Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

Stable quantum-correlated many-body states through engineered dissipation

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Physical modulation of mesenchymal stem cell exosomes: A new perspective for regenerative medicine

Mesenchymal stem cell-derived exosomes (MSC-Exo) offer promising therapeutic potential for various refractory diseases, presenting a novel therapeutic strategy. However, their clinical application encounters several obstacles, including low natural secretion, uncontrolled biological functions and inherent heterogeneity. On the one hand, physical stimuli can mimic the microenvironment dynamics where MSC-Exo reside. These factors influence not only their secretion but also, significantly, their biological efficacy. Moreover, physical factors can also serve as techniques for engineering exosomes. Therefore, the realm of physical factors assumes a crucial role in modifying MSC-Exo, ultimately facilitating their clinical translation. This review focuses on the research progress in applying physical factors to MSC-Exo, encompassing ultrasound, electrical stimulation, light irradiation, intrinsic physical properties, ionizing radiation, magnetic field, mechanical forces and temperature. We also discuss the current status and potential of physical stimuli-affected MSC-Exo in clinical applications. Furthermore, we address the limitations of recent studies in this field. Based on this, this review provides novel insights to advance the refinement of MSC-Exo as a therapeutic approach in regenerative medicine.

General requirements for the production of extracellular vesicles derived from human stem cells

'General requirements for the production of extracellular vesicles derived from human stem cells' is the first guideline for stem cells derived extracellular vesicles in China, jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research. This standard specifies the general requirements, process requirements, packaging and labelling requirements and storage requirements for preparing extracellular vesicles derived from human stem cells, which is applicable to the research and production of extracellular vesicles derived from stem cells. It was originally released by the China Society for Cell Biology on 30 August 2022. We hope that the publication of this guideline will promote institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardisation of extracellular vesicles derived from human stem cells.

Dynamic navigation-assisted bone ring technique for partially edentulous patients with severe vertical ridge defects

The autogenous bone ring technique is among the approaches for vertical alveolar ridge augmentation, and this technique can enable simultaneous implantation. However, the outcomes can be compromised due to donor site morbidity, shifting of the bone ring graft positioning, and inaccurate implant placement. In recent decades, dynamic navigation systems have been introduced into the field of implantology, allowing the accuracy of outcomes to be improved. This Technical Note describes the use of dynamic navigation to guide bone ring surgery, which is expected to enable more precise and predictable bone augmentation and implantation procedures, reduce the risk of injuries to the adjacent anatomical structures, and achieve better treatment outcomes.

Hemoglobin variability in patients receiving EPO and roxadustat during maintenance hemodialysis: a self-control study

OBJECTIVE

The aim of this study was to investigate the hemoglobin variability in patients undergoing maintenance hemodialysis during the application of erythropoietin (EPO) and roxadustat.

PATIENTS AND METHODS

For this retrospective study, we analyzed the clinical records of 80 patients with renal anemia on maintenance hemodialysis (MHD) admitted to our hospital between January 2017 and December 2022. We adopted a self-control design comparing the hemoglobin variability of the values before and after roxadustat administration in each patient. The patients received EPO from January 2017 to December 2019 and roxadustat from January 2020 to December 2022. We compared the levels of serum ferritin, transferrin saturation, and hemoglobin and calculated the hemoglobin variabilities by comparing values before and after roxadustat treatments.

RESULTS

We found higher transferrin saturation levels at different time points after the roxadustat treatments (p<0.01); meanwhile, the serum ferritin and hemoglobin levels were significantly higher after the roxadustat treatment (p<0.001). During the treatments with EPO and roxadustat, the transferrin saturation, serum ferritin, and hemoglobin levels differed significantly at different time points for each patient (p<0.05). After roxadustat administration, the hemoglobin levels were significantly higher than after EPO administration (p<0.001) and changed more rapidly after roxadustat administration than after EPO administration (p<0.05). The hemoglobin variability after roxadustat administration was significantly lower than that after EPO administration (p<0.05).

CONCLUSIONS

Treatment with roxadustat led to higher hemoglobin levels and less hemoglobin variability than the treatment with EPO, with high transferrin saturation and higher ferritin levels in patients with renal anemia on MHD.

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory1: by collapsing the wavefunction, it can enable phenomena such as teleportation2 and thereby alter the 'arrow of time' that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time3-10 that go beyond the established paradigms for characterizing phases, either in or out of equilibrium11-13. For present-day noisy intermediate-scale quantum (NISQ) processors14, the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping9,15-17 to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling3,4 to measurement-induced teleportation18. We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.

Adipose-derived mesenchymal stem cell therapy for reverse bleomycin-induced experimental pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive respiratory disease. Arguably, the complex interplay between immune cell subsets, coupled with an incomplete understanding of disease pathophysiology, has hindered the development of successful therapies. Despite efforts to understand its pathophysiology and develop effective treatments, IPF remains a fatal disease, necessitating the exploration of new treatment options. Mesenchymal stromal/stem cell (MSC) therapy has shown promise in experimental models of IPF, but further investigation is needed to understand its therapeutic effect. This study aimed to assess the therapeutic effect of adipose-derived mesenchymal stem cells in a bleomycin-induced pulmonary fibrosis model. First, MSC cells were obtained from mice and characterized using flow cytometry and cell differentiation culture methods. Then adult C57BL/6 mice were exposed to endotracheal instillation of bleomycin and concurrently treated with MSCs for reversal models on day 14. Experimental groups were evaluated on days 14, 21, or 28. Additionally, lung fibroblasts challenged with TGF-β1 were treated with MSCs supernatant or MSCs to explore the mechanisms underlying of pulmonary fibrosis reversal. Mesenchymal stem cells were successfully isolated from mouse adipose tissue and characterized based on their differentiation ability and cell phenotype. The presence of MSCs or their supernatant stimulated the proliferation and migration of lung fibrotic cells. MSCs supernatant reduced lung collagen deposition, improved the Ashcroft score and reduced the gene and protein expression of lung fibrosis-related substances. Bleomycin-challenged mice exhibited severe septal thickening and prominent fibrosis, which was effectively reversed by MSCs treatment. MSC supernatant could suppress the TGF-β1/Smad signaling pathway and supernatant promotes fibroblast autophagy. In summary, this study demonstrates that MSCs supernatant treatment is as effective as MSCs in revert the core features of bleomycin-induced pulmonary fibrosis. The current study has demonstrated that MSCs supernatant alleviates the BLM-induced pulmonary fibrosis in vivo. In vitro experiments further reveal that MSC supernatant could suppress the TGF-β1/Smad signaling pathway to inhibit the TGF-β1-induced fibroblast activation, and promotes fibroblast autophagy by Regulating p62 expression. These findings contribute to the growing body of evidence supporting the therapeutic application of MSCs in cell therapy medicine for IPF.

