[Analysis of prognostic factors of pediatric kidney transplantation]

Objective: To evaluate the short-and mid-term efficacy of pediatric kidney transplantation and the risk factors for kidney graft and recipient. Methods: The baseline data and postoperative complications of pediatric donors and recipients of 284 kidney transplants were retrospectively analyzed in the Department of Kidney Transplantation in the First Affiliated Hospital of Zhengzhou University from August 2010 to May 2021 and all subjects were followed up until December 31, 2021. According to the survival status of donors and recipients, they were divided into the graft-loss group and the graft-survival group, and the recipient death group and survival group, respectively. Univariate comparison between groups was performed by Log-rank test, and Cox proportional risk model was used to explore the independent risk factors for the graft and recipient survival. Results: Among the 284 children recipients, 184 cases (64.8%) were male and 100 cases(35.2%) were female, and 19 cases (6.7%) were living relative donor renal transplantation, 19 cases (6.7%) were preemptive transplantation, and 8 cases were secondary transplantation. The age of 284 recipients at the time of transplantation was 13.0 (9.0, 15.0) years, among whom 29 cases aged 0-6 years, 96 cases aged 7-11 years old, and 159 cases aged 12-18 years. The 1, 3, and 5 year survival rates were 92.3%, 88.9% and 84.8% for the kidney grafts, and were 97.1%, 95.6% and 94.4% for the recipients, respectively. Multivariate analysis showed postoperative acute rejection (HR=3.14, 95%CI 1.38-7.15, P=0.006) and perioperative vascular complications (HR=4.73, 95%CI 2.03-11.06, P<0.001) were independent risk factors for the survival of kidney graft. Postoperative infection (HR=14.23, 95%CI 3.45-58.72, P<0.001) was an independent risk factor for the postoperative mortality of recipients. Conclusions: Pediatric kidney transplantation shows a good short-and mid-term prognosis. Postoperative acute rejection and perioperative vascular complications are the risk factors for the survival of kidney graft, and postoperative infection is the risk factor affecting the survival of recipient.

Epidemiological characteristics and pathological changes of primary glomerular diseases

Objective

By analyzing the pathological characteristics and clinical data of renal biopsy in our hospital in the past 20 years, to further understand the epidemic characteristics and pathological changes of primary glomerular disease, and to provide regional data for the big data of kidney disease in my country.

Methods

A retrospective analysis of 9448 patients with primary glomerular disease who were hospitalized in our hospital from January 1, 2000 to December 31, 2019, aged 18 years or older, and undergoing renal biopsy. Divided every 5 years into a group, a total of 4 groups (first group 2000.1.1–2004.12.31, second groups 2005.1.1–2009.12.31; third groups 2010.1.1–2014.12.31, fourth groups 2015.1.1–2019.12.31).

Results

① There were more males than females, and male: female vs 1.53:1. The proportion of men in the past five years has increased compared with the previous 15 years. ② Mostly middle-aged, with a median age of 41.39 years old. The age is increasing over time. There are differences between the four groups, P <0.001; ③ The most common clinical manifestations are nephrotic syndrome, followed by chronic glomerulonephritis. Occult glomerulonephritis, the proportion of patients with nephrotic syndrome increases over time, first to fourth group (40.08%< 42.64% < 47.08%< 53.69%); ④ The most common pathology type from 2000 to 2009 was mesangial proliferative glomerulonephritis. IgA nephropathy was the most common type from 2010 to 2014, but the proportion of membranous nephropathy increased year by year, and it became the most common pathological type from 2015 to 2019; ⑤ The clinical and pathological manifestations of different genders are different, but there is no statistical difference.

Conclusion

In the past 20 years, the primary glomerular disease is mainly middle-aged. There are more men than women. The most common type of clinical manifestation is nephrotic syndrome. The pathological type is mesangial proliferative glomerulonephritis. Over time, the average age is increasing, and the proportion of patients with renal syndrome is increasing. IgA nephropathy is the most common pathological type from 2010 to 2014, and membranous nephropathy has become the main pathological type in the past 5 years.

