[Quality control of perioperative management after radical surgery for locally advanced gastric cancer]

Gastric cancer is a common malignant tumor in China. Most gastric cancer patients are already in the locally advanced stage when they seek medical treatment. Radical surgery is the main treatment for gastric cancer. The quality control of postoperative perioperative management is of great significance in improving the surgical treatment effect and the quality of life of patients. This article systematically summarizes seven aspects, including diet and nutrition management, antimicrobial drug management, pain management, prophylactic anticoagulation management, airway management, postoperative complication management, and discharge and follow-up management, establishes clear quality standards, and achieves the goals of reducing postoperative complications, standardizing perioperative medication use, reducing hospitalization time and costs, thereby reducing patient burden and improving the economic and social benefits of medical institutions.

Cross-reaction mediated by distinct key amino acid combinations in the complementary-determining region (CDR) of a monoclonal antibody

In immunology, cross-reaction between antigens and antibodies are commonly observed. Prior research has shown that various monoclonal antibodies (mAbs) can recognize a broad spectrum of epitopes related to influenza viruses. However, existing theories on cross-reactions fall short in explaining the phenomena observed. This study explored the interaction characteristics of H1-74 mAb with three peptides: two natural peptides, LVLWGIHHP and LPFQNI, derived from the hemagglutinin (HA) antigen of the H1N1 influenza virus, and one synthetic peptide, WPFQNY. Our findings indicate that the complementarity-determining region (CDR) of H1-74 mAb comprised five antigen-binding sites, containing eight key amino acid residues from the light chain variable region and 16 from the heavy chain variable region. These critical residues formed distinct hydrophobic or hydrophilic clusters and functional groups within the binding sites, facilitating interaction with antigen epitopes through hydrogen bonding, salt bridge formation, and π-π stacking. The study revealed that the formation of the antibody molecule led to the creation of binding groups and small units in the CDR, allowing the antibody to attach to a variety of antigen epitopes through diverse combinations of these small units and functional groups. This unique ability of the antibody to bind with antigen epitopes provides a new molecular basis for explaining the phenomenon of antibody cross-reaction.

3D collagen porous scaffold carrying PLGA-PTX/SDF-1α recruits and promotes neural stem cell differentiation for spinal cord injury repair

Spinal Cord Injury (SCI), one of the major factors of disability, can cause irreversible motor and sensory impairment. There are no effective therapeutic drugs and technologies available in domestic or foreign countries currently. Neural stem cells (NSCs), with the potential for multidirectional differentiation, are a potential treatment for SCI. However, it has been demonstrated that NSCs primarily differentiated into astrocytes rather than neurons due to the inflammatory microenvironment, and the current challenge remains to direct the differentiation of NSCs into neurons in the lesion site. It was reported that the microtubule-stabilizing agent paclitaxel (PTX) was able to promote the differentiation of NSCs into neurons rather than astrocytes after SCI. SDF-1α can recruit NSCs and thus guide the migration of stem cells. In this study, we developed a functional collagen scaffold by loading SDF-1α and nanoparticle-encapsulated PLGA-PTX into a 3D collagen porous scaffold, allowing for slow release of PTX. When the functional scaffolds were implanted into the injury site, it provided a neural regeneration conduit channel for the migration of NSCs and neuronal differentiation. Neural regeneration promoted the recovery of motor function and reduced glial scar formation after SCI. In conclusion, a 3D collagen porous scaffold combined with PLGA-PTX and SDF-1α is a promising therapeutic strategy for SCI repair.

pH/Temperature Responsive Curcumin-Loaded Micelle Nanoparticles Promote Functional Repair after Spinal Cord Injury in Rats via Modulation of Inflammation

BACKGROUND

The formation of an inhibitory inflammatory microenvironment after spinal cord injury (SCI) remains a great challenge for nerve regeneration. The poor local microenvironment exacerbates nerve cell death; therefore, the reconstruction of a favorable microenvironment through small-molecule drugs is a promising strategy for promoting nerve regeneration.

METHODS

In the present study, we synthesized curcumin-loaded micelle nanoparticles (Cur-NPs) to increase curcumin bioavailability and analyzed the physical and chemical properties of Cur-NPs by characterization experiments. We established an in vivo SCI model in rats and examined the ability of hind limb motor recovery using Basso-Beattie-Bresnahan scoring and hind limb trajectory assays. We also analyzed neural regeneration after SCI using immunofluorescence staining.

RESULTS

The nanoparticles achieved the intelligent responsive release of curcumin while improving curcumin bioavailability. Most importantly, the released curcumin attenuated local inflammation by modulating the polarization of macrophages from an M1 pro-inflammatory phenotype to an M2 anti-inflammatory phenotype. M2-type macrophages can promote cell differentiation, proliferation, matrix secretion, and reorganization by secreting or expressing pro-repair cytokines to reduce the inflammatory response. The enhanced inflammatory microenvironment supported neuronal regeneration, nerve remyelination, and reduced scar formation. These effects facilitated functional repair in rats, mainly in the form of improved hindlimb movements.

CONCLUSION

Here, we synthesized pH/temperature dual-sensitive Cur-NPs. While improving the bioavailability of the drug, they were also able to achieve a smart responsive release in the inflammatory microenvironment that develops after SCI. The Cur-NPs promoted the regeneration and functional recovery of nerves after SCI through anti-inflammatory effects, providing a promising strategy for the repair of SCIs.

Multi-Omics Analysis Reveals the Gut Microbiota Characteristics of Diarrheal Piglets Treated with Gentamicin

The involvement of alterations in gut microbiota composition due to the use of antibiotics has been widely observed. However, a clear picture of the influences of gentamicin, which is employed for the treatment of bacterial diarrhea in animal production, are largely unknown. Here, we addressed this problem using piglet models susceptible to enterotoxigenic Escherichia coli (ETEC) F4, which were treated with gentamicin. Gentamicin significantly alleviated diarrhea and intestinal injury. Through 16s RNS sequencing, it was found that gentamicin increased species richness but decreased community evenness. Additionally, clear clustering was observed between the gentamicin-treated group and the other groups. More importantly, with the establishment of a completely different microbial structure, a novel metabolite composition profile was formed. KEGG database annotation revealed that arachidonic acid metabolism and vancomycin resistance were the most significantly downregulated and upregulated pathways after gentamicin treatment, respectively. Meanwhile, we identified seven possible targets of gentamicin closely related to these two functional pathways through a comprehensive analysis. Taken together, these findings demonstrate that gentamicin therapy for diarrhea is associated with the downregulation of arachidonic acid metabolism. During this process, intestinal microbiota dysbiosis is induced, leading to increased levels of the vancomycin resistance pathway. An improved understanding of the roles of these processes will advance the conception and realization of new therapeutic and preventive strategies.

Engineering and Purification of Microcin C7 Variants Resistant to Trypsin and Analysis of Their Biological Activity

Microcin C7 (McC) as a viable form of antimicrobial has gained substantial attention due to its distinctive antimicrobial activity, by targeting aspartyl tRNA synthetase. McC can be a potential solution against pathogenic microbial infections in the postantibiotic era. However, considering that degradation by digestive enzymes can disrupt the function of this peptide in the gastrointestinal tract, in this study, we attempt to design McC variants to overcome several barriers that may affect its stability and biological activity. The mccA gene encoding the McC peptide precursor was mutated and 12 new McC variants with trypsin resistance were found. The Yej+rimL- strain was used as an indicator to determine the minimum inhibitory concentrations (MICs). The results showed that three variants, including R2A, R2T and R2Q, among 12 variants formed by the replacement of the second arginine of the McC peptide with different amino acids, were resistant to trypsin and had an outstanding antimicrobial ability, with MIC values of 12.5, 25, and 25 μg/mL, respectively. Taken together, our findings show that the engineering of the site-directed mutagenesis of McC significantly enhances McC trypsin resistance and maintains a great antimicrobial activity.

