Expression and purification of a recombinant ELRL-MAP30 with dual-targeting anti-tumor bioactivity.

MAP30 (Momordica antiviral protein 30kD) is a single-chain Ⅰ-type ribosome inactivating protein with a variety of biological activities, including anti-tumor ability. It was reported that MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer. To determine whether adding two tumor targeting peptides could improve the antitumor activities of MAP30, we genetically modified MAP30 with an RGD motif and a EGFRi motif, which is a ligand with high affinity for αvß3 integrins and with high affinity for EGFR. The recombinant protein ELRL-MAP30 (rELRL-MAP30) containing a GST-tag was expressed in E. coli. The rELRL-MAP30 was highly expressed in the soluble fraction after induction with 0.15 mM IPTG for 20 h at 16 °C. The purified rELRL-MAP30 appeared as a band on SDS-PAGE. It was identified by western blotting. Cytotoxicity of recombinant protein to HepG2, MDA-MB-231, HUVEC and MCF-7 cells was detected by MTT analysis. Half maximal inhibitory concentration (IC50) values were 54.64 µg/mL, 70.13 µg/mL, 146 µg/mL, 466.4 µg/mL, respectively. Proliferation inhibition assays indicated that rELRL-MAP30 could inhibit the growth of Human liver cancer cell HepG2 effectively. We found that rELRL-MAP30 significantly induced apoptosis in liver cancer cells, as evidenced by nuclear staining of DAPI. In addition, rELRL-MAP30 induced apoptosis in human liver cancer HepG2 cells by up-regulation of Bax as well as down-regulation of Bcl-2. Migration of cell line were markedly inhibited by rELRL-MAP30 in a dose-dependent manner compared to the recombinant MAP30 (rMAP30). In summary, the fusion protein displaying extremely potent cytotoxicity might be highly effective for tumor therapy.

Simultaneous bilateral fractures of the femoral neck caused by high energy: A case report and literature review.

Simultaneous bilateral fractures of the femoral neck are rare injuries, which are reportedly induced by low-speed energy with predisposing factors including systemic diseases, medications and eclamptic seizures. Those caused by high energy are even rarer. High energy-induced bilateral fractures of the femoral neck conceive of high incidence of mortality and present great challenges in the early management. We report one case of a 52-year-old man with simultaneous bilateral fractures of the femoral neck which resulted from a motor pedestrian accident. One-stage closed reduction and internal fixation was done following the emergent resuscitation and neurosurgical management for concomitant brain injuries. The fractures united. There was no pain in the hips, and they had a normal range of motion. The treatment protocol, mechanism of the injury and possible postoperative complications were discussed to expand a comprehensive understanding about these infrequent types of fractures.

WblAch, a pivotal activator of natamycin biosynthesis and morphological differentiation in Streptomyces chattanoogensis L10, is positively regulated by AdpAch.

Detailed mechanisms of WhiB-like (Wbl) proteins involved in antibiotic biosynthesis and morphological differentiation are poorly understood. Here, we characterize the role of WblAch, a Streptomyces chattanoogensis L10 protein belonging to this superfamily. Based on DNA microarray data and verified by real-time quantitative PCR (qRT-PCR), the expression of wblAch was shown to be positively regulated by AdpAch. Gel retardation assays and DNase I footprinting experiments showed that AdpAch has specific DNA-binding activity for the promoter region of wblAch. Gene disruption and genetic complementation revealed that WblAch acts in a positive manner to regulate natamycin production. When wblAch was overexpressed in the wild-type strain, the natamycin yield was increased by ∼30%. This provides a strategy to generate improved strains for natamycin production. Moreover, transcriptional analysis showed that the expression levels of whi genes (including whiA, whiB, whiH, and whiI) were severely depressed in the ΔwblAch mutant, suggesting that WblAch plays a part in morphological differentiation by influencing the expression of the whi genes.

[Antimicrobial resistance of Gram-negative bacilli isolated from 13 teaching hospitals across China].