Multicentric reticulohistiocytosis with prominent skin lesions and arthritis: A case report

BACKGROUND

Multicentric reticulohistiocytosis (MRH) is a rare non-Langerhans histiocytosis of unknown etiology characterized by papulonodular skin lesions and progressive, erosive arthritis. To date, there have been approximately 300 cases of MRH reported worldwide. The majority of patients are Caucasian from western countries, and Asian patients are rare. Here, we report a case of MRH in a Chinese patient.

CASE SUMMARY

A 38-year-old male was admitted to the hospital with a rash that had persisted for over 2 years and bilateral knee pain for over 1 year. The patient’s symptoms had previously been misdiagnosed as eczema when there were only skin symptoms and was finally diagnosed as MRH after a skin biopsy of the left upper back. The patient was treated with glucocorticoids combined with an immunosuppressive regimen. While the skin lesions on both arms, abdomen, and back subsided, the skin lesions on the rest of the body did not increase. The interphalangeal joints of both thumbs and bilateral knee joints remained swollen and painful.

CONCLUSION

The case will help clinicians better identify and treat this disease in the absence of epidemiological studies or randomized controlled data.

Complete genome sequence of Bacillus velezensis WB, an isolate from the watermelon rhizosphere: Genomic insights into its antifungal effects

OBJECTIVES

Here, we report the complete genome of strain WB, isolated from the rhizosphere of a healthy watermelon from a Fusarium wilt diseased field, which possesses antifungal activity against Fusarium oxysporum f. sp. niveum (Fon) and reduces the incidence of Fusarium wilt in watermelon.

METHODS

Genome sequences were determined using the Illumina HiSeq and PacBio platforms. Genome assembly was performed by Unicycler software. Gene clusters responsible for secondary metabolite biosynthesis were predicted using antiSMASH.

RESULTS

The size of the genome was 3 896 799 base pairs, and there were 3 977 coding DNA sequences (CDSs). The G+C content of the circular genome was 46.65%, and there were 27 rRNAs and 86 tRNAs. Strain WB was finally designated Bacillus velezensis based on phylogenomic analyses. In addition, 13 gene clusters were related to the synthesis of antimicrobial secondary metabolites, including surfactin, fengycin, iturin, bacillibactin, bacilysin, bacillaene, and butirosin.

CONCLUSIONS

The complete genome sequence of strain WB reported here will be a valuable reference for studying the biocontrol mechanisms of Fusarium wilt in watermelon.

Quantum Dots Tracking Endocytosis and Transport of Proteins Displayed by Mammalian Cells

Mammalian cell display technology uses eukaryotic protein expression system to display proteins on cell surfaces and has become an important method in biological research. Although mammalian cell display technology has many advantages and development potential, certain attributes of the displayed protein remain uncharacterized, such as whether the displayed proteins re-enter the cell and how displayed proteins move into the cell. Here, we present the endocytosis mechanism, motility behavior, and transport kinetics of displayed proteins determined using HaloTag as the displayed protein and quantum dot-based single-particle tracking. The displayed protein enters the cell through clathrin-mediated endocytosis and is transported through the cell in three stages, which is dependent on microfilaments and microtubules. The dynamic information obtained in this study provides answers to questions about endocytosis and postendocytosis transport of displayed proteins and, therefore, is expected to facilitate the development of surface display technology.

Three-dimensional self-supporting superstructured double-sided nanoneedles arrays of iron carbide nanoclusters embedded in manganese, nitrogen co-doped carbon for highly efficient oxygen reduction reaction