Non-Abelian braiding of graph vertices in a superconducting processor

Indistinguishability of particles is a fundamental principle of quantum mechanics¹. For all elementary and quasiparticles observed to date-including fermions, bosons and Abelian anyons-this principle guarantees that the braiding of identical particles leaves the system unchanged^2,3. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions^4-8. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well-developed mathematical description of non-Abelian anyons and numerous theoretical proposals^9-22, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. Whereas efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasiparticles, superconducting quantum processors allow for directly manipulating the many-body wavefunction by means of unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons^9,10, we implement a generalized stabilizer code and unitary protocol²³ to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of using the anyons for quantum computation and use braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and, through the future inclusion of error correction to achieve topological protection, could open a path towards fault-tolerant quantum computing.

IGFBP-7 secreted by adipose-derived stem cells inhibits keloid formation via the BRAF/MEK/ERK signaling pathway

BACKGROUND

Adipose tissue-derived stem cells (ASCs) have important clinical significance as regulators of skin scar tissue regeneration. ASCs inhibit keloid formation and increase insulin-like growth factor-binding protein-7 (IGFBP-7) expression. However, whether ASCs inhibit keloid formation through IGFBP-7 remains unclear.

OBJECTIVE

We aimed to assess the roles of IGFBP-7 in keloid formation.

METHODS

We analyzed the proliferation, migration, and apoptosis of keloid fibroblasts (KFs) treated with recombinant IGFBP-7 (rIGFBP-7) or by co-culture with ASCs using CCK8 assays, transwell assays, and flow cytometry, respectively. In addition, immunohistochemical staining, quantitative polymerase chain reaction, human umbilical vein endothelial cell tube formation, and western blotting experiments were used to assess keloid formation.

RESULTS

IGFBP-7 expression was significantly lower in keloid tissues than that in normal skin tissues. Stimulation of KFs with rIGFBP-7 at different concentrations or by co-culture with ASCs resulted in decreased KF proliferation. Additionally, KF stimulation with rIGFBP-7 resulted in increased apoptosis of KFs. IGFBP-7 also reduced angiogenesis in a concentration-dependent manner, and stimulation with different rIGFBP-7 concentrations or co-culture of KFs with ASCs inhibited the expression of transforming growth factor-β1, vascular endothelial growth factor, collagen I, interleukin (IL)-6, IL-8, B-raf proto-oncogene (BRAF), mitogen-activated protein kinase kinase (MEK), and extracellular signal-regulated kinase (ERK) in KFs.

CONCLUSION

Collectively, our findings suggested that ASC-derived IGFBP-7 prevented keloid formation by inhibiting the BRAF/MEK/ERK signaling pathway.

SARS-CoV-2 surface and air contamination in an acute healthcare setting during the first and second pandemic waves

BACKGROUND

Surfaces and air in healthcare facilities can be contaminated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Previously, the authors identified SARS-CoV-2 RNA on surfaces and air in their hospital during the first wave of the coronavirus disease 2019 pandemic (April 2020).

AIM

To explore whether the profile of SARS-CoV-2 surface and air contamination had changed between April 2020 and January 2021.

METHODS

This was a prospective, cross-sectional, observational study in a multi-site London hospital. In January 2021, surface and air samples were collected from comparable areas to those sampled in April 2020, comprising six clinical areas and a public area. SARS-CoV-2 was detected using reverse transcription polymerase chain reaction and viral culture. Sampling was also undertaken in two wards with natural ventilation alone. The ability of the prevalent variants at the time of the study to survive on dry surfaces was evaluated.

FINDINGS

No viable virus was recovered from surfaces or air. Five percent (N=14) of 270 surface samples and 4% (N=1) of 27 air samples were positive for SARS-CoV-2, which was significantly lower than in April 2020 [52% (N=114) of 218 surface samples and 48% (N=13) of 27 air samples (P<0.001, Fisher's exact test)]. There was no clear difference in the proportion of surface and air samples positive for SARS-CoV-2 RNA based on the type of ventilation in the ward. All variants tested survived on dry surfaces for >72 h, with a <3-log10 reduction in viable count.

CONCLUSION

This study suggests that enhanced infection prevention measures have reduced the burden of SARS-CoV-2 RNA on surfaces and air in healthcare facilities.

Trends in cutaneous squamous cell carcinoma on the lip incidence and mortality in the United States, 2000-2019

Objective

This study provided a systematic analysis of the trend in incidence and incidence-based mortality for cutaneous squamous cell carcinoma (cSCC) on the lips in the USA using demographic characteristics from the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

Patients diagnosed with cSCC on the lips between 2000 and 2019 from the 17 registries of the USA were identified. Incidence and incidence-based mortality rates were analyzed using SEER*Stat 8.4.0.1 software. This paper calculated incidence rates and incidence-based mortality rates by 100,000 person-years for sex, age, race, SEER registries, median household income ($/year), rural-urban distribution, and primary site. The annual percent changes (APC) in incidence and incidence-based mortality rates were then calculated using joinpoint regression software.

