Research on fatigue optimization simulation of polymeric heart valve based on the iterative sub-regional thickened method.

Prosthetic polymeric heart valves (PHVs) have the potential to overcome the inherent material and design limitations of traditional valves in the treatment of valvular heart disease; however, their durability remains limited. Optimal design of the valve structure is necessary to improve their durability. This study aimed to enhance the fatigue resistance of PHVs by improving the stress distribution. Iterative subregional thickening of the leaflets was used, and the mechanical stress distribution and hemodynamics of these polymeric tri-leaflet valves were characterized using a fluid-structure interaction approach. Subregional thickening led to a reduction in stress concentration on the leaflet, with the effective orifice area still meeting ISO 5840-3 and the regurgitant volume achieving a similar value to those in previous studies. The maximum stress in the final iteration was reduced by 28% compared with that of the prototype. The proposed method shows potential for analyzing the stress distribution and hemodynamic performance of subregional thickened valves and can further improve the durability of PHVs.

Prediction of cardiac arrest in critically ill patients based on bedside vital signs monitoring.

PURPOSE: Cardiac arrest (CA) is the most serious death-related event in critically ill patients and the early detection of CA is beneficial to reduce mortality according to clinical research. This study aims to develop and verify a real-time, interpretable machine learning model, namely cardiac arrest prediction index (CAPI), to predict CA of critically ill patients based on bedside vital signs monitoring. METHODS: A total of 1,860 patients were analyzed retrospectively from the Medical Information Mart for Intensive Care III (MIMIC-III) database. Based on vital signs, we extracted a total of 43 features for building machine learning model. Extreme Gradient Boosting (XGBoost) was used to develop a real-time prediction model. Three-fold cross validation determined the consistency of model accuracy. SHAP value was used to capture the overall and real-time interpretability of the model. RESULTS: On the test set, CAPI predicted 95% of CA events, 80% of which were identified more than 25 min in advance, resulting in an area under the receiver operating characteristic curve (AUROC) of 0.94. The sensitivity, specificity, area under the precision-recall curve (AUPRC) and F1-score were 0.86, 0.85, 0.12 and 0.05, respectively. CONCLUSION: CAPI can help predict patients with CA in the vital signs monitoring at bedside. Compared with previous studies, CAPI can give more timely notifications to doctors for CA events. However, current performance was at the cost of alarm fatigue. Future research is still needed to achieve better clinical application.

MicroRNA-132 in the Adult Dentate Gyrus is Involved in Opioid Addiction Via Modifying the Differentiation of Neural Stem Cells / 神经科学通报·英文版

MicroRNA-132 (miR-132), a small RNA that regulates gene expression, is known to promote neurogenesis in the embryonic nervous system and adult brain. Although exposure to psychoactive substances can increase miR-132 expression in cultured neural stem cells (NSCs) and the adult brain of rodents, little is known about its role in opioid addiction. So, we set out to determine the effect of miR-132 on differentiation of the NSCs and whether this effect is involved in opioid addiction using the rat morphine self-administration (MSA) model. We found that miR-132 overexpression enhanced the differentiation of NSCs in vivo and in vitro. Similarly, specific overexpression of miR-132 in NSCs of the adult hippocampal dentate gyrus (DG) during the acquisition stage of MSA potentiated morphine-seeking behavior. These findings indicate that miR-132 is involved in opioid addiction, probably by promoting the differentiation of NSCs in the adult DG.

Development of Competitive Enzyme-Linked Immunosorbent Assays for Antibody Detection Based on Bluetongue Virus Monoclonal Antibodies.

Bluetongue is a ruminant infectious disease that is characterized by hyperpyrexia, leukocyte decrease and mucosal ulcerative inflammation changes. In this study, three segments of Bluetongue virus (BTV)-8 VP2 protein (BTV-8A, 8B, and 8C) were cloned into pET-28a (+) and pMAl-c5X vectors and expressed in Escherichia coli BL21 (DE3) as histidine (His)-tagged (His-8A/8B/8C) and maltose-binding protein (MBP)-tagged (MBP-8A/8B/8C) fusion proteins. After purification, His-8A/8B/8C were used to immunize BALB/mice and MBP-8A/8B/8C were used to screen for monoclonal antibody (mAb)-secreting hybridomas. Two mAbs (8B-5D4 and 8B-3G11) that could recognize BTV-8 were obtained. Two competitive enzyme-linked immunosorbent assays with good specificity and sensitivity using mAbs 8B-5D4 or 8B-3G11 as competitive antibody were established. With the joint reaction of these methods, serum samples containing anti-BTV-7 or anti-BTV-8 antibody could be screened out, suggesting that these methods would be useful for the diagnosis and epidemiological studies of BTV-8.