Nitrogen- and transition metal-dual doped carbon materials with low cost and high catalytic performances are considered as one of promising alternatives for noble metal catalysts in acceleration of oxygen reduction reaction (ORR). In this work, three-dimensional (3D) self-supporting superstructures of iron carbide (Fe₃C) nanoclusters entrapped in manganese (Mn)- and nitrogen (N)-dual doped carbon nanosheets covered with double-sided nanoneedles carbon arrays (Fe₃C/Mn,N-NCAs) are simply synthesized by a coordination pyrolysis method, in which dicyandiamide mainly behaves as nitrogen source and 1-(2-pyridylazo)-2-naphthol (PAN) as carbon source. Integration of the unique 3D self-supporting superstructures and synergistic effects of the multi-compositions, the as-obtained catalyst displays appealing ORR performance such as the much positive onset potential (E_onset = 0.98 V vs. RHE) and half-wave potential (E_1/2 = 0.88 V vs. RHE), as well as a just 10 mV negative shift in E_1/2 after 2000 cycles, surpassing commercial Pt/C. This work provides some valuable perspectives for preparation of high-efficiency and low-cost non-noble metal ORR electrocatalysts in energy transformation and storage correlated systems.

[Analysis of hemagglutinin-neuraminidase gene characteristics of human parainfluenza virus type 3 among children with acute respiratory tract infection in Qingdao city]

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.

Uncovering the F-Actin-Based Nuclear Egress Mechanism of Newly Synthesized Influenza A Virus Ribonucleoprotein Complexes by Single-Particle Tracking

Nuclear trafficking of viral genome is an essential cellular process in the life cycles of viruses. Despite substantial progress in uncovering a wide variety of complicated mechanisms of virus entry, intracellular transport of viral components, virus assembly, and egress, the temporal and spatial dynamics of viral genes trafficking within the nucleus remains poorly understood. Herein, using single-particle tracking, we explored the real-time dynamic nuclear trafficking of influenza A virus (IAV) genes packaged as the viral ribonucleoprotein complexes (vRNPs) by combining a four-plasmid DNA transfection system for the reconstruction of green fluorescent protein (GFP)-labeled vRNPs and a spinning disk super-resolution fluorescence microscope. We found that IAV infection significantly induced the formation of actin microfilaments (F-actin) in the nucleus. In combination with the fluorescent protein-tagged nuclear F-actin probe, we visualized the directed movement of GFP-labeled vRNPs foci along the nuclear F-actin with a speed of 0.18 μm/s, which is similar to the microfilaments-dependent slow directed motion of IAVs in the cytoplasm. The disruption of nuclear F-actin after treatment with microfilament inhibitors caused a considerable decrease in vRNPs motility and suppressed the nuclear export of newly produced vRNPs, indicating that the slow, directed movement plays a crucial role in facilitating the nuclear egress of vRNPs. Our findings identified a nuclear F-actin-dependent pathway for IAV vRNPs transporting from the nucleus into the cytoplasm, which may in turn uncover a novel target for antiviral treatment.

How different are the surfaces of semiconductor Ag2Se quantum dots with various sizes?

The surface of nanocrystals plays a dominant role in many of their physical and chemical properties. However, controllability and tunability of nanocrystal surfaces remain unsolved. Herein, we report that the surface chemistry of nanocrystals, such as near-infrared Ag₂Se quantum dots (QDs), is size-dependent and composition-tunable. The Ag₂Se QDs tend to form a stable metal complex on the surface to minimize the surface energy, and therefore the surface chemistry can be varied with particle size. Meanwhile, changes in surface inorganic composition lead to reorganization of the surface ligands, and the surface chemistry also varies with composition. Therefore, the surface chemistry of Ag₂Se QDs, responsible for the photoluminescence (PL) quantum yield and photostability, can be tuned by changing their size or composition. Accordingly, we demonstrate that the PL intensity of the Ag₂Se QDs can be tuned reversely by adjusting the degree of surface Ag⁺ enrichment via light irradiation or the addition of AgNO₃. This work provides insight into the control of QD surface for desired PL properties.

Near-Infrared-II Quantum Dots for In Vivo Imaging and Cancer Therapy

In vivo fluorescence imaging can perform real-time, noninvasive, and high spatiotemporal resolution imaging to accurately obtain the dynamic biological information in vivo, which plays significant roles in the early diagnosis and treatment of cancer. However, traditional in vivo fluorescence imaging usually operates in the visible and near-infrared (NIR)-I windows, which are severely interfered by the strong tissue absorption, tissue scattering, and autofluorescence. The emergence of NIR-II imaging at 1000-1700 nm significantly breaks through the imaging limitations in deep tissues, due to less tissue scattering and absorption. Benefiting from the outstanding optical properties of NIR-II quantum dots (QDs), such as high brightness and good photostability, in vivo fluorescence imaging exhibits excellent temporal-spatial resolution and large penetration depth, and QDs have become a kind of promising fluorescent biomarkers in the field of in vivo fluorescence imaging. Herein, the authors review NIR-II QDs from preparation to modification, and summarize recent applications of NIR-II QDs, including in vivo imaging and imaging-guided therapies. Finally, they discuss the special concerns when NIR-II QDs are shifted from in vivo imaging applications to further in-depth applications.

