Application of multidirectional stitching technology in a laparoscopic suturing instructional program: a randomized controlled trial.

BACKGROUND: Surgeon suturing technology plays a pivotal role in patient recovery after laparoscopic surgery. Intracorporal suturing and knot tying in minimally invasive surgery are particularly challenging and represent a key skill for advanced procedures. In this study, we compared the application of multidirectional stitching technology with application of the traditional method in a laparoscopic suturing instructional program. METHODS: We selected forty residents within two years of graduation to assess the specialized teaching of laparoscopic suturing with laparoscopic simulators. The forty students were randomly divided into two groups, a control group and an experimental group, with twenty students in each group. The control group was scheduled to learn the traditional suture method, and the experimental group applied multidirectional stitching technology. The grades for suturing time, thread length, accuracy of needle entry, stability of the knot, tissue integrity, and tightness of the tissue before and after the training program were calculated. RESULTS: There was no significant difference between the two groups before the learning intervention. After the program, both groups significantly improved in each subject. There were significant differences between the control group and the experimental group in suture time (P = 0.001), accuracy of needle entry and exit (P = 0.035), and whether the suture tissue had cracks (P = 0.030). However, the two groups showed non-significant differences in thread length (P = 0.093), stablity of the knot (P = 0.241), or tightness of the tissue (P = 0.367). CONCLUSIONS: Multidirectional stitching technology improves the efficiency and effectiveness of traditional laparoscopic suture instructional programs. It might be a practicable, novel training method for acquiring proficiency in manual laparoscopic skills in a training setting.

Three-dimensional poly-(ε-caprolactone) nanofibrous scaffolds directly promote the cardiomyocyte differentiation of murine-induced pluripotent stem cells through Wnt/ß-catenin signaling.

BACKGROUND: Environmental factors are important for stem cell lineage specification, and increasing evidence indicates that the nanoscale geometry/topography of the extracellular matrix (ECM) directs stem cell fate. Recently, many three-dimensional (3D) biomimetic nanofibrous scaffolds resembling many characteristics of the native ECM have been used in stem cell-based myocardial tissue engineering. However, the biophysical role and underlying mechanism of 3D nanofibrous scaffolds in cardiomyocyte differentiation of induced pluripotent stem cells (iPSCs) remain unclear. RESULTS: Here, we fabricated a 3D poly-(ε-caprolactone) (PCL) nanofibrous scaffold using the electrospinning method and verified its nanotopography and porous structure by scanning electron microscopy. We seeded murine iPSCs (miPSCs) directly on the 3D PCL nanofibrous scaffold and initiated non-directed, spontaneous differentiation using the monolayer method. After the 3D PCL nanofibrous scaffold was gelatin coated, it was suitable for monolayer miPSC cultivation and cardiomyocyte differentiation. At day 15 of differentiation, miPSCs differentiated into functional cardiomyocytes on the 3D PCL nanofibrous scaffold as evidenced by positive immunostaining of cardiac-specific proteins including cardiac troponin T (cTnT) and myosin light chain 2a (MLC2a). In addition, flow cytometric analysis of cTnT-positive cells and cardiac-specific gene and protein expression of cTnT and sarcomeric alpha actinin (α-actinin) demonstrated that the cardiomyocyte differentiation of miPSCs was more efficient on the 3D PCL nanofibrous scaffold than on normal tissue culture plates (TCPs). Furthermore, early inhibition of Wnt/ß-catenin signaling by the selective antagonist Dickkopf-1 significantly reduced the activity of Wnt/ß-catenin signaling and decreased the cardiomyocyte differentiation of miPSCs cultured on the 3D PCL nanofibrous scaffold, while the early activation of Wnt/ß-catenin signaling by CHIR99021 further increased the cardiomyocyte differentiation of miPSCs. CONCLUSION: These results indicated that the electrospun 3D PCL nanofibrous scaffolds directly promoted the cardiomyocyte differentiation of miPSCs, which was mediated by the activation of the Wnt/ß-catenin signaling during the early period of differentiation. These findings highlighted the biophysical role of 3D nanofibrous scaffolds during the cardiomyocyte differentiation of miPSCs and revealed its underlying mechanism involving Wnt/ß-catenin signaling, which will be helpful in guiding future stem cell- and scaffold-based myocardium bioengineering.

