Identification of osteogenic differentiation-related miRNA-mRNA regulatory network of human periodontal ligament stem cells.

This study aimed to investigate the hub genes and miRNA-mRNA regulatory network around periodontal ligament stem cells (PDLSC) for osteogenic differentiation through bioinformatic analysis. The dataset with osteogenic differentiation of human PDLSC was downloaded from the GEO database. The Weighted gene coexpression network analysis (WGCNA) was performed to identify key modules and hub genes. In addition, differentially expressed genes (DEGs) analysis was conducted with limma. The functional enrichment of differentially expressed hub genes was implemented with KEGG and GSEA analysis. The targeted genes of differentially expressed miRNA were predicted based on miRWalk database. The miRNA-mRNA interaction network of osteogenic differentiation of PDLSC was constructed and visualized. The WGNCA results showed that the light-cyan module was positively correlated with osteogenic differentiation (r=0.98, P<0.05). A total of 3125 hub genes and 1426 differentially expressed hub genes were detected in OG group. Innate immune-related signaling pathways and metabolic pathways were involved in the osteogenic differentiation. In addition, total of 2 upregulated miRNAs with 63 targeted DEGs and 6 downregulated miRNAs with 214 targeted DEGs were detected, which contributed to osteogenic differentiation by regulating amino acid metabolism signaling pathway. We identified hub genes and miRNA-mRNA regulatory network contributing to osteogenic differentiation of human PDLSC, which will provide novel strategy for periodontal disease therapy.

Peripheral Th and NK cells are associated with response to lenvatinib plus PD-1 inhibitor in unresectable hepatocellular carcinoma.

The value of peripheral blood lymphocyte subpopulations in predicting responses to lenvatinib combination with programmed death-1 (PD-1) inhibitors in unresectable hepatocellular carcinoma (HCC) was investigated. Fifteen patients received objective responses (OR) and sixteen patients had non-objective responses (NOR) were analyzed. The counts of peripheral blood lymphocyte subpopulations from patients were measured before treatment, second (at week 3), and third doses (at week 6) of the PD-1 inhibitor administration, and correlated with responses. Helper T (Th) cells and natural killers (NK) cells were more abundant in the OR group and found to be important predictors of OR in a stepwise multivariate logistic regression analysis. These cutoff values of Th and NK cells could help to distinguish OR from NOR cases accurately and provide clinical benefits.

Conversion surgery for advanced hepatocellular carcinoma after combination treatment of lenvatinib and camrelizumab: a case report.

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive malignancy with high morbidity and mortality. Conversion therapy can improve surgical resection rate and prolong survival time for patients with advanced HCC. We show that combination therapy with lenvatinib and camrelizumab is a novel approach to downstage unresectable HCC. CASE PRESENTATION: A 49-year-old man was diagnosed with massive HCC with hilar lymph node and lung metastases. Since radical resection was not feasible, lenvatinib and camrelizumab were administered as first-line therapy. After 10 cycles of camrelizumab and continuous oral administration of lenvatinib, the tumor exhibited striking shrinkage in volume indicating a partial radiological response, accompanied by a reduction in the alpha-fetoprotein levels, followed by salvage resection. Intriguingly, an improvement in predictive biomarkers, like lactate dehydrogenase (LDH) and neutrophil-to-lymphocyte ratio (NLR), was observed. Notably, the pathological examination found high levels of necrosis in the resected tumor, and flow cytometry analysis indicated a significant increase in the ratio of CD5+ and CD5- B lymphocytes in the peripheral blood. After the treatment, the overall survival period was over 24 months, and no recurrence was observed 17-month post-surgery. CONCLUSIONS: A combination of lenvatinib and camrelizumab may be a new conversion therapy for initially unresectable HCC to resectable HCC, thus contributing to improve the disease prognosis. In addition, the combination regimen could cause an activated immune response, and LDH, NLR, and CD5+ B-cell levels might be predictors for immunotherapy efficacy.

