Discovering a mitochondrion-localized BAHD acyltransferase involved in calystegine biosynthesis and engineering the production of 3ß-tigloyloxytropane.

Solanaceous plants produce tropane alkaloids (TAs) via esterification of 3α- and 3ß-tropanol. Although littorine synthase is revealed to be responsible for 3α-tropanol esterification that leads to hyoscyamine biosynthesis, the genes associated with 3ß-tropanol esterification are unknown. Here, we report that a BAHD acyltransferase from Atropa belladonna, 3ß-tigloyloxytropane synthase (TS), catalyzes 3ß-tropanol and tigloyl-CoA to form 3ß-tigloyloxytropane, the key intermediate in calystegine biosynthesis and a potential drug for treating neurodegenerative disease. Unlike other cytosolic-localized BAHD acyltransferases, TS is localized to mitochondria. The catalytic mechanism of TS is revealed through molecular docking and site-directed mutagenesis. Subsequently, 3ß-tigloyloxytropane is synthesized in tobacco. A bacterial CoA ligase (PcICS) is found to synthesize tigloyl-CoA, an acyl donor for 3ß-tigloyloxytropane biosynthesis. By expressing TS mutant and PcICS, engineered Escherichia coli synthesizes 3ß-tigloyloxytropane from tiglic acid and 3ß-tropanol. This study helps to characterize the enzymology and chemodiversity of TAs and provides an approach for producing 3ß-tigloyloxytropane.

Biosynthesis of Scopoletin in Sweet Potato Confers Resistance against Fusarium oxysporum.

Fusarium wilt is a severe fungal disease caused by Fusarium oxysporum in sweet potato. We conducted transcriptome analysis to explore the resistance mechanism of sweet potato against F. oxysporum. Our findings highlighted the role of scopoletin, a hydroxycoumarin, in enhancing resistance. In vitro experiments confirmed that scopoletin and umbelliferone had inhibitory effects on the F. oxysporum growth. We identified hydroxycoumarin synthase genes IbF6'H2 and IbCOSY that are responsible for scopoletin production in sweet potatoes. The co-overexpression of IbF6'H2 and IbCOSY in tobacco plants produced the highest scopoletin levels and disease resistance. This study provides insights into the molecular basis of sweet potato defense against Fusarium wilt and identifies valuable genes for breeding wilt-resistant cultivars.

RGSB-UNet: Hybrid Deep Learning Framework for Tumour Segmentation in Digital Pathology Images.

Colorectal cancer (CRC) is a prevalent gastrointestinal tumour with high incidence and mortality rates. Early screening for CRC can improve cure rates and reduce mortality. Recently, deep convolution neural network (CNN)-based pathological image diagnosis has been intensively studied to meet the challenge of time-consuming and labour-intense manual analysis of high-resolution whole slide images (WSIs). Despite the achievements made, deep CNN-based methods still suffer from some limitations, and the fundamental problem is that they cannot capture global features. To address this issue, we propose a hybrid deep learning framework (RGSB-UNet) for automatic tumour segmentation in WSIs. The framework adopts a UNet architecture that consists of the newly-designed residual ghost block with switchable normalization (RGS) and the bottleneck transformer (BoT) for downsampling to extract refined features, and the transposed convolution and 1 × 1 convolution with ReLU for upsampling to restore the feature map resolution to that of the original image. The proposed framework combines the advantages of the spatial-local correlation of CNNs and the long-distance feature dependencies of BoT, ensuring its capacity of extracting more refined features and robustness to varying batch sizes. Additionally, we consider a class-wise dice loss (CDL) function to train the segmentation network. The proposed network achieves state-of-the-art segmentation performance under small batch sizes. Experimental results on DigestPath2019 and GlaS datasets demonstrate that our proposed model produces superior evaluation scores and state-of-the-art segmentation results.

Silicate Nanoplatelets Promotes Neuronal Differentiation of Neural Stem Cells and Restoration of Spinal Cord Injury.