Results

Among 8,625 patients diagnosed with cSCC on the lips from 2000 to 2019, men (74.67%), white (95.21%), and 60-79 years old were the most common population, and 3,869 deaths from cSCC on the lips occurred. The overall incidence of cSCC on the lips was 0.516 per 100,000 person-years. cSCC on the lip incidence rates were highest among men, white, and patients aged 60-79 years old. cSCC on the lip incidence rates decreased by 3.210%/year over the study period. The incidence of cSCC on the lips has been decreasing in all sexes, ages, high- or low-income households, and urban or rural patients. The overall incidence-based mortality rate of cSCC on the lips during 2000-2019 was 0.235 per 100,000 person-years. cSCC on the lip incidence-based mortality rates were highest among men, whites, and people older than 80 years old. cSCC on the lip incidence-based mortality increased by 4.975%/year over the study period. cSCC on the lip incidence-based mortality rates increased for all sexes, races, ages, primary sites, high- or low-income households, and urban or rural patients during the study period.

Conclusion

Among patients in the USA diagnosed with cSCC on the lips from 2000 to 2019, the overall incidence decreased by 3.210% annually, and incidence-based mortality increased by 4.975%/year. These findings update and supplement the epidemiological information of cSCC on the lips in the USA.

Formation of robust bound states of interacting microwave photons

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Noise-resilient edge modes on a chain of superconducting qubits

Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model, which exhibits nonlocal Majorana edge modes (MEMs) with ℤ 2 parity symmetry. We find that any multiqubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment.

[Efficacy comparison among high risk factors questionnaire and Asia-Pacific colorectal screening score and their combinations with fecal immunochemical test in screening advanced colorectal tumor]

Objective: To investigate the effects of high risk factors questionnaire (HRFQ), Asia-Pacific colorectal screening (APCS) score and their combinations with fecal immunochemical test (FIT) in screening advanced colorectal neoplasia, in order to provide an evidence for further optimization of cancer screening program. Methods: A retrospective cohort study method was used to summarize and analyze the results of colorectal tumor screening in Jiashan County, Zhejiang Province from March 2017 to July 2018. Those with severe diseases that were not suitable for colonoscopy and those with mental and behavioral abnormalities who can not cooperate with the screening were excluded. Those who met any one or more of the followings in the HRFQ questionnaire were classified as high-risk people of HRFQ: (1) first-degree relatives with a history of colorectal cancer; (2) subjects with a history of cancer or any other malignant tumor; (3) subjects with a history of intestinal polyps; (4) those with two or more of the followings: chronic constipation (constipation lasted for more than 2 months per year in the past two years), chronic diarrhea (diarrhea lasted for more than 3 months in the past two years, and the duration of each episode was more than one week), mucus and bloody stools, history of adverse life events (occurring within the past 20 years and causing greater trauma or distress to the subject after the event), history of chronic appendicitis or appendectomy, history of chronic biliary disease or cholecystectomy. In this study, those who were assessed as high risk by HRFQ were recorded as "HRFQ (+)", and those who were not at high risk were recorded as "HRFQ (-)". The APCS questionnaire provided risk scores based on 4 risk factors including age, gender, family history and smoking: (1) age: 2 points for 50-69 years old, 3 points for 70 years old and above; (2) gender: 1 point for male, 0 point for women; (3) family history: 2 points for first-degree relatives suffering from colorectal cancer; (4) smoking: 1 point for current or past smoking, 0 point for non-smokers. The population was divided into low-risk (0-1 point), intermediate-risk (2-3 points), and high-risk (4-7 points). Those who were assessed as high risk by APCS were recorded as "APCS (+)", and those with intermediate and low risk were recorded as "APCS (-)". The hemoglobin threshold for a positive FIT was set to 100 μg/L. Those who were assessed as high risk by APCS with positive FIT were recorded as "APCS+FIT (+)". Those who were assessed as high risk by APCS with negative FIT, those who were assessed by APCS as low-middle risk with positive FIT, and those who were assessed by APCS as low-middle with negative FIT were all recorded as "APCS+FIT(-)". Observation indicators in this study were as follows: (1) the screening compliance rate of the cohort and the detection of advanced colorectal tumors; (2) positive predictive value, negative predictive value, sensitivity and specificity of HRFQ and APCS and their combination with FIT for screening advanced colorectal tumors; (3) comparison of the detection rate between HRFQ and APCS questionnaire for different colorectal lesions. Using SPSS 21.0 software, the receiver operating characteristic (ROC) curve was drawn to evaluate the clinical value of HRFQ and APCS combined with FIT in screening advanced colorectal tumors. Results: From 2017 to 2018 in Jiashan County, a total of 53 268 target subjects were screened, and 42 093 people actually completed the questionnaire, with a compliance rate of 79.02%. A total of 8145 cases underwent colonoscopy. A total of 3607 cases among HRFQ positive population (5320 cases) underwent colonoscopy, and the colonoscopy compliance rate was 67. 80%; 8 cases were diagnosed with colorectal cancer and 88 cases were advanced colorectal adenoma. A total of 2977 cases among APCS positive population (11 942 cases) underwent colonoscopy, and the colonoscopy compliance rate was 24.93%; 17 cases were diagnosed with colorectal cancer and 148 cases were advanced colorectal adenoma. The positive rate of HRFQ screening was lower than that of APCS [12.6% (5320/42 093) vs. 28.4% (11 942/42 093), χ²=3195. 547, P<0.001]. In the FIT positive population (6223 cases), a total of 4894 cases underwent colonoscopy, and the colonoscopy compliance rate was 78.64%; 34 cases were diagnosed with colorectal cancer and 224 cases were advanced adenoma. The positive predictive values of HRFQ and APCS and their combination with FIT for screening advanced colorectal tumors were 2.67%, 5.54%, 5.44%, and 8.56%; negative predictive values were 94.89%, 96.85%, 96.11% and 96.99%; sensitivity was 29.27%, 50.30%, 12.20 % and 39.02%; specificity was 55.09%, 64.03%, 91.11% and 82.51%, respectively. The ROC curves constructed by HRFQ, APCS, FIT, HRFQ+FIT and APCS+FIT indicated that APCS+FIT presented the highest efficacy in screening advanced colorectal tumors (AUC: 0.608, 95%CI: 0.574-0.642). The comparison of the detection rates of different colorectal lesions between HRFQ and APCS questionnaires showed that there were no significant differences in detection rate of inflammatory polyps and hyperplastic polyps between the two questionnaires (both P>0.05). However, as compared to HRFQ questionnaire, APCS questionnaire had higher detection rates in non-advanced adenomas [26.10% (777/2977) vs. 19.43% (701/3607), χ²=51.228, P<0.001], advanced adenoma [4.97% (148/2977) vs. 2.44% (88/3607), χ²=30.249, P<0.001] and colorectal cancer [0.57% (17 /2977) vs. 0.22% (8/3607), χ²=5.259, P=0.022]. Conclusions: APCS has a higher detection rate of advanced colorectal tumors than HRFQ. APCS combined with FIT can further improve the effectiveness of advanced colorectal tumor screening.

