Endoluminal Vacuum-Assisted Closure Therapy for Upper Gastrointestinal Leak, Perforation, and Fistula: A Case Series and Literature Review.

BACKGROUND: With the increasing incidence of upper digestive tract tumors, more upper digestive tract surgeries are performed each year, and surgeons have difficulty in the postoperative management of gastrointestinal anastomotic fistula. The use of a new minimally invasive technique, endoluminal vacuum-assisted closure (E-VAC), has increased the success rate of the treatment of gastrointestinal fistula. METHODS: We present 6 cases of gastrointestinal fistula treated in our hospital in 2021: 3 cases of anastomotic fistula after esophageal cancer surgery, 2 cases of anastomotic fistula after gastric cancer surgery, and one case of esophageal rupture after trauma. With E-VAC and other adjuvant treatment measures, the gastrointestinal fistulas were eventually closed or significantly reduced. RESULTS: Both local and systemic infections in all 6 patients were controlled with the use of E-VAC device, resulting in significant reduction or closure of fistulas. CONCLUSION: E-VAC devices can effectively help in the removal of the exudate and necrotic tissue around the fistula, promote the proliferation of granulation tissue, and support closure of the fistula. However, further improvements to the device are needed to improve patient comfort and operational safety.

[Characteristics of Microplastic Pollution in Sediment of Silty Coast in Culture Bay].

Microplastic pollution is a central issue of great concern in the current environmental field. Microplastic pollution in marine environmental media is widely reported, but the characteristics of microplastic pollution in deep sediments are rarely reported. Based on this, three sampling points were set up on the muddy coast near the Haizhou Bay, a typical aquaculture sea area, to analyze the characteristics of microplastic pollution in sediment column samples. The study showed that the abundance of microplastics in the sediments of the study area was(0.12 ± 0.07)n·g-1, which was at the medium pollution level. The total amount of microplastics in the sediment column was 3.43-6.00 times the abundance of microplastics in the surface sediment (5 cm). The abundance of microplastics in the sediment column samples showed regional differences. There was no significant difference in the abundance of microplastics in the sediment at different depths, but the index decreased with the increase in depth. The relationship between sediment moisture content, depth, and microplastics indicated that the abundance of microplastics in sediment was related to the physical properties of the sediment. Transparent and black microplastics accounted for the highest proportion in each station. Fiber was the most common form of microplastics in the sediment, and microplastics with small particle size accounted for the majority. The density of microplastics did not prevent its appearance in the sediment. The pollution characteristics of microplastics varied greatly in different depths of sediments.

Dietary resveratrol supplementation on growth performance, immune function and intestinal barrier function in broilers challenged with lipopolysaccharide.

This study discusses the effects of resveratrol (RES) on the productive performance, immune function and intestinal barrier function of broiler chickens challenged with lipopolysaccharide (LPS). Two hundred and forty 1-day-old male Arbor Acres broilers were randomly divided into 4 groups of 6 replicates each, with 10 broilers per replicate. This experiment used a 2 × 2 factorial design with dietary factors (basal diets or basal diets supplemented with 400 mg/kg RES were administered from d 1 to 21) and stress factors (intraperitoneal injection of 0.5 mg/kg BW of saline or LPS at 16, 18 and 20 d of age). The results showed that LPS challenge had a significant adverse effect on average daily gain (ADG) in broilers at 16 to 21 d of age (P < 0.05), whereas the addition of RES to the diet inhibited the LPS-induced decrease in ADG (P < 0.05). RES also alleviated LPS-induced immune function damage in broilers, which was manifested by the decrease of spleen index (P < 0.05) and the recovery of serum immunoglobulin M and ileal secretory immunoglobulin A content (P < 0.05). The LPS challenge also disrupts intestinal barrier function and inflammation, and RES mitigates these adverse effects in different ways. RES attenuated LPS-induced reduction of villus height in the jejunum and ileum of broilers (P < 0.05). LPS also caused an abnormal increase in plasma D-lactic acid levels in broilers (P < 0.05), which was effectively mitigated by RES (P < 0.05). LPS challenge resulted in a significant decrease in mRNA expression of occludin in the intestinal mucosa (P < 0.05), which was mitigated by the addition of RES (P < 0.05). RES significantly decreased the mRNA expression of toll-like receptor 4, nuclear factor kappa-B and tumor necrosis factor alpha in the ileum tissue stimulated by LPS (P < 0.05). Taken together, this study shows that RES exerts its beneficial effect on broilers challenged with LPS by alleviating immune function damage, relieving intestinal inflammation and barrier damage, and thus improving growth performance.

