[A descriptive analysis on body mass index distribution in adult twin pairs in China]

Objective: To describe the differences in body mass index (BMI) distribution in adult twins registered in Chinese National Twin Registry (CNTR), and provide evidence for the risk factor analysis and prevention and control of overweight or obesity. Methods: A total of 32 725 twin pairs aged 18 years and above who completed the questionnaire survey during 2010-2018 and had complete registered information in CNTR and normal body weight and length were included in the analysis on the population and region specific distributions of BMI of twin pairs and the difference in BMI in twin pairs. Results: The twin pairs included in the analysis were aged (34.6±12.4) years, the twin pairs of same gender accounted for 79.7%. The average BMI was 22.5 kg/m². The overall prevalence of obesity and overweight was 4.9% and 23.7%, respectively. Participants who were men, 50-59 years old, married, had lower education level, and lived in northern China had higher overweight rate and obesity rate (P<0.001). The difference in overweight or obesity prevalence between monozygotic (MZ) twin pars and dizygotic (DZ) twin pairs was not significant, but firstborn twin pairs had slightly higher rates of overweight and obesity than later-born twin pairs (P<0.05). The analysis in same gender-twin pairs indicated that the difference in BMI was associated with age (trend test: P<0.001), and the difference was more obvious in DZ twin pair in MZ pair and this difference increased with age. The concordant rate of BMI was higher in MZ twin pairs than DZ twin pairs (P<0.05). Conclusion: The distribution of BMI of twin pairs varied with population and region and BMI varied with age due to its genetic nature.

[The incidence risk of elevated fasting blood glucose in people with fatty liver disease: a cohort study of 40 000 people over the past 10 years]

Objective: To analyze the time point when patients with fatty liver disease had a significantly higher risk of elevated fasting blood glucose than those without in the physical examination group in Karamay Central Hospital, factors affecting the incidence of elevated blood glucose in patients with fatty liver disease, and the influence of the number of influencing factors on it. Methods: Physical examination data from Karamay Central Hospital during September 2008 to April 2017 were retrospectively analyzed. Combined with the survival analysis, the 1-,3-, 5-, and 7-year prevalence rates of elevated fasting glucose occurs in people with and without fatty liver disease were analyzed. Z-test was used to compare the survival rate difference at each time point. Cox regression model was used for multivariate analysis. Results: 10 802 people were in the fatty liver group. The elevated fasting blood glucose incidence density was 61/1 000 person-years, and the 1-, 3-, 5-, and 7-year prevalence rates were 2%, 16%, 28%, and 38%, respectively. 29 579 people were in the non-fatty liver group. The elevated fasting blood glucose incidence density was 23/1000 person-years, and the 1-, 3-, 5-, and 7-year prevalence rates were 1%, 7%, 11%, and 16%, respectively. The short-term and long-term elevated fasting blood glucose incidence risk were significantly higher in fatty liver group than non-fatty liver group(P < 0.001). The elevated fasting blood glucose incidence risk was apparently higher in fatty liver group than that of non-fatty liver group from the first year onward (P < 0.001). Age≥50 year's old (HR = 1.954, 95% CI :1.792-2.132), elevated body mass index (HR = 1.397, 95% CI : 1.198-1.629), blood pressure (HR = 1.284, 95% CI : 1.181-1.397), triglycerides (HR = 1.171, 95% CI: 1.077-1.274) were independent risk factors, which promoted the elevated fasting blood glucose incidence risk in patients with fatty liver disease. Fatty liver combined with the above 2, 3, and 4 risk factors had apparently increased the incidence risk of elevated fasting blood glucose (P < 0.001). Conclusion: People with fatty liver disease had a higher risk of elevated fasting blood glucose from the first year than those without. Age≥50 year's old, elevated blood pressure, body mass index and triglyceride might increase risk of elevated fasting blood glucose in patients with fatty liver disease, combined with the above 2,3 or 4 risk factors can increase the risk of elevated fasting blood glucose.

Reactive-oxygen-species-scavenging nanomaterials for resolving inflammation

Reactive oxygen species (ROS) mediate multiple physiological functions; however, the over-accumulation of ROS causes premature aging and/or death and is associated with various inflammatory conditions. Nevertheless, there are limited clinical treatment options that are currently available. The good news is that owing to the considerable advances in nanoscience, multiple types of nanomaterials with unique ROS-scavenging abilities that influence the temporospatial dynamic behaviors of ROS in biological systems have been developed. This has led to the emergence of next-generation nanomaterial-controlled strategies aimed at ameliorating ROS-related inflammatory conditions. Accordingly, herein we reviewed recent progress in research on nanotherapy based on ROS scavenging. The underlying mechanisms of the employed nanomaterials are emphasized. Furthermore, important issues in developing cross-disciplinary nanomedicine-based strategies for ROS-based inflammatory conditions are discussed. Our review of this increasing interdisciplinary field will benefit ongoing studies and clinical applications of nanomedicine based on ROS scavenging.