OBJECTIVE: To explore the antimicrobial resistance of nosocomial Gram-negative bacilli across China. METHODS: A total of 1247 consecutive and non-repetitive Gram-negative bacilli were isolated from 13 Chinese teaching hospitals from March to August 2012. All isolates were sent to a central laboratory for reidentification and susceptibility testing. The minimal inhibitory concentration (MICs) of meropenem and other antibacterial agents were determined by agar dilution method. And the data were analyzed with WHONET-5.6 software. RESULTS: The activity of antimicrobial agents against Enterobacteriaceae was in the following descending order of susceptibility rate: meropenem (97.5%, 849/871) , amikacin (94.5%, 823/871) , imipenem (93.6%, 815/871) , ertapenem (92.9%, 809/871) , piperacillin/tazobactam (89.9%, 783/871) , cefoperazone/sulbactam (83.5%, 727/871) , cefepime (78.1%, 680/871) , polymyxin B (77.0%, 670/871) , cefiazidime (69.6%, 606/871) , levofloxacin (69.2%, 603/871) , ciprofloxacin (63.6%, 554/871) , minocyline (63.1%, 550/871) , ceftriaxone (55.7%, 485/871) , cefotaxime (54.2%, 472/871) and cefoxitin (51.4%, 448/871) . The prevalence of extended-spectrum beta-lactamase (ESBL) was 64.3% (117/182) in Escherichia coli (E. coli) and 32.1% (60/187) in Klebsiella pneumonia (K. pneumoniae) . The sensitivities of E. coli to meropenem and imipenem were 100%. And over 90% of E. coli was sensitive to ertapenem, amikacin, piperacillin/tazobactam and polymyxin B. However, over 60% of E. coli was resistant to ciprofloxacin, levofloxacin, ceftriaxone and cefotaxime. The susceptibility of K. pneumoniae to meropenem, imipenem, amikacin and polymyxin B maintained at over 90%. The activities of antimicrobial agents against E. cloacae, E. aerogenes and Citrobacter freundii were in the following descending order of susceptibility rate: meropenem (96.0%-100%) , imipenem (96.0%-100%) , polymyxin B (95.8%-100%) , amikacin (92.2%-100%) , ertapenem (85.6%-93.3%) , cefepime (77.8%-93.3%) , cefoperazone/sulbactam (78.4%-90.0%) and piperacillin/tazobactam (65.0%-89.8%) . The most susceptible agent against Acinetobacter baumannii (A. baumannii) was polymyxin B (100%) . The susceptibilities of A.baumannii to imipenem, meropenem and minocyline were 37.8% (65/172) , 36.0% (62/172) and 62.8% (108/172) respectively. The most active agents against Pseudomonas aeruginosa (P. aeruginosa) were polymyxin B (97.2%, 173/178) , followed by amikacin (89.3%, 159/178) and cefiazidime (83.7%, 149/178) . Clinical and Laboratory Standards Institute revised P.aeruginosa susceptibility standard in 2012. The sensitivity of piperacillin/tazobactam changed from 83.7% (149/178) to 77.5% (138/178) . The sensitivity of meropenem decreased from 78.1% ( 139/178 ) to 71.3% ( 127/178 ) while that of imipenem declined from 69.7% (124/178) to 59.6% (106/178) . The prevalence of multi-drug resistant A. baumannii and P. aeruginosa were 65.7% (113/172) and 9.0% (16/178) respectively. CONCLUSIONS: Carbapenems remain highly active against Enterobacteriaceae. Increasing resistance of A. baumannii to all antimicrobial agents is noted. New breakpoint to P.aeruginosa has obvious effects on antimicrobial sensitivity.