Diol glycidyl ether-bridged cyclens: preparation and their applications in gene delivery.

Polymeric 1,4,7,10-tetraazacyclododecanes (cyclens) using diol glycidyl ether with different chain length as bridges (5a-e) were designed and synthesized from various diols, 1,7-diprotected cyclen and epichlorohydrin. The molecular weights of the title polymers were measured by GPC with good polydispersity. Agarose gel retardation and fluorescent titration using ethidium bromide showed good DNA-binding ability of 5. They could retard plasmid DNA (pDNA) at an N/P ratio of 4-6 and form polyplexes with sizes around 100-250 nm from an N/P ratio of 10 to 60 and relatively low zeta-potential values (5-22 mV). The cytotoxicity of 5 assayed by MTT is much lower than that of 20 kDa PEI. In vitro transfection against A549 and 293 cells showed that the transfection efficiency (TE) of 5c/DNA polyplexes is close to that of 20 kDa PEI at an N/P ratio of 5. Structure-activity relationship (SAR) of 5 was discussed in their DNA-binding, cytotoxicity, and transfection studies. The TE of 5c/DNA polyplexes could be improved by the introduction of 50 µM of chloroquine, the endosomolytic agents, to pretreated cells. These studies may extend the application areas of macrocyclic polyamines, especially for cyclen.

[Indicator Function of Ragworm (Nereididae) on Sediment Microplastic in Haizhou Bay Intertidal Zone].

Sediment samples were collected from nine sites of three sections, in the intertidal zone of Haizhou bay in July 2018. The abundance and characteristics of microplastics in the sediments (and ragworms within the sediments) were then determined to identify the source of microplastics in ragworms, and to explore the effects of ragworms on microplastics in sediment. The average abundance of microplastics in tidal flat sediments was (0.49±0.17) n·g-1, which was at a high level in domestic offshore environmental studies. Among all the microplastics detected, the most common form and color were fiber and black-gray, respectively, and the materials were mainly polyethylene (PE), polyester (PET), and polystyrene (PS). The detection rate of microplastics in ragworm was 77.78%-86.67%, with an average abundance of (6.68±2.21) n·ind-1; the abundance was significantly correlated with individual mass (r=0.42, P=0.002). The microplastic abundance was significantly higher in ragworms with individual mass over 1.5 g than in those with a mass of<0.5 g or 0.5-1 g (F3=141.029, P=0.000). In ragworms, microplastics were dominated by small black or blue fibers, and the main materials were PE and PET. By analyzing the various characteristics of microplastics with a particle size of 0-3 mm, it was found that the abundance of microplastics in sediments was strongly correlated with that in ragworms (r=0.79,P=0.01); the main form (r=0.90, P=0.035) and the material composition (r=0.73, P=0.024) also showed significant correlation between sediments and ragworms. This indicates that ragworms ingest microplastics in the sedimentary environment and exchange the microplastics with the sediments. Therefore, ragworms can be used as an indicator species of microplastic pollution in sediments.

A synchronous demodulation technology based on sample-and-hold for eddy current sensors.

This paper proposes a synchronous demodulation technology based on sample-and-hold which shows significant advantages in the application of precision sensors. The traditional synchronous demodulation methods are discussed, and then the working principle of the proposed method is theoretically analyzed in detail. It is found that the proposed method can not only effectively suppress the harmonic components caused by the signal source but is also beneficial to improving the dynamic range of precision sensors. The eddy current sensor is adopted as an example of precision sensors, and a high-precision eddy current displacement sensor prototype was designed and tested. The results show that with the proposed method, the harmonics in the output signal are suppressed more effectively, and the demodulation circuit is relatively simplified. This synchronous demodulation method has an extensive application prospect in precision sensors.