Neural stem cell (NSC) transplantation has been suggested as a promising therapeutic strategy to replace lost neurons after spinal cord injury (SCI). However, the low survival rate and neuronal differentiation efficiency of implanted NSCs within the lesion cavity limit the application. Furthermore, it is difficult for transplanted cells to form connections with host cells. Thus, effective and feasible methods to enhance the efficacy of cell transplantation are needed. In this study, the effect of Laponite nanoplatelets, a type of silicate nanoplatelets, on stem cell therapy is explored. Laponite nanoplatelets can induce the neuronal differentiation of NSCs in vitro within five days, and RNA sequencing and protein expression analysis demonstrated that the NF-κB pathway is involved in this process. Moreover, histological results revealed that Laponite nanoplatelets can increase the survival rate of transplanted NSCs and promote NSCs to differentiate into mature neurons. Finally, the formation of connections between transplanted cells and host cells is confirmed by axon tracing. Hence, Laponite nanoplatelets, which drove neuronal differentiation and the maturation of NSCs both in vitro and in vivo, can be considered a convenient and practical biomaterial to promote repair of the injured spinal cord by enhancing the efficacy of NSC transplantation.

A reactive oxygen species-responsive hydrogel encapsulated with bone marrow derived stem cells promotes repair and regeneration of spinal cord injury.

Spinal cord injury (SCI) is an overwhelming and incurable disabling event accompanied by complicated inflammation-related pathological processes, such as excessive reactive oxygen species (ROS) produced by the infiltrated inflammatory immune cells and released to the extracellular microenvironment, leading to the widespread apoptosis of the neuron cells, glial and oligodendroctyes. In this study, a thioketal-containing and ROS-scavenging hydrogel was prepared for encapsulation of the bone marrow derived mesenchymal stem cells (BMSCs), which promoted the neurogenesis and axon regeneration by scavenging the overproduced ROS and re-building a regenerative microenvironment. The hydrogel could effectively encapsulate BMSCs, and played a remarkable neuroprotective role in vivo by reducing the production of endogenous ROS, attenuating ROS-mediated oxidative damage and downregulating the inflammatory cytokines such as interleukin-1 beta (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), resulting in a reduced cell apoptosis in the spinal cord tissue. The BMSCs-encapsulated ROS-scavenging hydrogel also reduced the scar formation, and improved the neurogenesis of the spinal cord tissue, and thus distinctly enhanced the motor functional recovery of SCI rats. Our work provides a combinational strategy against ROS-mediated oxidative stress, with potential applications not only in SCI, but also in other central nervous system diseases with similar pathological conditions.

RGGC-UNet: Accurate Deep Learning Framework for Signet Ring Cell Semantic Segmentation in Pathological Images.

Semantic segmentation of Signet Ring Cells (SRC) plays a pivotal role in the diagnosis of SRC carcinoma based on pathological images. Deep learning-based methods have demonstrated significant promise in computer-aided diagnosis over the past decade. However, many existing approaches rely heavily on stacking layers, leading to repetitive computational tasks and unnecessarily large neural networks. Moreover, the lack of available ground truth data for SRCs hampers the advancement of segmentation techniques for these cells. In response, this paper introduces an efficient and accurate deep learning framework (RGGC-UNet), which is a UNet framework including our proposed residual ghost block with ghost coordinate attention, featuring an encoder-decoder structure tailored for the semantic segmentation of SRCs. We designed a novel encoder using the residual ghost block with proposed ghost coordinate attention. Benefiting from the utilization of ghost block and ghost coordinate attention in the encoder, the computational overhead of our model is effectively minimized. For practical application in pathological diagnosis, we have enriched the DigestPath 2019 dataset with fully annotated mask labels of SRCs. Experimental outcomes underscore that our proposed model significantly surpasses other leading-edge models in segmentation accuracy while ensuring computational efficiency.

