Metagenomic data-analysis reveals enrichment of lipopolysaccharide synthesis in the gut microbiota of atrial fibrillation patients / 中华心血管病杂志

Objective: To investigate the functional changes of key gut microbiota (GM) that produce lipopolysaccharide (LPS) in atrial fibrillation (AF) patients and to explore their potential role in the pathogenesis of AF. Methods: This was a prospective cross-sectional study. Patients with AF admitted to Beijing Chaoyang Hospital of Capital Medical University were enrolled from March 2016 to December 2018. Subjects with matched genetic backgrounds undergoing physical examination during the same period were selected as controls. Clinical baseline data and fecal samples were collected. Bacterial DNA was extracted and metagenomic sequencing was performed by using Illumina Novaseq. Based on metagenomic data, the relative abundances of KEGG Orthology (KO), enzymatic genes and species that harbored enzymatic genes were acquired. The key features were selected via the least absolute shrinkage and selection operator (LASSO) analysis. The role of GM-derived LPS biosynthetic feature in the development of AF was assessed by receiver operating characteristic (ROC) curve, partial least squares structural equation modeling (PLS-SEM) and logistic regression analysis. Results: Fifty nonvalvular AF patients (mean age: 66.0 (57.0, 71.3), 32 males(64%)) were enrolled as AF group. Fifty individuals (mean age 55.0 (50.5, 57.5), 41 males(82%)) were recruited as controls. Compared with the controls, AF patients showed a marked difference in the GM genes underlying LPS-biosynthesis, including 20 potential LPS-synthesis KO, 7 LPS-biosynthesis enzymatic genes and 89 species that were assigned as taxa harbored nine LPS-enzymatic genes. LASSO regression analysis showed that 5 KO, 3 enzymatic genes and 9 species could be selected to construct the KO, enzyme and species scoring system. Genes enriched in AF group included 2 KO (K02851 and K00972), 3 enzymatic genes (LpxH, LpxC and LpxK) and 7 species (Intestinibacter bartlettii、Ruminococcus sp. JC304、Coprococcus catus、uncultured Eubacterium sp.、Eubacterium sp. CAG:251、Anaerostipes hadrus、Dorea longicatena). ROC curve analysis revealed the predictive capacity of differential GM-derived LPS signatures to distinguish AF patients in terms of above KO, enzymatic and species scores: area under curve (AUC)=0.957, 95%CI: 0.918-0.995, AUC=0.940, 95%CI 0.889-0.991, AUC=0.972, 95%CI 0.948-0.997. PLS-SEM showed that changes in lipopolysaccharide-producing bacteria could be involved in the pathogenesis of AF. The key KO mediated 35.17% of the total effect of key bacteria on AF. After incorporating the clinical factors of AF, the KO score was positively associated with the significantly increased risk of AF (OR<0.001, 95%CI:<0.001-0.021, P<0.001). Conclusion: Microbes involved in LPS synthesis are enriched in the gut of AF patients, accompanied with up-regulated LPS synthesis function by encoding the LPS-enzymatic biosynthesis gene.

Increased early activation of CD56dimCD16dim/- natural killer cells in immunological non-responders correlates with CD4+ T-cell recovery / 中华医学杂志(英文版)