Injury-to-surgery interval does not affect postfracture osteonecrosis of the femoral head in young adults: a systematic review.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common and severe complication following femoral neck fractures in young adults. Despite significant advances in surgical techniques, radiological evaluation and comprehensive treatment for the prevention of ONFH, the incidence of traumatic ONFH has remained unchanged at approximately 20% in recent decades. The injury-to-surgery interval is considered as a principal factor affecting the occurrence of ONFH, and traditionally, femoral neck fractures are treated emergently. However, the relationship between the injury-to-surgery interval and ONFH occurrence is poorly understood, and previous reviews have not provided a precise explanation due to the lack of strict selection criteria for studies. METHODS: We reviewed previously published articles and included in current systematic review those studies with accurate multivariate analyses that included age, fracture type, operation method, follow-up, ONFH occurrence and injury-to-surgery interval. RESULTS: Six case studies were included and reevaluated. The studies included 263 hips for final analysis, with an overall incidence of postfracture ONFH of 17.5%. Patients were categorized into groups of less/more than 8 h, less/more than 24 h, less/more than 48 h and less/more than 3 weeks based on the individual injury-to-surgery interval. The postfracture ONFH incidence ranged from 13.3% (<8 weeks) to 21.7% (>3 weeks). Operations performed within 3 weeks of injury resulted in a lower ONFH incidence compared with operations performed after 3 weeks; however, this difference was not statistically significant. The ONFH incidence remained relatively stable when the operations were performed within 3 weeks of injury. CONCLUSIONS: The injury-to-surgery interval did not significantly affect the incidence of postoperative ONFH.

Opportunities and challenges for ribosome-inactivating proteins in traditional Chinese medicine plants.

Ribosome-inactivating proteins (RIPs) are a class of cytotoxic rRNA N-glycosylase, which widely exist in higher plants in different taxonomy, including many traditional Chinese medicinal materials and vegetables and fruits. In this paper, the traditional Chinese medicinal plants containing RIPs protein were sorted out, and their pharmacological effects and clinical applications were analyzed. Since many RIPs in traditional Chinese medicine plants exhibit antiviral and antitumor activities and show great clinical application potential, people's interest in these proteins is on the rise. This paper summarizes the possible mechanism of RIPs's anti-virus and anti-tumor effects, and discusses its potential problems and risks, laying a foundation for subsequent research on how to exert its anti-virus and anti-tumor effects.

USP18 enhances the resistance of BRAF-mutated melanoma cells to vemurafenib by stabilizing cGAS expression to induce cell autophagy.

This study aims to discern the possible molecular mechanism of the effect of ubiquitin-specific peptidase 18 (USP18) on the resistance to BRAF inhibitor vemurafenib in BRAF V600E mutant melanoma by regulating cyclic GMP-AMP synthase (cGAS). The cancer tissues of BRAF V600E mutant melanoma patients before and after vemurafenib treatment were collected, in which the protein expression of USP18 and cGAS was determined. A BRAF V600E mutant human melanoma cell line (A2058R) resistant to vemurafenib was constructed with its viability, apoptosis, and autophagy detected following overexpression and depletion assays of USP18 and cGAS. Xenografted tumors were transplanted into nude mice for in vivo validation. Bioinformatics analysis showed that the expression of cGAS was positively correlated with USP18 in melanoma, and USP18 was highly expressed in melanoma. The expression of cGAS and USP18 was up-regulated in cancer tissues of vemurafenib-resistant patients with BRAF V600E mutant melanoma. Knockdown of cGAS inhibited the resistance to vemurafenib in A2058R cells and the protective autophagy induced by vemurafenib in vitro. USP18 could deubiquitinate cGAS to promote its protein stability. In vivo experimentations confirmed that USP18 promoted vemurafenib-induced protective autophagy by stabilizing cGAS protein, which promoted resistance to vemurafenib in BRAF V600E mutant melanoma cells. Collectively, USP18 stabilizes cGAS protein expression through deubiquitination and induces autophagy of melanoma cells, thereby promoting the resistance to vemurafenib in BRAF V600E mutant melanoma.

Injury-to-surgery interval does not affect the occurrence of osteonecrosis of the femoral head: a prospective study in a canine model of femoral neck fractures.