Linear cyclen-based polyamine as a novel and efficient reagent in gene delivery.

Linear cyclen-based polyamine (LCPA, M(w) = 7392, M(w)/M(n) = 1.19) as a novel non-viral gene vector was designed and synthesized from 1,7-diprotected 1,4,7,10-tetraazacyclododecane (cyclen), bis(beta-hydroxylethyl)amine and epichlorohydrin. Agarose gel retardation and fluorescent titration using ethidium bromide showed the good DNA-binding ability of LCPA. It could retard pDNA at an N/P ratio of 4 and form polyplexes with sizes around 250-300 nm from an N/P ratio of 10 to 60 and relatively lower zeta-potential values (< +3 mV) even at the N/P ratio of 60. The cytotoxicity of LCPA assayed by MTT is much lower than that of 25 kDa PEI. In vitro transfection against A549 and 293 cells showed that the transfection efficiency of LCPA/DNA polyplexes is close to that of 25 kDa PEI at an N/P ratio of 10-15, indicating that the new material could be a promising non-viral polycationic reagent for gene delivery.

Enantioselective hydrolysis of (R)-2, 2-dimethylcyclopropane carboxamide by immobilized cells of an R-amidase-producing bacterium, Delftia tsuruhatensis CCTCC M 205114, on an alginate capsule carrier.

Immobilized cells of Delftia tsuruhatensis CCTCC M 205114 harboring R-amidase were applied in asymmetric hydrolysis of (R)-2, 2-dimethylcyclopropane carboxamide (R - 1) from racemic (R, S)-2, 2-dimethylcyclopropane carboxamide to accumulate (S)-2, 2-dimethylcyclopropane carboxamide (S - 1). Maximum R-amidase activity of 13.1 U/g wet cells (0.982 U/g beads) was obtained under conditions of 3% sodium alginate, 2.5% CaCl(2), 15 h crosslinking and 2 mm bead size, which was 53.9% of that of free cells (24.3 U/g wet cells). In addition, characterization of the immobilized cells was examined. The optimum R - 1 hydrolysis conditions were identified as follows: substrate concentration 10 mM, pH 8.5, temperature 35 degrees C and time course 40 min. Under optimum conditions, the maximum yield and enantiomeric excess of (R)-2, 2-dimethylcyclopropanecarboxylic acid were 49.5% and >99%, respectively. This afforded S - 1 with a yield >49% and an e.e. of 97.7%. With good operational stability and excellent enanotioselectivity, the immobilized cells could be potentially utilized in industrial production of S - 1.

[Study on invasion and metastasis-associated genes of lung cancer related with NM23-H1 gene].

OBJECTIVE: To study on invasion and metastasis-associated genes of lung cancer related with NM23-H1 gene. METHODS: Human gene expression chip based on the subtracted cDNA libraries was constructed. After microarray hybridization, clones sequencing, sequence homology search, the information of differently expressed genes in human large cell lung cancer cell line of L9981 and L9981-nm23-H1 were obtained and then further confirmed by real-time quantitative PCR. RESULTS: Gene expression profiling chips of differently expressed genes in human large cell lung cancer cell line L9981 and L9981-nm23-H1 were successfully constructed. After microarray hybridization, sequence homology search, 19 differentially expressed genes were observed. After real-time quantitative PCR evaluation, we found that the mRNA of 8 genes including PSMA7, SBDS, ODC1, YARS, CSDA, PTP4A1, SHPRH and TOMM7 was up-regulated in the cell line of L9981 after transfected with NM23-H1 gene, whereas the mRNA of PKM2 and GMNN was down-regulated. CONCLUSION: NM23-H1 gene may be the upstream regulator of metastasis-associated genes, which can regulate the downstream genes to achieve a series of lung cancer metastatic potential.

