AIM:This study was designed to examine the potential mechanism underlying these roles of platelet-rich plasma in treating diabetic foot ulcers (DFUs).METHODS:Staphylococcus aureus and HaCaT were co-cultured under high glucose conditions to serve as an in vitro model for infected cells in DFUs. Platelet-rich gel (PRG) or extract liquid of platelet-rich gel (EPG) were used to interfere with the model to observe the growth of HaCaT cells and S. aureus, and the effect of miR-21 changes in HaCaT cells on PDCD4, NF-κB activity and related inflammatory factors.RESULTS:Incubation of HaCaT cells with S. aureus promoted the decline of cell proliferation. Under this condition, the level of PDCD4 and the activity of NF-κB were increased in HaCaT cells with concomitant increased of IL-6, TNF-α and decreased IL-10, TGF-β1 in cultured supernatant. Both of PRG and EPG exhibited specific anti-S. aureus activity where they protect HaCaT cells from bacterial damage and promote cell proliferation. Meanwhile, EPG was observed to increase intracellular miRNA-21 while reduce PDCD4 expression and inhibit NF-κB activity to suppress the inflammation in HaCaT cells.CONCLUSION:This in vitro model provides a valuable tool for study of wound healing in the treatment of DFUs. Our results suggest that miRNA-21 may regulate the expression of NF-κB through PDCD4 where it plays an anti-inflammatory role and promote proliferation in infected DFUs treated by PRP. These findings could provide novel therapeutic targets for refractory wounds.

Streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (STSS) in China. Our previous research demonstrated that a type IV secretion system (T4SS) harbored in the 89K pathogenicity island contributes to the pathogenicity of S. suis 2. In the present study, a shotgun proteomics approach was employed to identify the effectors secreted by T4SS in S. suis 2, and surface-associated subtilisin-like protease-1 (SspA-1) was identified as a potential virulence effector. Western blot analysis and pull-down assay revealed that SspA-1 secretion depends on T4SS. Knockout mutations affecting sspA-1 attenuated S. suis 2 and impaired the pathogen's ability to trigger inflammatory response in mice. And purified SspA-1 induced the secretion of IL-6, TNF-α, and IL-12p70 in THP-1 cells directly. SspA-1 is the first T4SS virulence effector reported in Gram-positive bacteria. Overall, these findings allow us to gain further insights into the pathogenesis of T4SS and STSS.

Acute cerebral infarction (ACI) caused by cervical arterial dissection (CAD) is a rare clinical disease. Therapeutic approaches include anticoagulant therapy, antiplatelet aggregation, and thrombolytic therapy. Currently, anticoagulant therapy or antiplatelet aggregation is the primary choice, whereas the thrombolytic therapy is still controversial. In this article, we report a patient with ACI caused by right CAD, which led to a compensatory increase in blood supply to the right middle cerebral artery through the anterior communicating artery. After treatment with intravenous thrombolysis, the clinical symptoms of the patient improved, and the National Institutes of Health Stroke Scale (NIHSS) score declined to 2 points from the initial 14 points. In addition, cranial computed tomography scans showed that there were no signs of intracranial or extracranial hemorrhage, but that the vessel occlusion was still uncured. After 17 days of antiplatelet aggregation treatment, a cranial magnetic resonance angiography scan showed complete recanalization of the right internal carotid artery. Furthermore, the NIHSS score was reduced to 1 point when the patient discharged, and for 3 months of follow-up.

Streptococcus suis has emerged as a causative agent of human meningitis and streptococcal toxic shock syndrome over the last years. The high pathogenicity of S.suis may be due in part to a laterally acquired pathogenicity island (renamed SsPI-1), which can spontaneously excise and transfer to recipients. Cells harboring excised SsPI-1 can potentially lose this island if cell division occurs prior to its reintegration; however, attempts to cure SsPI-1 from the host cells have been unsuccessful. Here, we report that an SsPI-1-borne Epsilon/Zeta toxin-antitoxin system (designated SezAT) promotes SsPI-1 stability in bacterial populations. The sezAT locus consists of two closely linked sezT and sezA genes encoding a toxin and its cognate antitoxin, respectively. Overproduction of SezT induces a bactericidal effect that can be neutralized by co-expression of SezA, but not by its later action. When devoid of a functional SezAT system, large-scale deletion of SsPI-1 is straightforward. Thus, SezAT serves to ensure inheritance of SsPI-1 during cell division, which may explain the persistence of epidemic S.suis. This report presents the first functional characterization of TA loci in S.suis, and the first biochemical evidence for the adaptive significance of the Epsilon/Zeta system in the evolution of pathogen virulence.

