaluation for MSC therapy of cutaneous wound healing and strength evidence to adjust therapeutic regimen. In the present study, noninvasive Raman microspectroscopy was used for tracing the regeneration status of collagen during diabetic wound healing with MSCs. Wound tissues of normal mice, diabetic mice, and MSC-treated diabetic mice were subjected to Masson trichrome staining assay and submitted to spectroscopic analysis by Raman microspectroscopy after wounding 7, 14, and 21 days. Masson trichrome staining demonstrated that there was more collagen deposition in diabetic + MSCs group relative to diabetic group. The relative intensity of Raman collagen peak positions at 937, 1004, 1321, 1452, and 1662 cm−1 increased in MSC-treated diabetic group compared to diabetic group, although normal mice group had the highest relative intensity of collagen peak bands. Correlation analysis suggested that the spectral bands had a high positive correlation with the collagen intensity detected by Masson trichrome staining in wound tissues of three groups. Our results demonstrate that Raman microspectroscopy has potential application in rapidly and quantitatively assessing diabetic wound healing with MSCs by monitoring collagen variation, which may provide a novel method for the study of skin regeneration.

Propofol can induce acute neuronal apoptosis or long-term cognitive dysfunction when exposed at early age in rodents, but it is unclear how the neurotoxicity including neuronal apoptosis and synaptic loss will change in a dynamic manner with brain development after multiple or single exposure of propofol, and the role of neuronal apoptosis and synaptic loss in propofol-induced long-term cognitive impairment needs to be elucidated. In this study, we investigated dynamic changes of neuronal apoptosis, neuronal density, synaptic density in hippocampal CA1 region and the prelimbic cortex (PrL), and long-term cognitive function after multiple or single exposure of propofol in neonatal rats. Results showed that single exposure of propofol only induced great neuronal apoptosis and deficit at postnatal day 9(P9); while multiple exposures of propofol could induce significant neuronal apoptosis, neuronal deficit and synaptic loss at P9, P14, P21, or P35 compared with intact, and spatial learning and memory impairment from P36 to P41. Results suggest that single exposure of propofol only induces transient neuronal apoptosis and deficit, while multiple exposures of propofol induce persistent neuronal apoptosis, neuronal deficit, synaptic loss, and long-term cognitive impairment. Furthermore, persistent neuronal deficit and disturbances in synapse formation but not transient neuronal apoptosis may contribute to long-term cognitive impairment.

Objective To investigate the effect of small interfering RNA (siRNA)-mediated silencing of the Bmi-1 gene on cell proliferation and invasion of MCF-7 human mammary carcinoma cell line and the potential molecular mechanisms. Methods Real-time quantitative PCR was used to detect the levels of Bmi-1 mRNA in the paired breast cancer and adjacent noncancerous breast tissues which were confirmed by pathological diagnosis. Bmi-1-siRNA was transfected into MCF-7 cells by a Lipofectamine(R) RNAiMAX transfection reagent. Flow cytometry was used to detect cell cycle and apoptosis of MCF-7 cells transfected by Bmi-1-siRNA. Western blotting was performed to detect the protein levels of P21, Bax and Bcl-2. Matrigel Transwell(TM) invasion assay was used to determine the cell invasion of MCF-7 cells with Bmi-1 silencing. The protein levels of E-cadherin, N-cadherin, vimentin were tested by Western blotting. Results The expression of Bmi-1 mRNA in the breast cancer tissues was higher than that in the adjacent noncancerous breast tissues. Bmi-1 silencing significantly suppressed the cell growth, arrested the cells in the G1/S phase and promoted the apoptosis of MCF-7 cells. Compared with blank control group or negative control group, the Bmi-1-silenced group showed the increased expressions of P21 and Bax and the decreased expression of Bcl-2. In addition, Bmi-1 silencing significantly suppressed the cell invasion and promoted the expression of E-cadherin as well as downregulated the expressions of N-cadherin and vimentin in MCF-7 cells. Conclusion The invasion of MCF-7 cells can be inhibited by Bmi-1 silencing, of which the molecular regulation mechanism might be associated with the inhibition of tumor cell epithelial-mesenchymal transition.

In this study, we report permeability coefficients of 30% glucose diffusion by the optical coherence tomography signal slope (OCTSS) method in four kinds of human lung tissue in vitro: normal lung tissue, benign granulomatosis lung tissue, squamous cell carcinoma and adenocarcinoma tumor. To quantify the permeability coefficient of the agent, the monitored region was 80 μm thickness at a tissue depth of ca 230 μm from the surface. The permeability coefficients of 30% glucose from 10 independent experiments were averaged and found to be (1.35 ± 0.13) × 10(-5) cm s(-1) from the normal lung tissue, (1.78 ± 0.21) × 10(-5) cm s(-1) from the benign granulomatosis lung tissue, (2.88 ± 0.19) × 10(-5) cm s(-1) from the adenocarcinoma tumor and (3.53 ± 0.25) × 10(-5) cm s(-1) from the squamous cell carcinoma, respectively. It could be clearly seen that the permeability coefficients of 30% glucose increase ca 32%, 113% and 162% in the benign granulomatosis, adenocarcinoma tumor and squamous cell carcinoma of human lung tissue compared with that from the normal lung tissue, respectively. Therefore, we inferred from this pilot study that the OCT imaging is a feasible method to distinguish normal and cancer lung tissue.