A novel prognostic signature based on four glycolysis-related genes predicts survival and clinical risk of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common cancer with limited cure and poor survival. In our study, a bioinformatic analysis was conducted to investigate the role of glycolysis in the pathogenesis and progression of HCC. METHODS: Single-sample gene set enrichment analysis (ssGESA) was used to calculate enrichment scores for each sample in TCGA-LIHC and GEO14520 according to the glycolysis gene set. Weighted gene co-expression network analysis identified a gene module closely related to glycolysis, and their function was investigated. Prognostic biomarkers were screened from these genes. Cox proportional hazard model and least absolute shrinkage and selection operator regression were used to construct the prognostic signature. Kaplan-Meier (KM) and receiver operating characteristic (ROC) curve analyses evaluated the prediction performance of the prognostic signature in TCGA-LIHC and ICGC-LIRI-JP. Combination analysis data of clinical features and prognostic signature constructed a nomogram. Area under ROC curves and decision curve analysis were used to compare the nomogram and its components. RESULTS: The glycolysis pathway was upregulated in HCC and was unfavorable for survival. The determined gene module was mainly enriched in cell proliferation. A prognostic signature (CDCA8, RAB5IF, SAP30, and UCK2) was developed and validated. KM and ROC curves showed a considerable predictive effect. The risk score derived from the signature was an independent prognostic factor. The nomogram increased prediction efficiency by combining risk signature and TNM stage and performed better than component factors in net benefit. CONCLUSION: The gene signature may contribute to individual risk estimation, survival prognosis, and clinical management.

Lysobacter chengduensis sp. nov. Isolated from the Air of Captive Ailuropoda melanoleuca Enclosures in Chengdu, China.

A novel bacterial strain, designated as CF21(T), was isolated from the air of Ailuropoda melanoleuca enclosures in China. Cells were gram-negative, aerobic, non-motile, and rod shaped. Strain CF21(T) grew at 10-40 °C (optimum 28-30 °C) and pH 6.0-9.0 (optimum pH 7.0-8.0) and in the presence of NaCl concentrations ranging from 0.0% (w/v) to 2.0 % (optimum 0.0-1.0%). 16SrRNA gene sequence analysis indicated that strain CF21(T) belonged to genus Lysobacter within class Gammaproteobacteria and was most closely related to Luteimonas dalianensi OB44-3(T) (95.8% similarity), Lysobacter ruishenii CTN-1(T) (95.1%), Lysobacter spongiicola KMM329(T) (94.8 %), and Lysobacter daejeonensis GH1-9T (94.6%). The genomic G+C DNA content was 68.72 mol%. Major cellular fatty acids of CF21(T) were iso-C16:0 (30.22%), iso-C15:0 (25.70%), and the sum of 10-methyl C16 : 0 and/or iso-C17 : 1ω9c (21.94%). The prominent isoprenoid quinone was ubiquinone 8 (Q-8). Primary polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unknown phospholipid. DNA sequence relatedness between strain CF21(T) and L. ruishenii CTN-1(T) was 56%, which was clearly below the 70% threshold for prokaryotic species delineation. These analyses indicated that CF21(T) is a novel member of genus Lysobacter, for which the name Lysobacter chengduensis sp. nov. is proposed. The type strain is CF21(T) (=CGMCC1.15145(T) = DSM 100306(T)).

Efficacy and Safety of Coenzyme Q10 Supplementation in the Treatment of Polycystic Ovary Syndrome: a Systematic Review and Meta-analysis.

The aim of this study is to evaluate the efficacy and safety of coenzyme Q10 supplementation in the treatment of polycystic ovary syndrome (PCOS). We first searched PubMed, Wanfang Data, CNKI, Embase, ClinicalTrial.gov, and other databases. The retrieval time from the establishment of the database to January 2021. We collected relevant randomized controlled trials (RCTs) about coenzyme Q10 in the treatment of PCOS. Risk of bias assessment and meta-analysis of RCTs were performed using RevMan 5.0 software. This systematic review and meta-analysis include a total of 9 RCTs involving 1021 patients. The results show that the addition of coenzyme Q10 may improve insulin resistance (HOMA-IR (WMD - 0.67 [- 0.87, - 0.48], P < 0.00001); fasting insulin (WMD - 1.75 [- 2.65, - 0.84], P = 0.0002); fasting plasma glucose (WMD - 5.20 [- 8.86, - 1.54], P = 0.005)), improve sex hormone levels (FSH (SMD - 0.45 [0.11, 0.78], P = 0.009); testosterone (SMD - 0.28 [- 0.49, - 0.06], P = 0.01)), and improve blood lipids (triglycerides (SMD - 0.49 [- 0.89, - 0.09], P = 0.02); total cholesterol (SMD - 0.35 [- 0.56, - 0.14], P = 0.001); LDL-C (SMD - 0.22 [- 0.43, - 0.01], P = 0.04); HDL-C (SMD 0.22 [0.01, 0.43], P = 0.04)). Only one RCT reported adverse events, and they found that patients had no adverse effects or symptoms following supplementation. Based on the current evidence, it could be considered that the addition of CoQ10 is a safe therapy to improve PCOS by improving insulin resistance (reduce HOMA-IR, FINS, FPG), increasing sex hormone levels (increase FSH, reduce testosterone), and improving blood lipids (reduce TG, TC, LDL-C, and increased HDL-C).

