Is histological healing more clinically valuable than endoscopic healing in Crohn's disease?

OBJECTIVES: Small bowel (SB) endoscopic healing has not been well explored in patients with Crohn's disease (CD). This study aimed to assess the clinical utility of SB endoscopic mucosal and histological healing in patients with CD. METHODS: In total, 99 patients with CD in clinical-serological remission were retrospectively followed after they underwent colonoscopy and double-balloon enteroscopy. Time until clinical relapse (CD activity index of >150 with an increase of >70 points) and serological relapse (abnormal elevation of C-reactive protein levels) constituted the primary endpoints. RESULTS: Of the 99 patients, 75 (74.7%) exhibited colonoscopic healing and 43 (43.4%) exhibited SB endoscopic healing. Clinical relapse, serological relapse, hospitalization, and surgery occurred in 8 (18.6%), 11 (25.6%), 11 (25.6%), and 2 (4.6%) patients, respectively. Of the 43 patients who exhibited SB endoscopic healing, 21 (48.8%) achieved histological healing. Clinical relapse, serological relapse, hospitalization, and surgery occurred in 4 (19.0%), 7 (33.3%), 7 (33.3%), and 1 (4.8%) patient, respectively. There was no statistically significant difference in the number of patients who relapsed, were hospitalized, or underwent surgery between those who exhibited histological healing and those who did not. CONCLUSION: A substantial number of patients who were in clinical-serological remission did not undergo SB endoscopic healing, and the lesions increased their risk of clinical relapse. Thus, endoscopic healing may be of greater clinical value than histological healing when evaluating the remission of patients with CD.

Integrative Proteome Analysis Revels 3-Hydroxybutyrate Exerts Neuroprotective Effect by Influencing Chromatin Bivalency.

3-hydroxybutyrate (3OHB) has been proved to act as a neuroprotective molecule in multiple neurodegenerative diseases. Here, we employed a quantitative proteomics approach to assess the changes of the global protein expression pattern of neural cells upon 3OHB administration. In combination with a disease-related, protein-protein interaction network we pinpointed a hub marker, histone lysine 27 trimethylation, which is one of the key epigenetic markers in multiple neurodegenerative diseases. Integrative analysis of transcriptomic and epigenomic datasets highlighted the involvement of bivalent transcription factors in 3OHB-mediated disease protection and its alteration of neuronal development processes. Transcriptomic profiling revealed that 3OHB impaired the fate decision process of neural precursor cells by repressing differentiation and promoting proliferation. Our study provides a new mechanism of 3OHB's neuroprotective effect, in which chromatin bivalency is sensitive to 3OHB alteration and drives its neuroprotective function both in neurodegenerative diseases and in neural development processes.

Treatment of pyogenic granuloma in children with a 595 nm pulsed dye laser: A retrospective study of 212 patients.

BACKGROUND: Pyogenic granuloma (PG) is a common vascular neoplasm in children. Data on 595 nm pulsed dye lasers for the treatment of PG in children remain scarce. OBJECTIVE: To summarize the clinical characteristics and to evaluate the effectiveness and safety of the 595 nm pulsed dye laser for the treatment of PG in children. STUDY DESIGN: Retrospective case series. METHODS: A retrospective study was performed on 212 patients treated for PG with a 595 nm pulsed dye laser. SPSS version 19.0 was used for statistical analysis. RESULTS: Among all 212 patients treated, 208 showed complete resolution of the lesion, and 4 dropped out after one treatment due to bleeding. A single treatment was sufficient in 139 (66.8%) patients, while two or three treatments were sufficient in 69 (33.2%) patients. Male patients responded better than female patients (χ2 = 7.603, p =0.006). Lesions in the nonorbital region responded better than those in the orbital region (χ2 = 7.445, p =0.006). The size of the lesion affected the effectiveness, and lesions with smaller diameters (t = -5.776, p <0.01) and heights (t = -10.368, p <0.01) showed better results. COMPLICATIONS AND SIDE EFFECTS: Twelve patients (5.8%) were reported to have local complications and side effects, including edematous erythema, slight bleeding, hyperpigmentation, and hypopigmentation. The edematous erythema and slight bleeding disappeared gradually after several days. The localized pigment changes usually resolved spontaneously and disappeared completely after 6 months. CONCLUSIONS: Our experience confirmed the efficacy and safety of the 595 nm pulsed dye laser for the treatment of PG in children.