Antioxidant Activity of Phenolic Extraction from Different Sweetpotato (Ipomoea batatas (L.) Lam.) Blades and Comparative Transcriptome Analysis Reveals Differentially Expressed Genes of Phenolic Metabolism in Two Genotypes.

Sweetpotato (Ipomoea batatas (L.) Lam.), which has a complex genome, is one of the most important storage root crops in the world. Sweetpotato blades are considered as a potential source of natural antioxidants owing to their high phenolic content with powerful free radical scavenging ability. The molecular mechanism of phenolic metabolism in sweetpotato blades has been seldom reported thus far. In this work, 23 sweetpotato genotypes were used for the analysis of their antioxidant activity, total polyphenol content (TPC) and total flavonoid content (TFC). 'Shangshu19' and 'Wan1314-6' were used for RNA-seq. The results showed that antioxidant activity, TPC and TFC of 23 genotypes had significant difference. There was a significant positive correlation between TPC, TFC and antioxidant activity. The RNA-seq analysis results of two genotypes, 'Shangshu19' and 'Wan1314-6', which had significant differences in antioxidant activity, TPC and TFC, showed that there were 7810 differentially expressed genes (DEGs) between the two genotypes. Phenylpropanoid biosynthesis was the main differential pathway, and upregulated genes were mainly annotated to chlorogenic acid, flavonoid and lignin biosynthesis pathways. Our results establish a theoretical and practical basis for sweetpotato breeding with antioxidant activity and phenolics in the blades and provide a theoretical basis for the study of phenolic metabolism engineering in sweetpotato blade.

Gas-phase ion migration spectrum analysis of the volatile flavors of large yellow croaker oil after different storage periods.

The large yellow croaker, a species of fish found in the northwestern Pacific, is favored by consumers because of its prevalence in saltwater bodies, golden yellow abdomen, high calcium content, high protein, high fat content, and a flavor that originates from its lipids and volatile components. Volatile organic compounds significantly affect the aroma of food. In this work, electronic nose and headspace gas chromatography-ion mobility spectrometry were applied to analyze the flavor differences in fish oil durations. Through electronic nose system analysis, sensors W1C, W3S, W6S, and W2S directly affected fish oil flavor, and their flavor components were different. Gas chromatography-ion mobility spectrometry identified 26 volatile components (19 aldehydes, 3 ketones, 2 alcohols, 1 furan, and 1 olefin). (E,E)-2,4-hexadienal (D), (E,E)-2,4-hexadienal (M), 2,4-heptadienal (M), (E)-2-octenal, 2-propanone, 2-heptanone (M), 3-pentanone (D), and 1-octen-3-ol were the key flavor components of the fish oil. In conclusion, the combination of GC-IMS and PCA can identify the differences in flavor changes of large yellow croaker oil during 0-120 days storage. After 60 days storage, the types and signals of 2-propanone, 2-heptanone (M) components increase significantly. When 120 days storage, at this time, (E,E)-2,4-hexadienal (D), (E,E)-2,4-hexadienal (M), 2,4-heptadienal (M), (E)-2-octenal,(E)-2-octenal significantly. It has become the main flavor substance of fish oil. In summary, as the storage period increases, the components increase, and the oxidizing substances will increase, resulting in the deterioration of fish oil.

Changes of Volatile Flavor Compounds in Large Yellow Croaker (Larimichthys crocea) during Storage, as Evaluated by Headspace Gas Chromatography-Ion Mobility Spectrometry and Principal Component Analysis.