[Real-world data studies of medical products in the context of special healthcare policy: study designs and key considerations]

Boao Lecheng International Medical Tourism Pilot Area is the only administrative area in China where the pilot application of real-world data is performed. Based on the special healthcare policy in Boao Lecheng, conducting real-world data study to provide real-world evidence for the clinical evaluations and approvals of innovated medical products has become an important field that supports the reform of China's evaluation and approval system of medical products. Trustworthy real-world evidence needs to rely on both high-quality real-world data and reasonable and rigorous study designs. Based on the real-world data research guidelines and specifications issued by relevant academic research and regulatory authorities both at home and abroad, combined with the special policy environment of Boao Lecheng and previous practice experience, this paper summarizes the study designs of real world data in Boao Lecheng and discusses the key considerations of different study design in the context of special healthcare policies in Boao Lecheng in order to provide reference for the further study of real-world data.

Downregulation of GNAS inhibits osteogenesis of bone marrow mesenchymal stem cells and promotes osteoporosis through the Wnt pathway

OBJECTIVE

This study aims to explore the role of GNAS in accelerating the progression of osteoporosis by inhibiting osteogenesis of BMSCs by the Wnt pathway.

PATIENTS AND METHODS

GNAS levels in OP tissues and BMSCs undergoing osteogenesis for different time points were detected. Regulatory effects of GNAS on osteogenesis-related gene expressions, ALP activity, capability of mineralization, and activation of the Wnt pathway in BMSCs were assessed through a series of functional experiments. At last, rescue experiments were performed to further verify the significance of the Wnt pathway during GNAS-mediated osteogenesis development.

RESULTS

GNAS was downregulated in OP tissues relative to normal bone tissues. With the prolongation of osteogenesis, GNAS level gradually increased in BMSCs. Knockdown of GNAS downregulated expression levels of ALP and RUNX2, and attenuated ALP activity and capability of mineralization in BMSCs. GNAS was able to activate the Wnt pathway in BMSCs. Notably, overexpression of Wnt3a could reverse the regulatory effects of GNAS on osteogenesis-related gene expressions, ALP activity, and capability of mineralization in BMSCs.

CONCLUSIONS

Downregulation of GNAS suppresses osteogenesis of BMSCs through the Wnt pathway, thus aggravating the progression of osteoporosis.

Effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis by regulating Wnt/β-catenin signaling pathway

We aimed to explore the effects of probiotics on intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and to verify the Wnt/β-catenin signaling pathway that regulates this process. A total of 30 SD rats were randomly divided into 3 groups, namely, control group (n=10), model group (n=10) and probiotic group (n=10). Rats in the model group were used to construct liver cirrhosis models using carbon tetrachloride (CCL4) method, and those in the probiotic group were administered with probiotic preparations by gavage for 8 weeks. Then the feces of rats in each group were taken to detect the composition of intestinal flora, and changes in the content of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP-1) and interferon-gamma (IFN-γ), in peripheral blood collected were examined by enzyme-linked immunosorbent assay (ELISA). Next, changes in the degree of liver cirrhosis were analyzed by hematoxylin and eosin (H&E) staining, and the expression levels of the Wnt/β-catenin signaling pathway-related molecules, including β-catenin, glycogen synthase kinase (GSK)-3β and Frizzled-2, in liver tissues in each group were detected via polymerase chain reaction (PCR) and Western blotting (WB). Compared with rats in the control group, those in the model group had a disordered structure of hepatic lobule and hyperplasia of a large number of fibrous tissues. In contrast to those in the model group, the liver lobule structure was greatly improved, the edema cells were obviously reduced, and the hyperplasia of collagen fibers was remarkably alleviated in the probiotic group. Moreover, the degree of liver cirrhosis in the probiotic group was significantly reduced compared with that in the model group. Moreover, the rats in the model group exhibited a higher Bifidobacterium level in the intestinal tract, while those in the probiotic group displayed higher levels of microorganisms in the intestinal tract, such as Lachnospiraceae, Ruminococcaceae, Actinbacteria, Slackia and Pasteurellaceae. In comparison with that in the control group, the level of salt-tolerant Lactobacillus in the intestinal tract of rats in the model group was significantly decreased, while that in the probiotic group was partially increased (P=0.023). Meanwhile, some intestinal flora of rats in the control group, model group and probiotic group were closely correlated. Specifically, highly positive correlations were found between Bacteroidetes and Paraeggerthella (r=0.423, P=0.034) and between Firmicutes and Lactobacillus (r=0.318, P=0.027), but strongly negative associations were detected between Firmicutes and Paraeggerthella (r=-0.691, p=0.004) and between Paraeggerthella and Lactobacillus (r=-0.384, P=0.047). In addition, the levels of inflammatory cytokines TNF-α IL-6, MCP-1 and IFN-γ in the plasma of rats in the model group were markedly higher than those in the control group (P<0.05), whereas such levels in the probiotic group were decreased compared with those in the model group (P<0.05). PCR results revealed that the expression levels of β-catenin and Frizzled-2 in the model group were higher than those in the control group, whereas they were lower in the probiotic group than those in the model group (P<0.05). Furthermore, the model group had a decreased level of GSK-3β in comparison with the control group, but the probiotic group had a higher level of GSK-3β than the model group (P<0.05). WB results were consistent with PCR results. Probiotics can affect intestinal flora, inflammation and degree of liver cirrhosis in rats with liver cirrhosis, and its mechanism may be related to the Wnt/β-catenin signaling pathway.