[The etiology of 340 infants with early-onset epilepsy]

Objective: To investigate the etiology of epilepsy onset before 6 months old and improve clinical understanding. Methods: The medical history, electroencephalogram, brain imaging, genetic examination and other clinical data of 340 patients who were diagnosed with epilepsy with onset under 6 months of age and were hospitalized in the Department of Neurology, Beijing Children's Hospital, Capital Medical University between January 2017 and December 2018 were retrospectively analyzed. Rank sum test was used to compare the ages of onset of different etiologic groups. Results: Of the 340 patients, 196 were males and 144 were females. The age of onset was 90.5 (48.0, 135.5) days. In the 250 (73.5%) underwent genetic test, 103 (41.2%) had pathogenic or likely pathogenic variants, involving 43 single gene variants and 2 chromosomal abnormalities. Seventy-nine patients (23.2%) had genetic etiology, 66 (19.4%) had structural etiology, 19 (5.6%) had metabolic etiology, 13 (3.8%) had multiple etiologies, and 163 (47.9%) had unknown etiology. In the 79 cases with genetic etiology, 30 single gene variants were detected, including 19 cases of PRRT2, 10 cases of KCNQ2, 7 cases of SCN1A, 6 cases of SCN2A, 6 cases of STXBP1, 5 cases of CDKL5, 2 cases of ARX, and 1 case of each of 23 gene variants. Two cases had chromosomal abnormalities which were 21-trisomy and 16p11.2 microdeletion syndrome respectively. Among the 66 cases with structural etiologies, 37 cases had acquired factors such as perinatal brain injury, 28 cases had congenital factors such as cortical malformation and 1 case was perinatal brain injury combined megalencephaly. The onset age of genetic etiology was 95 (26, 128) days, that of structural etiology was 90 (58, 30) days, and that of metabolic etiology was 57 (30, 90) days. The onset age of metabolic etiology was earlier than that of structural etiology (U=436.500, P=0.044). Conclusions: Genetic etiology is the most common defined etiology of infants with early-onset epilepsy aged 0-6 months, and there are certain differences in the age of onset between different etiologies. Proper application of genetic test is helpful to identify the etiology and guide treatment.

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.

Single-cell RNA sequencing reveals cell type- and artery type-specific vascular remodelling in male spontaneously hypertensive rats

AIMS

Hypertension is a major risk factor for cardiovascular diseases. However, vascular remodelling, a hallmark of hypertension, has not been systematically characterized yet. We described systematic vascular remodelling, especially the artery type- and cell type-specific changes, in hypertension using spontaneously hypertensive rats (SHRs).

METHODS AND RESULTS

Single-cell RNA sequencing was used to depict the cell atlas of mesenteric artery (MA) and aortic artery (AA) from SHRs. More than 20 000 cells were included in the analysis. The number of immune cells more than doubled in aortic aorta in SHRs compared to Wistar Kyoto controls, whereas an expansion of MA mesenchymal stromal cells (MSCs) was observed in SHRs. Comparison of corresponding artery types and cell types identified in integrated datasets unravels dysregulated genes specific for artery types and cell types. Intersection of dysregulated genes with curated gene sets including cytokines, growth factors, extracellular matrix (ECM), receptors, etc. revealed vascular remodelling events involving cell-cell interaction and ECM re-organization. Particularly, AA remodelling encompasses upregulated cytokine genes in smooth muscle cells, endothelial cells, and especially MSCs, whereas in MA, change of genes involving the contractile machinery and downregulation of ECM-related genes were more prominent. Macrophages and T cells within the aorta demonstrated significant dysregulation of cellular interaction with vascular cells.

CONCLUSION

Our findings provide the first cell landscape of resistant and conductive arteries in hypertensive animal models. Moreover, it also offers a systematic characterization of the dysregulated gene profiles with unbiased, artery type-specific and cell type-specific manners during hypertensive vascular remodelling.

Clinical significance of TBX2 in esophageal squamous cell carcinomas and its role in cell migration and invasion

OBJECTIVE

To explore the role of T-box 2 (TBX2) in esophageal squamous cell carcinomas (ESCC).

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (PCR) and Western blot (WB) assays were used to detect the expression level of TBX2 in tissues and cells. Transwell assays were conducted for determination of cell invasion and migration.

RESULTS

The results suggested that the TBX2 was upregulated in ESCC tissues. Further, high expression of TBX2 expression was associated with tumor size, differentiation, distant metastasis, and TNM stage. In our in-vitro study, we decreased the expression of TBX2 in ESCC cells by transfection using LipofectamineTM 3000. The results from the transwell assay suggested that the downregulation of TBX2 could significantly suppress cell migration and invasion. Besides, WB results indicated that epithelial-mesenchymal transition (EMT)-related protein expressions were also changed after transfection.

CONCLUSIONS

TBX2, as an oncogene, could promote the progress of ESCC by affecting the transfer ability in tumor cells.