The characteristics of Laennec's capsule around the hepatic veins: A histological study based on 71 liver surgical specimens.

Background: Laennec's capsule is a fibrous membrane attached to the surface of the liver, which is independent of the hepatic veins. However, the presence of Laennec's capsule surrounding the peripheral hepatic veins is controversial. This study aims to describe the characteristic of Laennec's capsule around the hepatic veins at all levels. Methods: Seventy-one hepatic surgical specimens were collected along the cross and longitudinal sections of the hepatic vein. Tissue sections of 3-4 mm were cut and stained with hematoxylin and eosin (H&E), resorcinol-fuchsin (R&F), and Victoria blue (V&B). Elastic fibers were observed around the hepatic veins. They were measured using K-Viewer software. Results: Morphologically, we observed a thin, dense fibrous layer (so-called Laennec's capsule) around the hepatic veins at all levels, which was different from the thick elastic fibers of the hepatic vein wall. Therefore, there was a potential gap between Laennec's capsule and the hepatic veins. Laennec's capsule was visualized significantly better with R&F and V&B staining compared to H&E staining. The thickness of Laennec's capsule around the main, first, and secondary branches of the hepatic vein were 79.86 ± 24.20 µm, 48.41 ± 18.25 µm, and 23.56 ± 10.03 µm in the R&F staining, and 80.15 ± 21.85 µm, 49.46 ± 17.52 µm, and 25.05 ± 11.03 µm in the V&B staining, respectively. They were significantly different from each other (P < .001). Conclusion: The hepatic veins were surrounded by Laennec's capsule at all levels, including the peripheral hepatic veins. However, it is thinner along the vein branches. The gap between the Laennec's capsule and hepatic veins shows potential supplemental value for liver surgery.

A novel clinical model for risk prediction and stratification of new-onset diabetes mellitus after distal pancreatectomy.

Background: The incidence of new-onset diabetes mellitus (NODM) after distal pancreatectomy (DP) remains high. Few studies have focused on NODM in patients with pancreatic benign or low-grade malignant lesions (PBLML). This study aimed to develop and validate an effective clinical model for risk prediction and stratification of NODM after DP in patients with PBLML. Methods: A follow-up survey was conducted to investigate NODM in patients without preoperative DM who underwent DP. Four hundred and forty-eight patients from Peking Union Medical College Hospital (PUMCH) and 178 from Guangdong Provincial People's Hospital (GDPH) met the inclusion criteria. They constituted the training cohort and the validation cohort, respectively. Univariate and multivariate Cox regression, as well as least absolute shrinkage and selection operator (LASSO) analyses, were used to identify the independent risk factors. The nomogram was constructed and verified. Concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) were applied to assess its predictive performance and clinical utility. Accordingly, the optimal cut-off point was determined by maximally selected rank statistics method, and the cumulative risk curves for the high- and low-risk populations were plotted to evaluate the discrimination ability of the nomogram. Results: The median follow-up duration was 42.8 months in the PUMCH cohort and 42.9 months in the GDPH cohort. The postoperative cumulative 5-year incidences of DM were 29.1% and 22.1%, respectively. Age, body mass index (BMI), length of pancreatic resection, intraoperative blood loss, and concomitant splenectomy were significant risk factors. The nomogram demonstrated significant predictive utility for post-pancreatectomy DM. The C-indexes of the nomogram were 0.739 and 0.719 in the training and validation cohorts, respectively. ROC curves demonstrated the predictive accuracy of the nomogram, and the calibration curves revealed that prediction results were in general agreement with the actual results. The considerable clinical applicability of the nomogram was certified by DCA. The optimal cut-off point for risk prediction value was 2.88, and the cumulative risk curves of each cohort showed significant differences between the high- and low-risk groups. Conclusions: The nomogram could predict and identify the NODM risk population, and provide guidance to physicians in monitoring and controlling blood glucose levels in PBLML patients after DP.