[Relationship of early tumor shrinkage and depth of response with the prognosis and treatment effect of trastuzumab combined with chemotherapy as first-line treatment in advanced gastric cancer patients with epidermal growth factor receptor 2 positive]

Objective: To explore the relationship of early tumor shrinkage (ETS) and depth of response (DpR) with the prognosis and treatment effect of trastuzumab combined with chemotherapy as first-line treatment in advanced gastric cancer with epidermal growth factor receptor 2 (HER-2) positive. Methods: We retrospectively analyzed the clinical and pathological data of 23 patients with metastatic gastric adenocarcinoma diagnosed by imaging in The Second Affiliated Hospital of Zhejiang University School of Medicine from January 1st, 2008 to December 31th, 2017. Kaplan-Meier method and the log-rank test were used for the survival analysis. Cox regression was used to analyze the factors associated with prognosis. Results: The objective response rate (ORR) of the 23 patients was 43.5% and the disease control rate (DCR) was 82.6%. Univariate analysis showed the median progress-free survival (mPFS) of ETS≥20% and ETS<20% were 13.0 months and 4.5 months, respectively, with statistical significance (P<0.001). The median overall survival (mOS) of ETS≥20% and ETS<20% were 26.8 months and 10.1 months, respectively, with statistical significance (P<0.001). The median progress-free survival (mPFS) of DpR≥15% and DpR<15% were 13.0 months and 4.5 months, respectively, with statistical significance (P=0.001). The median overall survival (mOS) of DpR≥15% and DpR<15% were 26.8 months and 9.5 months, respectively, with statistical significance (P<0.001). Multivariable Cox regression analysis revealed ETS was an independent factor of PFS (P=0.030), tumor site and Eastern Cooperative Oncology Group (ECOG) score were independent factors of OS (P<0.05). Conclusion: ETS and DpR might be used to predict the treatment efficacy and prognosis of trastuzumab combined with chemotherapy as the first-line treatment of HER-2 positive gastric cancer.

Effect of LGR4 on synovial cells and inflammatory factors in rats with traumatic osteoarthritis

OBJECTIVE

Traumatic arthritis is one of the most common diseases in orthopedics. LGR4 is involved in bone formation and bone development. However, the role of LGR4 in synovial cells of rats with traumatic osteoarthritis has not been reported.

MATERIALS AND METHODS

Sprague Dawley (SD) rats were randomly divided into the control group and model group. The Real Time-Polymerase Chain Reaction (RT-PCR), Western blot, and Enzyme-Linked Immunosorbent Assay (ELISA) were used to analyze the expression of LGR4 in synovial tissue and synovial fluid. Synovial cells were isolated and cultured, followed by transfection of LGR4-pcDNA3.1 plasmid into cells. Cell proliferation was analyzed by MTT and EdU assay, and the Caspase-3 activity was assessed using the Caspase-3 activity kit. The secretion of the inflammatory factors interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) was detected by ELISA. NF-κB signaling pathway changes were evaluated by the Western blot.

RESULTS

In the model group, LGR4 mRNA expression in synovial tissue was significantly decreased, and the secretion of LGR4 in the synovial fluid was significantly decreased compared with the control group (p<0.05). LGR4 protein expression in the synovial membrane in the model group tissue was reduced. The transfection of LGR4-pcDNA3.1 plasmid into synovial cells promoted the LGR4 expression, inhibited the proliferation of synoviocytes, increased the Caspase-3 activity, the secretion of IL-1, TNF-α, and IL-6, as well as the decreased expression of NF-κB with a statistical significance, compared with the control group (p<0.05).

CONCLUSIONS

LGR4 expression is reduced in the rat model of traumatic osteoarthritis. The upregulation of LGR4 expression can inhibit the secretion of the inflammatory factors and inhibit the proliferation of the synovial cells by regulating NF-κB signaling pathway, which may alleviate the development of the joint inflammation.

AQP5 regulates the proliferation and differentiation of epidermal stem cells in skin aging

The epidermis, the outermost layer of the skin, is the first barrier that comes into contact with the external environment. It plays an important role in resisting the invasion of harmful substances and microbial infections. The skin changes with age and external environmental factors. This study aimed to investigate epidermal stem cells during the process of aging. This study enrolled 9 volunteers with benign pigmented nevus for clinical dermatologic surgery. The phenotypes associated with skin aging changes such as skin wrinkles and elasticity of the unexposed/healthy parts near benign pigmented skin were measured, and epidermal stem cells from this region were isolated for transcriptome sequencing. The results showed that epidermal stem cells could be obtained by magnetic activated cell sorting (MACS) with high purity. Results of the transcriptome sequencing revealed that aquaporin (AQP)5 significantly decreased in the epidermal stem cells with age, and further functional experiments revealed that AQP5 could promote the proliferation and dedifferentiation of HaCaT, but did not influence cell apoptosis. In summary, AQP5 regulated the proliferation and differentiation of epidermal stem cells in skin aging, and it may play an important role in the balance of proliferation and differentiation. However, further studies are needed to determine the mechanism by which AQP5 regulates the proliferation and differentiation of epidermal skin cells in aging.