[Prevalence betel nut abuse and its related factors among residents in Haikou City from 2013 to 2014]

From 2013 to 2014, the age of 924 residents recruited in Haikou City was (38±13) years old, of which 57.3% (529) were males. Those who chewed betel nuts accounted for 17.4% (161). According to the diagnostic criteria of substance abuse in the Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders, the detection rate of betel nut abuse was 7.0% (65). Compared with those who were>30 years old, educated>6 years and non-smokers, people aged 15 to 30 years, education level less than 6 years and smoking behavior had higher risk of betel nut abuse, with the OR (95%CI) about 4.21 (1.48-11.99), 7.81 (1.92-31.69), and 13.53 (4.15-44.11), respectively.

[MiR-600 suppresses HeLa cell proliferation by inhibiting hypoxia-inducible factor-1α signaling pathway]

OBJECTIVE

To determine whether miR-600 suppresses the proliferation of HeLa cells by inhibiting hypoxia-inducible factor-1α (HIF-1α) signaling pathway and its effect on expressions of cyclin D1 and vascular endothelial growth factor (VEGF).

OBJECTIVE

HeLa cells were transfected with miR-600 mimic and plasmid-HIF-1α, either alone or in combination, to up-regulate miR-600 and HIF-1α expressions in the cells. Six hours after the transfection, the cell viability was assessed using MTT assay, and the mRNA and protein expressions of VEGF, cyclin D1, and HIF-1α were analyzed with qPCR and Western blotting.

OBJECTIVE

The viability of HeLa cells showed no obvious changes 6 h after transfection with miR-600 mimic or Plasmid-HIF-1α. At 24 h and 48 h, the cells transfected with miR-600 mimic showed a time-dependent reduction of cell viability, while the cells transfected with Plasmid-HIF-1α alone and with both miR-600 mimic and Plasmid-HIF-1α showed increased cell viability. The cell viabilities in Plasmid-HIF-1α group were significantly higher than those in miR-600 mimic+Plasmid-HIF-1α group at 24 h and 48 h. Six hours after transfection with miR-600 mimic, the cells exhibited significantly decreased expressions of VEGF, cyclin D1, and HIF-1α, which were all significantly up-regulated in Plasmid-HIF-1α group and miR-600 mimic+Plasmid-HIF-1α group. VEGF, cyclin D1, and HIF-1α expressions were significant higher in Plasmid-HIF-1α group than in miR-600 mimic+ Plasmid-HIF-1α group.

OBJECTIVE

miR-600 suppresses the proliferation of HeLa cells and down-regulate the expressions of cyclin D1 and VEGF by inhibiting HIF-1α signaling pathway.

NSun2 regulates aneurysm formation by promoting autotaxin expression and T cell recruitment

Abdominal aortic aneurysm (AAA) is characterized by inflammatory cell infiltration and aggravated by hyperhomocysteinemia (HHcy). It is unknown whether the homocysteine (Hcy)-activated RNA methyltransferase NOP2/Sun domain family member 2 (NSun2) is associated with AAA. Here, we found that NSun2 deficiency significantly attenuated elastase-induced and HHcy-aggravated murine AAA with decreased T cell infiltration in the vessel walls. T cell labeling and adoptive transfer experiments confirmed that NSun2 deficiency inhibited the chemotaxis of vessels to T cells. RNA sequencing of endothelial cells showed that Hcy induced the accumulation of various metabolic enzymes of the phospholipid PC-LPC-LPA metabolic pathway, especially autotaxin (ATX). In the elastase-induced mouse model of AAA, ATX was specifically expressed in the endothelium and the plasma ATX concentration was upregulated and even higher in the HHcy group, which were decreased dramatically by NSun2 knockdown. In vitro Transwell experiments showed that ATX dose-dependently promoted T cell migration. HHcy may upregulate endothelial ATX expression and secretion and in turn recruit T cells into the vessel walls to induce vascular inflammation and consequently accelerate the pathogenesis of AAA. Mechanistically, secreted ATX interacted with T cells by binding to integrin α4, which subsequently activated downstream FAK/Src-RhoA signaling pathways and then induced T cell chemokinesis and adhesion. ATX overexpression in the vessel walls reversed the inhibited development of AAA in the NSun2-deficient mice. Therefore, NSun2 mediates the development of HHcy-aggravated AAA primarily by increasing endothelial ATX expression, secretion and T cell migration, which is a novel mechanism for HHcy-aggravated vascular inflammation and pathogenesis of AAA.