Laboratory scoring system to predict hepatic indocyanine green clearance ability during fluorescence imaging-guided laparoscopic hepatectomy.

BACKGROUND: Indocyanine green (ICG) fluorescence played an important role in tumor localization and margin delineation in hepatobiliary surgery. However, the preoperative regimen of ICG administration was still controversial. Factors associated with tumor fluorescence staining effect were unclear. AIM: To investigate the preoperative laboratory indexes corelated with ICG fluorescence staining effect and establish a novel laboratory scoring system to screen specifical patients who need ICG dose adjustment. METHODS: To investigate the predictive indicators of ICG fluorescence characteristics in patients undergoing laparoscopic hepatectomy from January 2018 to January 2021 were included. Blood laboratory tests were completed within 1 wk before surgery. All patients received 5 mg ICG injection 24 h before surgery for preliminary tumor imaging. ImageJ software was used to measure the fluorescence intensity values of regions of interest. Correlation analysis was used to identify risk factors. A laboratory risk model was established to identify individuals at high risk for high liver background fluorescence. RESULTS: There were 110 patients who were enrolled in this study from January 2019 to January 2021. The mean values of fluorescence intensity of liver background (FI-LB), fluorescence intensity of gallbladder, and fluorescence intensity of target area were 18.87 ± 17.06, 54.84 ± 33.29, and 68.56 ± 36.11, respectively. The receiver operating characteristic (ROC) curve showed that FI-LB was a good indicator for liver clearance ability [area under the ROC curve (AUC) = 0.984]. Correlation analysis found pre-operative aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, adenosine deaminase, and lactate dehydrogenase were positively associated with FI-LB and red blood cell, cholinesterase, and were negatively associated with FI-LB. Total laboratory risk score (TLRS) was calculated according to ROC curve (AUC = 0.848, sensitivity = 0.773, specificity = 0.885). When TLRS was greater than 6.5, the liver clearance ability of ICG was considered as poor. CONCLUSION: Preoperative laboratory blood indicators can predict hepatic ICG clearance ability. Surgeons can adjust the dose and timing of ICG preoperatively to achieve better liver fluorescent staining.

A Pyroptosis-Based Prognostic Model for Immune Microenvironment Estimation of Hepatocellular Carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC), an aggressive malignant tumor, has a high incidence and unfavorable prognosis. Recently, the synergistic effect of pyroptosis in antitumor therapy and regulation of tumor immune microenvironment has made it possible to become a novel therapeutic method, but its potential mechanism still needs further exploration. METHODS: Differentially expressed genes with prognostic value in Liver Hepatocellular Carcinoma Project of The Cancer Genome Atlas (TCGA-LIHC) cohort were screened and incorporated into the risk signature by Cox proportional hazards regression model and least absolute shrinkage and selection operator. Kaplan-Meier (KM) curves and receiver operating characteristic (ROC) curves were applied to conduct survival comparisons and estimate prediction ability. The dataset of Liver Cancer-RIKEN, Japan Project from International Cancer Genome Consortium (ICGC-LIRI-JP) cohort was used to verify the reliability of the signature. Correlation analysis between clinicopathological characteristics, immune infiltration, drug sensitivities, and risk scores was conducted. Functional annotation analyses were performed for the genes differentially expressed between high-risk and low-risk groups. RESULTS: A risk signature consisting of 6 pyroptosis-related genes in HCC was developed and validated. KM curves and ROC curves revealed its considerable predictive accuracy. Higher risk scores meant more advanced grade, higher alpha-fetoprotein level, and stronger invasive ability. Overexpressed genes in high-risk population were more enriched in the immune-associated pathways, and these patients might be more sensitive to immune checkpoint inhibitors instead of Sorafenib. Intriguingly, 6 identified genes were promising to be prognostic biomarkers and therapeutic targets of HCC. CONCLUSIONS: The signature may have crucial clinical significance in predicting survival prognosis, immune infiltration, and drug efficacy based on pyroptosis-related genes.