BACKGROUND@#Natural killer (NK) cells play a critical role in suppressing human immunodeficiency virus-1 (HIV-1) infection, but knowledge on whether and how NK cells affect immune reconstitution in HIV-1-infected individuals who receive antiretroviral therapy (ART) is limited.@*METHODS@#We performed a case-control study with 35 healthy individuals and 66 HIV-1-infected patients including 32 immunological non-responders (INRs) with poor CD4+ T-cell recovery (500 cells/μL after 4 years of ART). NK cell phenotype, receptor repertoire, and early activation in INRs and IRs were investigated by flow cytometry.@*RESULTS@#A significantly higher proportion of CD56dimCD16dim/- NK cells was observed in INRs than IRs before ART and after 4 years of ART. The number of CD56dimCD16dim/- NK cells was inversely correlated with CD4+ T-cell counts in INRs before ART (r = -0.344, P = 0.050). The more CD69-expressing NK cells there were, the lower the CD4+ T-cell counts and ΔCD4, and these correlations were observed in INRs after ART (r = -0.416, P = 0.019; r = -0.509, P = 0.003, respectively). Additionally, CD69-expressing CD56dimCD16dim/- NK cells were more abundant in INRs than those in IRs (P  = 0.018) after ART, both of which had an inverse association trend towards significance with CD4+ T-cell counts. The expression of the activating receptors NKG2C, NKG2D, and NKp46 on CD56dimCD16dim/- NK cell subsets were higher in IRs than that in INRs after 4 years of ART (all P < 0.01). Strong inverse correlations were observed between CD69 expression and NKG2C, NKG2A-NKG2C+, NKG2D, and NKp46 expression on CD56dimCD16dim/- NK cells in INRs after ART (NKG2C: r = -0.491, P = 0.004; NKG2A-NKG2C+: r = -0.434, P = 0.013; NKG2D: r = -0.405, P = 0.021; NKp46: r = -0.457, P = 0.008, respectively).@*CONCLUSIONS@#INRs had a larger number of CD56dimCD16dim/- NK cells characterized by higher activation levels than did IRs after ART. The increase in the CD56dimCD16dim/- NK cell subset may play an adverse role in immune reconstitution. Further functional studies of CD56dimCD16dim/- NK cells in INRs are urgently needed to inform targeted interventions to optimize immune recovery.

Enhancement of sodium taurocholate to the absorption of cefquinome

The objective of the research was to detect the enhancement effect of sodium taurocholate on the absorption of cefquinome both in Caco-2 cells and rats. The absorption efficiency of cefquinome was determined by high performance liquid chromatography and calculated with apparent permeability coefficients [Papp] after Caco-2 cell monolayers treated odium taurocholate [2 mmol/L] and cefquinome. The results showed that the absorption of cefquinome in Caco-2 cell monolayers was significantly increased with the sodium taurocholate [2mmol/L]. Similar results were also detected in the rats orally administrated with 1 mL PBS of cefquinome [20mg/mL] containing different concentration of sodium taurocholate [5 mmol/L, 10mmol/L and 20mmol/L] respectively. Compared with control group, sodium taurocholate at 10 and 20 mmol/L increased the absorption of cefquinome in rats from 0.26 +/- 0.04micro g/mL to 0.57 +/- 0.03micro g/mL, 0.78 +/- 0.07micro g/mL respectively. These results indicated that sodium taurocholate could increase the intestinal permeability in a concentration-dependent mode, which will be useful for clinical treatment

Pharmacological postconditioning with lactic acid and low dose edaravone could attenuate myocardial reperfusion injury through mitochondrial pathway / 中华心血管病杂志

