Removal of collagen three-dimensional scaffold bubbles utilizing a vacuum suction technique.

The process of generating type I/II collagen scaffolds is fraught with bubble formation, which can interfere with the three-dimensional structure of the scaffold. Herein, we applied low-temperature vacuum freeze-drying to remove mixed air bubbles under negative pressure. Type I and II rubber sponges were acid-solubilized via acid lysis and enzymolysis. Thereafter, vacuum negative pressure was applied to remove bubbles, and the cover glass press method was applied to shape the type I/II original scaffold. Vacuum negative pressure was applied for a second time to remove any residual bubbles. Subsequent application of carbamide/N-hydroxysuccinimide cross-linked the scaffold. The traditional method was used as the control group. The structure and number of residual bubbles and pore sizes of the two scaffolds were compared. Based on the relationship between the pressure and the number of residual bubbles, a curve was created, and the time of ice formation was calculated. The bubble content of the experimental group was significantly lower than that of the control group (P < 0.05). The pore diameter of the type I/II collagen scaffold was higher in the experimental group than in the control group. The time of icing effect of type I and II collagen solution was 136.54 ± 5.26 and 144.40 ± 6.45 s, respectively. The experimental scaffold had a more regular structure with actively proliferating chondrocytes that possessed adherent pseudopodia. The findings indicated that the vacuum negative pressure method did not affect the physical or chemical properties of collagen, and these scaffolds exhibited good biocompatibility with chondrocytes.

Prediction of microvascular invasion in hepatocellular carcinoma with magnetic resonance imaging using models combining deep attention mechanism with clinical features / 南方医科大学学报

OBJECTIVE@#To investigate the consistency and diagnostic performance of magnetic resonance imaging (MRI) for detecting microvascular invasion (MVI) of hepatocellular carcinoma (HCC) and the validity of deep learning attention mechanisms and clinical features for MVI grade prediction.@*METHODS@#This retrospective study was conducted among 158 patients with HCC treated in Shunde Hospital Affiliated to Southern Medical University between January, 2017 and February, 2020. The imaging data and clinical data of the patients were collected to establish single sequence deep learning models and fusion models based on the EfficientNetB0 and attention modules. The imaging data included conventional MRI sequences (T1WI, T2WI, and DWI), enhanced MRI sequences (AP, PP, EP, and HBP) and synthesized MRI sequences (T1mapping-pre and T1mapping-20 min), and the high-risk areas of MVI were visualized using deep learning visualization techniques.@*RESULTS@#The fusion model based on T1mapping-20min sequence and clinical features outperformed other fusion models with an accuracy of 0.8376, a sensitivity of 0.8378, a specificity of 0.8702, and an AUC of 0.8501 for detecting MVI. The deep fusion models were also capable of displaying the high-risk areas of MVI.@*CONCLUSION@#The fusion models based on multiple MRI sequences can effectively detect MVI in patients with HCC, demonstrating the validity of deep learning algorithm that combines attention mechanism and clinical features for MVI grade prediction.

Construction of tissue-engineered nucleus pulposus by stimulation with periodic mechanical stress and BMP-2.

Intervertebral disc (IVD) degeneration, which is common among elderly individuals, mainly manifests as low back pain and is caused by structural deterioration of the nucleus pulposus (NP) due to physiological mechanical stress. NP mesenchymal stem cells (NPMSCs) around the IVD endplate have multidirectional differentiation potential and can be used for tissue repair. To define favorable conditions for NPMSC proliferation and differentiation into chondroid cells for NP repair, the present study simulated periodic mechanical stress (PMS) of the NP under physiological conditions using MSC chondrogenic differentiation medium and recombinant human BMP-2 (rhBMP-2). rhBMP-2 effectively promoted NPMSC proliferation and differentiation. To clarify the mechanism of action of rhBMP-2, integrin alpha 1 (ITG A1) and BMP-2 were inhibited. PMS regulated the BMP-2/Smad1/RUNX2 pathway through ITG A1 and promoted NPMSC proliferation and differentiation. During tissue-engineered NP construction, PMS can effectively reduce osteogenic differentiation and promote extracellular matrix protein synthesis to enhance structural NP recovery.

Comparison of the Effectiveness of Simple Plate Fixation and Plate Combined with Local Fixation of Broken Ends in the Treatment of Oblique Fracture of Midshaft Clavicle.