Potentials of straw return and potassium supply on maize (Zea mays L.) photosynthesis, dry matter accumulation and yield

Maize (Zea mays L.) is considered one of the most important grains in the world. Straw return has the effect of reducing soil bulk density and increasing soil porosity. Straw returning and potassium fertilizer can supplement soil potassium content. The improvement of soil structure and the optimization of soil nutrient levels provide a good environment for high yield and high efficiency of maize. Therefore, three field experiments were carried out over a three-year period (2018-2020) to study the effects of straw returning on photosynthesis, dry matter accumulation and yield of maize 'Xianyu 335' under two different fertilization methods and four potassium application levels. The results showed that straw returning and potassium application had significant effects on the above indicators. The above indicators were significantly improved by deep tillage straw returning compared with no tillage straw returning. Increasing potassium supply can promote the effect of straw returning. The photosynthesis, dry matter accumulation and yield parameters of maize treated with straw returning and deep tillage combined with 60 kg/hm2 potassium fertilizer (SFK60) reached the highest in the three harvest seasons. The corn planting profit of SFK45 treatment is the highest, which is $1868.92 per ha. Therefore, SFK45 is an effective way to ensure stable and high yield of corn and maximize farmers' income.

Essential role of MALAT1 in reducing traumatic brain injury

As a highly evolutionary conserved long non-coding RNA, metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was first demonstrated to be related to lung tumor metastasis by promoting angiogenesis. To investigate the role of MALAT1 in traumatic brain injury, we established mouse models of controlled cortical impact and cell models of oxygen-glucose deprivation to mimic traumatic brain injury in vitro and in vivo. The results revealed that MALAT1 silencing in vitro inhibited endothelial cell viability and tube formation but increased migration. In MALAT1-deficient mice, endothelial cell proliferation in the injured cortex, functional vessel density and cerebral blood flow were reduced. Bioinformatic analyses and RNA pull-down assays validated enhancer of zeste homolog 2 (EZH2) as a downstream factor of MALAT1 in endothelial cells. Jagged-1, the Notch homolog 1 (NOTCH1) agonist, reversed the MALAT1 deficiency-mediated impairment of angiogenesis. Taken together, our results suggest that MALAT1 controls the key processes of angiogenesis following traumatic brain injury in an EZH2/NOTCH1-dependent manner.

Spatiotemporal Quantification of Endosomal Acidification on the Viral Journey

Many enveloped viruses utilize endocytic pathways and vesicle trafficking to infect host cells, where the acidification of virus-containing endosomes triggers the virus-endosome fusion events. Therefore, simultaneous correlation of intracellular location, local pH, and individual virus dynamics is important for gaining insight into viral infection mechanisms. Here, an imaging approach is developed for spatiotemporal quantification of endosomal acidification on the viral journey in host cells using a fluorescence resonance energy transfer based ratiometric pH sensor consisting of a photostable and high-brightness QD, pH-sensitive fluorescent dyes, and virus-binding proteins. Ratiometric analysis of sensor-based single-virus tracking data enables to dissect a two-step endosomal acidification process during the infection of influenza viruses and elucidates the occurrence of the fission and sorting of virus-containing endosomes to recycling endosomes after initial acidification. This technique should serve as a robust approach for in situ quantification of endosomal acidification on the viral journey.