Inflammatory demyelinating pseudotumor usually occurs in the brain and rarely occurs in the spinal cord. On imaging, inflammatory demyelinating pseudotumor appears very similar to intramedullary tumors such as gliomas. It is often misdiagnosed as intramedullary tumor and surgically resected. In view of this, the clinical and magnetic resonance imaging manifestations and the pathological features of 36 cases of inflammatory demyelinating pseudotumor in the spinal cord were retrospectively analyzed and summarized. Most of these cases suffered from acute or subacute onset and exhibited a sensorimotor disorder. Among them, six cases were misdiagnosed as having intramedullary gliomas, and inflammatory demyelinating pseudotumor was only identified and pathologically confirmed after surgical resection. Lesions in the cervical and thoracic spinal cord were common. Magnetic resonance imaging revealed edema and space-occupying lesions to varying degrees at the cervical-thoracic junction, with a predominant feature of non-closed rosette-like reinforcement (open-loop sign). Pathological examination showed perivascular cuffing of predominantly dense lymphocytes, and demyelination was observed in six of the misdiagnosed cases. These results suggest that tumor-like inflammatory demyelinating disease in the spinal cord is a kind of special demyelinating disease that can be categorized as inflammatory pseudotumor. These solitary lesions are easily confused with intramedullary neoplasms. Patchy or non-closed reinforcement (open-ring sign) on magnetic resonance imaging is the predominant property of inflammatory demyelinating pseudotumor, and inflammatory cell infiltration and demyelination are additional pathological properties.

Objective To analyze the clinical and radiological features of young stroke caused by vertebral artery dissection to discuss its therapy and outcome.Methods Nine patients with confirmed diagnosis of young stroke caused by vertebral artery dissection,admitted to our hospitals from January 2008 to December 2011,were chosen in our study; their history data and radiological features were retrospectively analyzed,and DSA presentations were summarized at 3,6,and 12 months after anticoagulant therapy.Results Nine patients all had diziness or vertigo,including five patients having inducement of acute neck activity and seven patients having occipital or posterior cervical pain.Most patients manifested cerebellum or brainstem infarction or Wallenberg syndrome in MRI.All patients had vertebral artery dissection (V3 segnent primarily),including five patients with string sign or rat tail sign,one patient with double cavity sign,two patients with vertebral occlusion and the last one patient with aneurysm expansion.Among 9 patients,the one with aneurysm expansion was directly treated with stent,the other 8 patients were treated with anticoagulant drug; DSA was performed at 3,6,and 12 months,and the rate of complete recanalization was 50％ (4/8) at 3 months,75％ (6/8) at 6 months and 75％(6/8) at 12 months; the patients without recanalization were then treated with stent.The average follow-up was 18 months without noting stroke recurrences.Conclusions Young stroke induced by vertebral artery dissection often merely manifests occipital or posterior cervical pain; cerebrovascular detection is very important to the diagnosis.Standard anticoagulant therapy can alleviate clinical symptoms and improve blood vessel status,and recanalization of vertebral artery dissection occurs mainly within the first 6 months of anticoagulant therapy.

OBJECTIVE To construct the virB1-89K gene knockout mutant and its complementary strain of Streptococcus suis serotype 2 (SS2) highly virulent strain 05ZYH33 and evaluate the role of virB1-89K in the pathogenesis of SS2. METHODS The virB1-89K gene was knocked out by homologous recombination, then multiple-PCR and sequence analysis were used to identify the knockout strain deltavirB1-89K. The virB1-89K gene and its upstream promoter were cloned into the E. coli-S. suis shuttle vector pSET1, and the recombinant plasmid was electrotransformed into the deltavirB1-89K mutant to generate the complementary strain CvirB1-89K. The effects of virB1-89K deletion on the basic biological characteristics and virulence of SS2 were then determined in this study. RESULTS The isogenic mutant deltavirB1-89K and its complementary strain CvirB1-89K were successfully constructed. No significant differences in biological characteristics were found among the three strains. However, the virulence of the deltavirB1-89K mutant was reduced to 30% of the wild-type level and functional complementation of virB1-89K restored its pathogenicity. CONCLUSION The virB1-89K gene plays an important role in the pathogenesis of S. suis 2 infection.

[Objective] Bioinformatics analysis revealed that the 89K pathogenicity island (PAI) of highly pathogenic Streptococcus suis serotype 2(SS2) in China encodes a putative type II toxin-antitoxin(TA) system named SezAT,which is homologous to the epsilon-zeta system from S.pyogenes.SezAT is presumed to be requisite for the stability of the 89K PAI in SS2.To confirm the SezAT system is a functional TA system.[Methods] The sequence characteristics of SezAT were subjected to further bioinformatics analysis.RT-PCR was performed to analyze the transcriptions of the sezAT locus and the flanking genes.The SezT toxin and SezA antitoxin proteins were selectively overexpressed in Escherichia coli.Deletion mutagenesis was carried out to obtain a SezAT-deficient mutant.[Results] Bioinformatics analysis and RT-PCR results suggest that sezAT are in the same operon.Overexpression of SezT led to severe growth inhibition of the host bacteria,while this toxicity was counteracted by the expression of SezA.Finally,the toxin-encoding gene sezT was successfully knockout by allelic replacement.[Conclusion] All of these results suggest that SezAT is an activated toxin-antitoxin(TA) system.Moreover,our results provide foundations for investigating the potential stabilized effect of SezAT in the 89K PAI,and screening an 89K-negative mutant to better understand the pathopoiesis of 89 K in highly pathogenic SS2.

