Objectives: To study the effects of Porphyromonas gingivalis (Pg) injected through tail vein on the molecular expression levels of biomarkers of neural stem cells (NSC) and neurons in the hippocampus of wild-type adult rats, and the effects on hippocampal neurogenesis. Methods: Eighteen male Sprague-Dawley (SD) rats were randomly divided into 3 groups based on the table of random numbers (n=6 in each group). In low-intensity group and high-intensity group, rats were injected intravenously through tail vein with 200 μl Pg ATCC33277 [1.0×103 and 1.0×108 colony forming unit (CFU), respectively] 3 times per week for 8 weeks. In the sham group, 200 μl of phosphate buffer saline (PBS) was given instead. Behavioral tests: the navigation and the exploration tests using Morris water maze (MWM) were applied to evaluate learning and memory ability of rats. Immunohistochemistry was performed to detect cells positively expressing nestin, doublecortin (DCX) and neuronal nuclei (NeuN) in the subgranular zone (SGZ) of rats in each group. Western blotting was used to evaluate the expression levels of nestin, DCX and NeuN in rat hippocampus. Results: Learning and memory abilities: on day 5 of navigation test, the lagency time was 22.83 (16.00, 38.34) s in the high-intensity group, significantly longer than the sham group [5.59 (5.41, 6.17) s] (t=-11.17, P<0.001). There were no significant differences between the low-intensity group [9.85 (8.75, 21.01) s] and the sham group (t=-6.83, P=0.080). Results in the exploration test showed that, in the high-intensity group, the number of fime crossing over the previous platform area within 60 s was 1.50 (1.00, 2.00), significantly less than the sham group [4.00 (2.75, 4.00)] (t=9.75, P=0.003); no significant differences between the low-intensity group [2.50 (2.00, 3.00)] and the sham one (t=4.50, P=0.382). Immunohistochemistry showed that the nestin+ cell density in the low-intensity group [(35.36±4.32) cell/mm2] and high-intensity group [(26.51±5.89) cell/mm2] were significantly lower than the sham group [(59.58±14.15) cell/mm2] (t=24.21, P=0.018; t=33.07, P=0.005); as for the mean absorbance of DCX+ cells, the low-intensity group (0.007±0.002) and the high-intensity group (0.006±0.002) were significantly lower than the sham group (0.011±0.001) (t=0.004, P=0.018; t=0.006, P=0.005); compared with the sham group [(1.13±0.14)×103 cell/mm2], the density of NeuN+ neurons in the high-intensity group [(0.75±0.08)×103 cell/mm2] was significantly reduced (t=0.38, P=0.017), and was not significantly changed in the low-intensity group [(0.88±0.19)×103 cell/mm2] (t=0.25, P=0.075). Western blotting results showed that, compared with the sham group, the expression levels of nestin, DCX, and NeuN were significantly reduced in the high-intensity group (t=0.74, P<0.001; t=0.18, P=0.014; t=0.35, P=0.008), but were not statistically changed in the low-intensity group (t=0.18, P=0.108; t=0.08, P=0.172; t=0.19, P=0.077). Conclusions: Pg injected through tail vein may reduce learning and memory abilities of wild-type rats, and may reduce the number of nestin, DCX, and NeuN-positive cells, and the protein expression levels of the above molecules in the hippocampus.目的： 观察尾静脉注射牙龈卟啉单胞菌（Porphyromonas gingivalis，Pg）对野生成年大鼠海马神经干细胞和神经元标志分子表达水平的影响，初步探讨Pg入血对海马神经发生的作用。 