[Typical case analysis of COVID-19 cluster epidemic in Shaanxi, 2020]

Objective: By analyzed the transmission patterns of 4 out of the 51 COVID-19 cluster cases in Shaanxi province to provide evidences for the COVID-19 control and prevention. Methods: The epidemiological data of RT-PCR test-confirmed COVID-19 cases were collected. Transmission chain was drawn and the transmission process was analyzed. Results: Cluster case 1 contained 13 cases and was caused by a family of 5 who traveled by car to Wuhan and returned to Shaanxi. Cluster case 2 had 5cases and caused by initial patient who participated family get-together right after back from Wuhan while under incubation period. Cluster case 3 contained 10 cases and could be defined as nosocomial infection. Cluster case 4 contained 4 cases and occurred in work place. Conclusion: Higher contact frequency and smaller places were more likely to cause a small-scale COVID-19 cluster outbreak, with potential longer incubation period. COVID-19 control strategies should turn the attention to infection prevention and control in crowded places, management of enterprise resumption and prevention of nosocomial infection.

[Analysis of transmission characteristics of COVID-19 in Shaanxi Province]

A total of 245 cases of COVID-19 in Shaanxi Province reported in the China information system for disease control and prevention as of February 24, 2020 were selected as the research objects, the cases are divided into imported cases (116 cases, 47.3%) and local cases (129 cases, 52.7%), their basic characteristics, time distribution, transmission mode, intergenerational interval and latent period transmission are analyzed. The age of local cases [(51.74±15.67) years old], female patients (69 cases, 53.5%), housework and retired staff (40 cases, 31.0%), and patients isolated at the time of onset (50 cases, 38.8%) were higher than imported cases, respectively[(40.66±15.41) years old, (45 cases, 38.8%), (21 cases, 18.1%), (17 cases, 14.6%)] (P values were < 0.05); The infection rate was 0.8% (31/3 666) in close contacts with local cases, which was lower than imported cases 2.0% (69/3 435) (P<0.001); The main source of infection in local cases was relatives (70 cases, 54.3%), and the main way of infection was living together and party (90 cases, 69.8%); the proportion of latent period transmission in our province was 15.5% (20 cases), and the interval between the second-generation case and the source of infection was about 4 days, and the interval between generations was about 6 days. In summary, the main way of infection of local cases in Shaanxi Province was living together and party, there were a certain proportion of latent period transmission cases at present, it's suggested that the investigation of close contacts should be started 4 days or earlier before the onset of the case.

[Epidemiological characteristics of COVID-19 in Shaanxi province]

Objective: To understand the incidence trend and epidemiological characteristics of COVID-19 in Shaanxi province. Methods: The incidence data of COVID-19 reported in Shaanxi as of 22 February, 2020 were collected for an epidemiological descriptive analysis. Results: A total of 245 confirmed cases of COVID-19 were reported in Shaanxi. Most cases were mild (87.76%). As time passed, the areas where confirmed cases were reported continued to increase. The case number in Xi'an was highest, accounting for nearly half of the total reported cases in the province. The epidemic pattern in Shaanxi had gradually shifted from imported case pattern to local case pattern, and the transmission of local cases was mainly based on family cluster transmission. The confirmed cases from different sources had caused the secondary transmission in Shaanxi. After February 7, the number of reported cases began to fluctuate and decrease stably, indicating a decrease-to-zero period. Conclusions: At present, the overall epidemic of COVID-19 in Shaanxi has gradually been mitigated. However, considering the approaching of return to work and study and the increasing of imported cases from other countries, the prevention and control of COVIS-19 in Shaanxi will face new challenges.

High-resolution imaging of the human incudostapedial joint using synchrotron-radiation phase-contrast imaging

The incudostapedial joint (ISJ) of the middle ear is important for proper transmission of sound energy to the cochlea. Recently, the biomechanics of the ISJ have been investigated using finite-element (FE) modelling, using simplified geometry. The objective of the present study was to investigate the feasibility of synchrotron-radiation phase-contrast imaging (SR-PCI) in visualising the ISJ ultrastructure. Three human cadaveric ISJs were dissected and scanned using SR-PCI at 0.9 µm isotropic voxel size. One of the samples was previously scanned at 9 µm voxel size. The images were visually compared and contrast-to-noise ratios (CNRs) were calculated (of both bone and soft tissues) for quantitative comparisons. The ISJ ultrastructure as well as adjacent bone and soft tissues were clearly visible in images with a 0.9 µm voxel size. The CNRs of the 0.9 µm images were relatively lower than those of the 9 µm scans, while the ratio of bone to soft tissue CNRs were higher, indicating better discernibility of bone from soft tissue in the 0.9 µm scans. This study was the first known attempt to image the ISJ ultrastructure using an SR-PCI scanner at submicron voxel size and results suggest that this method was successful. Future studies are needed to optimise the contrast and test the feasibility of imaging the ISJ in situ. LAY DESCRIPTION: The human middle ear consists of the eardrum, three small bones (the malleus, incus and stapes) and two joints connecting the bones (the incudostapedial joint and the incudomallear joint). The role of the middle ear is to amplify and transfer sound energy to the cochlea, the end organ of hearing. The incudostapedial joint (ISJ) of the middle ear is a synovial joint which is important for proper transmission of sound energy to the cochlea. Similar to other synovial joints it consists of meniscus, fluid and articulating surfaces. Recently, the biomechanics of the ISJ have been investigated using computational models, using grossly simplified geometry. Synchrotron radiation phase contrast imaging (SR-PCI) is a high-resolution imaging technique used to visualise small structures in three dimensions. The objective of the present study was to investigate the feasibility of using SR-PCI in visualising the ISJ ultrastructure. Three human cadaveric ISJs were dissected and scanned using SR-PCI at 0.9 µm isotropic voxel size. One of the samples was previously scanned at 9 µm voxel size. The images were both qualitatively and quantitatively compared. This study was the first known attempt to image the ISJ ultrastructure using an SR-PCI scanner at submicron voxel size and results suggest that this method was successful. Future studies are needed to optimise the contrast and feasibility of imaging the ISJ in situ.