Efficacy and Safety of Curcumin Supplement on Improvement of Insulin Resistance in People with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Diabetes is a major public health concern. In addition, there is some evidence to support curcumin as part of a diabetes treatment program. METHODS: Data from randomized controlled trials were obtained to assess the effects of curcumin versus placebo or western medicine in patients with type 2 diabetes mellitus (T2DM). The study's registration number is CRD42018089528. The primary outcomes included homeostasis model assessment-insulin resistance (HOMA-IR), glycosylated hemoglobin (HbAlc), total cholesterol (TC), and triglyceride (TG). RESULTS: Four trials involving 453 patients were included. The HOMA-IR of curcumin group is lower in Asia (WMD: -2.41, 95% CI: -4.44 to -0.39, P=0.02) and the Middle East subgroups (WMD: -0.60, 95% CI: -0.74 to -0.46, P < 0.00001). The HbAlc in the curcumin group is lower than that in the control group (WMD: -0.69; 95% CI: -0.91, -0.48; P < 0.0001). The TC and TG levels of the curcumin group are lower in the Asia subgroup (TC: WMD: -23.45, 95% CI: -40.04 to -6.84, P=0.006; TG: WMD: -54.14, 95% CI: -95.71 to -12.57, P=0.01), while in the Middle East the difference was of not statistically significant (TC: WMD: 22.91, 95% CI: -16.94 to 62.75, P=0.26; TG: WMD: -4.56, 95% CI: -19.28 to 10.16, P=0.54). CONCLUSION: Based on the current evidence, curcumin may assist in improving the insulin resistance, glycemic control, and decreased TG and TC in patients with T2DM.

Efficacy and Safety of Resveratrol Supplements on Blood Lipid and Blood Glucose Control in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Diabetes is a major public health concern. Resveratrol has shown great beneficial effects on hyperglycemia and insulin resistance and as an antioxidant. METHODS: We searched the Chinese and English databases (such as CNKI, PubMed, and Embase) and extracted data from randomized controlled trials (RCTs). Then, RevMan 5.3 was used for bias risk assessment and meta-analysis. The primary outcome indicators include insulin-resistance-related indicators and blood-lipid-related indicators. This systematic review and meta-analysis was registered in PROSPERO (CRD42018089521). RESULTS: Fifteen RCTs involving 896 patients were included. For insulin-resistance-related indicators, the summary results showed that, compared with the control group, homeostasis model assessment for insulin resistance (HOMA-IR) in the resveratrol group is lower (WMD: -0.99; 95% CI -1.61, -0.38; P=0.002). For blood-lipid-related indicators, the total cholesterol (TC) and triglyceride (TG) in the resveratrol group is of no statistical significance (for TC, WMD: -7.11; 95% CI -16.28, 2.06; P=0.13; for TG, WMD: -2.15; 95% CI -5.52, 1.22; P=0.21). For adverse events, the summary results showed that there was no statistical difference in the incidence of adverse events between the resveratrol and control groups (WMD: 2; 95% CI 0.44, 9.03; P=0.37). CONCLUSION: Based on the current evidence, resveratrol may improve insulin resistance, lower fasting blood glucose and insulin levels, and improve oxidative stress in patients with type 2 diabetes mellitus.

A Novel Blood Index-Based Model to Predict Hepatitis B Virus-Associated Hepatocellular Carcinoma Recurrence After Curative Hepatectomy: Guidance on Adjuvant Transcatheter Arterial Chemoembolization Choice.

BACKGROUND: Postoperative recurrence is a significant obstacle in hepatocellular carcinoma (HCC) treatment. This study aimed to construct a blood index-based model to predict hepatitis B virus-associated HCC (HBV-HCC) recurrence after curative hepatectomy. METHODS: A total of 370 patients who received initially curative hepatectomy for HBV-HCC were included in this study. A novel blood index signature (BIS) was identified and systematically analyzed for its recurrence predictive value. Following this, multivariate Cox regression analysis was performed to build a blood index-based nomogram. RESULTS: A BIS based on the aminotransferase-to-platelet ratio index and a systemic inflammatory response index was used to construct a nomogram. The model showed good clinical applicability and reliability. Notably, the patients in the high recurrence risk group tended to benefit from adjuvant transcatheter arterial chemoembolization (TACE). CONCLUSION: A reliable model was constructed to predict the HBV-HCC recurrence after curative hepatectomy. This model can guide the surgeons in selecting patients with high recurrence risk patients who may benefit from adjuvant TACE.