Dissecting Sperm Mitochondrial G-Quadruplex Structures Using a Fluorescent Probe Biomarker to Monitor and Regulate Fertilization Capability

To monitor the levels of mitochondrial DNA G-quadruplexes (mtDNA G4s) in spermatozoa and to explore the possibility using mtDNA G4s as a reliable marker in patients with multiple clinical insemination failures, a novel chemical TPE-mTO probe engineered in our previous work was used on both samples from the mice sperm and from patients with fertilization failure. Expression of valosin-containing protein and the zona-free hamster egg assay were used to evaluate mitophagy and human sperm penetration. RNA-sequencing was used to explore expression changes of key genes affected by mtDNA G4s. Results showed that the probe can track mtDNA G4s in spermatozoa easily and quickly with fewer backgrounds. Significantly increased mtDNA G4s were also found in patients with fertilization failure, using the flow-cytometry-based TPE-mTO probe detection method. A sperm-hamster egg penetration experiment showed that abnormal fertilization caused by increased mtDNA G4s can be effectively restored by a mitophagy inducer. This study provides a novel method for monitoring etiological biomarkers in patients with clinical infertility and treatment for patients with abnormal fertilization caused by mtDNA G4 dysfunction.

Disc regeneration by injectable fucoidan-methacrylated dextran hydrogels through mechanical transduction and macrophage immunomodulation

Modulating a favorable inflammatory microenvironment that facilitates the recovery of degenerated discs is a key strategy in the treatment of intervertebral disc (IVD) degeneration (IDD). More interestingly, well-mechanized tissue-engineered scaffolds have been proven in recent years to be capable of sensing mechanical transduction to enhance the proliferation and activation of nucleus pulposus cells (NPC) and have demonstrated an increased potential in the treatment and recovery of degenerative discs. Additionally, existing surgical procedures may not be suitable for IDD treatment, warranting the requirement of new regenerative therapies for the restoration of disc structure and function. In this study, a light-sensitive injectable polysaccharide composite hydrogel with excellent mechanical properties was prepared using dextrose methacrylate (DexMA) and fucoidan with inflammation-modulating properties. Through numerous in vivo experiments, it was shown that the co-culture of this composite hydrogel with interleukin-1β-stimulated NPCs was able to promote cell proliferation whilst preventing inflammation. Additionally, activation of the caveolin1-yes-associated protein (CAV1-YAP) mechanotransduction axis promoted extracellular matrix (ECM) metabolism and thus jointly promoted IVD regeneration. After injection into an IDD rat model, the composite hydrogel inhibited the local inflammatory response by inducing macrophage M2 polarization and gradually reducing the ECM degradation. In this study, we propose a fucoidan-DexMA composite hydrogel, which provides an attractive approach for IVD regeneration.

Evaluation of Effectiveness and Safety of Microcin C7 in Weaned Piglets

The effects and safety of dietary supplementation with Microcin C7 (C7) were evaluated in 216 weaned piglets. The pigs were given a control corn−soybean meal basal diet or C7 diet (control diet supplemented with 250, 500, 750, 1000, or 5000 mg C7/kg diets). Compared with the control group, the 500 mg/kg C7 supplementation group had better intestinal morphological indicators (p < 0.05), which may help maintain intestinal epithelial function and increase the growth performance (p < 0.05) and apparent total tract digestibility (p < 0.05). The diarrhea indexes of the 250, 500, and 750 mg/kg groups were significantly lower than that of the control group at 0−28 d (p < 0.05), and the 500 mg/kg group had the lowest diarrhea indexes (linear and quadratic, p < 0.05). A comprehensive analysis showed that microbial structure was significantly correlated with the degree of diarrhea, and the diarrhea-alleviating effect of C7 may be related to its selective regulation of specific microbial taxa. The 250 and 500 mg/kg C7 supplementation also significantly improved several immune indices of piglets (p < 0.05). Compared with the control diet, 5000 mg/kg C7 supplementation had no significant adverse effect on all parameters. Overall, the 250−500 mg/kg dose had the best effect, and the highest dose (5000 mg/kg) posed no toxicity risk. Therefore, C7 appears safe for use as an alternative to antibiotic growth promoters in weaned piglets.

Are we ready for the revision of the 14-day rule? Implications from Chinese legislations guiding human embryo and embryoid research

The ISSCR recently released new guidelines that relaxed the 14-day rule taking away the tough barrier, and this has rekindled relevant ethical controversies and posed a fresh set of challenges to each nation's legislations and policies directly or indirectly. To understand its broad implications and the variation and impact of China's relevant national policies, we reviewed and evaluated Chinese laws, administrative regulations, departmental rules, and normative documents on fundamental and preclinical research involving human embryos from 1985 to 2022 in this paper. We have historically examined whether these regulations, including a 14-day rule, had restrictions on human embryo research, and whether and how these policies affected human embryo and embryoid research in China. We also discussed and assessed the backdrop in which China has endeavored to handle such as the need for expanding debates among justice practice, academia, and the public, and the shifting external environment influenced by fast-developing science and technology and people's culture and religions. In general, Chinese society commonly opposes giving embryos or fetuses the legal status of humans, presumably due to the Chinese public not seeming to have any strong religious beliefs regarding the embryo. On this basis, they do not strongly oppose the potential expansion of the 14-day rule. After the guidelines to strengthen governance over ethics in science, and technology were released by the Chinese government in 2022, Chinese policymakers have incorporated bioethics into the national strategic goals using a "People-Centered" approach to develop and promote an ecological civilization. Specifically, China follows the "precautionary principle" based on ethical priority as it believes that if scientific research carries any potential technological and moral risks on which no social ethical consensus has been attained, there would be a need to impose oversight for prevention and precaution. At the same time, China has adopted a hybrid legislative model of legislation and ethical regulations with criminal, civil and administrative sanctions and a 14-day limit specified within its national hESCs guidelines. This would certainly be a useful example for other countries to use when considering the possibility of developing a comprehensive, credible and sustainable regulatory framework.

The novel BRDT inhibitor NHWD870 shows potential as a male contraceptive in mice

Small molecule inhibitors of the bromodomain and extraterminal domain (BET) family proteins have emerged as promising options not only for the treatment of multiple cancers but also for disturbing the process of sperm maturation with potential for use as viable contraceptive targets. In this study, we find that the BET family inhibitor NHWD870 and BRDT can bind well in vitro through bioinformatics software prediction and protein binding inhibition experiments. NHWD870 can produce a good contraceptive effect through animal experiments in vivo, and the fertility can be restored to normal after drug withdrawal. Transcriptomics and proteomics results suggest that NHWD870 affects pathways related to spermatogenesis and maturation, further contributing to the male infertility phenotype. Our results show that NHWD870 can induce a complete and reversible contraceptive effect in mice, which is stronger than that of JQ1 and its synthesized derivatives. This study is expected to eventually lead to clinical trials.

Correlation between novel compound heterozygous ADAMTSL4 variants and primary phenotypes of ectopia lentis et pupillae

PURPOSE

To investigate molecular pathogenesis of congenital ectopia lentis accompanied by various ophthalmic manifestations in a pedigree.