A PI3Kγ mimetic peptide triggers CFTR gating, bronchodilation, and reduced inflammation in obstructive airway diseases.

Cyclic adenosine 3',5'-monophosphate (cAMP)-elevating agents, such as ß2-adrenergic receptor (ß2-AR) agonists and phosphodiesterase (PDE) inhibitors, remain a mainstay in the treatment of obstructive respiratory diseases, conditions characterized by airway constriction, inflammation, and mucus hypersecretion. However, their clinical use is limited by unwanted side effects because of unrestricted cAMP elevation in the airways and in distant organs. Here, we identified the A-kinase anchoring protein phosphoinositide 3-kinase γ (PI3Kγ) as a critical regulator of a discrete cAMP signaling microdomain activated by ß2-ARs in airway structural and inflammatory cells. Displacement of the PI3Kγ-anchored pool of protein kinase A (PKA) by an inhaled, cell-permeable, PI3Kγ mimetic peptide (PI3Kγ MP) inhibited a pool of subcortical PDE4B and PDE4D and safely increased cAMP in the lungs, leading to airway smooth muscle relaxation and reduced neutrophil infiltration in a murine model of asthma. In human bronchial epithelial cells, PI3Kγ MP induced unexpected cAMP and PKA elevations restricted to the vicinity of the cystic fibrosis transmembrane conductance regulator (CFTR), the ion channel controlling mucus hydration that is mutated in cystic fibrosis (CF). PI3Kγ MP promoted the phosphorylation of wild-type CFTR on serine-737, triggering channel gating, and rescued the function of F508del-CFTR, the most prevalent CF mutant, by enhancing the effects of existing CFTR modulators. These results unveil PI3Kγ as the regulator of a ß2-AR/cAMP microdomain central to smooth muscle contraction, immune cell activation, and epithelial fluid secretion in the airways, suggesting the use of a PI3Kγ MP for compartment-restricted, therapeutic cAMP elevation in chronic obstructive respiratory diseases.

An Individual Driving Behavior Portrait Approach for Professional Driver of HDVs with Naturalistic Driving Data.

More than 50% major road accidents are caused by risk driving behaviors from professional drivers of Heavy Duty Vehicles (HDVs). The quantitative estimation of driving performance and driving behaviors portrait for professional drivers is helpful to measure the driver's driving risk and inherent driving style. Previous studies have attempted to evaluate risk driving behavior, but most of them rely on high-demand vehicle and driving data. However, few studies can dig into the causes and correlations behind individual driving behavior and quantify the driving behaviors portrait for professional driver based on long-term naturalistic driving. In this study, the data is from On-Board Unit (OBU) devices mounted in the HDVs in China. Based on the driving behavior pattern diagram and the frequency and ranking of drivers' typical driving patterns, a driving behavior portrait approach is proposed by comprehensively considering the vehicle safety, driving comfort, and fuel economy indicators. The similarities and differences of different drivers' driving behaviors are quantitatively analyzed. The high precision and sampling frequency data from vehicles are used to verify the proposed approach. The results demonstrated that the driving behavior portrait approach can digitally describe the individual driving behaviors styles and identify the potential driving behaviors with long-term naturalistic driving data. The development of this approach can help quantitatively evaluate the individual characteristic of risk driving behaviors to prevent road accidents.

Visualization and Analysis of Mapping Knowledge Domain of Heterogeneous Traffic Flow.

Mapping knowledge domain (MKD) is an important application in bibliometrics, which is a method of visually presenting and explaining newly developed interdisciplinary scientific fields using data mining, information analysis, scientific measurement, and graphic rendering. This study combines applied mathematics, visual analysis technology, information science, and scientometrics to systematically analyze the development status, research distribution, and future trend of the heterogeneous traffic flow by using the MKD software tools VOSviewer and CiteSpace. Based on the MKD and Bibliometrics approaches, 4709 articles have been studied, which were published by Science Citation Index Expanded (SCIE) and Social Sciences Citation Index (SSCI) from 2004 to 2021 in the field of heterogeneous traffic flows. Firstly, this paper presents the annual numbers of articles, origin countries, main research organizations, and groups as well as the source journals on heterogeneous traffic flow studies. Then, cocitation analysis is used to divide heterogeneous traffic flow into three main research directions, which include "heterogeneous traffic flow model," "traffic flow capacity analysis," and "traffic flow stability analysis." The keyword cooccurrence analysis is applied to identify five dominant clusters: "modeling and optimization methods," "traffic flow characteristics analysis," "driving behavior analysis," "simulation experiment," and "policies and barriers." Finally, burst keywords were studied according to the publication date to present more clearly the change of research focus and direction over time.