Construction of Nomograms for Predicting Lung and Bone Metastases in Patients with Intrahepatic Cholangiocarcinoma and Identification of Patients Who Can Benefit from Chemotherapy.

OBJECTIVE: The purpose of our study is to build nomograms for predicting the possibility of lung metastasis (LM) and bone metastasis (BM) in patients with intrahepatic cholangiocarcinoma (ICC). METHODS: 1527 patients diagnosed with ICC between 2010 and 2016 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable logistic regression analyses were used to recognize the predictors of LM and BM, respectively. Then two nomograms were established. We applied the C-index, calibration plot, receiver-operating characteristic (ROC) curve, and decision curve analysis (DCA) to evaluate the novel nomograms. The maximum values of the Youden indexes from the ROC curves were utilized to select the cutoff points of the nomograms. The Kaplan-Meier survival curves were used to evaluate the effect of chemotherapy in different groups. The bootstrap resampling method was chosen for internal validation. RESULTS: Five predictors for LM and three predictors for BM were identified, and two nomograms were constructed. The nomograms had high values of C-indexes, reaching 0.821 (95% CI 0.772-0.871) for LM and 0.759 (95% CI 0.700-0.818) for BM. C-indexes of 0.814 for LM and 0.749 for BM were also observed in internal validation. The calibration plots, ROC curves, and DCAs exhibited favorable performances for predicting LM and BM. The cutoff points of total points in nomograms were 108 for LM and 144 for BM, which could distinguish between high-risk and low-risk groups for LM and BM. Chemotherapy is suggested to undergo for patients in high-risk groups. CONCLUSIONS: The nomograms could assess the possibility of LM and BM in ICC patients and determine the optimal treatment.

Crystal Structure of ATP-Bound Human ABCF1 Demonstrates a Unique Conformation of ABC Proteins.

Gene translation requires the correct selection of start codon AUG in mRNA. ATP-binding cassette subfamily F member 1 (ABCF1) plays a key role in the accuracy of start codon selection. However, the function of human ABCF1 is not clearly understood. Here, we solve the crystal structure of an ATP-bound wild-type human ABCF1 at 2.3-Å resolution. The comparative studies indicate that the structure is in a pre-activation intermediate conformation. This conformation is stabilized by the interaction between ATP and protein. Thus, we propose that this conformation is an important step in the activation of ABCF1. This study extends our understanding of ABC (ATP-binding cassette) protein activation at the molecular level.

Relationship between drug resistance and the clustered, regularly interspaced, short, palindromic repeat-associated protein genes cas1 and cas2 in Shigella from giant panda dung.

BACKGROUND: To detect drug resistance in Shigella obtained from the dung of the giant panda, explore the factors leading to drug resistance in Shigella, understand the characteristics of clustered, regularly interspaced, short, palindromic repeats (CRISPR), and assess the relationship between CRISPR and drug resistance. METHODS: We collected fresh feces from 27 healthy giant pandas in the Giant Panda Conservation base (Wolong, China). We identified the strains of Shigella in the samples by using nucleotide sequence analysis. Further, the Kirby-Bauer paper method was used to determine drug sensitivity of the Shigella strains. CRISPR-associated protein genes cas1 and cas2 in Shigella were detected by polymerase chain reaction (PCR), and the PCR products were sequenced and compared. RESULTS: We isolated and identified 17 strains of Shigella from 27 samples, including 14 strains of Shigella flexneri, 2 strains of Shigella sonnei, and 1 strain of Shigella dysenteriae. Further, drug resistance to cefazolin, imipenem, and amoxicillin-clavulanic acid was identified as a serious problem, as multidrug-resistant strains were detected. Further, cas1 and cas2 showed different degrees of point mutations. CONCLUSION: The CRISPR system widely exists in Shigella and shares homology with that in Escherichia coli. The cas1 and cas 2 mutations contribute to the different levels of resistance. Point mutations at sites 3176455, 3176590, and 3176465 in cas1 (a); sites 3176989, 3176992, and 3176995 in cas1 (b); sites 3176156 and 3176236 in cas2 may affect the resistance of bacteria, cause emergence of multidrug resistance, and increase the types of drug resistance.

Chryseobacterium chengduensis sp. nov. isolated from the air of captive giant panda enclosures in Chengdu, China.