Low-Frequency Vibration Promotes Tumor Necrosis Factor-α Production to Increase Cartilage Degeneration in Knee Osteoarthritis

OBJECTIVE

Low-frequency vibration accelerates cartilage degeneration in knee osteoarthritis (KOA) rat model. In this article, we investigated whether whole-body vibration (WBV) increases cartilage degeneration by regulating tumor necrosis factor-α (TNF-α) in KOA.

DESIGN

Proteomics analysis was used to filter candidate protein from synovial fluid (SF) in KOA people after WBV. Enzyme-linked immunosorbent assay (ELISA) was used to estimate changes in TNF-α levels in SF. The C57 mice and TNF-α knock-out mice were sacrificed for the KOA model and WBV intervention. The cartilage was tested by ELISA, histology, terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL), immunohistochemistry, and reverse transcriptase polymerase chain reaction. Luciferase activity test in vitro study was conducted to confirm the relationship between TNF-α and the candidate protein.

RESULTS

Differentially expressed proteins were enriched in the glycolytic process, glucose catabolic, and regulation of interleukin-8 (IL-8) secretion processes. Phosphoglycerate kinase, triosephosphate isomerase 1, T cell immunoglobulin- and mucin-domain-containing molecules 2, fumarylacetoacetate hydrolase (FAH), and TNF were the hub node. TNF-α expression increased in SF after WBV (P < 0.05). The cartilage was more degenerated in the TNF-α^-/- mice group compared to controls. A significant change was observed in collagen II and FAH (P < 0.05). TNF-α expression improved in C57 mice (P < 0.05). Apoptosis of chondrocytes was inhibited in TNF-α^-/- mice by the TUNEL test. Luciferase activity significantly increased in TNF-α + FAH-Luc cells (P < 0.05).

CONCLUSION

A novel mechanism underlying WBV-triggered cartilage degeneration was found in KOA that demonstrated the critical regulatory function of TNF-α and FAH during WBV.

Band-selective Holstein polaron in Luttinger liquid material A0.3MoO3 (A = K, Rb)

(Quasi-)one-dimensional systems exhibit various fascinating properties such as Luttinger liquid behavior, Peierls transition, novel topological phases, and the accommodation of unique quasiparticles (e.g., spinon, holon, and soliton, etc.). Here we study molybdenum blue bronze A_0.3MoO₃ (A = K, Rb), a canonical quasi-one-dimensional charge-density-wave material, using laser-based angle-resolved photoemission spectroscopy. Our experiment suggests that the normal phase of A_0.3MoO₃ is a prototypical Luttinger liquid, from which the charge-density-wave emerges with decreasing temperature. Prominently, we observe strong renormalizations of band dispersions, which are recognized as the spectral function of Holstein polaron derived from band-selective electron-phonon coupling in the system. We argue that the strong electron-phonon coupling plays an important role in electronic properties and the charge-density-wave transition in blue bronzes. Our results not only reconcile the long-standing heavy debates on the electronic properties of blue bronzes but also provide a rare platform to study interesting excitations in Luttinger liquid materials.

Arthroscopic Reconstruction of the Posterior Cruciate Ligament with a Ligament-advanced Reinforcement System and Hamstring Tendon Autograft: A Retrospective Study

OBJECTIVE

Both ligament-advanced reinforcement system (LARS) and hamstring tendon autograft can serve as grafts for posterior cruciate ligament (PCL) reconstruction. However, few studies have compared the effectiveness of these two approaches. This study therefore aimed to compare the clinical efficacy of arthroscopic reconstruction of the PCL using either the LARS or hamstring tendon autograft.

METHODS

A total of 36 patients who underwent PCL reconstruction were retrospectively analyzed. Within this cohort, 15 patients received a reconstruction using the LARS (LARS group) and 21 using the hamstring tendon autograft (HT group).

RESULTS

The pre- and post-operative subjective scores and knee stability were evaluated and the patients were followed up for a period of 2 to 10.5 years (4.11±2.0 years on average). The last follow-up showed that functional scores and knee stability were significantly improved in both groups (P<0.05). Six months after operation, Lysholm scores and IKDC subjective scores were higher in the LARS group than in the HT group (P<0.05). Nonetheless, the last follow-up showed no significant differences in the functional scores or the posterior drawer test between the two groups (P>0.05). In the LARS and HT groups, 12 and 9 patients, respectively exhibited KT1000 values <3 mm, with the difference being statistically significant (P<0.05). In the HT group, the diameter of the four-strand hamstring tendon was positively correlated with height (P<0.05), which was 7.37±0.52 mm in males and 6.50±0.77 mm in females (P<0.05).