[Construction and identification of eukaryotic co-expression plasmid carrying FUS1 and recombinant human IL-12 genes and its effection on apoptosis of A549 cells].

OBJECTIVE: To construct a eukaryotic co-expression plasmid containing FUS1 and IL-12, and to investigate the influence of the recombinant plasmid on the cultured human lung cancer cell line A549. METHODS: RT-PCR was applied to amplify FUS1 from MRC-5 cell, the cDNA fragment of IL-12 was derived from pORF-hIL-12 by PCR, FUS1 cDNA fragment and IL-12 cDNA fragment were inserted into the multiple cloning sites of pVITRO2 to generate the eukaryotic co-expression plasmid pVITRO2-FUS1-IL-12. The recombinant plasmid was confirmed by restriction endonuclease treatment and sequenceing and transfected into A549 cells. The expression of genes in pVITRO2-FUS1-IL-12 were identified by RT-PCR, ELISA and Western blot. The function of pVITRO2-FUS1-IL-12 inducing the apoptosis of lung cancer was identified by Hoechst33258 and flow cytometry. RESULTS: The restriction endonuclease digestion and sequencing suggested that co-expression vector pVITRO2-FUS1-IL-12 was constructed successfully, the expression of FUS1 and IL-12 could be detected in A549 cells. The expressions of the two genes in pVITRO2 were not affected. The A549 cells transfected with pVITRO2-FUS1-IL-12 exhibited significant cell apoptosis. CONCLUSION: The recombinant eukaryotic expression vector pVITRO2-FUS1-IL-12 was constructed and expressed in eukaryotic cell successfully, which would contribute to a novel and effective treatment strategies for combined gene therapy for lung cancer.

Design of an adaptive stator for bundled piezo-walk motors.

Bundled piezoelectric motors combine several actuators to achieve high output power. However, mutual interference between the actuators leads to reduction in working efficiency. This work presents an adaptive stator that can reduce the mutual interference in bundled piezowalk motors. The stator consists of leaf springs for improving motor contact condition and proof masses that serve as an inertial body for maintaining high output force. Parameters of the proof masses and leaf springs are analyzed, and the working zone of the stator is discussed. A prototype of a linear motor with the designed adaptive stator is fabricated and tested. The maximum speed of a six-leg motor is 103 mm/s, and the stall force is approximately 1.2 N, driven with sinusoidal waveforms of 25Vpp at 30 kHz. Mutual interference between actuators is reduced remarkably with the adaptive stator. A comparison of six- and four-leg motors proves that motor performance has a linear relationship with the number of actuators, thereby indicating the potential of increasing output capability with additional actuators.

[Comparative proteomic analysis of human large cell lung cancer cell line with high and low metastasis potentials].

OBJECTIVE: A comparative proteomic analysis on two human large cell lung cancer strains with high metastasis potential (L9981) and low metastasis potential (NL9980) were conducted. METHODS: The total proteins of the two cell lines were separated by immobilized pH gradient (IPG )-based two-dimensional gel electrophoresis. The differential expression proteins of the two cell lines were analyzed using image analysis software. Thirteen differential expressed proteins were further identified using in-gel digestion with trypsin, of which peptide extracts were prepared for MALDI-TOF MS/MS analysis by Daltonics AutoFlex TOF-TOF LIFT Mass Spectrometer (Bruker). Protein identifications were searched in the NCBInr protein database using the Mascot search engine. RESULTS: Protein image analysis indicated that 8 protein spots were observed only in L9981, not in NL9980; 8 protein spots were observed only in NL9980, not in L9981; 19 protein spots were detected in both L9981 and NL9980, of which 9 showed significantly higher volumes in L9981 than in NL9980 and 10 showed significantly higher volumes in NL9980 than in L9981. MS and biological informatics study found that the expressions of heat shock 70 kD protein 9B precursor, MTHSP75 and glutathione synthetas incerased in L9981 cells. However, a variant of P47 protein, immunoglobulin heavy chain variable region, enolasel, heat shock protein and eukaryotic translation initiation fact 3 were down-regulated in L9981 cells. Pyruvate kinase (PK) was only expressed in L9981 cells while WD-40 repeat protein was only expressed in NL9980 cells. CONCLUSIONS: The metastatic lung cancer cell lines display different protein profiles compared to the non metastatic lung cancer cell lines. The identified proteins are likely to be associated with tumor metastasis, 4hich could serve as a basis for searching potential prognosis markers of lung cancer and elucidating the mechanisms of the metastasis of lung cancer.

Expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin on dendritic cells generated from human peripheral blood monocytes.

AIM: To generate dendritic cells (DCs) from human peripheral blood and to detect the expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin (DC-SIGN; CD209) for the further study of DC-SIGN in hepatitis C virus (HCV) transmission. METHODS: Peripheral blood monocytes were isolated from blood of healthy individuals by Ficoll-Hypaque sedimentation and cultured in complete medium containing rhGM-CSF and rhIL-4. Cells were cultured for seven days, with cytokine addition every two days to obtain immature DCs. Characteristics of the cultured cells were observed under light and scanning microscope, and the expression of DC-SIGN was detected by immunofluorescence staining. RESULTS: After seven-day culture, a large number of cells with typical characteristics of DCs appeared. Their characteristics were observed under light and scanning electron microscope. These cells had a variety of cell shapes such as those of bipolar elongate cells, elaborate stellate cells and DCs. DC-SIGN was detected by immunofluorescence staining and its expression level on cultivated dendritic cells was high. CONCLUSION: DCs with a high expression of DC-SIGN can be generated from human peripheral blood monocytes in complete medium containing rhGM-CSF and rhIL-4.

High-fidelity AFM scanning stage based on multilayer ceramic capacitors.

A kind of multilayer ceramic capacitors (MLCCs) has been verified to have good micro-actuating properties, thus making them good candidates for nano-positioning. In this paper, we successfully employed the MLCCs as lateral scanners for a tripod scanning stage. The MLCC-based lateral scanners display hysteresis under 1.5% and a nonlinearity less than 2% even with the simplest open-loop voltage drive. The developed scanning stage was integrated into a commercial AFM to evaluate its imaging performance. Experimental results showed that sample images with high fidelities were obtained. SCANNING 38:184-190, 2016. © 2015 Wiley Periodicals, Inc.

Note: A valve-type piezoelectric reciprocating pump with secondary resonant vibrator.

A valve-type piezoelectric diaphragm pump using secondary resonant vibrator is introduced in this paper. The secondary resonant vibrator, which is mainly composed of a first vibrator and a second vibrator, is used to coordinate the frequency incompatibility between piezoelectric elements and check valves. The intermittent vibration of the first vibrator excites the resonant vibration of the second vibrator. The diaphragm in the pump chamber moves with the second vibrator, resulting in chamber volume and pressure variations. Control circuit capable of frequency tracking is designed. Vibration displacement and flow rate changing with driving voltage amplitude, frequency, and backpressure are studied in experiments. The flow rate of a prototype driven by voltage of 712 Vpp is 13.94 ml/min at secondary resonant frequency of 6 Hz.

Differential effects of neurotrophins and schwann cell-derived signals on neuronal survival/growth and synaptogenesis.