METHODS

Three female siblings, their spouse and offspring underwent ophthalmic and general medical examinations. Genetic variants were screened with the whole exome sequencing and analyzed in either a dominant or recessive inheritance manner. Gene mutations were ascertained with the Sanger sequencing after the polymerase chain reaction.

RESULTS

All three female siblings were diagnosed as the Ectopia lentis et pupillae (ELeP) through combination of clinical examination and genetic analysis. No characteristic pathological changes of skeletal, metabolic and cardiac abnormalities were observed. Thirteen genetic variants were selected out through analyzing in the dominant or recessive inheritance manner, but they were not associated with EL. Among them, ALOX15B variant may explain the skin disease in this pedigree. After inspection the known genes related to EL, novel compound heterozygous mutations (p.Ser264LeufsX37/p.Gly757ValfsX62) in ADAMTSL4 were discreetly identified in this ELeP pedigree.

CONCLUSIONS

Novel compound heterozygous ADAMTSL4 variants are responsible for ELeP in the current pedigree. Correlation between ADAMTSL4 variants and ELeP was firstly established based on our 12 years follow-up studies and previous reports of ELeP and of ADAMTSL4-related eye disorders. The primary phenotypes caused by ADAMTSL4 variants include EL, EP, poor pupillary dilation, and axial elongation. Highly varying phenotypes including glaucoma, high myopia retinapathy, and poor vision and so on may be the secondary impairments. All these secondary impairments may be improved if proper clinical interventions are implemented in time.

Effectiveness and safety evaluation of graded levels of N-carbamylglutamate in growing-finishing pigs

The aim of this study was as follows: 1) to investigate the effects of graded levels of N-carbamylglutamate (NCG) on performance, blood biochemical indexes, carcass traits and related indicators in growing-finishing pigs, and 2) to determine the optimal supplemental level. The toxicity of high-dose (much higher than recommended levels) NCG was assessed by routine blood tests and blood biochemical and histopathologic examinations of the heart, liver, spleen, lung, kidney and stomach. One hundred and forty-four growing-finishing pigs (Duroc × Large White × Landrace, 32.24 ± 1.03 kg) were used in a 74-d experiment and each treatment was replicated 6 times with 4 pigs (2 barrows and 2 gilts) per replicate. The dietary treatments were a corn-soybean meal basal diet supplemented with 0% (control), 0.05%, 0.1%, 0.15%, 0.2% or 1% NCG. The first 5 groups were used to explore the optimal supplemental level of NCG, while the control, 0.1% and 1% NCG groups were used to explore the safety of high-dose NCG. Compared with the normal control group, the final body weight and average daily gain tended to be higher in the 0.1% group (P = 0.08), the lean percentage tended to be higher in the 0.05% group (P = 0.07), the levels of free amino acids in the blood significantly increased in the 0.1% group (P < 0.05), both 0.1% and 0.15% NCG supplementation increased the levels of nitric oxide (NO) in serum (P = 0.07) and muscle growth- and lipid metabolism-related gene expression (P < 0.05) and NCG supplementation improved C18:1N9C monounsaturated fatty acids (MUFA) in a dose-dependent manner (P = 0.08). In addition, routine blood tests, blood biochemical indexes and histopathological examination revealed no abnormalities. Overall, increasing the levels of NCG did not linearly improve the above indicators; the 0.1% dose showed the best effect, and a high dose (1%) did not pose a toxicity risk.

Reconsidering the need for gain-of-function research on enhanced potential pandemic pathogens in the post-COVID-19 era

The dual-use risk of infectious disease research using enhanced potential pandemic pathogens (ePPP), particularly gain-of-function (GOF) research, has been debated since 2011. As of now, research is supported on the condition that the research plan is reviewed and the actual experiment is supervised. However, the kinds of research conducted and what benefits they have brought to our society have not been adequately verified. Nevertheless, due to the COVID-19 pandemic that began at the end of 2019 and caused numerous deaths and wide economic disruption, the importance of infectious disease control from an international perspective has been recognized. Although complete control of the pandemic is still far off, positive signs include generating epidemiological trends based on genome analysis, therapeutic drug and vaccine development, clinical patient management, and public health policy interventions. In this context, the time has come to reconsider the true significance of GOF research on ePPP and the state of research governance in the post-COVID-19 era. In particular, the risks of such research are clearer than before, whereas its benefits seem less apparent. In this paper, we summarize the history of discussions on such GOF research, its significance in the light of the current COVID-19 pandemic, and the direction we shall take in the future.

A loss-of-function variant in SSFA2 causes male infertility with globozoospermia and failed oocyte activation

Globozoospermia (OMIM: 102530) is a rare type of teratozoospermia (< 0.1%). The etiology of globozoospermia is complicated and has not been fully revealed. Here, we report an infertile patient with globozoospermia. Variational analysis revealed a homozygous missense variant in the SSFA2 gene (NM_001130445.3: c.3671G > A; p.R1224Q) in the patient. This variant significantly reduced the protein expression of SSFA2. Immunofluorescence staining showed positive SSFA2 expression in the acrosome of human sperm. Liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) and Coimmunoprecipitation (Co-IP) analyses identified that GSTM3 and Actin interact with SSFA2. Further investigation revealed that for the patient, regular intracytoplasmic sperm injection (ICSI) treatment had a poor prognosis. However, Artificial oocyte activation (AOA) by a calcium ionophore (A23187) after ICSI successfully rescued the oocyte activation failure for the patient with the SSFA2 variant, and the couple achieved a live birth. This study revealed that SSFA2 plays an important role in acrosome formation, and the homozygous c.3671G > A loss-of-function variant in SSFA2 caused globozoospermia. SSFA2 may represent a new gene in the genetic diagnosis of globozoospermia, especially the successful outcome of AOA-ICSI treatment for couples, which has potential value for clinicians in their treatment regimen selections.

Towards Better Governance on Biosafety and Biosecurity: China’s Advances and Perspectives in Medical Biotechnology Legislation

In this paper, we systematically investigated and assessed China’s evolving medical biotechnology legislative and regulatory regime. 89 laws, rules, measures, guidelines, and views from 1985 to 2022 were systematically analogized and 28 were found to be involved in medical biotechnology legislation, including the recently passed Biosecurity Law. We classified the legislations and performed a comparative analysis for their legal binding based on the legal subject and extent of application, then further analyzes some of the legislative challenges in governing medical biotechnology risks in the context of China’s upgrading its regulatory and legal regime in the last 3 years. We concluded that policymakers in China have now incorporated medical biotechnology-related biosafety and biosecurity into the national strategic goals of a “People-Centered” approach to establish and foster an ecological civilization, particularly in the aftermath of the “He Jiankui affair.” Instead of relying on a patchwork of existing regulations and measures relating to the emerging field of medical biotechnology, China is attempting to integrate a patchwork of existing regulations and measures into a comprehensive legal framework, such as the constitution, National Security Law, Biosecurity Law, administrative regulations, departmental and local rules, and has begun to use the Civil Code and Criminal Law to explicitly identify actions relating to medical biotechnology. In general, China follows the “precautionary principle” as it thinks that uncertainty in science and technology should not be used to justify delaying the adoption of measures to prevent injuries or dangers, stating that whoever advances biotechnology must face the burden of proof of no harm. There would be a need to impose oversight for prevention and precaution if any biotechnology breakthrough that carries risks on which no scientific consensus has been reached. We argued that the “top-down” formulation of general objectives by the active political leadership and “bottom-up” innovation in the implementation are the keys to achieving these goals. Given the rapid advancements in medical biotechnology, countries all over the world must examine the governance landscape around biosafety and biosecurity and quickly consider options for their own comprehensive, credible, and long-lasting regulatory frameworks and experiences learned from China’s governance will help chart a scalable future roadmap.