[Ultrasonic and pathological comparative analysis of different subtypes of breast encapsulated papillary carcinoma]

Objective: To investigate the clinicopathological and ultrasonic characteristics of patients with breast encapsulated papillary carcinoma (EPC) and the comparative analysis of different subtypes. Methods: A total of 57 patients with pathological diagnosis of breast EPC in the First Affiliated Hospital of Nanjing Medical University from September 2014 to August 2020 were retrospectively collected. Based on pathological diagnosis, patients were divided into 3 subtypes, and their clinical, pathological and ultrasonic manifestations were compared and analyzed. Results: Among the enrolled patients, there were 2 males and 55 females, aged 41-88 (63±11) years. The lesion diameter of EPC was 7.0-7.5 (2.9±1.9) cm. There were 16 cases of simple EPC, 9 cases of EPC with ductal carcinoma in situ (DCIS), and 32 cases of EPC with infiltration. The molecular classification was mainly luminal (55/57, 96.6%), of which 38 cases were Luminal A type and 17 cases were Luminal B type. The majority ultrasound images of EPC showed nodules with size greater than 2 cm (68.4%), regular morphology (64.9%), edge finishing (54.4%), no burr forming angles (82.5%), and no calcification (93%). There were differences between different subtypes. The simple EPC was closer to the nipple than the EPC with infiltration, with regular shape and smooth edge (P<0.05). Compared with the EPC with DCIS, the EPC with infiltration had richer blood flow and was farther away from the nipple (P<0.05). There was no significant difference between the simple EPC and the EPC with DCIS (P>0.05). Conclusion: The simple EPC often showed benign signs on ultrasound, such as regular morphology, smooth edge, and cystic-solid internal structure. If the distance between the lesion and the nipple was greater than 3 cm, the shape was irregular, and the edge was blurred, the possibility of EPC with infiltration was high. Multi-modality image fusion was helpful for accurate diagnosis and treatment of EPC.

[Effects and mechanism of copper oxide nanozymes on wound healing of full-thickness skin defects in diabetic mice]

Objective: To investigate the effects and mechanism of copper oxide nanozymes on wound healing of full-thickness skin defects in diabetic mice. Methods: (1) Copper oxide nanozymes were synthesized through the reaction of copper chloride and L-ascorbic acid. Transmission electron microscope was used for observing the particle size and morphology of copper oxide nanozymes, and dynamic light scattering particle size analyzers and Zeta potentiometer were used to analyze the hydrated particle size and surface potential of copper oxide nanozymes, respectively. (2) The hydrogen peroxide detection kit, superoxide anion determination kit, and 3, 3', 5, 5'-tetramethylbenzidine were used to test the hydrogen peroxide, superoxide anion, and hydroxyl radicals scavenging ability of 150 ng/mL copper oxide nanozymes, respectively, and the scavenging proportions of hydrogen peroxide, superoxide anion, and hydroxyl radicals were calculated. The sample numbers were all 3. (3) Mouse fibroblast cell line 3T3 cells were divided into blank control group, simple hydrogen peroxide group, and hydrogen peroxide+ copper oxide group according to the random number table (the same grouping method below), with 3 wells in each group. Cells in hydrogen peroxide+ copper oxide group were pre-treated with copper oxide nanozymes in final mass concentration of 25 ng/mL for 30 minutes, and then hydrogen peroxide in final molarity of 250 μmol/L was added into simple hydrogen peroxide group and hydrogen peroxide+ copper oxide group. Cells in blank control group were routinely cultured. After 24 hours of culture, 2', 7'-dichlorodihydrofluorescein diacetate fluorescence probe was used to detect the level of reactive oxygen species (indicated by green fluorescence intensity) in cells and cell counting kit-8 assay was performed to detect and calculate the cell survival rate. (4) Ten male BALB/c mice aged 6-8 weeks (the same gender and age below) were divided into phosphate buffer saline (PBS) group and copper oxide group, with 5 mice in each group. The mice in the copper oxide group were injected with 800 ng/kg copper oxide nanozyme at a concentration of 200 ng/mL via the caudal vein, and the mice in PBS group were treated with the same volume of PBS. The mice in the two groups were treated once a day for seven consecutive days. On the eighth day, 5 mice from each group were conducted and blood samples were taken for analysis of blood panel and serum biochemistry, and then the heart, liver, spleen, lung, and kidney were harvested for histopathological observation by hematoxylin-eosin (HE) staining after the mice were sacrificed. (5) Twenty mice were divided into PBS group and copper oxide group, with 10 mice in each group. Diabetes was induced by streptozotocin and high-sugar and high-fat diet and a full-thickness skin defect wound with diameter of 6 mm was reproduced on the back of each diabetic mouse. Immediately after injury, 20 μL PBS and 20 μL copper oxide nanozymes at the concentration of 200 ng/mL were added respectively to the wounds of mice in PBS group and copper oxide group, with the treatment being continued for twelve consecutive days. Three mice were selected from each group, and the wound healing was observed on post injury day (PID) 0 (immediately), 3, 6, 9, and 12 and the un-healed area was calculated. On PID 6, three mice from each group that were not for wound observation were sacrificed, and the content of interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6 in the wound tissue were determined by enzyme-linked immunosorbent assay. On PID 12, the rest 7 mice in each group were sacrificed for observation of the length of regenerated epidermis in wound tissue by HE staining, and the level of reactive oxygen species (indicated as red fluorescence intensity) in wound tissue by dihydroethidium staining. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, independent sample t test, and Bonferroni test. Results: (1) The prepared copper oxide nanozymes were uniform in size with an average diameter of 3.5-4.0 nm in dry state, the hydrated particle size of 4.5 nm, and the surface potential of (-9.8±0.3) mV. By comprehensive judgment, copper oxide nanozymes had been successfully prepared. (2) After being treated with copper oxide nanozyme for 2 hours, 10 minutes, and 5 minutes, respectively, the scavenging proportions of hydrogen peroxide, superoxide anion, and hydroxyl radicals were (77±5)%, (45±5)%, and (84±4)%, respectively. (3) After 24 hours of culture, the cells in simple hydrogen peroxide group showed a significantly increased level of reactive oxygen species with abnormal morphology and decrease in cell number, while the cells in hydrogen peroxide+ copper oxide group showed a remarkably decreased level of reactive oxygen species with normal morphology similar to that of blank control group. The cell survival rate in simple hydrogen peroxide group was obviously reduced compared with the rates in blank control group and hydrogen peroxide+ copper oxide group (P<0.01), while there was no significant difference in cell survival rate between hydrogen peroxide+ copper oxide group and blank control group. (4) After 7 days of injection, there were no obvious differences in liver and kidney function indexes and blood panel indexes between mice in PBS group and copper oxide group. No necrosis, hyperaemia or hemorrhage in heart, liver, spleen, lung, or kidney was observed in mice in copper oxide group, which was similar to that in PBS group. (5) Compared with that of PBS group, wounds of mice in copper oxide group showed an accelerated healing trend with less redness. On PID 6, 9, and 12, the areas of un-healed wound of mice in copper oxide group (28.8±1.9), (17.6±3.8), and (10.4±1.8) mm(2), respectively, significantly lower than (38.0±4.3), (30.2±3.0), and (24.2±3.0) mm(2) in PBS group (t=3.706, 5.075, 5.558, P<0.01). On PID 6, the content of IL-1β, TNF-α, and IL-6 in wounds of mice in copper oxide group were significantly lower than that in PBS group (t=6.115, 11.762, 11.725, P<0.01). On PID 12, the length of regenerated epidermis in wounds of mice in copper oxide group was obviously longer than that in PBS group, the level of reactive oxygen species in wounds of mice in copper oxide group was obviously lower than that in PBS group. Conclusions: Copper oxide nanozyme not only has good biocompatibility, but also has efficient reactive oxygen species scavenging activity. It can eliminate the over-expressed reactive oxygen species in the full-thickness defect wounds of diabetic mice, reduce oxidative stress and inflammation, thus promoting wound repair.