Recent studies have shown that the survival of mammalian motoneurons in vitro is promoted by neurotrophins (NTs) and cAMP. There is also evidence that neurotrophins enhance transmitter release. We thus investigated whether these agents also promote synaptogenesis. Cultured Xenopus spinal cord neurons were treated with a mixture of BDNF, glia-derived neurotrophic factor, NT-3, and NT-4, in addition to forskolin and IBMX or the cell-permeant form of cAMP, to elevate the cAMP level. The outgrowth and survival of neurons were dramatically increased by this trophic stimulation. However, when these neurons were cocultured with muscle cells, the trophic agents resulted in a failure of synaptogenesis. Specifically, the induction of ACh receptor (AChR) clustering in cultured muscle cells was inhibited at nerve-muscle contacts, in sharp contrast to control, untreated cocultures. Because AChR clustering induced by agrin or growth factor-coated beads in muscle cells was unaffected by trophic stimulation, its effect on synaptogenesis is presynaptic in origin. In the control, agrin was deposited along the neurite and at nerve-muscle contacts. This was significantly downregulated in cultures treated with trophic stimuli. Reverse transcriptase-PCR analyses showed that this decrease in agrin deposition was caused by an inhibition of agrin synthesis by trophic stimuli. Both agrin synthesis and induction of AChR clustering were restored under trophic stimulation when Schwann cell-conditioned medium was introduced. These results suggest that trophic stimulation maintains spinal neurons in the growth state, and Schwann cell-derived factors allow them to switch to the synaptogenic state.

Induction of hepatitis C virus-specific cytotoxic T and B cell responses by dendritic cells expressing a modified antigen targeting receptor.

AIM: To find a novel antigen (Ag) presentation strategy to improve the immune responses induced by dendritic cell (DC) vaccine expressing hepatitis C virus (HCV) core antigen (pcDNA3HCV C-Fc) in Balb/c mice (H-2d). METHODS: pcDNA3HCV C-Fc plasmid and eukaryotic expression vector pcDNA3 were injected into mice sc. Immune responses to pcDNA3HCV C-Fc were studied. Meanwhile the effect of pcDNA3HCV C-Fc on anti-translated subcutaneous tumor of SP2/0 cells stably expressing HCV C Ag (SP2/0-HCV C-FC) was also studied. Anti-HCV C in serum was detected by enzyme-linked immunoadsordent assay (ELISA) and HCV specific cytotoxic T lymphocyte (CTL) activity was measured by LDH release assay. After 3 wk of DNA immunization, the cells of SP2/0-HCV C-FC were inoculated into mice subcutaneously and tumor growth was measured every 5 d. The survival rate and living time of mice were also calculated. RESULTS: After 4 wk of DC immunization, the A(450 nm) values of sera in mice immunized with pcDNA3HCV C-Fc-DC and pcDNA3-DC were 0.56+/-0.17 and 0.12+/-0.03 respectively. The antibody titres in mice codeliveried with pcDNA3HCV C-Fc with DC were significantly higher than those of mice injected with pcDNA3-DC. The HCV specific CTL activities in mice coinjected with DC and pcDNA3HCV C-Fc or empty expression vectors were (73.2+/-3.1)% and (24.4+/-8.8)%, which were significantly higher than those of mice injected with water. The DC vaccine could evidently inhibit tumor growth, prolong the survival time of mice and improve the survival rate of mice and these effects could be improved by HCV C-Fc (pcDNA3HCV C-Fc) gene codelivered. CONCLUSION: DC vaccine has a strong antigenicity in humoral and cellular immunities, which can be promoted by transduced pcDNA3HCV C-Fc expressing HCV C or Fc. Thus, pcDNA3HCV C-Fc-transduced DCs may be a promising candidate for a CTL-based vaccine against HCV.

[Enhancement of thrombolytic activities of Carthamus tinctorius processed with fermentation with a bacillus sp. C2-13].

A processing method to enhance thrombolytic effect of Carthamus tinctorius using a fermentation technology with bacillus sp. C2-13 was investigated. The fibrinolysis and anticoagulation activity of thrombolytic extracts from an optimized fermentation process was studied using a carrageenan induced mice model. The fermented extracts resulted in significantly better thrombolytic activity, suggesting that the process was promising for use in the study and preparation of nature medicines.

Switched capacitor charge pump used for low-distortion imaging in atomic force microscope.

The switched capacitor charge pump (SCCP) is an effective method of linearizing charges on piezoelectric actuators and therefore constitute a significant approach to nano-positioning. In this work, it was for the first time implemented in an atomic force microscope for low-distortion imaging. Experimental results showed that the image quality was improved evidently under the SCCP drive compared with that under traditional linear voltage drive.