BACKGROUND: It is controversial whether an early reduction and internal fixation can reduce the occurrence of femoral neck fracture-induced osteonecrosis of the femoral head (ONFH). This prospective study was designed to reflect the relationship between injury-to-surgery interval (ISI) and traumatic ONFH based on a canine model of femoral neck fractures. MATERIAL/METHODS: Twenty-four dogs were equally divided randomly into 3 groups. A lateral L-shape approach centered left great trochanter was used for exposure of the femoral neck. A low-speed drill was used for making displaced fractures in the narrow femoral neck, with the femoral head kept in situ with ligamentum teres intact. In Group A, the fracture was immediately reduced and fixed with 3 parallel pins; while the operation was done 3 days later in Group B, and 3 weeks later in Group C. Another 2 dogs had their fractures untreated. Postoperatively, all dogs were fed separately and received regular x-ray examination. Left femoral heads were harvested for histological examination with a postoperative follow-up of 3.5 months. RESULTS: The canine model of femoral neck fractures could be achieved successfully. Radiological signs of post-fracture ONFH could not be detected at intervals of 2 weeks, 4 weeks, 1 month and 2 months. Histologically, there were 2 cases with ONFH in Group A, 1 case in Group B, and 2 cases in Group C. The difference had no statistical significance. For untreated fractures, obvious ONFH could be found radiologically. CONCLUSIONS: A shorter ISI may not reduce the incidence of fracture-induced ONFH, which suggests that intrinsic factors play an important role in the occurrence of ONFH.

[The effect and mechanism of Yiqi Tongluo Jiedu capsule against cerebral ischemia reperfusion injury].

To observe the effect and mechanism of Yiqi Tongluo Jiedu capsule aganist cerebral ischemia reperfusion injury, the SD rats were randomly divided into following groups: sham-operated group, model group, the group of low, medium and high dose of Yiqi Tongluo Jiedu capsule, and nimodipine group. Using focal middle cerebral artery embolization (MCAO) model, following items were observed: symptoms of neurological deficit score; infarct volume; activity of SOD, content of MDA and NO, activity of NOS of ischemic brain tissue; Bcl-2 and Bax protein expression; content of IL-1beta, IL-6 and TNFalpha in serum; IL-1beta mRNA expression of ischemic brain tissue. Results showed that Yiqi Tongluo Jiedu capsule could significantly reduce the symptoms of neurological deficits, promote the recovery symptoms of neurological deficits; narrow infarct volume of brain tissue obviously, reduce the percentage of infarct volume; raise activity of SOD, reduce content of MDA and NO, reduce activity of NOS; increase Bcl-2 protein, reduce Bax expression; reduce content of IL-1beta, IL-6 and TNFa in serum; reduce IL-1beta mRNA expression of ischemic brain tissue. Yiqi Tongluo Jiedu capsule has significant protective effects against ischemic brain injury, it has significant anti-apoptotic, antioxidant and anti-inflammatory effects.

A Systematic Review and Network Meta-Analysis about the Efficacy and Safety of Tripterygium wilfordii Hook F in Rheumatoid Arthritis.

Objective: This study aims to evaluate the efficacy of various conventional synthetic DMARDs, including Tripterygium wilfordii Hook F (TwHF) for treating rheumatoid arthritis (RA) by network meta-analysis. Methods: We retrieved the related literature from online databases and supplemented it by using a manual retrieval method. Data was extracted from the literature and analyzed with STATA software. Results: A total of 21 trials (5,039 participants) were identified. Assessment of ACR20 response found that TwHF combined with methotrexate (MTX) had the greatest probability for being the best treatment option among the treatments involved, while TwHF used singly was second only to TwHF combined with MTX. Assessment of ACR50 response found that TwHF combined with MTX ranked second in all treatment options after cyclosporine A (CsA) combined with leflunomide (LEF) and TwHF alone, followed by TwHF combined with MTX. Assessment of ACR70 response found that CsA combined with LEF ranked first, TwHF combined with LEF ranked second, TwHF combined with MTX ranked third, and TwHF used singly ranked fourth. In the safety analysis, TwHF had the least probability of adverse event occurrence, followed by TwHF combined with MTX, which ranked first and second, respectively. Conclusion: Compared with the current csDMARDs for treating RA, the efficacy of TwHF was clear, and TwHF combined with MTX performed well under various endpoints. In the future, large, rigorous, and high-quality RCTs are still needed to confirm the benefits of TwHF therapy on RA.

BRD4 inhibitor GNE987 exerts anti-cancer effects by targeting super-enhancers in neuroblastoma.