[Characteristics and risk factors of functional constipation in children aged 0-4 years in Xi 'an]

Objective: To investigate the epidemiology, characteristics and risk factors of functional constipation (FC) in children aged 0-4 years in Xi'an. Methods: From October, 2020 to June, 2021, a prevalence survey was conducted among 2 615 children aged 0-4 years in Xi'an by group sampling. The related factors of FC were investigated by questionnaire designed based on Rome Ⅳ diagnostic criteria.The children were divided into FC group and non-FC group. The prevalence, symptoms and signs of FC were analyzed, and its risk factors were analyzed by multivariate Logistic regression. Results: A total of 2 985 valid questionnaires were handed out, and 2 711 (90.8%) were received back. A total of 2 615 questionnaires were valid, with an effective rate of 96.5%. There were 1 338 males (51.2%) and 1 277 females (48.8%). There were 260 cases in FC group and 2 355 cases in non-FC group. The prevalence of FC in children aged 0-4 years in Xi 'an was 10.6%.There were significant differences in FC prevalence among children of different ages and sex (χ²=14.58,4.39, both P<0.05), but not in urban or rural residence (χ²=3.29, P=0.070). The main symptoms of FC group in the last month were large-diameter feces (73.5%, 191/260), painful defecation or dry and hard defecation (65.8%, 171/260). In the last month, FC group had higher incidences of the Bristol type 1, 2 and 3 stool, fecal retention, prolonged defecation, abdominal pain and incomplete defecation compared with non-FC group, with statistical significance (all P<0.05). Parental history of childhood constipation (OR=2.13, 95%CI 1.55-2.92), fever in the last month (OR=1.86, 95%CI 1.32-2.63), history of constipation (OR=3.24, 95%CI 2.46-4.26) and taking probiotics in the last month (OR=1.45, 95%CI 1.11-1.91) were risk factors of FC in children aged 0-4 years. Stratified with age, the results showed that complementary feeding earlier than 5 months of age or later than 6 months of age (OR=2.42, 95%CI 1.13-5.20), dry stools during the complementary feeding (OR=11.27, 95%CI 5.15-24.66), history of constipation (OR=2.29, 95%CI 1.23-4.29) and taking probiotics in the last month (OR=1.88, 95%CI 1.10-3.23) were risk factors of FC in children aged 0-<1 year, and breastfeeding (OR=0.53, 95%CI 0.29-0.94) was a protective factor of FC in children aged 0-<1 year. Family members' recent constipation history (OR=2.02, 95%CI 1.06-3.85) and past history of constipation (OR=3.06, 95%CI 1.74-5.38) were FC risk factors for children aged 1-<2 years. Parental history of childhood constipation (OR=3.12, 95%CI 2.00-4.85), frequency of eating vegetables less than 3 times per week (OR=3.28, 95%CI 2.00-5.38), history of constipation (OR=3.66, 95%CI 2.42-5.53) and taking antibiotics in the last month (OR=1.65, 95%CI 1.06-2.55) were risk factors for FC in children aged 2-4 years. Conclusions: FC in children aged 0-4 years in Xi'an is mainly manifested with large-diameter feces and painful defecation or dry and hard defecation in the last month. It is associated with a variety of risk factors, which are different in different age groups.

Implication of a de novo Variant in ciliary rootlet coiled- coil (CROCC) with assimilation of atlas (AOA)

Assimilation of atlas is a rare skeletal malformation causing nerve compression with high risk of fatal. However, the genetic etiology of assimilation of atlas AOA is currently lacking. In this paper, the whole-exome sequencing (WES) analysis was employed to study a Chinese family having a sporadic proband son of assimilation of atlas AOA but other healthy family members. We identified a novel variant in ciliary rootlet coiled-coil gene (NM_014675.5 (CROCC): c.4702C>T (r.4702c>u, p.(Arg1568Cys)). The variant had different genotypes between the proband and healthy family members but with high conservations of “damage” to protein structure based on MutationTaster and SIFT prediction. CROCC gene can be obtained in both healthy (n=220) and non-mutated assimilation of atlas AOA patient samples (n=68) but absented in five sporadic patients with the novel variant. Furthermore, abnormal of cilia was observed after editing the target sequence on CROCC using CRISPR-Cas9. These results suggested that assimilation of atlas AOA might be caused by the mutation of CROCC: c.4702C>T (r.4702c>u, p.(Arg1568Cys)). With strong amino acid conservation and interaction regulation, the variant mutation could cause the signal disorder of skeletal development which may lead to the defective bone formation and finally cause the development of assimilation of atlas AOA.

[P4HA2 promotes occurrence and progression of liver cancer by regulating the PI3K/Akt/mTOR signaling pathway]

OBJECTIVE

To investigate the role of proline 4-hydroxylase Ⅱ (P4HA2) in the occurrence and progression of liver cancer.

METHODS

GEPIA and Human Protein Atlas database were used to predict the expression of P4HA2 in hepatocellular carcinoma (HCC), and K-M plotter online database was used to analyze the relationship between P4HA2 expression and the prognosis of HCC. We also examined the expressions of P4HA2 in HCC cells and normal hepatocytes using qRT-PCR and Western blotting. With lentivirus-mediated RNA interference, P4HA2 expression was knocked down in hepatoma SNU-449 and Hep-3B cells, and the changes in cell proliferation, migration and invasion were assessed using cell counting kit-8 (CCK-8) assay, colony formation test, scratch test and Transwell assay. The changes in the expressions of epithelial-mesenchymal transition (EMT) and PI3K/Akt/mTOR signal pathway-related proteins were detected using Western blotting.

RESULTS

Online database analysis showed that the expression of P4HA2 was significantly higher in HCC tissues than in normal liver tissues (P < 0.05). The expression levels of P4HA2 mRNA and protein were also significantly higher in HCC cell lines than in normal hepatocytes (P < 0.01). Lentivirus-mediated RNA interference of P4HA2 significantly lowered the expression levels of P4HA2 mRNA and protein in the hepatoma cells (P < 0.05) and caused obvious inhibition of cell proliferation, migration and invasion. P4HA2 knockdown significantly increased the expression of E-cadherin protein, lowered the expressions of N-cadherin and Snail, and obviously decreased the expressions of phosphorylated PI3K, AKT and mTOR (P < 0.05).

CONCLUSION

P4HA2 enhances the proliferation, migration, invasion, and EMT of hepatoma cells by activating the PI3K/Akt/mTOR signaling pathway to promote the occurrence and progression of liver cancer.

Dynamic changes in the thermal growing season and their association with atmospheric circulation in China

Vegetation phenology is one of the key agroclimatic indices that is sensitive to climate change. Analyzing the variation in plant phenology under a changing environment can provide reference information to assess the impact of climate change on ecosystems and agricultural management. In this study, we focused on the thermal growth season, an important phenology index. We defined four growing season indices based on the surface temperature to quantify the changes in thermal growth season and analyze their association with atmospheric circulation in China. The results showed that the start date of the growing season exhibited a significant advanced trend (P < 0.001), while the end date exhibited a significant delayed trend (P < 0.001). The length of growing season and the number of ≥ 10℃ days increased significantly in China (P < 0.001) from 1960 to 2018. The variation in thermal growth season differed in different regions. The Qinghai-Tibet Plateau and the Loess Plateau were the regions in which thermal growing season was the most sensitive to climate changes. Atmospheric circulation was one of the main factors affected the change in thermal growing season indices. The West Pacific Subtropical High Intensity Index and the Arctic Oscillation Index significantly negatively correlated with the start date of the growing season (P < 0.05), and significantly positively correlated with the length of growing season and the number of ≥ 10℃ days (P < 0.01). Atmospheric circulation affected the change in temperature and subsequently affected the thermal growth season. These findings will provide useful information to assess the risk assessment of climate change and take action to reduce in the impact of climate change on ecosystems and agricultural management.