CONCLUSION

Both LARS and hamstring tendon approaches achieved good efficacy for PCL reconstruction, but patients in the LARS group exhibited faster functional recovery and better knee stability in the long term. LARS is especially suitable for those who hope to resume activities as early as possible.

Water-Soluble High-Quality Ag2Te Quantum Dots Prepared by Mutual Adaptation of Synthesis and Surface Modification for In Vivo Imaging

Near-infrared (NIR) in vivo fluorescence imaging has exhibited the distinct advantage of high optical resolution at deeper penetration into biological tissues. Ag₂Te quantum dots (QDs), with a relatively narrow band gap, show great promise for fluorescence emission at long wavelengths in the second near-infrared (NIR-II) window for bioimaging. However, existing Ag₂Te QDs have severely hindered the application of in vivo bioimaging due to their poor fluorescence brightness and stability, so it is important to prepare Ag₂Te QDs with high quantum yield and stability as well as high biocompatibility in the NIR-II window. Herein, we designed an integrated method for the preparation of water-soluble Ag₂Te QDs by mutual adaptation of QD synthesis and surface modification. We first synthesized high-quality Ag₂Te QDs with different NIR-II emission wavelengths and the photoluminescence quantum yields (PLQYs) up to 6.51% by rapidly injecting the TBP-Te precursor into a hot solvent to form a highly fluorescent Ag₂Te core. Then water-dispersible Ag₂Te QDs were obtained by direct exchange of the hydrophobic Ag₂Te QD surface ligands with thiol ligands. The PLQY of the water-soluble Ag₂Te QDs obtained by this method can still be maintained at 4.94%. With these highly bright and stable Ag₂Te QDs, the abdominal vessels, hindlimb arterial vessels, venous vessels, sacral lymph nodes, and tumor vessels were visualized non-invasively in vivo in the NIR-II window in mice. The results demonstrate that the integrated strategy of QD synthesis and modification provides valuable technical support for further in-depth applications of Ag₂Te QDs.

Regulatory effects of miR-138 and RUNX3 on Th1/Th2 balance in peripheral blood of children with cough variant asthma

OBJECTIVES

To study the expression levels of microRNA-138 (miR-138) and Runt-related transcription factor 3 (RUNX3) in peripheral blood of children with cough variant asthma (CVA) and their regulatory effects on Th1/Th2 balance.

METHODS

Sixty-five children with CVA (CVA group) and 30 healthy children (control group) were enrolled. Peripheral venous blood samples were collected for both groups, and CD4⁺ T cells were isolated and cultured. Enzyme-linked immunosorbent assay was used to measure the levels of interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-5, and IL-13 that were secreted by CD4⁺ T cells. Flow cytometry was used to determine the percentages of Th1 and Th2 cells. Quantitative real-time PCR was used to measure the level of RUNX3 mRNA in CD4⁺ T cells and the level of miR-138 in peripheral blood. Western blot was used to determine the protein expression of RUNX3 in CD4⁺ T cells. The dual-luciferase reporter assay was used to determine the targeting effects of miR-138 and RUNX3. The RUNX3-mimic plasmid was transfected into CD4⁺ T cells, and the effects on the levels of IFN-γ, IL-2, IL-4, IL-5, and IL-13 and the percentages of Th1 and Th2 cells were measured.