BACKGROUND: Neuroblastoma (NB) is a common extracranial malignancy with high mortality in children. Recently, super-enhancers (SEs) have been reported to play a critical role in the tumorigenesis and development of NB via regulating a wide range of oncogenes Thus, the synthesis and identification of chemical inhibitors specifically targeting SEs are of great urgency for the clinical therapy of NB. This study aimed to characterize the activity of the SEs inhibitor GNE987, which targets BRD4, in NB. RESULTS: In this study, we found that nanomolar concentrations of GNE987 markedly diminished NB cell proliferation and survival via degrading BRD4. Meanwhile, GNE987 significantly induced NB cell apoptosis and cell cycle arrest. Consistent with in vitro results, GNE987 administration (0.25 mg/kg) markedly decreased the tumor size in the xenograft model, with less toxicity, and induced similar BRD4 protein degradation to that observed in vitro. Mechanically, GNE987 led to significant downregulation of hallmark genes associated with MYC and the global disruption of the SEs landscape in NB cells. Moreover, a novel candidate oncogenic transcript, FAM163A, was identified through analysis of the RNA-seq and ChIP-seq data. FAM163A is abnormally transcribed by SEs, playing an important role in NB occurrence and development. CONCLUSION: GNE987 destroyed the abnormal transcriptional regulation of oncogenes in NB by downregulating BRD4, which could be a potential therapeutic candidate for NB.

An animal model of femoral head osteonecrosis induced by a single injection of absolute alcohol: an experimental study.

BACKGROUND: The lack of an experimental animal model that can reliably mimic all stages of osteonecrosis of the femoral head has hindered progress toward the successful prevention and treatment of the disease. MATERIAL/METHODS: A goat model of osteonecrosis of the femoral head (ONFH) was established and observed from the early to the intermediate-to-late stage of mechanical failure. Absolute alcohol was injected slowly into the center of bilateral femoral heads in 12 adult Small Tail Han goats. Postoperatively, the femoral heads were harvested and examined using macrostructural and histological analyses and radiographic and MRI examinations at weeks 4, 8, 12, and 25. RESULTS: Macrostructural and radiographic examinations revealed that the contour of both femoral heads was deformed slightly at 12 weeks, but a contour deformation with joint space narrowing was observed at 25 weeks. Histologically, a strong concordance with the natural history of ONFH in humans was found. The present model demonstrated bone trabeculae, marrow necrosis, a reconstruction deficiency and destruction of the microcirculation. CONCLUSIONS: Among quadrupedal models, the goat model of ONFH, which is induced by a single injection of absolute alcohol, may be suitable and valuable for the evaluation of various therapeutics and side effects in the treatment of ONFH.

Chuanxiongzine-astragaloside IV decreases IL-1ß and Caspase-3 gene expressions in rat brain damaged by cerebral ischemia/reperfusion: a study of real-time quantitative PCR assay.

The purpose of this study was to establish an absolute quantitative method to detect IL-1ß and Caspase-3 gene expressions in rat brain after cerebral ischemia-reperfusion (I/R) using real-time PCR. Rats were randomized into the following groups: sham operation group, model group (cerebral I/R group), astragaloside IV (AST IV) group, chuanxiongzine-AST IV group and nimodipine group (n = 10 in each group). The rats in all the groups except sham operation group were subjected to cerebral I/R treatment. Sham operation and model groups were treated by normal saline (5 mL/kg). AST IV, chuanxiongzine-AST IV and nimodipine groups received 20 mg/kg AST IV, 10 mg/kg chuanxiongzine plus 20 mg/kg AST IV, and 10 mg/kg nimodipine treatments, respectively. The administrations of drugs were performed with intraperitoneal injections at 0 and 12 h, 1 d, 2 d, 3 d, till to 7 d after I/R. A real-time quantitative PCR assay was developed for absolute quantification of the expressions of IL-1ß and Caspase-3 genes. The absolute quantification approach relies on the construction of an accurate standard curve. Thus, two plasmids which contained rat IL-1ß and Caspase-3 genes respectively were constructed. The cloned circular plasmids were then quantified using a spectrophotometer and used as standards. Standard curves were generated, and the copy numbers of IL-1ß and Caspase-3 mRNA isolated from I/R-damaged brain tissue were also calculated by SYBR Green I dye method using specific primers. The results showed that melting curves exhibited sharp peaks, and PCR product also generated prominent band with expected size in agarose gel electrophoresis, which validated the optimization of the selected primer sets of IL-1ß and Caspase-3 genes. The optimal annealing temperatures of IL-1ß and Caspase-3 genes were 59 °C and 61.2 °C, respectively. Real-time PCR results showed that the expression of IL-1ß and Caspase-3 genes in the model group was significantly elevated compared to that in the sham operation group. However, compared to those in the model group, IL-1ß and Caspase-3 gene expressions were obviously decreased in AST IV, chuanxiongzine-AST IV and nimodipine groups. Especially in chuanxiongzine-AST IV group, those two genes showed the most significant expression down-regulation. These results suggest the absolute quantitative method established in the present study is capable of detecting the changes of IL-1ß and Caspase-3 gene expressions in rat brain damaged by I/R.