Biosynthetic Microcin J25 Exerts Strong Antibacterial, Anti-Inflammatory Activities, Low Cytotoxicity Without Increasing Drug-Resistance to Bacteria Target

Multidrug resistant (MDR) bacterial infection has emerged, raising concerns about untreatable infections, and posing the highest health risks. Antimicrobial peptides (AMPs) are thought to be the best remedy for this problem. Here, we showed biosynthetic microcin J25 (MccJ25) exhibited excellent bactericidal activity against standard and clinically relevant veterinary MDR strains with high stability, no cytotoxicity, and no increase in drug resistance. Analysis of antimicrobial mechanism possessed by sensitive enterotoxigenic Escherichia coli (ETEC) based on electron microscopy and Sytox Green methods was carried out. Results showed excellent activity against ETEC was due to permeabilizing bacterial membranes and strong affinity. MccJ25 exhibited high endotoxin-neutralizing activity in both in vivo and in vitro environments, and mice exposed to lipopolysaccharide (LPS) showed decreased plasma LPS levels and improved survival after administration of MccJ25. In an LPS-treated mouse septicemia model, MccJ25 treatment significantly alleviated inflammatory responses by inhibiting proinflammatory factor secretion and expression. In a mouse E. coli infection model, administration of MccJ25 effectively improved host defense against clinically source cocktail of multidrug-resistant E. coli strains induced intestinal inflammation and bacteria dissemination. Results of studies on anti-inflammatory mechanisms showed that MccJ25 downregulated nuclear factor kappa B kinase and mitogen-activated protein kinase, thereby reducing the production of toll-like receptor 4, myeloid differentiation factor 88 and decreasing the key proinflammatory cytokines. These findings clarify MccJ25 may be an ideal antibacterial/antiendotoxic drug candidate that has the potential to further guide the development of anti-inflammatory and/or antimicrobial agents in the war against MDR bacterial infection.

Effects of Antimicrobial Peptide Microcin C7 on Growth Performance, Immune and Intestinal Barrier Functions, and Cecal Microbiota of Broilers

Microcin C7 is an antimicrobial peptide produced by Escherichia coli, composed of a heptapeptide with a modified adenosine monophosphate. This study was performed to evaluate the effects of Microcin C7 as a potential substrate to traditional antibiotics on growth performance, immune functions, intestinal barrier, and cecal microbiota of broilers. In the current study, 300 healthy Arbor Acres broiler chicks were randomly assigned to one of five treatments including a corn-soybean basal diet and basal diet supplemented with antibiotic or 2, 4, and 6 mg/kg Microcin C7. Results showed that Microcin C7 significantly decreased the F/G ratio of broilers; significantly increased the levels of serum cytokine IL-10, immunoglobulins IgG and IgM, and ileal sIgA secretion; significantly decreased the level of serum cytokine TNF-α. Microcin C7 significantly increased villus height and V/C ratio and significantly decreased crypt depth in small intestine of broilers. Microcin C7 significantly increased gene expression of tight junction protein Occludin and ZO-1 and significantly decreased gene expression of pro-inflammatory and chemokine TNF-α, IL-8, IFN-γ, Toll-like receptors TLR2 and TLR4, and downstream molecular MyD88 in the jejunum of broilers. Microcin C7 significantly increased the number of Lactobacillus and decreased the number of total bacteria and Escherichia coli in the cecum of broilers. Microcin C7 also significantly increased short-chain fatty acid (SCFA) and lactic acid levels in the ileum and cecum of broilers. In conclusion, diet supplemented with Microcin C7 significantly improved growth performance, strengthened immune functions, enhanced intestinal barrier, and regulated cecal microbiota of broilers. Therefore, the antimicrobial peptide Microcin C7 may have the potential to be an ideal alternative to antibiotic.

Building and implementing a multi-level system of ethical code for biologists under the Biological and Toxin Weapons Convention (BTWC) of the United Nations

The recent global COVID-19 pandemic has had profound economic and social impacts on the world. It has highlighted an urgent need to strengthen existing international biosecurity governance mechanisms to prevent the misuse and malicious abuse of life science research and maintain international biological arms control norms. Biologists are at the front line of biotechnology development and are key to maintaining biosecurity awareness and moral self-discipline. As an important first step, biologists need to actively participate in the formulation and implementation of relevant biosecurity policies and measures to ensure their effectiveness and sustainability. Furthermore, efforts should be made to advocate for and promote the establishment of an ethical code of conduct for biologists to share safety responsibilities for global biosecurity. To maximize the impact of this ethical code of conduct, an effective approach to implementing codes of conduct for biologists at both national and international levels should be established under the framework of the Biological and Toxin Weapons Convention (BTWC).

Xylan alleviates dietary fiber deprivation-induced dysbiosis by selectively promoting Bifidobacterium pseudocatenulatum in pigs

BACKGROUND

Low dietary fiber intake has been shown to disturb the gut microbiome community, damage the mucus barrier, and promote pathogen susceptibility. However, little is known about the temporal response of the gut microbiome to dietary fiber deprivation and the recovery induced by dietary fiber inclusion in pigs.

OBJECTIVE

In the present study, temporal responses of ileal and fecal microbiota to dietary fiber deprivation were profiled using an ileum cannulated growing pig model. In addition, the potential of dietary-resistant starch, β-glucan, and xylan to alleviate gut dysbiosis throughout the gastrointestinal tract, as well as its possible mechanisms were investigated.

METHODS

Six cannulated growing pigs were fed a fiber deprivation diet for 35 days. Ileal digesta and feces were collected at days 0, 7, 21, and 35 for 16S rRNA sequencing and short-chain fatty acid (SCFA) determination. Another twenty-four healthy growing pigs were assigned to one of four dietary treatments including (1) fiber-free diet, (2) resistant starch diet, (3) β-glucan diet, and (4) xylan diet. These twenty-four pigs were fed a corresponding diet for 35 days and slaughtered. Gut microbiome and SCFA concentration were profiled along the gastrointestinal tract.

RESULTS

Dietary fiber deprivation-induced consistent microbiota extinction, mainly Bifidobacterium and Lactobacillus, and decreased SCFA concentrations in both ileum and feces. The community structure partially recovered at day 35 compared with baseline while SCFA concentrations remained low. Xylan supplementation alleviated gut dysbiosis by selectively promoting Bifidobacterium pseudocatenulatum within the large intestine. SCFA concentration increased significantly after xylan supplementation and exhibited a positive association with B. pseudocatenulatum abundance. An elevated abundance of xylan degradation-related enzyme genes was also observed in the gut microbiome after xylan supplementation. In vitro growth assay further verified the xylan utilization capacity of B. pseudocatenulatum.

CONCLUSIONS

Dietary fiber deprivation could induce probiotic extinction and loss of the SCFA production while potential pathogen was promoted. Xylan intervention could partially restore dietary fiber deprivation-induced gut dysbiosis through selectively promoting B. pseudocatenulatum and therefore normalizing the gut environment. These findings collectively provide evidence that dietary fiber-driven microbiota metabolism bridges the interplay between microbiome and gut health. Video abstract.