<p><b>OBJECTIVE</b>To test the hypothesis that pharmacological postconditioning with lactic acid and low dose edaravone could mimic the upper trigger of mechanical postconditioning and relieve reperfusion injury through mitochondrial pathway.</p><p><b>METHODS</b>Rats were randomly divided into 6 groups (n = 18 each): sham, reperfusion/injury(I/R), postconditioning (IP), lactic acid (Lac, 60 µl), low dose edaravone (Eda, 3 µg/kg), and Lac+Eda. After 45 min myocardial ischemia, different drugs or saline were administrated around the infarct border according to different groups using micro syringe at the time of reperfusion. After 10 min reperfusion, right atrial plasma pH value was determined in all rats. Then the rats were sacrificed at 1, 6 and 24 h (n = 6 each), apoptotic index was measured by TUNEL, infarct area and ischemic area were measured through Evans blue-TTC double staining, mitochondrial absorbance, the contents of MDA and SOD in ischemic myocardium were detected by spectrophotometry, and the expression of apoptotic pathway molecules, such as Bcl-2, Bax and Cytochrome c (Cyt-c) , were detected by Western blot.</p><p><b>RESULTS</b>Right atrial plasma pH value was significantly lower, the content of MDA was significantly lower, and the content of SOD was significantly higher in IP and Lac+Eda groups than in I/R group (all P < 0.05). The mitochondrial absorbance in Lac+Eda group at all time points were all significantly higher than those in I/R group (all P < 0.05). The level of Bcl-2 in ischemic myocardium in Lac+Eda group was significantly higher than in I/R group (1.02 ± 0.19 vs.0.02 ± 0.01, P < 0.05), the level of Bax (0.38 ± 0.07 vs.2.40 ± 0.45, P < 0.05) and Cyt-c(0.78 ± 0.05 vs.6.54 ± 1.86, P < 0.05) were all lower than those in I/R group. The content of CK[(849 ± 228) vs.(1249 ± 211) U/L, P < 0.05] and CK-MB[(470 ± 266) vs. (966 ± 263) U/L, P < 0.05] in Lac+Eda group were all significantly lower than in I/R group, apoptotic index [(10.51 ± 1.52)% vs. (15.00 ± 1.90) %, P < 0.05] and infarct area [(27.12 ± 5.55)% vs. (45.66 ± 10.81)%, P < 0.05] in Lac+Eda group were all significantly lower than those in I/R group.</p><p><b>CONCLUSION</b>Pharmacological postconditioning with lactic acid and low dose edaravone could mimic the upper triggers of mechanical postconditioning and attenuate myocardial reperfusion injury through mitochondrial pathway.</p>

Cellular function of microRNA-15 family / 生理学报

microRNAs (miRNAs) are non-coding endogenous short RNAs which are involved in regulating gene expression at the post-transcriptional level. miR-15 family is increasingly found to play great roles in important cell processes, such as apoptosis, cell differentiation and stress response. Growing evidence indicates that miR-15 family members are implicated in tumor, cardiovascular disease and neurodegenerative disease. miRNAs have emerged as a new promising subset of therapeutic targets. The present paper reviewed the important function of miR-15 family and new approaches for miRNA-based therapy.

Steady-state pharmacokinetics of zidovudine in Chinese HIV-infected patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The pharmacokinetics of zidovudine (AZT) are possibly influenced by weight, age, sex, liver and renal functions, severity of disease, and ethnicity. Currently, little information is available on the steady-state pharmacokinetics of AZT in Chinese HIV-infected patients. The current study aimed to characterize the steady-state pharmacokinetics of AZT in a Chinese set-up.</p><p><b>METHODS</b>Eleven Chinese HIV-infected patients were involved in the steady-state pharmacokinetic study. In total, 300 mg of AZT, as a part of combination therapy, was given to patients, and serial blood samples were collected for 12 hours. The samples were measured by a high-performance liquid chromatography (HPLC) assay, and the results were analyzed by both the non-compartment model and the one-compartment model.</p><p><b>RESULTS</b>The C(max) of AZT in Chinese patients was higher than that in non-Asian patients. The half-life of AZT, analyzed by the non-compartment model (P = 0.02), in male patients ((1.02 ± 0.22) hours) was shorter than that of AZT in female patients ((1.55 ± 0.29) hours). The AZT clearance, analyzed by the one-compartment model (P = 0.045), in male patients ((262.60 ± 28.13) L/h) was higher than that in female patients ((195.85 ± 60.51) L/h).</p><p><b>CONCLUSION</b>The present study provides valuable information for the clinical practice of AZT-based highly active antiretroviral therapy in a Chinese set-up.</p>