The large yellow croaker is one of the most economically important fish in Zhoushan, Zhejiang Province, and is well known for its high protein and fat contents, fresh and tender meat, and soft taste. However, the mechanisms involved in its flavor changes during storage have yet to be revealed, although lipid oxidation has been considered to be one important process in determining such changes. Thus, to explore the changes in the flavor of large yellow croaker fish meat during different storage periods, the main physical and chemical characteristics of the fish meat, including the acid value, peroxide value, p-anisidine value, conjugated diene value, and identities of the various flavor substances, were investigated and analyzed by multivariable methods, including headspace gas chromatography-ion mobility spectrometry (GC-IMS) and principal component analysis (PCA). It was found that after 60 d storage, the types and contents of the aldehyde and ketone aroma components increased significantly, while after 120 d, the contents of ketones (2-butanone), alcohols (1-propanethiol), and aldehydes (n-nonanal) decreased significantly. More specifically, aldehyde components dominated over ketones and lipids, while the n-nonanal content showed a downward trend during storage, and the 3-methylbutanol (trimer), 3-methylbutanol (dimer, D), 3-pentanone (D), and 3-pentanone (monomer) contents increased, whereas these compounds were identified as the key components affecting the fish meat flavor. Furthermore, after 120 d storage, the number of different flavor components reached its highest value, thereby confirming that the storage time influences the flavor of large yellow croaker fish. In this context, it should be noted that many of these compounds form through the Maillard reaction to accelerate the deterioration of fish meat. It was also found that after storage for 120 d, the physical indices of large yellow croaker meat showed significant changes, and its physicochemical properties varied. These results therefore demonstrate that a combination of GC-IMS and PCA can be used to identify the differences in flavor components present in fish meat during storage. Our study provides useful knowledge for understanding the different flavors associated with fish meat products during and following storage.

Evaluation of lightwand-guided endotracheal intubation for patients with missing or no teeth: a randomized controlled study.

BACKGROUND: Unhealthy teeth can seriously affect general health and increase the risk of death in elderly people. There has been no confirmation of which device is most effective for elderly patients with teeth loss. Therefore, we compared four intubation devices in elderly patients with partial and total tooth loss aiming to reduce risk during anesthesia. METHODS: Two hundred patients were randomized to undergo tracheal intubation with the Macintosh laryngoscope, the Glidescope, the Fiberoptic bronchoscope or the Lightwand as part of general anesthesia. A unified protocol of anesthetic medications was used. HR and BP were measured at T0, T1, T2, T3, T4 and T5. Catecholamine (epinephrine and norepinephrine) blood samples were drawn at T0, T1 and T2. Intubation time and postoperative complications, including dental damage and losses, were recorded. RESULTS: Reduced fluctuations in HR, DBP, and SBP were observed in the Lightwand group. Intubation time was significantly shorter in the Lightwand group (p < 0.05). There was no statistically significant difference between the groups in epinephrine levels, but norepinephrine levels were less volatile in the Fiberoptic bronchoscope and Lightwand groups. Fewer patients in the Lightwand group experienced dental damage and other postoperative complications than in the other three groups. Although a higher success rate on the first attempt was as high as in the Fiberoptic bronchoscope group, shorter intubation time was observed only in the Lightwand group. CONCLUSION: The Lightwand offers less hemodynamic stimulation than the Macintosh laryngoscope, Glidescope, and Fiberoptic bronchoscope. Because it had the shortest intubation time, the Lightwand caused the least damage to the teeth and throat of elderly patients. Our findings showed that tracheal intubation with the Lightwand was advantageous for preventing cardiovascular stress responses with short intubation times and fewer postoperative complications.

The diagnostic performance of conventional ultrasound and strain elastography in malignant soft tissue tumors.

OBJECTIVE: To investigate the diagnostic value of conventional ultrasound (US) and strain elastography (SE) in malignant soft tissue tumors. METHOD: A total of 83 soft tissue masses were included prospectively. US and SE imaging were performed at the same time. Two observers assessed the B mode, color Doppler, elastic scores (ES), strain ratio (SR), and SE size to B mode size (EI/B) ratio and compared the consistency of the data between the observers. According to the pathological diagnosis of resection, the cases were divided into malignant and nonmalignant groups. The diagnostic value of conventional US and SE in the prediction of malignant soft tissue tumors was assessed. RESULTS: The pathology results divided cases into 36 malignant lesions and 47 nonmalignant lesions. There was no statistically significant difference in gender, location, maximum diameter, echo, tail sign, cystic component, Doppler scores, or SR between the two groups (p > 0.05). However, significant differences between the two groups were found in age, depth, heterogeneity, edge, ES, and EI/B (p < 0.05). The biggest area under the receiver operating characteristics curve (0.934) was the combination model of age, heterogeneity, edge, ES, and EI/B, and the sensitivity and specificity were 0.861 and 0.957, respectively. CONCLUSIONS: Conventional US and SE are significant for the diagnosis of malignant soft tissue tumors, and SE can be used as a complementary technique to the characterization of STTs using conventional US.