The soil physical properties of Chinese fir stand after clear cutting based on the determination of soil bulk density,capillary porosity,non-capillary porosity,total porosity and capillary moisture capacity at different layers(0~5 cm,5~10 cm,10~15 cm,15~20 cm,20~25 cm,25~30 cm,30~35 cm,35~40 cm,40~45 cm,45~50 cm,65~70 cm and 90~95 cm).The results showed that with the increase of soil depth,the soil bulk density and capillary porosity increased,while non-capillary porosity decreased after fluctuation,and total porosity and capillary moisture capacity decreased followed by a slight increase in clear cutting slash.The soil bulk density,porosity and capillary moisture capacity decreased in upper soil layers of the clear cutting slash compared with those of the Chinese fir stand.

Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen that infects pigs and sporadically causes serious infections in humans. Two recent large-scale outbreaks of human streptococcal toxic-shock-like syndrome with high mortality occurred in China, posing new challenges for global public health. However, the global regulation of the virulence of epidemic SS2 isolates lacks a systematic understanding. In this study, we performed a mutational and functional analysis of an SS2 two-component system that is orthologous to the VirR/VirS regulatory system of Clostridium perfringens. An isogenic knockout mutant of VirR/VirS (ΔvirRS) was found to exhibit marked phenotypic changes, including the formation of shorter chains and thinner capsular walls, more easily cleared in whole blood, and decreased oxidative stress tolerance. Furthermore, the ΔvirRS mutant was greatly attenuated in a mouse model. Comparative proteome analysis of the expression profiles of the wild-type strain with the ΔvirRS mutant allowed us to identify 72 proteins that are differentially expressed in the absence of the VirR/VirS system and that are directly responsible for the pleiotropic phenotype of the ΔvirRS mutant.

Streptococcus suis serotype 2 (S. suis 2) has evolved into a highly invasive pathogen that was found to be the cause of 2 large-scale outbreaks of streptococcus toxic shock syndrome (STSS) in China. However, the mechanism of action of this non-group A streptococcal (GAS) S. suis-caused STSS is still unknown. Previously, we identified a unique pathogenicity island (PAI) designated 89K that is specific to the STSS-causing epidemic strains of S. suis 2. In this study, we further report a functional type IV-like secretion system (T4SS-like system) harbored in the 89K PAI that contributes to the development of STSS. Knockout of the 2 key components (VirD4-89K and VirB4-89K) of the T4SS-like system eliminated the lethality of the highly virulent strain and impaired its ability to trigger host immune response in experimental infection of mice. Our findings provide a new insight into the pathogenesis of STSS caused by the highly pathogenic S. suis 2 isolates.

The effect of rare earth solution on the cold resistance of Chukrasia tabularis seedlings was studied. The results showed that under low temperature stress,the relative electrical conductivity of the seedlings sprayed with 300 mg·L~(-1) had a significantly increase,whereas those sprayed with 700-1 500 mg·L~(-1) significantly decreased or fluctuated slightly.The content of free proline in seedlings sprayed with various concentrations of rare earth solution increased in a certain degree,the content of soluble protein remained stable or increased slightly,the chlorophyll content increased or significantly increased,and the SOD activity remained stability. The MDA content of seedlings sprayed with 300 mg·L~(-1) increased,whereas that of seedlings sprayed with 700-1 500 mg·L~(-1) increased initially and then decreased or decreased significantly.The cold resistance of seedlings treated with five concentrations of rare earth solution was evaluated by analysis of principal components, the seedlings treated with 1 500 mg·L~(-1) rare earth solution had best cold resistance and then the cold resisitance order was 1 000 and 700 mg·L~(-1) treatments.

> CT及MRI技术的普及为疾病的临床诊断提供了更为直观的依据。水肿及占位效应被认为是区分中枢神经系统肿瘤与非肿瘤性病变的可靠依据之一,然而在临床工作中,我们经常还会遇到一类特殊表现的炎性脱髓鞘病,其临床及影像学表现与中枢神经系统原发性肿瘤如胶质瘤、淋巴瘤等十分相似,故常误诊而行手术治疗,给患者带来不必要的损伤。

This paper researches the license management of cluster job management system. It regards the software licenses as one of the resource object of resource management system in cluster. It presents the license management model PBSLM, which allows multiuser share limited software license in cluster, and illustrates the principle and implementation of this model.

利用DSP和CPLD来设计宽带信号源,将DSP软件控制上的灵活性和CPLD硬件上的高速、高集成度和可编程性有机地结合起来,一方面使得信号源控制简单、可靠,同时保证产生的信号高速、准确.