Mechanism of acupoint transcutaneous electric stimulation on analgesic anesthesia in the patients undergoing general anesthesia anorectal operation / 中国针灸

<p><b>OBJECTIVE</b>To observe the regulatory effects of acupoint electric stimulation on the analgesic substances and the relevant indices of nerve-immunity-endocrine system in the patients undergoing general anesthesia anorectal operation.</p><p><b>METHODS</b>One hundred and fifty-six patients undergoing hemorrhoids and anal fistula operation were randomized into three groups, 146 cases were included in the analysis. In the No.1 group (48 cases), the conventional intravenous general anesthesia was applied. In the No.2 group (50 cases), besides the conventional intravenous general anesthesia, the acupoint transcutaneous electric stimulation was combined at Neiguan (PC 6), Shenmen (HT 7), Shangliao (BL 31) and Ciliao (BL 32). operation in the No.2 and No.3 groups were lower apparently than that in the No.1 group (<0.05,<0.01).</p><p><b>CONCLUSIONS</b>During the general anesthesia anorectal operation, the acupoint transcutaneous electric stimulation achieves analgesic anesthesia through effectively promoting the release of body analgesic substance and reducing the stress level in the operation. With the comprehensive acupoint selection as Neiguan (PC 6) and Shenmen (HT 7) and the local acupoints, the therapeutic effects are better in comparison with the simple selection of local acupoints. In the No.3 group (48 cases), besides the conventional intravenous general anesthesia, the acupoint transcutaneous electric stimulation was combined at Shangliao (BL 31) and Ciliao (BL 32). The electric stimulation was maintained till the end of operation. The patients' saliva was collected 0.5 h before operation and 1 h after operation separately. The indices that reflect the body pain regulation and nerve-immune-endocrine secretion were detected, such as opiophin protein (OPI), secretory immunoglobulin A (SIgA), saliva amylase (sAA), cortisol (Cor) and tumor necrosis factor α (TNF-α). The pain degree was observed 1 h after operation.</p><p><b>RESULTS</b>In the No.2 group, OPI after operation was higher than that before operation (<0.05). The difference value of OPI in the No.2 group was higher apparently than that in the No.1 group and the No.3 group (both<0.05). SIgA after operation was higher than that before operation in the No.1 group (<0.05). The difference values of SIgA, sAA, Cor in the No.2 group were lower apparently than those in the No.1 group (<0.05,<0.01). TNF-αbefore and after operation and its difference value among the groups were not significant statistically (all>0.05). The pain degrees in 1 h after.</p>

Identification of epitope recognized by a monoclonal antibody against VP2 protein of bluetongue virus serotype 8 / 生物工程学报

To confirm the B cell epitope recognized by monoclonal antibody (MAb) 3G11 of bluetongue virus type 8 (BTV-8) VP2 protein prepared in our laboratory, antigen epitopes recognized by 3G11 were screened and identified by phage display technology. KLLAT sequence was found by sequencing of blue spot after four rounds panning and 283LL284 of common short peptide sequence was obtained after comparison to amino acid sequence of BTV-8 VP2 protein. The peptide sequences KLLAA, KALAT, KLAAT and KLLAT were synthesized and identified by indirect ELISA. KLLAA and KLLAT bound strongly with supernatant and as cites of 3G11 cells and reacted specifically with BTV-8 positive standard sera. Further sequence analysis showed that amino acid sequence 283LL284 was conserved among different serotypes of BTV-8 strains, and283LL284 was the key amino acids of antigen epitopes recognized by 3G11. This study laid the foundation to establish type 8 BTV specific immunological detection methods.

Establishment of two competitive ELISAs for specific detection of bluetongue virus serotype 4 / 生物工程学报

To develop a clinical diagnosis technique for bluetongue virus infection, we established serotype-specific methods to detect serotype 4 of bluetongue virus (BTV-4). Two monoclonal antibodies (mAbs) against VP2 protein of BTV-4, named 4A-1G7 and 4B-1B6, were used as competitive antibodies in the competitive enzyme-linked immunosorbent assays (C-ELISA). We detected 50 negative serum samples from sheep, goats and cattle by C-ELISA. The cut-off values of 4A-1G7 and 4B-1B6 mAbs were 49% and 40%, respectively. The results of the sensitivity, specificity and repeatability by detecting standard positive serum, were consistent with the general standard of Office International Des Epizooties. Furthermore, serum samples of BTV-4, BTV-18 and BTV-20 infection could be screened out through the combined C-ELISAs by 4A-1G7 and 4B-1B6 mAbs. Thus, this technique may diagnose BTV-4, BTV-18 and BTV-20 infections.