Duraplasty of PHBV/PLA/Col membranes promotes axonal regeneration by inhibiting NLRP3 complex and M1 macrophage polarization in rats with spinal cord injury.

Duraplasty after decompression decreases the lesion size and scar formation, promoting better functional recovery, but the underlying mechanism has not been clarified. Here, we fabricated a series of poly(hydroxybutyrate-co-hydroxyvalerate)/polylactic acid/collagen (PHBV/PLA/Col) membranes and cultured them with VSC4.1 motor neurons. The material characteristics and in vitro biological characteristics were evaluated. In the subcutaneous implantation test, PHBV/PLA/COl scaffolds supported the cellular infiltration, microvasculature formation, and decreased CD86-positive macrophage aggregation. Following contusion spinal cord injury at T10 in Sprague-Dawley rats, durotomy was performed with allograft dura mater or PHBV/PLA or PHBV/PLA/Col membranes. At 3 days post-injury, Western blot assay showed decreased the expression of the NLRP3, ASC, cleaved-caspase-1, IL-1ß, TNF-α, and CD86 expression but increased the expression of CD206. Immunofluorescence demonstrated that duraplasty with PHBV/PLA/Col membranes reduced the infiltration of CD86-positive macrophages in the lesion site, decreased the glial fibrillary acidic protein expression, and increased the expression of NF-200. Moreover, duraplasty with PHBV/PLA/Col membranes improved locomotor functional recovery at 8 weeks post-injury. Thus, duraplasty with PHBV/PLA/Col membranes decreased the glial scar formation and promoted axon growth by inhibiting inflammasome activation and modulating macrophage polarization in acute spinal cord injury.

Gelatin Methacrylate (GelMA)-Based Hydrogels for Cell Transplantation: an Effective Strategy for Tissue Engineering.

Gelatin methacrylate (GelMA)-based hydrogels are gaining a great deal of attention as potentially implantable materials in tissue engineering applications because of their biofunctionality and mechanical tenability. Since different natural tissues respond differently to mechanical stresses, an ideal implanted material would closely match the mechanical properties of the target tissue. In this regard, applications employing GelMA hydrogels are currently limited by the low mechanical strength and biocompatibility of GelMA. Therefore, this review focuses on modifications made to GelMA hydrogels to make them more suitable for tissue engineering applications. A large number of reports detail rational synthetic processes for GelMA or describe the incorporation of various biomaterials into GelMA hydrogels to tune their various properties, e.g., physical strength, chemical properties, conductivity, and porosity, and to promote cell loading and accelerate tissue repair. A novel strategy for repairing tissue injuries, based on the transplantation of cell-loaded GelMA scaffolds, is examined and its advantages and challenges are summarized. GelMA-cell combinations play a critical and pioneering role in this process and could potentially accelerate the development of clinically relevant applications.

Mitochondrial Transfer from Bone Marrow Mesenchymal Stem Cells to Motor Neurons in Spinal Cord Injury Rats via Gap Junction.