Human health-risk assessment based on chronic exposure to the carbonyl compounds and metals emitted by burning incense at temples.

Health effects resulting from the smoke of carbonyl compounds (aldehydes and ketones) and metal-containing incense particles at temples during incense burning periods were evaluated at temple A (without incense reduction activities) and B (with incense reduction activities), Nantou County, in 2018. The predominant size fractions of particles were PM1, PM1-2.5, and PM2.5-10 at both temples. The total particle mass at temple A was approximately 1.1 times that of temple B due to incense reduction at temple B. The most abundant metal elements in all particle size fractions at both temples were Fe, Al, and Zn. Metal species of incense smoke are divided into three groups by hierarchical cluster analysis and heatmaps, showing higher metal contents in groups PM1, PM18-10, and PM18-2.5 at temple A. In contrast, higher metal contents were observed in PM18-10 and PM2.5-1 at temple B. Most of the carbonyl species were formaldehyde and acetaldehyde, released during incense burning periods, with concentrations ranging from 6.20 to 13.05 µg/m3 at both temples. The total deposited fluxes of particle-bound metals at temples A and B were determined to be 83.00% and 84.82% using the International Commission on Radiological Protection (ICRP) model. Health-risk assessments revealed that the risk values of metals and carbonyls were above recommended guidelines (10-6) at temple A. Since worshippers and staff are exposed to incense burning environments with poor ventilation over a long period, these toxic organic compounds and metals increase health risks in the respiratory tract. Therefore, incense reduction is important to achieve healthy temple environments.

Stabilizing severely open fractures of the tibia with a surgical suture: an alternative and feasible method for osteosynthesis.

BACKGROUND: Outcomes concerning treatment of severely open fractures of the tibia have achieved great success with the advent of powerful antibiotics, superb microsurgery techniques, and advanced stabilization instruments. However, severe pollution in the wound and high comminution of the fragments may restrict application of internal or external fixators. The condition could appear more complicated if osteoporosis and polytrauma are present or if those special instruments are unavailable. CASE REPORT: We tried using a surgical suture to stabilize severely open fractures of the tibia in the elderly with osteoporosis. A 65-year-old woman with a severely open fracture of the tibia was treated with a surgical suture, and the result was satisfactory in early period. We discuss the new but traditional osteosynthesis method. CONCLUSIONS: A surgical suture osteosynthesis could act as an additional alternative when special fractures or conditions occur. Postoperative results in early period are satisfactory. Long-term results and clinical experience should be analyzed and discussed.

Gadolinium-doped mesoporous calcium silicate/chitosan scaffolds enhanced bone regeneration ability.

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/ß-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.

La-Doped mesoporous calcium silicate/chitosan scaffolds for bone tissue engineering.

Trace rare earth elements such as lanthanum (La) regulated effectively bone tissue performances; however, the underlying mechanism remains unknown. In order to accelerate bone defects especially in patients with osteoporosis or other metabolic diseases, we firstly constructed lanthanum-doped mesoporous calcium silicate/chitosan (La-MCS/CTS) scaffolds by freeze-drying technology. During the freeze-drying procedure, three-dimensional macropores were produced within the La-MCS/CTS scaffolds by using ice crystals as templates, and the La-MCS nanoparticles were distributed on the macropore walls. The hierarchically porous structures and biocompatible components contributed to the adhesion, spreading and proliferation of rat bone marrow-derived mesenchymal stem cells (rBMSCs), and accelerated the in-growth of new bone tissues. Particularly, the La3+ ions in the bone scaffolds remarkably induced the osteogenic differentiation of rBMSCs via the activation of the TGF signal pathway. A critical-sized calvarial-defect rat model further revealed that the La-MCS/CTS scaffolds significantly promoted new bone regeneration as compared with pure MCS/CTS scaffolds. In conclusion, the La-MCS/CTS scaffold showed the prominent ability in osteogenesis and bone regeneration, which showed its application potential for bone defect therapy.