Combined Fracture of Carpal and Volar Divergent Dislocation of the Second to Fifth Carpometacarpal Joints

The volar divergent dislocation of the second to fifth carpometacarpal joints and involving fracture of carpal is an extremely rare injury. We reported a case of 55-year-old man, victim of a motorbike, who was struck by a car, admitted at the emergency department unable to move his left hand with severe swelling. X-rays and CT scan showed a volar divergent dislocation of second to fifth carpometacarpal joints and involving fracture of carpal. Patient underwent closed reduction and plaster fixation right way, after one week, he received open reduction internal fixation with K-wire and plaster. Functional exercise was started progressively once K-wire and plaster were removed after six weeks. At six months follow-up, results were excellent and patient has regained all of his range of motion and hand activities. Key words: carpometacarpal joint, palmar, divergent, dislocation, hand, wrist.

[Effects and mechanism of Lactococcus lactis thermo-sensitive hydrogel on the wound healing of full-thickness skin defects in diabetic mice]

Objective: To explore the effects and mechanism of Lactococcus lactis (L. lactis) thermo-sensitive hydrogel on the wound healing of full-thickness skin defects in diabetic mice. Methods: (1) According to the volume ratio of bacteria to medium of 1∶100, about 5×10(8) colony forming units/mL (the same concentration below) L. lactis was cultured in M17GS liquid medium. The growth conditions were observed at 0 (immediately), 2, 4, 6, 8, 10, and 12 h of culture with a microplate reader. In addition, another colony of the bacteria was taken and cultured under the same condition mentioned above. The culture medium was collected at the same time points as mentioned above, and the supernatant of bacterial culture was isolated. With the supernatant, the pH value was measured with a desktop pH meter, and the concentration of L-lactic acid at 0 (immediately), 2, 4, 8, and 12 h of culture was determined by the L-lactic acid detection and analysis kit (n=3). (2) To prepare a simple thermo-sensitive hydrogel, the poloxamer thermo-sensitive polymer and M17GS liquid medium were mixed thoroughly according to the mass-volume ratio of 0.2 g∶1 mL. L. lactis was added to the simple thermo-sensitive hydrogel according to the volume ratio of bacteria to hydrogel of 1∶100, and the L. lactis thermo-sensitive hydrogel was prepared after thorough mixing. Afterwards, the morphology of L. lactis thermo-sensitive hydrogel was observed after 4 ℃, 37 ℃ incubation and again at 4 ℃ incubation after gelation. The storage modulus and loss modulus of the L. lactis thermo-sensitive hydrogel at 10-40 ℃ were measured by rheometer, and the gel forming temperature was observed. After freeze-drying the L. lactis thermo-sensitive hydrogel, the surface and the morphological structure of L. lactis in the hydrogel were observed by scanning electron microscope. (3) Mouse macrophages Raw264.7 cells were M1-type polarization stimulated by culturing with lipopolysaccharide and interferon γ in the final mass concentration of 100 and 10 ng/mL respectively for 24 h. The cells were divided into blank control group (without other treatment), L. lactis thermo-sensitive hydrogel group, and lactic acid group. L. lactis thermo-sensitive hydrogel in the volume of 1 mL was added to the cells of L. lactis thermo-sensitive hydrogel group, while lactic acid with the final molarity of 30 mmol/L was added to the cells in lactic acid group. After being cultured at 37 ℃ for 24 h, mRNA expressions of the markers arginase 1 and CD206 of M2-type macrophages were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) (n=3), and the immunofluorescence method was used to detect the protein localization and expression of arginase 1 and CD206. (4) Fifteen female BALB/c mice aged 8-10 weeks were induced into diabetic mouse models by the method of streptozotocin combined with high-sugar and high-fat diet, and a full-thickness wound with the diameter of 6 mm was made on the back of each mouse. The mice were divided into blank control group (without other treatment), thermo-sensitive hydrogel alone group, and L. lactis thermo-sensitive hydrogel group according to the random number table, with 5 mice in each group. The mice in the hydrogel treatment two groups were dripped with 200 μL corresponding hydrogel to the wound surface immediately after injury, and the hydrogel was replaced every day. After treatment for 0 (immediately), 3, 6, 9, and 12 days in the hydrogel treatment two groups, wound healing was observed, and wound area was measured. After 12 days of treatment, the wound tissue was taken to observe the thickness of granulation tissue by hematoxylin-eosin staining and CD206 and the marker of M1-type macrophages of inducible nitric oxide synthase (iNOS) positive cells by immunofluorescence method. The mice in blank control group were observed at the same time points as mentioned above. (5) Nine female BALB/c mice aged 8-10 weeks were induced into diabetic mouse models by the same method of experiment (4). Then, they were divided