Iso-damping fractional-order control for robust automated car-following.

This work deals with the control design and development of an automated car-following strategy that further increases robustness to vehicle dynamics uncertainties. The control algorithm is applied on a hierarchical architecture where high and low level control layers are designed for gap-control and desired acceleration tracking, respectively. A fractional-order controller is proposed due to its flexible frequency shape, fulfilling more demanding design requirements. The iso-damping loop property is sought, which yields a desired closed-loop stability that results invariant despite changes on the controlled plant gain. In addition, the graphical nature of the proposed design approach demonstrates its portability and applicability to any type of vehicle dynamics without complex reconfiguration. The algorithm benefits are validated in frequency and time domains, as well as through experiments on a real vehicle platform performing adaptive cruise control.

Development of a TEM-cell-integrated CO2 incubator for cell-based transient electromagnetic field bioeffect study.

To facilitate the cell-based experiment for pulsed electromagnetic field biological effect study, a novel TEM-cell-integrated CO2 incubator was developed. The integrated experimental system could simultaneously meet the requirement of standard cell culture condition and the various Transient Electromagnetic Field (TEF) exposure, which made it possible to study the relationship between different electromagnetic pulse exposure and the cellular responses in a reliable way. During the research, a comparison experiment was carried out to evaluate the necessity of the integrated incubator system: firstly, two different types of cell lines, which are the human prostate cancer cell line (PC3) and the pancreatic ß cell line (MIN6) were chosen and exposed in the TEM-cell which located in the open area and the integrated system, respectively, with the same EFT radiation conditions; then, the cells' viability, the cellular ROS level and the mitochondrial membrane potential (MMP) were detected, respectively. The results showed that in the same parameter of the EFT radiation, the processes of the cells had a significant difference and even opposite in the incubator and open area, and all the results could be reproducible. The phenomenon indicated the stability of the TEM-cell-integrated CO2 incubator, and also demonstrated the necessity to strictly control the cell culture condition when carrying out the precise mechanism study of the TEF bioresponse at the cellular levels.

Intention to control low central venous pressure reduced blood loss during laparoscopic hepatectomy: A double-blind randomized clinical trial.

BACKGROUND: Excessive intraoperative hemorrhage is a critical factor of poor prognoses after hepatectomy. Low central venous pressure during parenchymal transection is recognized to effectively reduce intraoperative hemorrhage in open procedures. However, the role of controlled low central venous pressure in laparoscopic hepatectomy is still controversial. METHODS: In the present randomized clinical trial, we set up a standard boundary of low central venous pressure according to our Pilot Study, then enrolled patients scheduled for elective laparoscopic hepatectomy and allocated them randomly to a group undergoing central venous pressure reduction by anesthesiologic interventions or a control group. The primary efficacy endpoint was total intraoperative blood loss and perioperative adverse events. Analyses were performed following the intention-to-treat principle, and patients and surgeons were blinded (ClinicalTrials.gov, Number: NCT03422913). RESULTS: Between January 2017 and October 2018, 146 out of 469 patients were randomized and eligible for inclusion in the final analyses. Based on the retrospective training cohort, we set a central venous pressure of 5 cm H2O as a cutoff value (standard low central venous pressure). Compared with patients in the control group, those in the controlled low central venous pressure group had a significantly lower central venous pressure during resection (4.83 ± 3.41 cm H2O vs 9.26 ± 3.38 cm H2O; P < .001) and significantly reduced total intraoperative blood loss (188.00 ± 162.00 mL vs 346.00 ± 336.00 mL; P < .001). The perioperative adverse events were comparable in both study groups (P = .313). CONCLUSION: The safety and efficacy of controlled low central venous pressure were demonstrated in complex laparoscopic hepatectomy for the first time by our study, and this technique is recommended to be applied routinely in laparoscopic hepatectomy.