A simple fixing method for tail vein injection in mice-cage lid pressing method / 中国比较医学杂志

Objective To introduce a simple fixing method for tail vein injection in mice.Methods Twenty tumor-bearing male BALB/c nude mice were used in this study.Tail vein injection was performed to these mice by two laboratory technicians A and B, respectively.The injection time and success rate were recorded and analyzed.Results Mouse tail vein injection was successfully completed by the two technicians with the cage lid pressing method.Conclusions Cage lid pressing method is a simple method for tail vein injection in mice, especially provides a more efficient method for those special form of mice.

YANG's pricking-cupping therapy for knee osteoarthritis: a multi-center randomized controlled trial / 中国针灸

<p><b>OBJECTIVE</b>To evaluate the clinical efficacy of YANG's pricking-cupping therapy for knee osteoar thritis (KOA). Methods This was a multi-center randomized parallel controlled trial. One hundred and seventy one patients with KOA were randomly allocated to a pricking-cupping group (89 cases) and a conventional acu puncture group (82 cases). Neixiyan (EX-LE 4), Dubi (ST 35) and ashi points were selected in the two groups. Patients in the pricking-cupping group were treated with YANG's pricking-cupping therapy; the seven-star needles were used to perform pricking at acupoints, then cupping was used until slight bleeding was observed. Patients in the conventional acupuncture group were treated with semi-standardized filiform needle therapy. The treatment was given for 4 weeks (from a minimum of 5 times to a maximum of 10 times). The follow-up visit was 4 weeks. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the visual analogue scale (VAS) were adopted for the efficacy assessments.</p><p><b>RESULTS</b>The pain score, stiffness score, physical function score and total score of WOMAC were all reduced after 4-week treatment and during follow-up visit in the two groups (all P<0. 0001). Except that the difference of stiffness score between the two groups was not significant after 4-week treatment (P>0. 05), each score and total score of WOMAC in the pricking-cupping group were lower than those in the conventional acupuncture group after 4-week treatment and during follow-up visit (P<0. 0001, P<0. 01). After 2-week treatment, 4-week treatment and during follow-up visit, the VAS was all reduced compared with that before treatment (all P<0. 0001) ; with the increase of the treatment, the reducing trend of VAS was more significant (P<0. 0001). The scores of VAS in the pricking-cupping group were lower than those in the conventional acupuncture group after 4-week treatment and during follow-up visit (P < 0. 01, P <0. 0001). CONCLUSION The YANG's pricking-cupping and conventional acupuncture therapy can both significantly improve knee joint pain and function in patients with KOA, which are relatively safe. The pricking cupping therapy is superior to conventional acupuncture with the identical selection of acupoints.</p>

Development of an antigen capture enzyme-linked immunosorbent assay for virus detection based on porcine epidemic diarrhea virus monoclonal antibodies.

Porcine epidemic diarrhea virus (PEDV), a coronavirus, can cause acute diarrhea and dehydration in pigs. In the current study, two positive monoclonal cell lines (5D7 and 3H4) specific for PEDV were established, and the immunoreactivity of the monoclonal antibodies was confirmed by immunofluorescence and dot-immunobinding assays. A method, termed antigen capture enzyme-linked immunosorbent assay (AC-ELISA), which used the monoclonal antibody 5D7 as the detecting antibody and rabbit antiserum of PEDV protein S as the capture antibody, was developed. Compared with the reverse transcription polymerase chain reaction method of detecting PEDV in fecal samples, AC-ELISA showed similar sensitivity and specificity. These results suggested that AC-ELISA would be useful for the diagnosis and epidemiological studies of PEDV.

Elucidation of Needling Depth in Nei Jing / 上海针灸杂志

This article was to elucidate that the needling depth is closely related to the meridian qi, disease location, disease nature and needled area based on the records of needling depth in Nei Jing (Canon of Internal Medicine). Moreover, different depths will produce different therapeutic efficacies;meanwhile, improper depth may lead to grave consequences.