What is an appropriate caesarean delivery rate for China: a multicentre survey

Objective

To assess the current status of caesarean delivery (CD) in China, propose reference CD rates for China overall, and by regions, investigate the main indications for CDs and identify possible areas for safe reduction.

Design

A multicentre cross‐sectional study.

Setting

A total of 94 hospitals across 23 provinces in China.

Population

A total of 73 977 randomly selected deliveries.

Methods

We used a modified Robson classification to characterise CDs in subgroups and by regions, and the World Health Organization (WHO) C‐Model to calculate reference CD rates.

Main outcome measures

CD rates in China.

Results

In 2015–2016, the overall CD rate in China was 38.9% (95% CI 38.6–39.3%). Considering the obstetric characteristics of the population, the multivariable model‐based reference CD rate was estimated at 28.5% (95% CI 28.3–28.8%). Accordingly, an absolute reduction of 10.4% (or 26.7% relative reduction) may be considered. The CD rate varied substantially by region. Previous CD was the most common indication in all regions, accounting for 38.2% of all CDs, followed by maternal request (9.8%), labour dystocia (8.3%), fetal distress (7.7%) and malpresentation (7.6%). Overall, 12.7% of women had prelabour CDs, contributing to 32.8% of the total CDs.

Conclusions

Nearly 39% of births were delivered by caesarean in China but a reduction of this rate by a quarter may be considered attainable. Repeat CD contributed more than one‐third of the total CDs. Given the large variation in maternal characteristics, region‐specific or even hospital‐specific reference CD rates are needed for precision management of CD.

Tweetable abstract

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

The caesarean rate in 2015–2016 in China was 38.9%, whereas the reference rate was 28.5%.

Linked article This article is commented on by M Varner, p. 148 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471-0528.16953.

Animal models used in the research of nanoparticles for cardiovascular diseases

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity worldwide. Tremendous progress has been made in the prevention and treatment of CVD; however, there are still lots of limitations and new technology is needed. Nanoparticles have been studied recently for CVD due to their nanoscale size and unique properties, and hold a potential to be a novel therapy for the treatment. To test the safety and effectiveness of drug-loaded nanoparticles for CVD prior to human studies, animal disease models are unavoidably needed. This review summarized the animal models used in the research of nanoparticles for CVD and provided a generic picture of current use of CVD animal models according to the different types of diseases which should be prioritized when considering the application of nanoparticles in treating CVD. This review would be useful resources not only for life science researchers and clinicians but also for those from chemistry and materials sciences background who may not have a systematic knowledge about CVD animal models.

Core Altered Microorganisms in Colitis Mouse Model: A Comprehensive Time-Point and Fecal Microbiota Transplantation Analysis

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is characterized by chronic and relapsing inflammation within the gastrointestinal tract. Antibiotics have been used to treat IBD, primarily utilizing metronidazole. Although there does seem to be a treatment effect, the broad-spectrum antibiotics that have been used to date are crude tools and have many adverse effects. Available evidence suggests that the host microbiome is implicated in the pathogenesis of IBD, though the key bacteria remain unknown. If the bacterial population can be modified appropriately, the use of antibiotics will have a better therapeutic effect. In this study, mice were fed dextran sodium sulfate (DSS) solution for 5 days, followed by 5 days of normal drinking water, to investigate the gut microbiota response to colitis and the initial alteration of microbiota in recovery phase. Day 0 was considered the normal control, while day 5 and day 10 were considered the colitis mouse model progressive phase and recovery phase, respectively. Results showed that inflammation could induce proportional changes in the gut microbiota. Furthermore, transplanting the microbiota in progressive phase to antibiotic-induced microbiota-depleted mice could induce inflammation similar to colitis, which proves the importance of initial alteration of the microbiota for IBD recovery and the potential of the microbiota as a target for the treatment of IBD. Meanwhile, we have also identified three possible target microorganisms in the development of colitis, namely genera Muribaculaceae (negative correlation), Turicibacter (positive correlation) and Lachnospiraceae (negative correlation) in inflammation status through comprehensive analysis.

Melanocortin receptor-4 mediates the anorectic effect induced by the nucleus tractus solitarius injection of glucagon-like Peptide-2 in fasted rats

Glucagon-like peptide-2 (GLP-2) is secreted from enteroendocrine L-type cells of the gut and also released from preproglucagonergic (PPG) neurons in the nucleus tractus solitarius (NTS) and adjacent medial reticular nucleus of the brain stem. The neurons in the NTS express GLP-2, and the neurons send extensive projections to the hypothalamus. Recent studies show that the intracerebroventricular administration of GLP-2 significantly suppresses food intake in animals and some evidence suggest that the melanocortin receptor-4 (MC4-R) signaling in the hypothalamus is required for intracerebroventricular GLP-2-mediated inhibition of feeding. There is proopiomelanocortin (POMC) positive neurons expressing MC4-R in the NTS. Suppression of MC4-R expressing neurons in the brain stem inhibits gastric emptying. In this study, we tested the effects of NTS GLP-2R activation and blockade on feeding behavior and evaluated the endogenous melanocortin system's role in the NTS in mediating effects of GLP-2 on feeding behavior in fed and fasted rats. Our results demonstrated that microinjection of GLP-2 into the NTS suppressed food intake in fasted-refeeding rats but did not affect food intake in free-feeding rats, and this inhibition was blocked by pretreatment of either Exendin _(9-39) or SHU 9119, suggesting the GLP-2 system in the NTS exerts an inhibitory action on food intake. MC4-R mediates this action in the NTS.

Recombinant antimicrobial peptide microcin J25 alleviates DSS-induced colitis via regulating intestinal barrier function and modifying gut microbiota

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is rising constantly all over the world. However, current medical treatments are not universally practical. Microcin J25 (MccJ25), a member of the lasso peptides class, has excellent antimicrobial activity both in vitro and in vivo. Here, we assessed the anti-inflammatory effects of MccJ25 through DSS-induced UC mouse model. MccJ25 significantly ameliorated the UC-associated parameters such as decreased body weight, increased disease activity index (DAI) and shortened colon length. MccJ25 also provides barrier protection by preserving structural integrity and reducing inflammatory infiltrates of colon epithelium. The underlying mechanism may be associated with gut microbiota. To test this uncertainty, co-housing experiment was performed, and results indicate homogenized microbiota could relief the inflammatory. Meanwhile, we also proved the prominent role of the possible targets of MccJ25, namely genus Lactobacillus, Bacteroides and Akkermansia (as well as the possible strains related to the important OTUs) in inflammation status through comprehensive analysis. In conclusion, MccJ25 effectively attenuates inflammation and improves disrupted barrier function, and the MccJ25-modified gut microbiota plays a central role in this process.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Association of Zinc deficiency, oxidative stress and increased double-stranded DNA breaks in globozoospermic infertile patients and its implication for the assisted reproductive technique

Background

Sperm DNA fragmentation and its adverse impact on outcomes of assisted reproductive techniques (ART) in globozoospermic infertile patients has been previously reported. However, the association of Zinc element with DNA damage and intracytoplasmic sperm injection (ICSI) outcome in globozoospermic infertile patients remains unclear.

Methods

Using flame atomic absorption spectrophotometer and superoxide dismutase (SOD) assay, the levels of Cu, Fe, Mn, Zn and SOD activities in seminal plasma from both globozoospermic infertile patients and fertile volunteers were tested respectively. Using sperm chromatin dispersion (SCD) test and Comet assay, the DNA damages in their semen samples from the two groups was detected. In addition, using Aniline Blue staining, their sperm nucleus maturations were also examined.