Modulative effects of lncRNA TCONS_00202959 on autonomic neural function and myocardial functions in atrial fibrillation rat model

OBJECTIVE

Atrial fibrillation (AF) is a typical cardiac arrhythmia. The autonomic nervous system can modulate the myocardial system with complicated mechanisms. Long non-coding RNA (lncRNA) is involved in myocardial diseases, and lncRNA TCONS_00202959 is down-regulated in AF. However, the detailed effects of AF on automatic functions or cardiomyocytes are not well known yet.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were randomly divided into control group, AF group (which was prepared by injecting the acetylcholine-CaCl2 solution) and treatment group (receiving lentiviral transfection of lncRNA TCONS_00202959 on AF rats). Real Time-quantitative PCR (RT-PCR) was used to measure the expression of lncRNA TCONS_00202959. Atrial effective refractory period (AERP) and AF induction rate were measured, along with heart rate variability (HRV) analysis to reveal autonomic nervous function. The expression of tyrosine hydroxylase (TH) and choline acetyltransferase (CHAT) was analyzed in atrial tissues.

RESULTS

The expression of lncRNA TCONS_00202959 was decreased in the AF group compared to the control group (p < 0.05), which also had shortened AERP and elevated AF induction rate. The analysis of the autonomic nervous function revealed lower standard deviation of NN intervals (SDNN), SDNN of atrial (SDANN), root mean square of successive differences (RMSSD) and SDNN intervals in all 5-min segments (SDNNindx), plus elevated power ratio of low frequency (LF)/high frequency (HF). TH expression was increased whilst CHAT expression was decreased (p < 0.05). The treatment group showed enhanced expression of lncRNA TCONS_00202959, elongated AERP plus decreased AF induction rate. The treatment rats also had higher SDNN, SDANN, RMSSD and SDNNindx, lower LF/HF ratio, decreased TH expression and increased CHAT expression (p < 0.05 compared to the AF group).

CONCLUSIONS

AF rats had decreased expression of lncRNA TCONS_00202959, which can help to prevent AF pathogenesis by suppressing cardiac autonomic nervous function.

An MDS-specific frailty index based on cumulative deficits adds independent prognostic information to clinical prognostic scoring

The frailty index (FI) is based on the principle that the more deficits an individual has, the greater their risk of adverse outcomes. It is expressed as a ratio of the number of deficits present to the total number of deficits considered. We developed an MDS-specific FI using a prospective MDS registry and assessed its ability to add prognostic power to conventional prognostic scores in MDS. The 42 deficits included in this FI included measurements of physical performance, comorbidities, laboratory values, instrumental activities of daily living, quality of life and performance status. Of 644 patients, 440 were eligible for FI calculation. The median FI score was 0.25 (range 0.05-0.67), correlated with age and IPSS/IPSS-R risk scores and discriminated overall survival. With a follow-up of 20 months, survival was 27 months (95% CI 24-30.4). By multivariate analysis, age >70, FI, transfusion dependence, and IPSS were significant covariates associated with OS. The incremental discrimination improvement of the frailty index was 37%. We derived a prognostic score with five risk groups and distinct survivals ranging from 7.4 months to not yet reached. If externally validated, the MDS-FI could be used as a tool to refine the risk stratification of current clinical prognostication models.

The use of noncultured regenerative epithelial suspension for improving skin color and scars: A report of 8 cases and review of the literature

BACKGROUND

Regenerative Epithelial Suspension can lead to the restoration of wound and repigmentation, which can be gained by ReCell medical device to treat scar and depigmentation diseases.

OBJECTIVES

To report the effectivity of ReCell combined with microdermabrasion in scar and depigmentation diseases and review the literature of this new technology.

METHODS

We gave a differential donor⁄recipient ratio of about 1:20-30 with vitiligo, 1:40 with postburn construction, 1:80 with acne scar, and 1:120 with adult congenital melanocytic nevus, 1:80 with pediatrics, respectively. Photographs of patients before treatment and 3 months following the last treatment session were used to evaluate the effectivity.

RESULTS

A total of 8 patients including vitiligo vulgaris, postburn reconstruction, acne scars, and congenital melanocytic nevi treated by ReCell technology combined with microdermabrasion showed significant improvement in skin texture and color. And 17 studies of the research on ReCell technology were totally included in the systematic review.

CONCLUSION

Our investigation showed that Regenerative Epithelial Suspension gained by ReCell technology combined with microdermabrasion may improve scar and depigmentation diseases.

Dihydromyricetin attenuates hypertrophic scar formation by targeting activin receptor-like kinase 5

Hypertrophic scar (HPS) is a manifestation of abnormal tissue repair, representing excessive extracellular matrix production and abnormal function of fibroblasts, for which no satisfactory treatment is available at present. Here we identified a natural product of flavonoid, dihydromyricetin, could effectively attenuate HPS formation. We showed that local intradermal injection of dihydromyricetin (50 μM) reduced the gross scar area, cross-sectional size of the scar and the scar elevation index in a mechanical load-induced mouse model. In addition, dihydromyricetin treatment also markedly decreased collagen density of the scar tissue. Furthermore, both in vitro and in vivo study both demonstrated that dihydromyricetin inhibited the proliferation, activation, contractile and migration abilities of hypertrophic scar-derived fibroblasts (HSFs) but did not affect HSFs apoptosis. Western blot analysis revealed that dihydromyricetin could down-regulate the phosphorylation of Smad2 and Smad3 of TGF-β signaling. Such bioactivity of dihydromyricetin may result from its selective binding to the catalytic region of activin receptor-like kinase 5 (ALK5), as suggested by the molecular docking study and kinase binding assay (12.26 μM). Above all, dihydromyricetin may prove to be a promising agent for the treatment of HPS and other fibroproliferative disorders.