Comparison of expression and antibacterial activities of recombinant porcine lactoferrin expressed in four Lactobacillus species / 生物工程学报

The coding sequence for the mature peptide of porcine lactoferrin (Plf) was synthesized according to the codon usage of lactobacillus, to establish optimized porcine lactoferrin Lactobacillus expression system. The gene was ligated into the Xho I/BamH I site of Lactobacillus expression vector pPG612.1 and the recombinant plasmid pPG612.1-plf was transformed individually into Lactobacillus casei ATCC393, Lactobacillus pentosus KLDS1.0413, Lactobacillus plantarum KLDS1.0344 or Lactobacillus paracasei KLDS1.0652 by electroporation. After induction with xylose, expression of the recombinant proteins was detected by Western blotting and confocal laser scanning microscopy. Secretion of recombinant Plf proteins from four recombinant species was determined quantitatively by ELISA. The antibacterial activities of recombinant proteins were measured by agar diffusion method. The result shows that Plf was correctly expressed in four species of recombinant lactobacillus, with molecular weight of about 73 kDa. The expression levels in recombinant Lactobacillus casei, Lactobacillus pentosus, Lactobacillus plantarum, Lactobacillus paracasei were 9.6 μg/mL, 10.8 μg/mL, 12.5 μg/mL and 9.9 μg/mL, respectively. Antimicrobial activity experiment shows that the recombinant proteins were active against E. coli, Staphylococcus aureus, Salmonella typhimurium, Listeria, Pasteurella. The recombinant Plf expressed by recombinant Lactobacillus plantarum showed the best antibacterial activity among all recombinant lactobacillus species. These data represent a basis for the development and application of porcine lactoferrin from recombinant lactobacillus.

Expression and biological activity of porcine interleukin-18 in recombinant Lactococcus lactis / 生物工程学报

To obtain active protein of pIL-18 expression in Lactococcus lactis, and to observe its biological activity, the total RNA was extracted as template from peripheral blood mononuclear cells. Porcine interleukin 18 (pIL-18) was amplified by RT-PCR. The resulting fragment was cloned into pAMJ399 L. lactis vector, and then transformed to L. lactis MG1363 cells by electroporation. Expression of pIL-18 protein was detected by SDS-PAGE and Western-blotting. Bioactivity of the product was tested by pig spleen lymphocyte proliferation test and cytopathogenic effect inhibition assay. The result of Western blotting and bioactivity test shows that the molecular weight of pIL-18 protein was 19 kDa. The react line was observed in both supernatant and precipitated of the recombinant bacteria pAMJ399-pIL18/MG1363. The expressed pIL-18 can promote the proliferation of pig spleen lymphocyte, and significantly inhibit virus multiplication. As conclusion, porcine interleukin-18 was successfully expressed in L. lactis, and the product was biologically active.

High-level expression and antimicrobial activity of recombinant N-terminal porcine lactoferrin / 生物工程学报

Lactoferrin in milk is a multifunctional protein. In addition, lactoferrin has antiviral, antifungal and antiparasitic activity. In this study, the N-terminus from porcine lactoferrin (PLF-N) was designed to express the antimicrobial action of recombinant porcine lactoferrin. We cloned a 1077 bp fragment of the PLF gene from mammary gland tissue of the lactating sow at the third day. Comparing nucleotide sequence with four strains of PLF gene published on GenBank, the homology was more than 99%. With the reference template of the cloned fragment of PLF-N and optimizing codon bias, we synthesized the gene of N-terminus encoding porcine lactoferrin (PLF-NS). The high expression gene of PLF-NS was cloned into the fusion expression vector pET30b and expressed in E. coli BL21 (DE3). After induced with Isopropyl beta-D-1-Thiogalactopyranoside (IPTG), the target fusion protein was successfully expressed and identified in inclusion bodies by SDS-PAGE and Western blotting. The protein had a molecular weight of 42 kDa and accounted for 32% of the total cellular protein. After purification and renaturation, the purity of the expressed protein was 98%. The expressed PLF-NS protein showed obviously antibacterial activity. This method provides an excellent way for high expression of antimicrobial proteins when optimizing codon bias.

Induction of immune response after oral inoculation of mice with Lactobacillus casei surface-displayed porcine epidemic diarrhea viral N protein / 生物工程学报