方法： 建立尾静脉注射Pg大鼠模型：18只雄性Sprague-Dawley（SD）大鼠按随机数字表法随机分为3组（每组6只）。低剂量组、高剂量组大鼠分别经尾静脉注射1.0×103 和1.0×108菌落形成单位（colony forming unit，CFU）的Pg菌液200 μl，假手术组大鼠注射等体积磷酸盐缓冲液（phosphate buffer saline，PBS），3组大鼠均每周注射3次，连续8周。行为学检测：应用莫里斯水迷宫（Morris water maze，MWM）定位航行实验、空间探索实验检测大鼠学习和记忆能力。免疫组织化学法检测各组大鼠海马颗粒下区（subgranular zone，SGZ）神经干细胞标志分子神经上皮干细胞蛋白（nestin）、神经母细胞和未成熟神经元标志分子双皮质素（doublecortin，DCX）、成熟神经元标志分子神经元核抗原（neuronal nuclei，NeuN）的阳性细胞分布。蛋白质印迹法检测各组大鼠海马组织nestin、DCX、NeuN的表达水平。 结果： 学习和记忆能力：MWM定位航行实验结果显示，第5天到达平台时间高剂量组［22.83（16.00，38.34）s］显著长于假手术组［5.59（5.41，6.17）s］（t=-11.17，P<0.001），低剂量组［9.85（8.75，21.01）s］与假手术组相比差异无统计学意义（t=-6.83，P=0.080）；MWM空间探索实验中60 s内穿越原平台位置次数，高剂量组［1.50（1.00，2.00）次］显著少于假手术组［4.00（2.75，4.00）次］（t=9.75，P=0.003），低剂量组［2.50（2.00，3.00）次］与假手术组相比差异无统计学意义（t=4.50，P=0.382）。免疫组织化学法结果显示，对于nestin阳性细胞密度，低剂量组［（35.36±4.32）个/mm2］和高剂量组［（26.51±5.89）个/mm2］均显著低于假手术组［（59.58±14.15）个/mm2］（t=24.21，P=0.018；t=33.07， P=0.005）；DCX阳性细胞平均吸光度值，低剂量组（0.007±0.002）和高剂量组（0.006±0.002）均显著低于假手术组（0.011±0.001）（t=0.004，P=0.018；t=0.006，P=0.005）；NeuN阳性神经元密度，高剂量组［（0.75±0.08）×103个/mm2］显著低于假手术组［（1.13±0.14）×103个/mm2］（t=0.38，P=0.017），低剂量组［（0.88±0.19）×103个/mm2］与假手术组相比差异无统计学意义（t=0.25，P=0.075）。蛋白质印迹法结果显示，与假手术组相比，高剂量组海马中nestin、DCX、NeuN表达水平均显著降低（t=0.74，P<0.001；t=0.18，P=0.014；t=0.35，P=0.008），低剂量组上述3个指标与假手术组相比差异均无统计学意义（t=0.18，P=0.108；t=0.08，P=0.172；t=0.19，P=0.077）。 结论： 尾静脉注射Pg后呈剂量依赖性降低野生大鼠学习和记忆能力，并显著降低大鼠海马神经干细胞和神经元标志分子nestin、DCX、NeuN阳性表达细胞数量和表达水平。.
Accurate assessment of infection presence risk level, timely diagnosis, and effective control are critical for decreasing mortality of Acute‑on‑chronic liver failure (ACLF). We aimed to develop and validate a novel diagnostic model to accurately assess infection presence risk level in ACLF patients. 185 ACLF patients with/without infection were enrolled, and their demographic, physical findings, immune-inflammatory, hepatic function, metabolism, and coagulation-fibrinolysis indicators were analyzed. Regression analysis was performed to identify the independent diagnostic parameters, which were further used to establish diagnostic models with a nomogram for visual. An area under receiver operating characteristic curve (AUROC), calibration plots, clinical impact curves, decision curve analysis, and net reclassification index were used to evaluate and identify the best model. An external validating cohort was introduced to verify the diagnostic accuracy. We screened out white blood cell (WBC) count, LYM%, blood urea nitrogen (BUN), and D-dimer for assessing infection presence risk levels in ACLF patients. WBD (WBC + BUN + D-dimer) was established and proposed as a novel diagnostic model for infection presence risk levels assessment in ACLF patients with an AUROC of 0.803 (95%CI 0.723-0.883), 0.885 (95%CI 0.786-0.984) in training and external cohorts, respectively. In stratification analysis by ACLF etiology and stages, WBD achieved an AUROC of 0.791 (95%CI 0.691-0.891) and 0.873 (95%CI 0.78-0.966) in HBV-related and early-stage patients, respectively. Whereas a higher AUROC of 0.905 (95%CI 0.807-1.00) in the early-stage of HBV-related ACLF patients indicated its optimum application scope. WBD, a novel laboratory-based nomogram, can serve as a decision-making support tool for clinicians to assess infection presence risk levels in ACLF patients.