into normal skin group (without other treatment), wound alone group, and L. lactis thermo-sensitive hydrogel group according to the random number table, with 3 mice in each group. Mice in wound alone group and L. lactis thermo-sensitive hydrogel group were prepared with full-thickness skin defect wounds according to the method of experiment (4). Mice in the former group was left untreated after injury, and in the latter group, 200 μL L. lactis thermo-sensitive hydrogel was dripped onto the wound surface immediately after injury. After treatment for 1 day in hydrogel treatment group, the wound tissue of mice was taken, and the mRNA expressions of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and nuclear factor κB were detected by real-time fluorescence quantitative RT-PCR; after the eyeball blood was collected, the leukocyte count, lymphocyte count, and monocyte count in peripheral blood were measured by an automatic blood cell analyzer, and the serum L-lactic acid concentration was measured by the L-lactic acid detection and analysis kit. At the same time point mentioned above, normal skin tissue was taken from the corresponding parts of mice in normal skin group, wound tissue was taken from mice in wound alone group, and blood was taken from mice of the two groups for corresponding detection. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Tukey, and Dunnett test. Results: (1) The growth of L. lactis reached the plateau in about 6 h of culture. In the culture supernatant of L. lactis, the pH value gradually decreased, reaching the nadir about 4.9 after 8 h of culture, and the L-lactic acid concentration gradually increased, which peaked about 70 mmol/L after 8 h of culture. (2) The L. lactis thermo-sensitive hydrogel was a liquid at 4 ℃, and a solid gel at 37 ℃. After gelation, it became a liquid again after incubating at 4 ℃. The gel forming temperature was about 25 ℃. The storage modulus was about 3 000 Pa, and the loss modulus was about 1 000 Pa after gelation. Under the scanning electron microscope, the L. lactis thermo-sensitive hydrogel showed a loose three-dimensional porous structure, and the L. lactis had an ellipsoidal shape being wrapped inside the hydrogel. (3) After 24 h of culture, compared with those in blank control group, the expression of arginase 1 increased significantly (q=11.620, 15.250, P<0.01), the expression of CD206 mRNA increased significantly (q=16.770, 19.030, P<0.01), and the expression of CD206 protein located in the cell membrane and arginase 1 protein located in the cytoplasm increased significantly in the macrophages of L. lactis thermo-sensitive hydrogel group and lactic acid group. The expressions of arginase 1 and CD206 mRNA in the macrophages between lactic acid group and L. lactis thermo-sensitive hydrogel group were similar (q=3.629, 2.259, P>0.05). (4) After 3-12 days of treatment, compared with those in blank control group and thermo-sensitive hydrogel alone group, the wound of mice in L. lactis thermo-sensitive hydrogel group healed faster, the wound area was significantly reduced, and the inflammation of the wound edge tissue was reduced. After treatment of 3, 6, 9, 12 days, the wound areas of mice in L. lactis thermo-sensitive hydrogel group were (25.8±5.9), (21.2±4.6), (16.0±2.4), (8.4±2.4) mm(2) respectively, which were significantly smaller than (31.8±5.3), (28.0±3.4), (22.6±3.7), (17.0±1.0) mm(2) in blank control group (q=3.506, 3.973, 3.856, 5.025, P<0.05 or P<0.01). After treatment of 3 and 6 days, the wound areas of mice in L. lactis thermo-sensitive hydrogel group were significantly smaller than those in thermo-sensitive hydrogel alone group (q=3.739, 3.739, P<0.05). After 12 days of treatment, compared with those in blank control group and thermo-sensitive hydrogel alone group, the wound granulation tissue of mice in L. lactis thermo-sensitive hydrogel group was thicker, with significantly reduced iNOS positive cells and increased CD206 positive cells in wound tissue. (5) After 1 day of treatment, the mRNA expressions of IL-1β, TNF-α, and nuclear factor κB in the wound tissue of mice in wound alone group were significantly higher than those of normal skin tissue of mice in normal skin group (q=9.253, 4.819, 6.020, P<0.01) but similar to those in L. lactis thermo-sensitive hydrogel group (q=2.850, 2.735, 2.556, P>0.05). The peripheral blood leukocyte count, lymphocyte count, and monocyte count of mice in wound alone group were significantly higher than those in normal skin group (q=3.523, 5.373, 5.279, P<0.05 or P<0.01) but similar to those in L. lactis thermo-sensitive hydrogel group (q=0.621, 1.240, 1.293, P>0.05). The serum L-lactic acid concentration of mice in the three groups remained within the normal range and the overall comparison among them was not statistically significant (F=4.095, P>0.05). Conclusions: The L. lactis thermo-sensitive hydrogel was safe to use locally on the wounds of diabetic mice with full-thickness skin defects. It can produce and deliver lactic acid in situ, promote the polarization of macrophages from M1 to M2, reshape the wound healing microenvironment, and promote efficient wound healing.