To evaluate the immune responses of recombinant Lactobacillus casei 393 expressing Porcine Epidemic Diarrhea Viral (PEDV) N protein as oral vaccine, n gene of PEDV was subcloned into the expression vector pPG-1, and then transformed into L. casei 393 by electroporation, resulting in recombinant strain pPG-1-n/L, casei 393. The recombinant strains were induced to express interest protein, which was detected by Western blotting, immunofluorescence microscopy and the whole bacteria ELISA. And then BALB/C mice were used as an animal model immunized with recombinant strains by oral administration, and the immune efficacy was analyzed. The recombinant PEDV N protein showed the antigenic specificity, and was located on the bacterial cell walls of pPG-1-n transformed L. casei. The results of ELISA showed that the mice immunized with recombinant strains could produce remarkable special sIgA level in the feces, and high level of anti-PEDV N protein IgG in the serum (P < 0.01), but the induced antibodies in serum did not demonstrated neutralizing effect. Statistical significant difference was observed among the spleen lymphocyte proliferation index (LPI) among the immunization groups of mice and control groups. And there was significant increase. of IFN-gamma and IL-4 contents in the supernatant of spleen cell culture in immunized group. In conclusion, the oral immunizations with recombinant L. casei 393 can induce significant specific mucosal PEDV N-specific IgA response as well as serum IgG responses, and can evoke both mucosal immune and system immune responses.

High-level prokaryotic expression of envelope exterior of membrane protein of porcine epidemic diarrhea virus.

The truncated fragment M' gene, encoding the exterior of the viral envelope protein of PEDV, was subcloned into prokaryotic expression vector pGEX-6p-1. The recombinant plasmid pGEX-6p-M' was constructed and transformed into E. coli BL21(DE3)pLysS for expression. SDS-PAGE analysis showed recombinant truncated M' protein was highly expressed by pGEX-6p-M' and the product fusion protein GST-M' reached 45% in the total bacteria proteins with the analysis of software AlphaImager2200. The preliminary purified recombinant protein was evaluated for its antigenicity and reactivity through Western blotting and indirect enzyme-linked immunosorbent assay (ELISA) with monoclonal antibody against M protein of PEDV and porcine polyclonal anti-PEDV antiserum as the primary antibody. The results indicated the recombinant truncated M' protein should be candidate as a feasible recombinant diagnostic reagent.

Cloning and sequence analysis of the N gene of porcine epidemic diarrhea virus LJB/03.

The nucleocapsid (N) gene of the porcine epidemic diarrhea virus (PEDV) strain LJB/03 which was previously isolated in Heilongjiang province, China, was cloned, sequenced and compared with published sequences of other avian and mammalian coronavirus. The nucleotide sequence encoding the entire N gene open reading frame (ORF) of LJB/03 was 1326 bases long and encoded a protein of 441 amino acids with predicted Mr of 49 kDa. It consisted of 405 adenines (30.5%), 294 cytosines (22.1%), 329 guanines (24.8%) and 298 thymines (22.5%) residues. Sequence comparison with other PEDV strains selected from GenBank revealed that the LJB/03 N gene has a high sequence homology to those of other PEDV isolates, 97.4% with JS2004, 95.6% with chinju99, 96.6% with Br1/87, and 96.8% with CV777. The encoded protein shared 96.4% amino acid identities compared with CV777, 96.1% with Brl/87, 98% with JS2004, 96.90% with chinju99, respectively. The amino acid sequence contained seven potential protein kinase C phosphorylation sites, nine Casein kinase II phosphorylation sites, one Tyrosine kinase phosphorylation site, two cAMP- and cGMP-dependent protein kinase phosphorylation sites.

Cloning and sequence analysis of the M gene of porcine epidemic diarrhea virus LJB/03.

Porcine epidemic diarrhea virus (PEDV) LJB/03 was isolated from the fece of piglets infected with PEDV on a pig farm, Heilongjiang province, China. The M gene of LJB/03 was amplified from the RNA extracted directly from the fece samples by RT-PCR and cloned into pMD18-T vector. The M gene cDNA was sequenced and encompasses an open reading frame of 681 nucleotides, encoding a 226-amino acid protein. The LJB/03 M gene has a base composition of 152 adenines (22%), 153 cytosines (23%), 161 guanines (24%), and 214 thymines (31%). Sequence comparison with other PEDV strains selected from GenBank revealed that the LJB/03 M gene has a high sequence homology to those of other PEDV isolates, 97.80% with JMe2, 96.92% with KPEDV-9 (Korean field isolate), 97.36% with KPEDV-9 (Korean), 97.80% with Br1/87, and 97.94% with CV777. The encoded protein shared 97.79% amino acid identities compared with CV777, 97.35% with Br1/87, 97.79% with JMe2, 96.90% with KPEDV-9 (Korean field isolate), 96.46% with KPEDV-9 (Korean). Sequence analysis of the M gene, including genetic distance measurement, phylogenetic tree analysis, and residue substitution analysis, showed that all other PED viruses analyzed fell into three groups, and the LJB/03 itself branched in an independent group. These data revealed that the M gene nucleotide sequence of LJB/03 has some mutations in comparison with the other PED viruses.