Introduction Compression of the nerve root by a lumbar disc herniation can cause radiating pain in the lower limbs, and the nerve root decompression treatment may leave some patients with motor dysfunction and reduced sensory function. Studies have shown that nerve growth factor (NGF) can promote nerve growth and repair, but high doses, long duration, and immune response have become bottlenecks of its clinical application. Methods To overcome this obstacle, we developed Prussian blue (PBs) nanoparticles with the bio-delivery function and antioxidant effects of nanoenzymes. NGF was conjugated to the surface of PBs nanoparticles (PBs-NGF), which can be directly delivered to nerve cells. Results The results showed that free PBs showed great advantages in scavenging oxygen free radicals and antioxidants, while PBs-NGF showed good biocompatibility. At the cellular level, cell proliferation assay and fluorescence microscopy analysis confirmed that PBs-NGF significantly promoted the proliferation, differentiation, and neurite outgrowth of neuron-like PC12 cells compared with free NGF. In a nerve root compression (NRC) rat model, behavioral observations (paw withdrawal threshold, PWT, and paw withdrawal latency, PWL) confirmed that PBs-NGF eased the pain caused by nerve root compression. H&E staining showed that PBs-NGF could significantly reduce the inflammatory infiltration of nerve roots, and ELISA results showed that the concentrations of inflammatory markers (IL-6, IL-1β, and TNF-α) were also significantly reduced. Conclusion In summary, the developed functional nanoplatform provides a basis for the clinical application of NGF in lumbar nerve root injury with disc herniation compression and a new treatment strategy for patients.
To make a further exploration of the mutation frequence of Chinese genetic deafness and make clear if the genetic deafness genealogy that we collected recently was resulted from the mutation of the deafness genes which had been cloned.We made regular otologic examination, hearing test and physical examination among the members of this genealogy, and also inspected the mutation of seven autosomal domiant deafness genes, HDIAI,GJB2, GJB3, DFNA5, a-tectorin(resulting in two types of genetic deafness, DFNA8 and DFNA12), MYO7A,POU4F3, with PCR-Sequencing method in this genealogy.1. The analysis of hereditary mode: There were forty-seven persons collected in five generations of this genealogy, and eighteen persons of them were deafness. It accorded with autosomal dominant inheritance from the pedigree. 2. The clinic feature: All patients with deafness were postlingual deafness. Their hearing decreased onset between sixteen to thirty years old, and the deafness was binaural symmetrical, progressive sensorineural and without other systems abnormity. 3. Analysis of mutation detection: We found two nucleotides changes in CX26 genes, A341G and GC257-258CG, and one changed nucleotide in POU4F3 gene,T90C. But we didn't think the changed nucleotides caused deafness after we analysed them. No mutation was found in other five genes.The possibility that the deafness of this genealogy was resulted from the cloned gene is relatively small. Now, We are scanning the whole gene groups and making linkage analysis on this pedigree, it is most probably to orientate a new deafness gene position.
Porphyromonas gingivalis (P. gingivalis) is an important pathogen that contributes to periodontal disease and causes infections that promote the progression of atherosclerosis. Our previous studies showed that macrophage migration inhibitory factor (MIF) facilitates monocyte adhesion to endothelial cells by regulating the expression of intercellular adhesion molecule-1 (ICAM-1) in P. gingivalis-infected endothelial cells. However, the detailed pathological role of MIF has yet to be elucidated in this context. To explore the functional receptor(s) of MIF that underlie its participation in the pathogenesis of atherosclerosis, we investigated the expression of the chemokine receptors CD74 and CXCR4 in endothelial cells, both of which were shown to be involved in the adhesion of monocytes to endothelial cells pretreated with P. gingivalis. Furthermore, the formation of a MIF, CD74, and CXCR4 ligand-receptor complex was revealed by our immunofluorescence staining and coimmunoprecipitation results. By interacting with the CD74/CXCR4 receptor complex, MIF may act as a crucial regulator of monocyte-endothelial cell adhesion and promote the atherosclerotic plaque formation induced by P. gingivalis.
Vesicular stomatitis virus (VSV) is the prototype for negative sense non segmented (NNS) RNA viruses which include potent human and animal pathogens such as Rabies, Ebola and measles. The polymerases of NNS RNA viruses only initiate transcription at or near the 3′ end of their genome template. We measured the dissociation constant of VSV polymerases from their whole genome template to be 20 pM. Given this low dissociation constant, initiation and sustainability of transcription becomes nontrivial. To explore possible mechanisms, we simulated the first hour of transcription using Monte Carlo methods and show that a one-time initial dissociation of all polymerases during entry is not sufficient to sustain transcription. We further show that efficient transcription requires a sliding mechanism for non-transcribing polymerases and can be realized with different polymerase-polymerase interactions and distinct template topologies. In conclusion, we highlight a model in which collisions between transcribing and sliding non-transcribing polymerases result in release of the non-transcribing polymerases allowing for redistribution of polymerases between separate templates during transcription and suggest specific experiments to further test these mechanisms.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)