Recent studies have demonstrated that bone marrow mesenchymal stem cells (BMSCs) protect the injured neurons of spinal cord injury (SCI) from apoptosis while the underlying mechanism of the protective effect of BMSCs remains unclear. In this study, we found the transfer of mitochondria from BMSCs to injured motor neurons and detected the functional improvement after transplanting. Methods: Primary rat BMSCs were co-cultured with oxygen-glucose deprivation (OGD) injured VSC4.1 motor neurons or primary cortical neurons. FACS analysis was used to detect the transfer of mitochondria from BMSCs to neurons. The bioenergetics profiling of neurons was detected by Extracellular Flux Analysis. Cell viability and apoptosis were also measured. BMSCs and isolated mitochondria were transplanted into SCI rats. TdT-mediated dUTP nick end labelling staining was used to detect apoptotic neurons in the ventral horn. Immunohistochemistry and Western blotting were used to measure protein expression. Re-myelination was examined by transmission electron microscope. BBB scores were used to assess locomotor function. Results: MitoTracker-Red labelled mitochondria of BMSCs could be transferred to the OGD injured neurons. The gap junction intercellular communication (GJIC) potentiator retinoid acid increased the quantity of mitochondria transfer from BMSCs to neurons, while GJIC inhibitor 18ß glycyrrhetinic acid decreased mitochondria transfer. Internalization of mitochondria improved the bioenergetics profile, decreased apoptosis and promoted cell survival in post-OGD motor neurons. Furthermore, both transplantation of mitochondria and BMSCs to the injured spinal cord improved locomotor functional recovery in SCI rats. Conclusions: To our knowledge, this is the first evidence that BMSCs protect against SCI through GJIC to transfer mitochondrial to the injured neurons. Our findings suggested a new therapy strategy of mitochondria transfer for the patients with SCI.

The harmonic scalpel versus electrocautery for parotidectomy: A meta - analysis.

OBJECTIVE: Parotidectomy is the most classic and unequivocal intervention for parotid neoplasm. The operative outcomes and postoperative complications of parotidectomy between harmonic scalpel and electrocautery gained more prominence in physician. In spite of much research work within the past years, there was an obvious lack of randomized controlled trial to resolve this question. Hence, a quantitative and qualitative meta-analysis was essential to evaluate the differences in these two types of hemostasis method. METHOD: The major electronic databases, including Pubmed, Embase, Cochrane library, Google Scholar, China National Knowledge Infrastructure and Chinese Scientific and Technological Journal databases were using the key words "electrocautery", "electrocoagulation", "harmonic scalpel", "ultrasonic scalpel", "ultrasonic dissector", "parotidectomy" and "parotid surgery". 9 articles were included in our systematic review and meta-analysis. The operative time, intraoperative blood loss, hospital stay, salivary fistula and transient facial nerve paralysis were the outcome measures. Odds ratios (ORs) with 95% confidence intervals (CIs) were employed to evaluate the effect size for categorical outcomes and mean differences (MDs) with 95% confidence intervals (CIs) for continuous outcomes. RESULTS: In our meta-analysis, there was a significant reduction in operation time [mean difference: -20.97; 95%CI=(-24.02,-17.92); P < 0.00001], intraoperative blood loss [mean difference: -20.75, 95%CI=(-22.32,-19.18); P < 0.00001], hospital stay [mean difference: -0.83; 95%CI=(-1.10,-0.57); P < 0.00001], salivary fistula [ORs: 0.30, 95%CI=(0.08,1.14)] and transient facial nerve paralysis [OR:0.33, 95%CI=(0.19,0.58),P = 0.0001] in harmonic scalpel group compared with electrocautery group. CONCLUSION: This meta-analysis indicated that compared with electrocautery, harmonic scalpel (HS)was transcendent in the aspects of operative time, intraoperative blood loss, hospital stay, salivary fistula and transient facial nerve paralysis. The harmonic scalpel, as an efficient and useful instrument, was advocated in parotidectomy.

Integration of mesenchymal stem cell sheet and bFGF-loaded fibrin gel in knitted PLGA scaffolds favorable for tendon repair.