Highly efficient biocatalytic synthesis of L-DOPA using in situ immobilized Verrucomicrobium spinosum tyrosinase on polyhydroxyalkanoate nano-granules.

L-DOPA (3,4-dihydroxyphenyl-L-alanine) is a preferred drug for Parkinson's disease, and is currently in great demand every year worldwide. Biocatalytic conversion of L-tyrosine by tyrosinases is the most promising method for the low-cost production of L-DOPA in both research and industry. Yet, it has been hampered by low productivity, low conversion rate, and low stability of the biocatalyst, tyrosinase. An alternative tyrosinase TyrVs from Verrucomicrobium spinosum with more efficient expression in heterologous host and better stability than the commercially available Agaricus bisporus tyrosinase was identified in this study. Additionally, it was prepared as a novel nano-biocatalyst based on the distinct one-step in situ immobilization on the surface of polyhydroxyalkanoate (PHA) nano-granules. The resulting PHA-TyrVs nano-granules demonstrated improved L-DOPA-forming monophenolase activity of 9155.88 U/g (Tyr protein), which was 3.19-fold higher than that of free TyrVs. The nano-granules also exhibited remarkable thermo-stability, with an optimal temperature of 50 °C, and maintained more than 70% of the initial activity after incubation at 55 °C for 24 h. And an enhanced affinity of copper ion was observed in the PHA-TyrVs nano-granules, making them even better biocatalysts for L-DOPA production. Therefore, a considerable productivity of L-DOPA, amounting to 148.70 mg/L h, with a conversion rate of L-tyrosine of 90.62% can be achieved by the PHA-TyrVs nano-granules after 3 h of biocatalysis under optimized conditions, without significant loss of enzyme activity or L-DOPA yield after 8 cycles of repeated use. Our study provides an excellent and robust nano-biocatalyst for the cost-effective production of L-DOPA.

Identification of compound D2923 as a novel anti-tumor agent targeting CSF1R.

Colony-stimulating factor 1 receptor (CSF1R) plays a critical role in promoting tumor progression in various types of tumors. Here, we identified D2923 as a novel and selective inhibitor of CSF1R and explored its antitumor activity both in vitro and in vivo. D2923 potently inhibited CSF1R in vitro kinase activity with an IC50 value of 0.3 nM. It exhibited 10- to 300-fold less potency against a panel of kinases tested. D2923 markedly blocked CSF-1-induced activation of CSF1R and its downstream signaling transduction in THP-1 and RAW264.7 macrophages and thus inhibited the in vitro growth of macrophages. Moreover, D2923 dose-dependently attenuated the proliferation of a small panel of myeloid leukemia cells, mainly by arresting the cells at G1 phase as well as inducing apoptosis in the cells. The results of the in vivo experiments further demonstrated that D2923 displayed potent antitumor activity against M-NFS-60 xenografts, with tumor growth inhibition rates of 50% and 88% at doses of 40 and 80 mg/kg, respectively. Additionally, D2923 was well tolerated with no significant body-weight loss observed in the treatment groups compared with the control. Furthermore, a western blot analysis and the immunohistochemistry results confirmed that the phosphorylation of CSF1R in tumor tissue was dramatically reduced after D2923 treatment, and this was accompanied by the depletion of macrophages in the tumor. Meanwhile, the expression of the proliferation marker Ki67 was also markedly decreased in the D2923 treatment group compared with the control group. Taken together, we identified D2923 as a novel and effective CSF1R inhibitor, which deserves further investigation.

Stromal cells attenuate the cytotoxicity of imatinib on Philadelphia chromosome-positive leukemia cells by up-regulating the VE-cadherin/ß-catenin signal.

ß-Catenin is a key regulator of leukemia stem cell maintenance and drug resistance. Herein, we investigated the protective effects of the stromal cell-mediated VE-cadherin-ß-catenin signal on Ph+ leukemia cells during imatinib treatment. We found stromal cells could desensitize imatinib and up-regulate VE-cadherin expression on Ph+ leukemia cells (K562 and SUP-B15 cells), which further stabilized and activated ß-catenin. Knockdown of VE-cadherin with shRNA diminished the ß-catenin protein and partly resensitized Ph+ leukemia cells to imatinib despite the presence of stromal cells, suggesting VE-cadherin is a potential target in the treatment of Ph+ leukemia.