Effect of ischemic postconditioning on activation of p38 mitogen activated protein kinase and cardiac myocyte apoptosis in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the change of phospho-p38 (P-p38) mitogen activated protein kinase(MAPK) and its influence on myocardial apoptosis in reperfusion injury in postconditioning.</p><p><b>METHODS</b>Totally 60 rats were equally and randomly divided into six groups: Sham group,reperfusion injury (R/I) group, postconditioning (Post) group, SB203580 (I_p38) group, anisomycin plus postconditioning (Ani+post) group,and anisomycin (Ani) group. After the model of acute myocardial infarction was established,placebo solution (DMSO), SB203580 (1 mg/kg), or anisomycin (2 mg/kg) was injected through jugular vein 5 minutes before reperfusion. Six hours later, 3 rats in each group were executed and the hearts were separated to measure the signaling molecules including phospho-p38,tumor necrosis factor-alpha (TNF-α), Caspase-8, Bcl-2/Bax, and cytochrome-c (Cyt-c). Twenty-four hours later,the hemodynamic data were measured in the remaining rats,and then blood was collected to determine the serum markers of cardiac damage. After that,hearts were separated to measure the infarction area and apoptosis.</p><p><b>RESULTS</b>Six hours after reperfusion,the expressions of P-p38 in Post and I_p38 group were significantly lower than those in R/I group (P<0.05), significantly higher in Ani+post and Ani group than in Post group (P<0.05), and significantly lower in Ani+post group than in R/I group (P<0.05). The expressions of TNF-α and Caspase-8 were significantly lower in Post and I_p38 group than in R/I group (P<.05) and significantly higher in Ani+post and Ani group than in Post group (P<0.05). The expression of TNF-α was significantly lower in Ani+post group than in R/I group (P<0.05). The expression of Bcl-2 was significantly higher in Post and I_p38 groups than in R/I group (P<0.05) and significantly lower in Ani+post and Ani groups than in Post group (P<0.05). The expression of Bax was significantly lower in Post and I_p38 groups than in R/I group (P<0.05) and were significantly higher in Ani+post and Ani group than in Post group (P<0.05). The expression of Cyt-c after the removal of the cytoplasm mitochondria was significantly lower in Post and I_p38 group than in R/I group (P<0.05) and was significantly higher in Ani+post and Ani group than in Post group (P<0.05). Twenty-four hours after reperfusion,the values of rate-pressure product and ± delta pressure/delta time max were significantly lower in R/I group than in Post and I_p38 groups (P<0.05) and was significantly higher in Post group than in Ani+post and Ani group (P<0.05). The apoptotic index (AI) was significantly lower in Post and I_p38 groups than in R/I group (P<0.05) and was significantly higher in Ani+post and Ani groups than in Post group (P<0.05). The values of creatine kinase and creatine kinase-MB were significantly lower in Post,Ani+post, and I_p38 groups than in R/I group (P<0.05) and were significantly higher in Ani+post and Ani group than in Post group (P<0.05). The area of necrosis/area at risk ratio was significantly lower in Post and I_p38 groups than in R/I group (P<0.05) and was significantly higher in Ani+post and Ani groups than in Post group (P<0.05).</p><p><b>CONCLUSION</b>Postconditioning can inhibit the phosphorylation of p38 MAPK,through which it can attenuate cardiac myocyte apoptosis by both extrinsic and mitochondria pathways.</p>

Treatment of chronic calcaneal osteomyelitis following internal fixation for calcaneal fractures / 中华创伤骨科杂志

Objective To study the treatment of the chronic calcaneus osteomyelitis combined with skin ulcers or defects of the posterior heel following internal fixation for calcaneal fractures.Methods From February 1999 to June 2005,17 cases of calcaneus osteomyelitis combined with skin ulcers or defects following internal fix- ation for their calcaneal fractures were treated with elimination of infection focuses and dead spaces,tissue trans- plants and continuous irrigation.Skin flaps or myocutaneous flaps were used to repair heel ulcers or defects and to fill the dead spaces.Drainage and irrigation tubes were placed into the flap covered areas to carry out the continuous irrigation.Results All the cases were followed up for 3 to 36 months(mean,25 months).All the grafts survived without recurrence of calcaneus osteomyelitis.Their posterior heels regained fair appearance.Thirteen cases obtained fine sensory recovery and friction tolerance and could walk with weight-bearing.Conclusion Calcaneus os- teomyelitis can be cured by simply and effectively tissue transplants and continuous irrigation,which can provide adequate anti-infection and improve blood circulation.