Tendon injuries are common and require a long time to heal, and are particularly associated with some adverse problems such as adhesion and rupture. Herein, we aim to develop new bioactive scaffolds endowed with stem cell sheets and growth factors to enable cell migration and proliferation favorable for tendon regeneration in situ. An exogenous basic fibroblast growth factor (bFGF)-loaded fibrin gel was firstly incorporated into the porous network of knitted poly(lactide-co-glycolide) (PLGA) scaffolds and then sheets of mesenchymal stem cells (MSCs) were also integrated into the scaffolds. It was shown that the pores in the knitted PLGA scaffold were readily filled with a complex network of fibrin fiber gel and the fibrin fibers were beneficial for the controlled release of bFGF over a long time period. After transplantation in a critical-size Achilles tendon defect model (7 mm) in the rat right hindlimb, gross observation revealed no immunologic incompatibility or rejection derived from the scaffold systems. It was observed that the MSC sheets contributed directly to tendon regeneration, and exerted an environment-modifying effect on the injuries in situ, consistent with the beneficial effect of bFGF. It was interesting that the knitted PLGA-fibrin gel scaffolds loaded with MSC sheets and bFGF showed the highest expression of tendon-related gene markers and outstanding repair efficacy, including appreciable biomechanical strength and native-like histological microstructures. Therefore, the integration of MSC sheets and bFGF into PLGA/bFGF-fibrin gel scaffolds may stimulate the proliferation and tenogenic differentiation of MSCs in situ and synergistically enhance the injured tendon reconstruction.

Injectable decellularized nucleus pulposus-based cell delivery system for differentiation of adipose-derived stem cells and nucleus pulposus regeneration.

Stem cell-based tissue engineering is a promising treatment for intervertebral disc (IVD) degeneration. A bio-scaffold that can maintain the function of transplanted cells and possesses favorable mechanical properties is needed in tissue engineering. Decellularized nucleus pulposus (dNP) has the potential to be a suitable bio-scaffold because it mimics the native nucleus pulposus (NP) composition. However, matrix loss during decellularization and difficulty in transplantation limit the clinical application of dNP scaffolds. In this study, we fabricated an injectable dNP-based cell delivery system (NPCS) and evaluated its properties by assessing the microstructure, biochemical composition, water content, biosafety, biostability, and mechanical properties. We also investigated the stimulatory effects of the bio-scaffold on the NP-like differentiation of adipose-derived stem cells (ADSCs) in vitro and the regenerative effects of the NPCS on degenerated NP in an in vivo animal model. The results showed that approximately 68% and 43% of the collagen and sGAG, respectively, remained in the NPCS after 30 days. The NPCS also showed mechanical properties similar to those of fresh NP. In addition, the NPCS was biocompatible and able to induce NP-like differentiation and extracellular matrix (ECM) synthesis in ADSCs. The disc height index (almost 81%) and the MRI index (349.05 ±â€¯38.48) of the NPCS-treated NP were significantly higher than those of the degenerated NP after 16 weeks. The NPCS also partly restored the ECM content and the structure of degenerated NP in vivo. Our NPCS has good biological and mechanical properties and has the ability to promote the regeneration of degenerated NP. STATEMENT OF SIGNIFICANCE: Nucleus pulposus (NP) degeneration is usually the origin of intervertebral disc degeneration. Stem cell-based tissue engineering is a promising treatment for NP regeneration. Bio-scaffolds which have favorable biological and mechanical properties are needed in tissue engineering. Decellularized NP (dNP) scaffold is a potential choice for tissue engineering, but the difficulty in balancing complete decellularization and retaining ECM limits its usage. Instead of choosing different decellularization protocols, we complementing the sGAG lost during decellularization by cross-linking via genipin and fabricating an injectable dNP-based cell delivery system (NPCS) which has similar components as the native NP. We also investigated the biological and mechanical properties of the NPCS in vitro and verified its regenerative effects on degenerated IVDs in an animal model.

Cervical lymph node metastases in salivary gland adenoid cystic carcinoma: a systematic review and meta-analysis.