The evidence for the contribution of the autism susceptibility candidate 2 (AUTS2) gene in heroin dependence susceptibility.

The single-nucleotide polymorphisms (SNP) rs6943555 in autism susceptibility candidate 2 (AUTS2) has been reported to be significantly associated with alcohol consumption in Europeans. In this study, we identified the SNP in AUTS2 contributing to the genetic susceptibility to heroin dependence. The potential association between heroin dependence and 21 SNPs (rs2270162, rs2851510, rs513150, rs595681, rs210606, rs10237984, rs13228123, rs10235781, rs6969375, rs6943555, rs10251416, rs17141963, rs12669427, rs723340, rs2293507, rs2293508, rs6960426, rs9886351, rs2293501, rs10277450, rs1918425) of AUTS2 was examined in a Chinese Han population using the MassARRAY system. The participants included 426 patients with heroin dependence and 416 healthy controls. Single SNP association, haplotype association, and clinical phenotype association were analyzed. Single SNP association revealed that AA homozygotes of rs6943555 were significantly over-represented in the patients with heroin dependence compared with the control subjects (P=0.0019). The patients with heroin dependence had a significantly higher frequency of the A allele (P=0.0003, odd ratio (OR)=1.429, 95% confidence interval (CI)=1.175-1.738). Strong linkage disequilibrium (LD) was observed in five blocks (D'>0.9). In block 2, significantly more A-A haplotypes (P=0.006 after Bonferroni corrections) and significantly fewer T-A haplotypes (P=0.040) were found in the patients with heroin dependence. The genotype and clinical phenotype correlation study of the rs6943555 carriers showed that the amount of heroin self-injection was lower in the patients with the AA genotype relative to AT+TT genotypes (P<0.01). Our results confirmed that, in addition to heroin consumption, the SNP rs6943555 of AUTS2 may also play an important role in the etiology of heroin dependence.

[Particle settling characteristics of alcohol precipitation mixture of Paeoniae Radix rubra extract and models establishment of settling velocity].

OBJECTIVE: To understand the particle settling characteristics of alcohol precipitation mixture of Paeoniae Radix rubra extract and establish models of the sedimentation rate. METHODS: Focusing on the particle settling characteristics such as particle settling curve, particle settling velocity (PSV), particle volume index (PVI), the particle settling process of alcohol precipitation was investigated. The effect of three key process factors on the settling process was discussed and mathematical models for describing the particle settling velocity were developed. RESULTS: Controlling of higher final alcohol concentration, higher density of Paeoniae Radix rubra extract, or lower initial alcohol concentration, was conducive to settlement of alcohol precipitation particles. In the constant speed phase, an empirical calculation formula of v(0) was established, with both the variables PSV and PVI (v(0)=-0.236PSV+0.022PVI+7.521). Another developed model was applied to predict the settling velocity in decelerated phase and the simulation was very good [v=k(1-n(1)X)(4)exp(-n(2)X)/X]. CONCLUSION: The results of this work will contribute to a better control and optimization of alcohol precipitation process, and help to implementation of accuracy control in the manufacture of botanical medicines.

Low concentration of serum helps to maintain the characteristics of NSCs/NPCs on alkali-treated PHBHHx film in vitro.