RESULTS

Compared with the control group, the CVA group showed significantly decreased levels of IFN-γ and IL-2 from CD4⁺ T cells, significantly increased levels of IL-4, IL-5, and IL-13 from CD4⁺ T cells, significantly decreased Th1 cell percentage and Th1/Th2 ratio, and a significantly increased Th2 cell percentage (P<0.05). The CVA group showed significantly lower relative expression levels of RUNX3 mRNA and protein in CD4⁺ T cells in peripheral blood than the control group (P<0.001). The relative expression level of miR-138 was significantly higher in the CVA group than in the control group (P<0.001). MiR-138 could target the expression of RUNX3. Upregulating the expression of RUNX3 in CD4⁺ T cells induced significantly increased levels of IFN-γ and IL-2, significantly decreased levels of IL-4, IL-5, and IL-13, significantly increased Th1 cell percentage and Th1/Th2 ratio, and a significantly decreased Th2 cell percentage (P<0.05).

CONCLUSIONS

MiR-138 regulates Th1/Th2 balance by targeting RUNX3 in children with CVA, providing a new direction for the treatment of CVA.

Artificial-regulated synthesis of nanocrystals in live cells

Live cells, as reservoirs of biochemical reactions, can serve as amazing integrated chemical plants where precursor formation, nucleation and growth of nanocrystals, and functional assembly can be carried out accurately following an artificial program. It is crucial but challenging to deliberately direct intracellular pathways to synthesize desired nanocrystals that cannot be produced naturally in cells, because the relevant reactions exist in different spatiotemporal dimensions and will never encounter spontaneously. This article summarizes progress in the introduction of inorganic functional nanocrystals into live cells via the ‘artificial-regulated space–time-coupled live-cell synthesis’ strategy. We also describe ingenious bio-applications of the nanocrystal–cell systems, and quasi-biosynthesis strategies expanded from live-cell synthesis. Artificial-regulated live-cell synthesis—which involves the interdisciplinary application of biology, chemistry, nanoscience and medicine—will enable researchers to better exploit the unanticipated potentialities of live cells and open up new directions in synthetic biology.

[Investigation of contamination of SARS-CoV-2 in imported frozen seafood from a foreign cargo ship and risk factors for infection in stevedores in Qingdao]

Objective: To investigate the contamination status of SARS-CoV-2 in imported frozen seafood from a Russia cargo ship in Qingdao and to analyze the risk factors for infection in local stevedores. Methods: The method of "two-stage, full coverage and mixed sampling" was used to collect the seafood packaging samples for the nucleic acid detection of SARS-CoV-2 by real-time fluorescent quantitative RT-PCR. A unified questionnaire was designed to investigate 71 stevedores in two shifts through telephone interview. The stevedores were divided into two groups, with 23 in the shit with two infections was group A and 48 in the shift without infection was group B. Software Epi Info7.2 was used to identify the risk factors for SARS-CoV-2 infections in the stevedores. Results: In the frozen seafood from a Russia cargo ship, the total positive rate of SARS-CoV-2 nucleic acid in the frozen seafood was 11.53% (106/919). The positive rate of SARS-CoV-2 nucleic acid in the frozen seafood unloaded by group A (14.29%,70/490) was significantly higher than that in the frozen seafood unloaded by group B (8.39%,36/429)(χ²=7.79,P=0.01) and the viral loads detected in the frozen seafood unloaded by group A were higher than those detected in the frozen seafood unloaded by group B. The scores of personal protection and behaviors in the stevedores in group A were significantly lower than those in group B (P<0.05), and toilet use, smoking and improper hand washing before meals were the risk factors for the infection. Conclusions: The imported frozen seafood was contaminated by SARS-CoV-2 and the contamination distribution was uneven. Supervision and management of personal occupational protection and behaviors of workers engaged in imported frozen food transportation should be strengthened. It is suggested that a closed-loop monitoring and management system for the whole process of "fishing-transport- loading/unloading" should be established by marine fishery authority.

Proximity-induced exponential amplification reaction triggered by proteins and small molecules

We proposed a method to regulate nucleic acid polymerization by proximity and designed an ultrasensitive biosensor based on proximity-induced exponential amplification reaction for proximity assay of proteins (streptavidin) and small molecules (adenosine triphosphate), which allows us to detect a variety of interesting targets by simply changing the binding sites of DNA.