BACKGROUND: The purpose of this research was to determine whether neck dissection is necessary for the adenoid cystic carcinoma (ACC) of head and neck. MATERIALS AND METHODS: This article screened the abstract and full-text papers that investigated salivary gland primary ACC of head and neck. Two independent reviewers searched for articles published before October 2017 in three databases (Web of Science, PubMed, and Ovid), having no limits in date and language. Statistical data were analyzed statistically by Review Manager 5.3. RESULTS: In total, 18 studies involving 2993 patients were included in the analysis. Of the 2993 patients, 473 patients had cervical lymph node metastasis, with a merge frequency of 16% (95% CI: 13-19). Among included articles, only 4 involved cervical lymph node occult metastases, with a merge frequency of 14% (95% CI: 9-20). There were 5 articles containing minor salivary glands (MiSGs) involving 370 patients of which 92 patients had cervical lymph node metastases and the merge frequency was 25% (95% CI: 11-38). Moreover, there were 4 studies on major salivary glands involving 904 patients of which 158 patients had cervical lymph node metastases and the merge frequency was 17% (95% CI: 15-20). CONCLUSION: Elective neck dissection is unnecessary for all patients with salivary gland ACC of head and neck. Moreover, compared with major salivary glands, MiSGs have a higher cervical lymph node metastases rate in ACC. The overall cervical lymph node metastases rate of MiSGs is 25%, which is enough to attract our attention. Therefore, we suggest that neck dissection might be applied to ACC of MiSGs.

Is Delayed Surgery After Unsuccessful Conservative Treatment Beneficial for Spinal Cord Injury Following Whiplash? A Retrospective Study in Elderly Patients.

BACKGROUND The aim of this study was to investigate the clinical outcomes of early and delayed surgery in cervical spinal cord injury following whiplash in elderly patients. MATERIAL AND METHODS Our retrospective review identified elderly patients (≥65 years old) with spinal cord injury following whiplash injury from 2006 to 2015. The neck disability index (NDI), modify Japanese Orthopedics Association (mJOA) score, and visual analogue scale (VAS) score were used to evaluate clinical outcomes preoperatively and during follow-up. The angular range of motion (ROM) for C2-C7 was measured by dynamic flexion and extension lateral cervical radiographs at each observation follow-up time point. Treatment-related complication data were collected, and the complication rates analyzed. RESULTS Forty-six elderly patients (age range 65-82 years) with spinal cord injury following whiplash injury were enrolled in this study. Twenty-four patients underwent early surgery and twenty-two patients (age range 65-78 years) received delayed surgery after conservative treatment failure. During the follow-up period, both groups had significant post-operative improvement in NDI, mJOA, and VAS scores (p<0.05), although the early surgery group had better outcomes than the delayed surgery after unsuccessful conservative treatment group (p<0.05). However, on average, no significant differences in sagittal C2-C7 ROM between the two groups were found during follow-up. Comparison of the two groups showed the incidences of pneumonia and deep vein thrombosis were significantly higher in the delayed surgery group (p<0.05). CONCLUSIONS This study indicated that delayed surgery after unsuccessful conservative treatment provided excellent clinical results for elderly patients; however, timely surgical intervention is necessary for neurological symptom deterioration.

Stem cell-derived mitochondria transplantation: a novel strategy and the challenges for the treatment of tissue injury.

Damage of mitochondria in the initial period of tissue injury aggravates the severity of injury. Restoration of mitochondria dysfunction and mitochondrial-based therapeutics represent a potentially effective therapeutic strategy. Recently, mitochondrial transfer from stem cells has been demonstrated to play a significant role in rescuing injured tissues. The possible mechanisms of mitochondria released from stem cells, the pathways of mitochondria transfer between the donor stem cells and recipient cells, and the internalization of mitochondria into recipient cells are discussed. Moreover, a novel strategy for tissue injury based on the concept of stem cell-derived mitochondrial transplantation is pointed out, and the advantages and challenges are summarized.