OBJECTIVE: Efforts have been made by tissue engineers to create a permissive environment for neural regeneration, and to enhance the efficiency of neural stem cell (NSC) transplantation. However, to acquire sufficient number of seed cells on the material appears to be the main obstacle to constructing functional transplantable NSC-biomaterial complexes. A culture system has been optimized in the current study to maintain the specific characteristics of NSCs/neural progenitor cells (NPCs) on the material and achieve sustaining increased multipotent seed cells. METHODS: The PHBHHx film was selected as biomaterial and the surface was firstly modified with NaOH treatment. The NSCs/NPCs isolated from the cerebral cortex of rat embryos were cultured on the treated PHBHHx films in growth medium containing 1%, 5%, and 10% fetal bovine serum (FBS). Then the attachment, survival, proliferation, and differentiation of NSCs/NPCs were assessed. RESULTS: NaOH treatment significantly increased the hydrophilicity of PHBHHx and enhanced NSCs/NPCs attachment. On the treated PHBHHx film, NSCs/NPCs survived well and actively proliferated in the medium containing 1% FBS. After 7-14 days in culture, approximately two-thirds of cells remained as nestin and Sox2 positive NSCs/NPCs. However, in the medium containing 5% and 10% FBS, NSCs/NPCs proliferation was reduced and differentiation, particularly glial differentiation was significantly promoted. CONCLUSION: Growth medium containing low concentration of FBS is favorable for maintaining the characteristics, in terms of self-renewal and multiple differentiation, of NSCs/NPCs on NaOH-treated PHBHHx films. This could be a useful method to construct functional transplantable NSCs/NPCs-biomaterial complex.

Microbial synthesized biodegradable PHBHHxPEG hybrid copolymer as an efficient intracellular delivery nanocarrier for kinase inhibitor.

BACKGROUND: Protein Kinases are key regulators of cell function and play essential roles in the occurrence and development of many human diseases. Many kinase inhibitors have been used for molecular targeted treatment of those diseases such as cancer and inflammation. However, those highly hydrophobic kinase inhibitors shared the common features of poor bioavailability and limited in vivo half-life, which strongly impeded their practical applications. Our previous study demonstrated that microbial synthesized biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a member of polyhydroxyalkanoates (PHAs) family, could serve as a promising delivery nanocarrier for those hydrophobic kinase inhibitors. Recently, a novel natural synthesized hybrid copolymer, PEG200 end-capped PHBHHx (PHBHHxPEG) was produced by Aeromonas hydrophila fermentation. In this study, the novel PHBHHxPEG NPs were prepared and investigated to serve as intracellular delivery nanocarriers for sustained release of hydrophobic kinase inhibitors. RESULTS: PHBHHxPEG nanoparticles (NPs) prepared by an emulsification-solvent evaporation method were spherical with a diameter around 200 nm. The entrapment efficiency on rapamycin in PHBHHxPEG NPs was 91.9% and the sustained release of rapamycin from PHBHHxPEG NPs could be achieved for almost 10 days. The cellular uptake of PHBHHxPEG NPs was significant higher than that of PHBHHx NPs. The anti-proliferation effect and mTOR inhibition ability of rapamycin-loaded PHBHHxPEG NPs was stronger than that of drug-loaded PHBHHx NPs and free rapamycin. CONCLUSIONS: PHBHHxPEG NPs could achieve the efficient entrapment and sustained release of rapamycin. The novel biodegradable PHBHHxPEG appeared a promising nanocarrier for sustained delivery of hydrophobic kinase inhibitors with improved cellular uptake and kinase inhibition efficiency.

[Application of DNA methyltransferase inhibitors for myelodysplastic syndrome].

Epigenetic research plays an important role in the malignant tumor genotyping and tumor clinical treatment recently. Epigenetics is the study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence, including DNA methylation and histone modifications. DNA methylation is one of the most important epigenetic modifications often occurring on the cytosine of CpG islands located in gene promoter regions, which is thought to be closely correlated with tumorigenesis. The inducibility and reversibility of DNA methylation provide us an insight into tumor development and treatment. Aberrant DNA hypermethylation is associated with the progress of myelodysplastic syndrome (MDS). The DNA methyltransferase inhibitors (azacytidine and decitabine) have achieved suc-cess in treating high-and intermediate-risk MDS. This will bring new ideas to understand the cause and develop the treat-ment of MDS. This review mainly introduces the latest progress of the action mechanism of those two medicines, the clini-cal effect and new problems during the clinical application on MDS.

Evaluation of a new method for placing nasojejunal feeding tubes.