Results

The levels of seminal Zinc and SOD activities were lower in the globozoospermic infertile patients and the double-stranded break DFI (DSB-DFI) were significantly higher than that in the fertile controls. Antioxidative insufficiency of SOD with a low Zn level might be responsible for oxidative stress, which may lead to DNA damage in globozoospermic spermatozoa. Zn deficiency might also have influence on the chromatin stabilization of globozoospermic spermatozoa during spermiogenesis, causing its more vulnerable to oxidative attack.

Conclusions

Serious DSBs in globozoospermia and antioxidative insufficiency due to Zinc element deficiency in spermatozoa might be responsible for the failure of ICSI in globozoospermia.

GLP-2 decreases food intake in the dorsomedial hypothalamic nucleus (DMH) through Exendin (9-39) in male Sprague-Dawley (SD) rats

Glucagon-like peptide 2 (GLP-2), a member of Glucagon peptide family involved in regulating energy metabolism, can be produced and secreted by preproglucagonergic (PPG) neurons in the brain. GLP-2 reduces food intake but at which brain sites GLP-2 exerts its feeding-suppress effects are still unclear. In this study, we used the stereological microinjection technique and behavioral test to examine the functions of locally delivered GLP-2 into DMH on feeding behavior. We compared effects of different concentration of GLP-2 on the food intake behavior in free-feeding rats and fasted-refeeding rats. We found that GLP-2 inhibited food intake in fasted rats after a short-term intervention in a dose-dependent manner. Importantly, the effects of locally delivered GLP-2 can be blocked by specific GLP-1 receptor antagonist Exendin_(9-39), but not the melanocortin-4 receptor antagonist SHU9119, indicating the involvement of specificity of GLP-2 signaling in regulating the feeding behavior. Taken together, our data revealed that GLP-2 peptide pharmacologically inhibited food intake in DMH and this effect could be blocked functionally by Exendin_(9-39).

Exploring the potential of the recombinant human collagens for biomedical and clinical applications: a short review

Natural animal collagen and its recombinant collagen are favourable replacements in human tissue engineering due to their remarkable biomedical property. However, this exploitation is largely restricted due to the potential of immunogenicity and virus contamination. Exploring new ways to produce human collagen is fundamental to its biomedical and clinical application. All human fibrillar collagen molecules have three polypeptide chains constructed from a repeating Gly-Xaa-Yaa triplet, where Xaa and Yaa represent one random amino acid. Using cDNA techniques to modify several repeat sequences of the cDNA fragment, a novel human collagen, named recombinant human-like collagen (rHLC), with low immunogenicity and little risk from hidden virus can be engineered and notably tailored to specific applications. Human-like collagen (HLC) was initially used as a coating to modify the tissue engineering scaffold, and then used as the scaffold after cross-link agents were added to increase its mechanical strength. Due to its good biocompatibility, low immunogenicity, stabilised property, and the ability of mass production, HLC has been widely used in skin injury treatments, vascular scaffolds engineering, cartilage, bone defect repair, skincare, haemostatic sponge, and drug delivery, including coating with medical nanoparticles. In this review, we symmetrically reviewed the development, recent advances in design and application of HLC, and other recombinant human collagen-based biomedicine potentials. At the end, future improvements are also discussed.

Inhibition of CD44 attenuates pressure overload-induced cardiac and lung inflammation, fibrosis, and heart failure progression

Background

Inflammation contributes to heart failure (HF) development and progression. CD44 is a member of the hyaluronate receptor family of cell adhesion molecules, which regulates tissue inflammation and fibrosis through modulating macrophage and lymphocyte migration and homing in several diseases. Here we evaluated the role and cellular mechanism of CD44 in regulating transverse aortic constriction (TAC)-induced HF development and progression in mice.

Methods and results

C57/B6 background CD44 KO and wild type mice (6–8 weeks) were subjected to TAC to evaluate the effect of CD44 on the development of TAC-induced LV hypertrophy and cardiac dysfunction. Due to the rapid response to TAC, Balb/c mice (6–8 weeks) were used to determine the effect of CD44 on the progression of TAC-induced congestive heart failure. We found that CD44 expression is dramatically increased in left ventricular (LV) tissues obtained from HF patients and mice. While CD44 gene knockout (KO) has no detectable effect on cardiac structure and function under control conditions, CD44 KO mice were protected from TAC-induced LV inflammation, fibrosis, hypertrophy, dysfunction, and lung remodeling as compared with wild type mice. In addition, we found that inhibition of CD44 signaling with blocking antibodies (Abs) significantly attenuated the transition from LV failure to lung remodeling, and right ventricular hypertrophy in mice with existing HF.

Conclusions

These data identify an important role of CD44 in attenuating cardiac and lung inflammation, fibrosis, HF development, and HF progression, suggesting that inhibition of CD44 signaling may be useful in preventing and treating HF.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Chinese National Natural Science Foundation Grants and American Heart Association

Development and validation of a risk perception scale of medical help-seeking behavior in Chinese adults

Background

When people require medical treatment, many risk factors including adverse medical events, economic burdens, and social–psychological consequences may contribute to their hesitation to seek medical help. Therefore, a reliable and valid instrument that can comprehensively assess the risk perception of medical help-seeking behavior among ordinary Chinese adults should be developed.

Methods

The basic dimensions of the scale were determined based on literature review and in-depth interviews with patients. Then, an item pool with 32 items and six dimensions was developed. After the item reduction process based on item and factor analyses, a three-factor, 16-item scale was established. From March 2019, this scale was distributed among 639 healthy adults, outpatients, or inpatients in 20 provinces and municipalities in the mainland of China by convenience sampling. Then, the reliability and validity of the scale were examined.

Results

The scale consists of three dimensions (treatment risks, burden risks, and stigma risks) and 16 items. The root-mean-square error of approximation, comparative fit index, and Tucker-Lewis index of this model were 0.069, 0.925, and 0.910, respectively. The internal consistency reliability of the scale was 0.893, and the test-retest reliability was 0.784. The criterion-related validity was 0.720 (P<0.01).

Conclusions

The risk perception scale of medical help-seeking behavior is a reliable and valid instrument to measure Chinese adults’ perception for potential risks in the process of medical treatment.

[Clinical and laboratory characteristics in patients with myeloid neoplasms complicated with clonal T large granular lymphocyte proliferation]

Objective: To analyze the clinical manifestations and laboratory features in patients with myeloid neoplasms complicated with clonal T large granular lymphocyte (T-LGL) proliferation. Methods: The clinical data of 5 patients with myeloid neoplasms complicated with clonal T-LGL proliferation from November 2017 to November 2018 in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College were analyzed retrospectively. Results: The median age was 60 years old. All patients had a history of abnormal peripheral blood cell counts for over 6 months. The absolute lymphocyte count in peripheral blood was less than 1.0×10(9)/L. In addition to the typical T-LGL phenotype, the immunophenotype was heterogenous including CD4(+)CD8(-) in 2 patients, the other 3 CD4(-)CD8(+). Four patients were αβ type T cells, the other one was γδ type. STAT3 mutation was detected in 1 patient by next-generation sequencing, the other 4 cases were negative. Conclusions: Clonal T-LGL proliferation with myeloid neoplasm develops in an indolent manner, mainly in elderly patients. Hemocytopenia is the most common manifestation. The diagnosis of T-LGL proliferation does not have specific criteria, that it should be differentiated from other T cell proliferative disorders, such as T-cell clones of undetermined significance. STAT3 or STAT5b mutation may help distinguish.