Single-cell gene profiling and lineage tracing analyses revealed novel mechanisms of endothelial repair by progenitors

Stem/progenitor cells (SPCs) have been implicated to participate in vascular repair. However, the exact role of SPCs in endothelial repair of large vessels still remains controversial. This study aimed to delineate the cellular heterogeneity and possible functional role of endogenous vascular SPCs in large vessels. Using single-cell RNA-sequencing (scRNA-seq) and genetic lineage tracing mouse models, we uncovered the cellular heterogeneity of SPCs, i.e., c-Kit+ cells in the mouse aorta, and found that endogenous c-Kit+ cells acquire endothelial cell fate in the aorta under both physiological and pathological conditions. While c-Kit+ cells contribute to aortic endothelial turnover in the atheroprone regions during homeostasis, recipient c-Kit+ cells of nonbone marrow source replace both luminal and microvessel endothelial cells in transplant arteriosclerosis. Single-cell pseudotime analysis of scRNA-seq data and in vitro cell experiments suggest that vascular SPCs display endothelial differentiation potential and undergo metabolic reprogramming during cell differentiation, in which AKT/mTOR-dependent glycolysis is critical for endothelial gene expression. These findings demonstrate a critical role for c-Kit lineage cells in aortic endothelial turnover and replacement, and may provide insights into therapeutic strategies for vascular diseases.

[Early onset epileptic encephalopathy caused by mitochondrial arginyl-tRNA synthetase gene deficiency: report of two cases and literature review]