AIM: To compare fluoroscopic, endoscopic and guide wire assistance with ultraslim gastroscopy for placement of nasojejunal feeding tubes. METHODS: The information regarding nasojejunal tube placement procedures was retrieved using the gastrointestinal tract database at Tongji Hospital affiliated to Tongji Medical College. Records from 81 patients who underwent nasojejunal tubes placement by different techniques between 2004 and 2011 were reviewed for procedure success and tube-related outcomes. RESULTS: Nasojejunal feeding tubes were successfully placed in 78 (96.3%) of 81 patients. The success rate by fluoroscopy was 92% (23 of 25), by endoscopic technique 96.3% (26 of 27), and by guide wire assistance (whether via transnasal or transoral insertion) 100% (23/23, 6/6). The average time for successful placement was 14.9 ± 2.9 min for fluoroscopic placement, 14.8 ± 4.9 min for endoscopic placement, 11.1 ± 2.2 min for guide wire assistance with transnasal gastroscopic placement, and 14.7 ± 1.2 min for transoral gastroscopic placement. Statistically, the duration for the third method was significantly different (P < 0.05) compared with the other three methods. Transnasal placement over a guidewire was significantly faster (P < 0.05) than any of the other approaches. CONCLUSION: Guide wire assistance with transnasal insertion of nasojejunal feeding tubes represents a safe, quick and effective method for providing enteral nutrition.

Heterologous expression of human costimulatory molecule B7-2 and construction of B7-2 immobilized polyhydroxyalkanoate nanoparticles for use as an immune activation agent.

BACKGROUND: Costimulation of T cells via costimulatory molecules such as B7 is important for eliciting cell-mediated antitumor immunity. Presenting costimulation molecules by immobilizing recombinant B7 on the surface of nanovectors is a novel strategy for complementary therapy. Polyhydroxyalkanoates (PHAs) are a family of biodegradable, non-toxic, biocompatible polyesters, which can be used as a nonspecific immobilizing matrix for protein presentation. Recombinant protein fusion with PHA granule binding protein phasin (PhaP) can be easily immobilized on the surface of PHA nanoparticles through hydrophobic interactions between PhaP and PHA, and therefore provides a low-cost protein presenting strategy. RESULTS: In this study, the extracellular domain of the B7-2 molecule (also named as CD86) was fused with PhaP at its N-terminal and heterogeneously expressed in recombinant Escherichia coli strain BL21 (DE3). The purified B7-2-PhaP protein was immobilized on the surface of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx)-based nanoparticles. Loading of 240 µg (3.2 pMol) of B7-2-PhaP protein per mg nanoparticles was achieved. Immobilized B7-2-PhaP on PHBHHx nanoparticles induced T cell activation and proliferation in vitro. CONCLUSIONS: A PHA nanoparticle-based B7-2 costimulation molecule-presenting system was constructed. The PHA-based B7 presenting nanosystem provided costimulation signals to induce T cell activation and expansion in vitro. The B7-2-PhaP immobilized PHA nanosystem is a novel strategy for costimulation molecule presentation and may be used for costimulatory molecule complementary therapy.

[Propagation of prdm1 gene knockout mouse and its genotype identification].

This study was aimed to propagate and identify the prdm1 gene-knockout mice, so as to lay the foundation for studying Blimp-1 protein. Two kinds of transgenic homozygous mice with B6.prdm1(flox/flox) and B6.Lck-Cre were feed and propagated; after successful propagating, the first passage mice were obtained; after the first passage mice were copulated once again, the genotypes were obtained as follows: B6. prdm1(wild/wild). Lck-Cre, B6. prdm1(wild/wild), B6.prdm1(flox/flox). Lck-Cre, B6.prdm1(flox/wild). Lck-Cre, B6.prdm1(flox/flox), B6. prdm1(flox/wild). The genomic DNA of second passage mice was extracted, the Cre and loxp gene fragments were amplified by PCR, then the size of Cre and loxp genomic DNA were detected by agarose gel electrophoresis. The mice with B6.prdm1(flow/flox). Lek-Cre were used as conditionally prdm1-knockout mice, B6.prdm1(flox/wild). Lck-Cre mice, B6.prdm1(flox/flox) and B6 mice were used as controls. The spleen T lymphocytes and B lymphocytes were sorted by using magnetic beads, the blimp-1 target protein was identified by Western blot. The results showed that the two transgenic homozygous mice had the ability to reproduce, and the separation ratio of second passage mice generated from propagation of their offspring cach other meet Mendelian laws, and the prdm1 gene-knockout mice also could successfully obtained. It is concluded that the application of Cre-loxp system may successfully obtain plentiful prdm1 gene-knockout mice.