FRI0261 DIFFERENTIAL EXPRESSION OF PERIPHERAL CD4+ T CELLS IN PATIENTS WITH SYSTEMIC SCLEROSIS AND MIXED CONNECTIVE TISSUE DISEASE

Background:

The CD4+T cell subsets plays an important role in its pathogenesis, and its new research are constantly being published, but its specific changes between SSc and MCTD are still unclear.

Objectives:

The aim of the present study was to explore the absolute numbers of CD4+T subsets in peripheral blood(PB) of patients with SSc and MCTD using our modified flow cryometric method and investigate the role in the pathogenesis of both.

Methods:

The PB samples from 54 patients with SSc, 51 patients with MCTD as well as 30 healthy control subjects were analyzed for lymphocyte subsets using flow cytometry. Of these patients, 19 had pulmonary involvement, including 9 patients with SSc and 10 patients with MCTD. Using directly the percentages from flow cytometry combined with internal standard beads calculated absolute number of peripheral lymphocyte subsets from the subjects in each group.

Results:

Although there were some changes among CD4+T cell subsets in PB from these SSc patients and MCTD patients, the major alteration was the reductions of Treg cells. Compared with the normal controls, the absolute number of CD4+CD25+FOXP3+Treg cells were significantly decreased in SSc patients and MCTD patients, and the absolute number of Th1 cells in MCTD patients is also significantly reduced. Notably, the absolute numbers of Th17 and Th2 cells were not different from those of normal controls, but the ratios of Th17/Treg in SSc patients and MCTD patients were significantly higher, causing by insufficient number of Treg cells (Fig 1). In addition, in patients with pulmonary involvement, we found that the absolute number of Treg cells was significantly reduced in patients with MCTD, while the absolute number of Th2 cells and Th17 cells was significantly reduced in patients with SSc(Fig 2).

Fig 1.

Comparison of the levels of CD4+T lymphocyte subsets in SSc patients, MCTD patients and healthy controls: (A) The absolute number of peripheral Th1 cells in patients with MCTD was significantly reduced; (B and C) There was no significant difference in the absolute number of Th2 cells in peripheral blood of different subjects; (D and E) The ratio of Th17/Treg cells in PB of patients with SSc and MCTD were significantly higher.*P< 0.05; **P< 0.01; ***P< 0.001.

Conclusion:

The number of peripheral Treg cells in patients with SSc and MCTD was significantly reduced, suggesting that that SSc and MCTD progression is associated with the imbalances between pro-inflammation cells to anti-inflammation Treg cells. In addition, we also found that the decrease in peripheral numbers of Treg cells may contribute to the development of MCTD-associated lung disease, whereas in SSc patients who had lung involvement, the reduce in peripheral number of Th17 cells may result in a severe imbalance of Th17/Treg cells, thereby promoting disease progression.

Fig 2.

Comparison of the levels of CD4+T lymphocyte subsets in patients who had pulmonary involvement and healthy controls: (A) There was no significant difference in the absolute number of Th1 cells in peripheral blood of different subjects; (B and C) The absolute number of peripheral Th2 cells and Th17 cells in patients with SSc were significantly reduced; (D and E) The ratio of Th17/Treg cells in PB of patients with MCTD were higher.*P< 0.05; **P< 0.01; ***P< 0.001.

References:

[1]Liu M, Wu W, Sun X, et al. New insights into CD4(+) T cell abnormalities in systemic sclerosis. Cytokine Growth Factor Rev. 2016 Apr; 28:31-6. doi: 10.1016/j.cytogfr.2015.12.002.

Acknowledgments:

None

Disclosure of Interests:

None declared

[Two cases of occupational frostbite]

The diagnosis, treatment, operation and diagnosis of two cases of occupational frostbite diagnosed in Shandong Academy of Occupational Healthy Occupational Medicine were analyzed retrospectively. In these two patients working in a low temperature environment, the finger frostbite did not arouse enough attention, one patient did not receive timely diagnosis and treatment, and one patient received timely medical treatment, but did not receive proper treatment, which ultimately led to the adverse consequences of finger amputation. The staff under the low temperature environment should strictly carry out the low temperature operation protection standard and improve their self-protection consciousness. If frostbite occurs, they should seek medical treatment in time, which can effectively reduce the disability rate.

Maternal milk and fecal microbes guide the spatiotemporal development of mucosa-associated microbiota and barrier function in the porcine neonatal gut

BACKGROUND

The early-life microbiota exerts a profound and lifelong impact on host health. Longitudinal studies in humans have been informative but are mostly based on the analysis of fecal samples and cannot shed direct light on the early development of mucosa-associated intestinal microbiota and its impact on GI function. Using piglets as a model for human infants, we assess here the succession of mucosa-associated microbiota across the intestinal tract in the first 35 days after birth.

RESULTS

Although sharing a similar composition and predicted functional profile at birth, the mucosa-associated microbiome in the small intestine (jejunum and ileum) remained relatively stable, while that of the large intestine (cecum and colon) quickly expanded and diversified by day 35. Among detected microbial sources (milk, vagina, areolar skin, and feces of sows, farrowing crate, and incubator), maternal milk microbes were primarily responsible for the colonization of the small intestine, contributing approximately 90% bacteria throughout the first 35 days of the neonatal life. Although maternal milk microbes contributed greater than 90% bacteria to the large intestinal microbiota of neonates upon birth, their presence gradually diminished, and they were replaced by maternal fecal microbes by day 35. We found strong correlations between the relative abundance of specific mucosa-associated microbes, particularly those vertically transmitted from the mother, and the expression levels of multiple intestinal immune and barrier function genes in different segments of the intestinal tract.

CONCLUSION

We revealed spatially specific trajectories of microbial colonization of the intestinal mucosa in the small and large intestines, which can be primarily attributed to the colonization by vertically transmitted maternal milk and intestinal microbes. Additionally, these maternal microbes may be involved in the establishment of intestinal immune and barrier functions in neonates. Our findings strengthen the notion that studying fecal samples alone is insufficient to fully understand the co-development of the intestinal microbiota and immune system and suggest the possibility of improving neonatal health through the manipulation of maternal microbiota.

Silver Nanoparticle-Mediated Cellular Responses in Human Keratinocyte Cell Line HaCaT in Vitro

The interactions between cells and nanoparticles has been the focus of recent research in the area. The effects of AgNPs on skin cell lines for further potential biological applications are highlighted. This study aimed to investigate the mechanism of cytotoxic and genotoxic effects of AgNPs nanoparticles on human skin keratinocytes (HaCaT). Genocytotoxic effects of AgNPs was assessed using changes in various cellular parameters of HaCaT cells involving viability, superoxide anion radical production, lactate dehydrogenase release and the levels of the antioxidant enzymes, namely, Catalase, Glutathione peroxidase (GPX) and Superoxide Dismutase (SOD). Superoxide anion was detected using nitroblue tetrazolium NBT reduction assay. LDH levels was evaluated using the standard kit, and activity of antioxidant enzymes such as catalase (CAT), glutathione peroxidase 1 (GPX-1) and superoxide dismutase 1 (SOD-1) were quantified using qPCR. Our results indicated that AgNPs caused severe HaCaT oxidative damage, accompanied by increased the production of superoxide anion levels as well as significant decrease in endogenous antioxidant enzyme of SOD, CAT, GPX expression involved in HaCat cells in vitro. Our study suggests that AgNPs exposure increased oxidative stress levels. Moreover; the low cytotoxic effect observed on human HaCaT keratinocytes suggested that these nano-compounds have a potential toxic effect at the skin level only after long-term exposure.