Objective: To summarize the clinical features of two early onset epileptic encephalopathy (EOEE) patients with arginyl-tRNA synthetase (RARS2) gene variations and to review related literature. Methods: The clinical data and genetic features of two pontocerebellar hypoplasia type 6 (PCH6) patients with RARS2 variation diagnosed by the Department of Neurology, Beijing Children's Hospital from January 2017 to December 2018 were analyzed retrospectively. A literature search with "RARS2" "pontocerebellar hypoplasia type 6" and "early onset epileptic encephalopathy" as key words was conducted at China national knowledge infrastructure (CNKI), Wanfang Data Knowledge Service Platform and PubMed (up to May 2020), literature about RARS2 gene variation patients and their complete clinical data were chosen and reviewed. Results: The onset age of the two cases (1 male, 1 female) were 2 months and 29 days respectively and the early onset symptom of them was epileptic encephalopathy. The main symptoms included seizures, development delay, microcephaly and lactic acidosis. In addition to these symptoms, the female also had dyspnea, hypoglycemia and metabolic acidosis after birth. Brain magnetic resonance imaging (MRI) of the two patients were normal at first. Follow up at four-month (case 1) and eight-month (case 2) MRI showed atrophy of cerebral and cerebellar, but the pons was not affected. All four heterozygous variations in RARS2 gene revealed by whole-exome sequencing (p.Arg560His and p.Arg6His from case 1, p.Arg254Trp and p.Phe5Ser from case 2) were novel. No eligible reports were found in Chinese journals, while 17 reports were found in English literature. Excluded cases with incomplete data together with these two cases, a total of 34 patients from 20 families were found. All patients had developmental delay while 94% (32/34) patients showed the initial symptoms within 3 months, 93% (28/30) patients were diagnosed as epilepsy, 89% (25/28) patients had progressively microcephaly and 52% (16/31) cases did not show the pons atrophy on brain MRI. Twenty of 28 cases (71%) were refractory epilepsy. There were 31 types of gene variations and most of them were missense variations (21/31, 68%). Conclusions: The majority of PCH6 cases caused by RARS2 gene variation show the initial symptoms within 3 months, characterized by EOEE, most of them are refractory epilepsy, accompanied by developmental delay, microcephaly and increased lactic acid. Brain MRI indicates progressive cerebral or pontocerebellar atrophy.

Geospatial Distribution and Predictors of Mortality in Hospitalized Patients With COVID-19: A Cohort Study

BACKGROUND

The global coronavirus disease 2019 (COVID-19) pandemic offers the opportunity to assess how hospitals manage the care of hospitalized patients with varying demographics and clinical presentations. The goal of this study was to demonstrate the impact of densely populated residential areas on hospitalization and to identify predictors of length of stay and mortality in hospitalized patients with COVID-19 in one of the hardest hit counties internationally.

METHODS

This was a single-center cohort study of 1325 sequentially hospitalized patients with COVID-19 in New York between March 2, 2020, to May 11, 2020. Geospatial distribution of study patients' residences relative to population density in the region were mapped, and data analysis included hospital length of stay, need and duration of invasive mechanical ventilation (IMV), and mortality. Logistic regression models were constructed to predict discharge dispositions in the remaining active study patients.

RESULTS

The median age of the study cohort (interquartile range [IQR]) was 62 (49-75) years, and more than half were male (57%) with history of hypertension (60%), obesity (41%), and diabetes (42%). Geographic residence of the study patients was disproportionately associated with areas of higher population density (r s = 0.235; P = .004), with noted "hot spots" in the region. Study patients were predominantly hypertensive (MAP > 90 mmHg; 670, 51%) on presentation with lymphopenia (590, 55%), hyponatremia (411, 31%), and kidney dysfunction (estimated glomerular filtration rate < 60 mL/min/1.73 m2; 381, 29%). Of the patients with a disposition (1188/1325), 15% (182/1188) required IMV and 21% (250/1188) developed acute kidney injury. In patients on IMV, the median (IQR) hospital length of stay in survivors (22 [16.5-29.5] days) was significantly longer than that of nonsurvivors (15 [10-23.75] days), but this was not due to prolonged time on the ventilator. The overall mortality in all hospitalized patients was 15%, and in patients receiving IMV it was 48%, which is predicted to minimally rise from 48% to 49% based on logistic regression models constructed to project disposition in the remaining patients on ventilators. Acute kidney injury during hospitalization (odds ratioE, 3.23) was the strongest predictor of mortality in patients requiring IMV.

CONCLUSIONS

This is the first study to collectively utilize the demographics, clinical characteristics, and hospital course of COVID-19 patients to identify predictors of poor outcomes that can be used for resource allocation in future waves of the pandemic.

MiR-4513 mediates the proliferation and apoptosis of oral squamous cell carcinoma cells via targeting CXCL17

OBJECTIVE

Emerging evidence has indicated that microRNAs (miRNAs) play crucial roles in regulating cancer carcinogenesis; however, its role in oral squamous cell carcinoma (OSCC) remains largely unknown. Our work was aimed to investigate the role of miR-4513 in regulating OSCC cells behaviors.

MATERIALS AND METHODS

MiR-4513 expression in OSCC cells was analyzed by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell proliferation, migration, invasion, and apoptosis were analyzed by the cell counting kit-8 (CCK-8) assay, wound-healing assay, transwell invasion assay, and flow cytometry, respectively. The connections of miR-4513 and CXC ligand 17 (CXCL17) were analyzed by luciferase reporter assay and Western blot assay.

RESULTS

MiR-4513 expression was found elevated in the OSCC cell lines. The downregulation of miR-4513 expression inhibits cell proliferation, migration, invasion and, at the same time, promotes apoptosis. Furthermore, we validated CXCL17 as a direct target of miR-4513. Knocking down the expression of CXCL17, inhibited the effects of miR-4513 on OSCC cell behaviors.

CONCLUSIONS

Our results suggested the oncogenic role of miR-4513 in OSCC, and therefore it might be used as a target for the OSCC treatment.