Patient-reported quality of life after endoscopic surgery for pituitary lesions: a meta-analysis

Patient-reported outcomes are now considered as an important part of overall outcome assessment of a surgical intervention. The objective of the current study was to evaluate the patient-reported quality of life (QoL) of the subjects of endoscopic pituitary surgery. A literature search was carried out in several electronic databases and study selection was based on pre-determined eligibility criteria. Meta-analyses of standardized mean difference (SMD) were conducted to observe significance of difference between preoperative and postoperative scores of important tools. Sixteen studies were included [931 patients; 51.16 years (95% CI 49.13, 53.19) age; 48.41 % (43.74, 53.08) males]. Generally, there was no significant differences between postoperative and preoperative health-related QoL after postoperative month 1 or after fourth postoperative month. QoL after endoscopic pituitary surgery remains unchanged predominantly but may deteriorate in regard to physical role and sinonasal outcome transiently.

Exendin-4 promotes proliferation of adipose-derived stem cells through PI3K/Akt-Wnt signaling pathways

Adipose-derived stem cell (ADSC) transplantation has emerged as a potential tool for the treatment of cardiovascular disease and skin wounds. However, with a limited renewal capacity and the need for mass cells during the engraftment, strategies are needed to enhance ADSC proliferative capacity. In this study, we explored the effects of Exendin-4, a glucagon-like peptide-1 analog, on the growth of ADSCs, focusing in particular on phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) and Wnt signaling pathways. Firstly, ADSCs were isolated and cultured in vitro. Then, flow cytometry demonstrated that ADSCs were positive for CD44, CD90 and CD29 but negative for CD31, CD34, and CD45. Exendin-4 (0-200 nM) treatment increased ADSC proliferation. In order to examine specific signaling pathways, a western blotting assay was performed. Our results demonstrate that after treated with 50 nM Exendin-4 for 48 h, the phosphorylation of PI3K, Akt, and GSK3β were increased and phosphorylation of β-catenin was decreased. From these results, we concluded that PI3K-Akt and Wnt-β-catenin signaling pathways mediate Exendin-4 induced ADSC proliferation, the function of which might contribute to the regulation of ADSC proliferation. Our findings provided new insights into the function of the mechanisms underlying Exendin-4 of ADSCs.

Rapamycin Protects Skin Fibroblasts from Ultraviolet B-Induced Photoaging by Suppressing the Production of Reactive Oxygen Species

BACKGROUND/AIMS

Ultraviolet B (UVB) irradiation alters multiple molecular pathways in the skin, thereby inducing skin photoaging. Murine dermal fibroblasts (MDFs) were subjected to a series of 4 sub-cytotoxic UVB doses (120 mJ/cm2), resulting in changes in cell shape, DNA damage, cell cycle arrest, extracellular matrix variations, reactive oxygen species (ROS) generation, and alterations in major intracellular antioxidant and cellular autophagy levels. Rapamycin (RAPA) is a new macrolide immunosuppressive agent that is primarily used in oncology, cardiology, and transplantation medicine and has been found to extend the lifespan of genetically heterogeneous mice. Several studies have shown that RAPA may have anti-aging effects in cells and organisms. Thus, in this study, we explored the effects and mechanisms of RAPA against the photoaging process using a well-established cellular photoaging model.

METHODS

We developed a stress-induced premature senescence (SIPS) model through repeated exposure of MDFs to ultraviolet B (UVB) irradiation. The cells were cultured in the absence or presence of RAPA for 48 h. Senescent phenotypes were assessed by examining cell viability, cell morphology, senescence-associated β-galactosidase (SA-β-gal) expression, cell cycle progression, intracellular ROS production, matrix metalloproteinase (MMP) synthesis and degradation, extracellular matrix (ECM) component protein expression, alterations in major intracellular antioxidant levels, and the cellular autophagy level.

RESULTS

Compared with the UVB group, pretreatment with RAPA (5 µM) significantly decreased the staining intensity and percentage of SA-β-gal-positive cells and preserved the elongated cell shape. Moreover, cells pretreated with RAPA showed inhibition of the reduction in the type I collagen content by blocking the UVB-induced upregulation of MMP expression. RAPA also decreased photoaging cell cycle arrest and downregulated p53 and p21 expression. RAPA application significantly attenuated irradiation-induced ROS release by modulating intracellular antioxidants and increasing the autophagy level.

CONCLUSIONS

Our study demonstrated that RAPA elicited oxidative damage in vitro by reducing ROS accumulation in photoaged fibroblasts. The anti-aging effect can be attributed to the maintenance of normal antioxidant and cellular autophagy levels. However, determination of the definitive mechanism requires further study.

[Application of Ischemia Modified Albumin for Acute Ischemic Heart Disease in Forensic Science]

OBJECTIVES

To explore the application value and forensic significance of ischemia modified albumin （IMA） in pericardial fluid to diagnose sudden cardiac death.

METHODS

IMA level in pericardial fluid was detected in acute ischemic heart disease group （n=36）, acute myocardial infarction group （n=6）, cardiomyopathy group （n=4） and control group （n=15） by albumin cobalt binding method. The levels of IMA were compared among these groups. The best cut-off IMA value was estimated and the sensitivity and specificity of acute myocardial ischemia group was distinguished from control group by receiver operating characteristics （ROC） curve.

RESULTS

The IMA level in acute ischemic heart disease group was significantly higher than that of control group （P<0.05）. Compared with acute myocardial infarction group and cardiomyopathy group, the IMA level in acute ischemic heart disease group had no significant difference （P>0.05）. The cut-off value for the identification of acute myocardial ischemia which obtained by ROC analysis was 40.65 U/mL. And the sensitivity and specificity for distinguishing acute ischemia cardiac disease was 60.0% and 80.5%, respectively.

CONCLUSIONS

The IMA value in pericardial fluid can be a reference marker for the diagnosis of acute myocardial ischemia, which also can provide objective basis for the forensic identification of sudden cardiac death.