A Gram-negative, aerobic, non-motile, rod-shaped bacterial strain, designated 25-1(T), was isolated from the air inside giant panda enclosures at the Chengdu Research Base of Giant Panda Breeding, China. Strain 25-1(T) grew optimally at pH 7.0-8.0, at 28-30 °C and in the presence of NaCl concentrations from 0.0% to 0.5 %. 16S rRNA gene sequence analysis indicated that strain 25-1(T) belongs to the genus Chryseobacterium within the family Flavobacteriaceae and is related most closely to C. carnis G81(T) (96.4% similarity), C. lathyri RBA2-6(T) (95.8% similarity), and C. zeae JM1085(T) (95.8% similarity). Its genomic DNA G+C molar composition was 36.2%. The major cellular fatty acids were iso-C15:0 (44.0%), iso-C17:0 3OH (19.8%) and C16:1 ω7c/16:1 ω6c (12.7%). The only isoprenoid quinone was menaquinone 6 (MK-6). The major polar lipids were phosphatidylethanolamine, two unidentified amino lipids and two unidentified lipids. The DNA-DNA relatedness between strain 25-1(T) and C. lathyri RBA2-6(T) was 38%. Phenotypic, genotypic, and phylogenetic characteristics indicated that strain 25-1(T) is a novel member of the genus Chryseobacterium, for which the name C. chengduensis sp. nov. is proposed. The type strain is 25-1(T) (CCTCC AB2015133(T)=DSM 100396(T)).

[Correlation of bone mineral density of the mandibular angle, hand and total body in 839 healthy individuals aged from 5 to 18 years].

OBJECTIVES: To investigate the correlation of bone mineral density (BMD) of mandibular angle, hand and total body in healthy individuals aged from 5 to 18 years. METHODS: Eight hundred and thirty-nine healthy individuals from 5 to 18 years old (422 males, 417 females) in 5 primary and secondary schools in Guangzhou were divided into 14 age groups. Dual energy X-ray absorptiometry (DXA) was used to measure the BMD of mandibular angle, hand and total body. The data were statistically analyzed using Pearson correlation analysis. RESULTS: The BMD of mandibular angle increased with age. In females, the BMD of mandibular angle increased quickly from 12 to 16 years old, and its increasing rate gradually slowed down after 16 years old. In males, the BMD of mandibular angle increased quickly after 14 years old, and its increase had not been stopped until 18 years old. Females in 12, 13, 14, 15, 16, 17-year-old group had significantly higher mandibular angle BMD [(0.95 ± 0.19), (1.01 ± 0.17), (1.11 ± 0.17), (1.25 ± 0.13), (1.28 ± 0.14), (1.30 ± 0.13) g/cm(2)] than males in the age-matched group (P < 0.05). There was no significant difference between mandibular angle BMD in males and in females at the age of 18, and from 5 to 11 years old (P > 0.05). For males, the mandibular angle BMD was highly correlated with age (r = 0.696, P < 0.001), hand BMD (r = 0.779, P < 0.001) and total body BMD (r = 0.831, P < 0.001). For females, the mandibular angle BMD was highly correlated with age (r = 0.795, P < 0.001), hand BMD (r = 0.839, P < 0.001) and total body BMD (r = 0.872, P < 0.001). CONCLUSIONS: The mandibular angle BMD in healthy individuals from 5 to 18 years old increased with age. The mandibular angle BMD was closely related to hand BMD and total body BMD.

Sensitive detection of Porcine circovirus-2 by droplet digital polymerase chain reaction.

Sensitive detection of Porcine circovirus-2 (PCV-2) is very important for surveillance of postweaning multisystemic wasting syndrome. Droplet digital polymerase chain reaction (ddPCR) is novel PCR method that can achieve high precision. Our study aimed to develop a sensitive assay utilizing ddPCR to detect PCV-2. Specificity of the assay was confirmed by the failure of amplification of DNA of other relevant viruses. The detection limit for ddPCR was 25 copies/µL, a 4-fold greater sensitivity than TaqMan real-time PCR. Both methods showed a high degree of linearity (R(2) = ~1), although TaqMan real-time PCR showed less sensitivity than ddPCR for clinical detection. Our findings indicate that ddPCR might represent a promising platform for detecting PCV-2 viral loads.