CircRNA circ-IQGAP1 Knockdown Alleviates Interleukin-1ß-Induced Osteoarthritis Progression via Targeting miR-671-5p/TCF4.

OBJECTIVE: To explore the function of circular RNA IQ motif-containing GTPase-activating protein 1 (circ-IQGAP1) in interleukin (IL)-1ß-induced osteoarthritis (OA) model and to explore whether circ-IQGAP1 can modulate microRNA-671-5p (miR-671-5p) and transcription factor 4 (TCF4) to regulate chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. METHODS: The cartilage tissues were collected from 32 OA patients or normal subjects. Human chondrocyte CHON-001 cells were challenged via different doses of IL-1ß for 24 hours. CHON-001 cells were transfected with circ-IQGAP1 overexpression vector, TCF4 overexpression vector, small interfering RNA (siRNA) for circ-IQGAP1, miR-671-5p mimic, miR-671-5p inhibitor or corresponding negative controls. Circ-IQGAP1, miR-671-5p and TCF4 abundances in cartilage tissues or CHON-001 cells were examined via quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot. Cell viability was investigated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). Cell apoptosis was measured by flow cytometry. The inflammatory injury was analyzed by the secretion levels of inflammatory cytokines (IL-6, IL-8 and tumor necrosis factor-α [TNF-α]) by enzyme-linked immunosorbent assay (ELISA). The extracellular matrix degradation was evaluated by expression of aggrecan and matrix metalloproteinase 13 (MMP13) via western blot. The target relationship of miR-671-5p and circ-IQGAP1 or TCF4 was analyzed via dual-luciferase reporter and RNA immunoprecipitation (RIP) analyses. RESULTS: Circ-IQGAP1 abundance was enhanced in the cartilage tissues from OA patients compared with normal subjects (n = 32), and its expression was increased in CHON-001 cells after treatment of IL-1ß in a dose-dependent pattern. MiR-671-5p expression was decreased in the cartilage tissues from OA patients (n = 32) and IL-1ß-challenged CHON-001 cells. MiR-671-5p expression was negatively associated with circ-IQGAP1 level in OA patients. Circ-IQGAP1 silence mitigated IL-1ß-caused chondrocyte viability reduction, apoptosis promotion, secretion of inflammatory cytokine (IL-6, IL-8 and TNF-α), and extracellular matrix degradation (reduction of aggrecan and increase of MMP13). MiR-671-5p was targeted and inhibited via circ-IQGAP1. MiR-671-5p knockdown attenuated the influence of circ-IQGAP1 interference on IL-1ß-caused chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. TCF4 was targeted via miR-671-5p, and TCF4 expression was increased in the cartilage tissues from OA patients (n = 32) and IL-1ß-challenged CHON-001 cells. TCF4 abundance in OA patients was negatively correlated with miR-671-5p expression. MiR-671-5p overexpression alleviated IL-1ß-mediated chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation via decreasing TCF4 expression. Circ-IQGAP1 silence reduced TCF4 expression via regulating miR-671-5p in IL-1ß-challenged CHON-001 cells. CONCLUSION: Circ-IQGAP1 knockdown attenuated IL-1ß-caused chondrocyte apoptosis, inflammatory injury, and extracellular matrix degradation. Circ-IQGAP1 could regulate miR-671-5p/TCF4 axis to modulate IL-1ß-caused chondrocyte damage. Circ-IQGAP1 might act as a new target for the treatment of OA.

A Cell Factory of a Fungicolous Fungus Calcarisporiumarbuscula for Efficient Production of Natural Products.