[Pharmacokinetics of PEG-rhG-CSF and rHSA-hG-CSF in mice determined with ELISA].

Double antibody sandwich-type ELISA was used to detect rhG-CSF in serum to study the pharmacokinetics of rhG-CSF, PEG-rhG-CSF and rHSA-hG-CSF in mice and to confirm that PEGlyation and albumin fusion of rhG-CSF technology can prolong half-life of G-CSF. Pharmacokinetic parameters were calculated with 3P87 software. T1/2 s of rhG-CSF, PEG-rhG-CSF and rHSA-hG-CSF are 2. 1 , 14.2 and 10. 6 h, respectively. T1/2 s of PEG- rhG-CSF and rHSA-hG-CSF are 7, 5 times than T1/2 s of rhG-CSF, respectively. Tpeak s of PEG-rhG-CSF and rHSA-hG-CSF are 15, 13 times than Tpeak of rhG-CSF, respectively. The result of ELISA indicates that PEGlyation and albumin fusion of rhG-CSF technology can prolong half-life of G-CSF.

[Surveillance of antimicrobial resistance among nosocomial gram-negative pathogens from 15 teaching hospitals in China in 2005].

OBJECTIVE: To investigate the antimicrobial resistance among the nosocomial gram-negative pathogens from 15 teaching hospitals located in different areas in China in 2005. METHODS: A total of 1927 non-repetitive nosocomial gram-negative pathogens were collected from 15 teaching hospitals in different areas in China and sent to the central lab for reidentification and susceptibility testing. The levels of minimal inhibitory concentration (MIC) of 18 antimicrobial agents were determined by agar dilution method. WHONET 5.4 software was used to analyze the data. RESULTS: The strains of Escherichia coli, Klebsiella pneumoniae, and Proteous mirabilis isolates that did not produce extended spectrum beta lactamases (ESBLs) showed high sensitivity to beta-lactams. The antibiotics with a susceptibility rates over 80% against the strains of Entorobacter cloacae, Enterobacter aerogene, Citrobacter spp, Serratia spp, and Proteous vulgaris producing AmpC enzyme included meropenem, imipenem, and piperacillin-tazobactam, and these 3 drugs showed a susceptibility rate of more than 80% against the ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae. Other antimicrobial agents showing a relatively high activity against Enterobacter spp, Citrobacter spp, Serratia spp and Proteous vulgaris included cefepime (67.3% - 100%), amikacin (67.3% - 95.2%), ceftazidime (52.9% - 100%) and cefoperazone-sulbactam (51.9% - 100%). The susceptibility rate of fluoroquinolones was 34.8% - 36.1% against non-ESBL-producing Escherichia coli and was 13.4% - 17.1% against ESBL-producing isolates. The most active agent against Pseudomonas aeruginosa was polymyxin B (95.6%). The agents with the activity rates of 70% - 80% included meropenem, imipenem, amikacin, and piperacillin-tazobactam. The antibiotic with a high susceptible rate against Acinetobacter baumannii was polymyxin B (98.3%), followed by imipenem (80.8%), meropenem (76.2%), and minocycline (67.4%). The susceptible rates of other agents were all below 60%. The agents with relatively high activity against Stenotrophomonas maltophilia included minocycline (85%), levofloxacin (82.5%), and trimethoprim-sulfamethoxazole (77.5%). The agents with a relatively high activity against Burkholderia cepacia included minocycline (77.2%) and meropenem (61.4%). CONCLUSION: Carbapenem, piperacillin-tazobactam, amikacin and cefepime remained relatively high activity against nosocomial Enterobacteriaceae, Non-fermenting pathogens have lower susceptibility to the antimicrobial agents than before.