LncRNA HCP5 in hBMSC-derived exosomes alleviates myocardial ischemia reperfusion injury by sponging miR-497 to activate IGF1/PI3K/AKT pathway

Ischemia/reperfusion (I/R) injury is an inevitable process during heart transplant and suppressing I/R injury could greatly improve the survival rate of recipients. Mesenchymal stem cells (MSCs) have positive effects on I/R. We aimed to investigate the mechanisms underlying the protective roles of MSCs in I/R. Both cell model and rat model of myocardial I/R were used. MTT assay and flow cytometry were used to measure cell viability and apoptosis, respectively. QRT-PCR and western blotting were employed to measure levels of lncRNA HCP5 (HLA complex P5), miR-497, apoptosis-related proteins, and insulin-like growth factor (IGF1)/PI3K/AKT pathway. Dual luciferase assay was used to validate interactions of HCP5 and miR-497, miR-497 and IGF1. Echocardiography was performed to evaluate cardiac function of rats. Serum levels of CK-MB and LDH were measured. H&E and Masson staining were used to examine morphology of myocardial tissues. hBMSC-derived exosomes (hBMSC-Exos) increased the viability of cardiomyocytes following hypoxia/reperfusion (H/R) and decreased apoptosis. H/R diminished HCP5 expression in cardiomyocytes while hBMSC-Exos recovered the level. Overexpression of HCP5 in hBMSC-Exos further enhanced the protective effects in H/R while HCP5 knockdown suppressed. HCP5 directly bound miR-497 and miR-497 targeted IGF1. miR-497 mimics or si-IGF1 blocked the effects of HCP5 overexpression. Further, hBMSC-Exos alleviated I/R injury in vivo and knockdown of HCP5 in hBMSC-Exos decreased the beneficial effects. AntagomiR-497 blocked the effects of HCP5 knockdown. HCP5 from hBMSC-Exos protects cardiomyocytes against I/R injury via sponging miR-497 to disinhibit IGF1/PI3K/AKT pathway. These results shed light on mechanisms underlying the protective role of hBMSC-Exos in I/R.

Quantum Dots: A Promising Fluorescent Label for Probing Virus Trafficking

Recent research has highlighted the immense potential of the quantum dot (QD)-based single-virus tracking (SVT) technique in virology. In these experiments, the infection behaviors of single viruses or viral components, labeled with QDs, could be tracked on time scales of milliseconds to hours in host cells. The trajectories of individual viruses are reconstructed with nanometer accuracy, and the underlying dynamic information on virus infection can be extracted to uncover the infection mechanisms of viruses. Therefore, QD-based single-virus tracking (QSVT) is an exquisitely selective and powerful approach to investigating how viruses are internalized in host cells dynamically to release their genome for viral replication and assembly that ensure the completion of viral life cycles.QDs are better candidates than organic dyes and fluorescent proteins for virus labeling and subsequent SVT due to the following considerations: (i) the high brightness of QDs makes it possible to label a virus with sufficient brightness using very few QDs or even just one QD; (ii) the extraordinary photostability of QDs allows one to track the infection process long term and quantify low probability events; (iii) the color-tunable emission property of QDs ensures multicolor labeling of various components of a virus simultaneously; and (iv) the abundant surface ligands of QDs facilitate the conjugation of a virus with a variety of labeling strategies. Therefore, the photoproperties of QDs make it possible to perform multicolor long-term SVT experiments quantitatively. Nowadays, the QD-based SVT (QSVT) technique has made prodigious achievements in unraveling the entry, trafficking, and uncoating mechanisms of viruses. This fascinating technique can provide spatiotemporal dynamic information on the viral journey in unprecedented detail and has revolutionized our understanding of virus infection.In this Account, we first introduce the advantages and the limitations of conventional SVT in virological research and the unique features of QDs as labels in the SVT field. We subsequently focus on the principles and related methods of QSVT and the current state of QD chemistry and QD-based virus labeling that resolves many issues associated with the tracking of individual viruses in live cells. Then we emphasize some new findings by this technique in the study of infection mechanisms. Finally, we will provide our insights into future challenges on this topic. With this Account, we hope to further stimulate the development of QSVT with a combined effort from different disciplines and, more importantly, to accelerate the applications of QSVT in virological research.