Fungal natural products are rich sources of clinical drugs. Particularly, the fungicolous fungi have a large number of biosynthetic gene clusters (BGCs) to produce numerous bioactive natural products, but most BGCs are silent in the laboratory. We have shown that a fungicolous fungus Calcarisporiumarbuscula NRRL 3705 predominantly produces the highly reduced polyketide-type mycotoxins aurovertins. Here after evaluation of the aurovertin-null mutant ΔaurA as an efficient host, we further screened two strong promoters aurBp and A07068p based on RNA-Seq, and successfully activated an endogenous gene cluster from C. arbuscula as well as three additional exogenous BGCs from other fungi to produce polyketide-type natural products. Thus, we showed an efficient expression system from the fungicolous fungus C. arbuscula, which will be highly beneficial and complementary to the conventional Aspergillus and Penicillium fungal cell factories, and provides a useful toolkit for genome-wide mining of bioactive natural products from fungicolous fungi.

Role of alpha- and beta-adrenergic receptors in cardiomyocyte differentiation from murine-induced pluripotent stem cells.

OBJECTIVES: Induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a promising source of cells for regenerative heart disease therapies, but progress towards their use has been limited by their low differentiation efficiency and high cellular heterogeneity. Previous studies have demonstrated expression of adrenergic receptors (ARs) in stem cells after differentiation; however, roles of ARs in fate specification of stem cells, particularly in cardiomyocyte differentiation and development, have not been characterized. MATERIALS AND METHODS: Murine-induced pluripotent stem cells (miPSCs) were cultured in hanging drops to form embryoid bodies, cells of which were then differentiated into cardiomyocytes. To determine whether ARs regulated miPSC differentiation into cardiac lineages, effects of the AR agonist, epinephrine (EPI), on miPSC differentiation and underlying signalling mechanisms, were evaluated. RESULTS: Treatment with EPI, robustly enhanced miPSC cardiac differentiation, as indicated by increased expression levels of cardiac-specific markers, GATA4, Nkx2.5 and Tnnt2. Although ß-AR signalling is the foremost signalling pathway in cardiomyocytes, EPI-enhanced cardiac differentiation depended more on α-AR signalling than ß-AR signalling. In addition, selective activation of α1 -AR signalling with specific agonists induced vigorous cardiomyocyte differentiation, whereas selective activation of α2 - or ß-AR signalling induced no or less differentiation, respectively. EPI- and α1 -AR-dependent cardiomyocyte differentiation from miPSCs occurred through specific promotion of CPC proliferation via the MEK-ERK1/2 pathway and regulation of miPS cell-cycle progression. CONCLUSIONS: These results demonstrate that activation of ARs, particularly of α1 -ARs, promoted miPSC differentiation into cardiac lineages via MEK-ERK1/2 signalling.

Expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths.

BACKGROUND: It has been studied that the distribution of bone morphogenetic protein 2 is regular under bone defect situation. OBJECTIVE: To observe the expression of bone morphogenetic protein 2 in rabbit radial defect site with different lengths. METHODS: Forty-eight New Zealand rabbits were divided into two groups randomly. 0.5 cm bone defect and 3.0 cm bone defect were made by wire saw at the middle part of radius bone after anaesthesia. RESULTS AND CONCLUSIONS: Western blot results showed that in the 0.5 cm bone defect group, the expression of bone morphogenetic protein 2 of the tissues in the bone defect site was increased gradually at 1, 3, 4 weeks after operation, and the expression in each defect group was increased when compared with that immediately after injury (P<0.05). In the 3.0 cm bone defect group, the expression of bone morphogenetic protein 2 of tissues in bone defect site was increased gradually and reached to its peak at 3 weeks after the operation (P<0.05). The peak value in the 3.0 cm bone defect group was significantly higher than that in 0.5 cm bone defect group (P<0.05). The peak value was maintained in high level. The comparison of bone callus formation showed that the bone callus formation of 3.0 cm bone defect group was less than that of the 0.5 cm bone defect group at 3 and 4 weeks after operation (P<0.05). The results indicate that expression of the bone morphogenetic protein 2 in 3.0 cm bone defect site is increased significantly, but the expression level cannot make the bone defect heal itself.