OBJECTIVE: To compare the clinical efficacy of performing simple plate fixation with that using a plate combined with fracture end fixation to investigate the necessity of fracture end fixation outside the plate in cases of oblique fracture of the middle clavicle. METHODS: This was a retrospective follow-up study of patients with middle clavicle oblique fractures (Robinson types 2A1 and 2A2) between 2015 and 2020. Patients were divided into two groups according to their treatment options: the simple plate fixation (SPF) group (n = 79; 43 men and 36 women; average age, 46.37 ± 14.54 years) and the plate combined with fracture local fixation (PLFP) group (n = 81; 36 men and 45 women; average age, 48.42 ± 12.55 years). Intraoperative blood loss, operation time, postoperative fracture healing time, postoperative shoulder function score (Constant-Murley and disabilities of the arm, shoulder, and hand [DASH] scores), clinical complications, and postoperative subjective satisfaction were compared between the two groups. RESULTS: One hundred sixty patients with a sufficient follow-up period were included in the final analysis: 79 in the SPF group (follow-up time: 16.24 ± 3.94 months) and 81 in the PLFP group (follow-up time: 16.15 ± 3.43 months). Age, sex, body mass index, follow-up duration, fracture classification, and cause of injury were not significantly different between the two groups. There was no significant difference in blood loss, Constant-Murley and DASH scores, follow-up period, and postoperative subjective satisfaction between the two groups (P > 0.05). The fracture healing time was shorter in the PLFP group than in the SPF group (4.41 ± 0.99 vs. 4.87 ± 1.60 months, P < 0.05), but the operation duration was longer in the PLFP group than in the SPF group (65.48 ± 16.48 min, P < 0.05). There were seven (complication rate, 8.86%) and five (complication rate, 6.17%) cases that had complications in the SPF and PLFP groups, respectively. There was no significant difference in the complication rates between the two groups (P > 0.05). CONCLUSION: Although the healing time was shorter in the PLFP group than in the SPF group, the clinical efficiency of the two methods in the treatment of oblique fracture of the middle clavicle was similar.

Negative pressure wound therapy, artificial skin and autogenous skin implantation in diabetic foot ulcers.

OBJECTIVE: Diabetic foot ulcers (DFUs) are one of the most serious diabetic consequences, leading to amputations. Various therapies have been used to treat DFUs; however, a combination of negative pressure suction, artificial skin and autogenous skin implantation have never been investigated. This study aimed to evaluate the effectiveness of a novel three-step therapy protocol using negative pressure wound therapy (NPWT), artificial skin and autogenous skin implantation in patients with DFUs. METHOD: At a single tertiary university hospital between 2015 and 2018, the three-step therapy protocol was applied to patients with DFUs and its safety and efficacy was investigated. RESULTS: A total of 21 patients took part in the study. The majority of the patients were female (62%), with a mean age of 65 years and a mean body mass index of 21kg/m2. A third (n=7) of operative sites experienced minor complications, with two requiring re-operation. At a median follow up of 24 months, the average time of complete wound healing was 46 days, and the wound healing rate was 71%. The first-stage wound healing rate was 90%. All patients had achieved remission without any further recurrence of disease. CONCLUSION: This comprehensive surgical technique for managing DFUs achieved a high local cure rate, minimal functional morbidity, and acceptable wound complication rates. The three-step therapy protocol has the potential to promote the healing process of DFUs, which is expected to serve as a new method for the treatment and cure of DFUs.

Genome-Wide Association Study of Body Weight Traits in Inner Mongolia Cashmere Goats.

Objective: Body weight is an important economic trait for a goat, which greatly affects animal growth and survival. The purpose of this study was to identify genes associated with birth weight (BW), weaning weight (WW), and yearling weight (YW). Materials and Methods: In this study, a genome-wide association study (GWAS) of BW, WW, and YW was determined using the GGP_Goat_70K single-nucleotide polymorphism (SNP) chip in 1,920 Inner Mongolia cashmere goats. Results: We discovered that 21 SNPs were significantly associated with BW on the genome-wide levels. These SNPs were located in 10 genes, e.g., Mitogen-Activated Protein Kinase 3 (MAPK3), LIM domain binding 2 (LDB2), and low-density lipoprotein receptor-related protein 1B (LRP1B), which may be related to muscle growth and development in Inner Mongolia Cashmere goats. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these genes were significantly enriched in the regulation of actin cytoskeleton and phospholipase D signaling pathway etc. Conclusion: In summary, this study will improve the marker-assisted breeding of Inner Mongolia cashmere goats and the molecular mechanisms of important economic traits.

Biomechanical Model Study of the Effect of Partial Facetectomy on Lumbar Stability Under Percutaneous Endoscopy.

OBJECTIVE: To investigate the effect of partial facetectomy on lumbar stability using percutaneous endoscopy. METHODS: Five male adult volunteers with no history of lumbar disease participated in the study. Based on computed tomography data, a three-dimensional model of the L3-S1 segment was created using the Mimics l5.0 and Ansys 13.0 software. The use of an 8.5-mm-diameter ring saw was simulated to cut through 5 different needle insertion points (IPs) commonly used in the clinic on the left-side facet joint (FJ) of L5 to perform facetectomy. The first to third IPs were on the apex of the superior FJ, the midpoint of the ventral side of the superior FJ, and the lowest point of the ventral side of the superior FJ. The fourth and fifth IPs represented the positions of the second and third IPs (8.5 mm/2) after the radius of the ring saw was translated to the dorsal side of the superior FJ. Physiologic load was applied to the human models. The pressure on the left and right FJ of the L5 vertebra, the pressure on the L4-5 intervertebral disc, and the range of motion of the lumbar spine were recorded when normal flexion and extension and lateral flexion and rotation of the lumbar spine model after facetectomy were simulated. RESULTS: Compared with the intact group, the second IP, maximum pressure on the L4-5 intervertebral disc after facetectomy was not significantly different under any condition (P > 0.05). The maximum pressure on the left FJ of L5 showed significant differences during right rotation of the lumbar spine (P < 0.05). The pressure on the right FJ of L5 was significantly different during left rotation of the lumbar spine (P < 0.05). The range of motion of the lumbar spine was not significantly different under any condition (P > 0.05). CONCLUSIONS: The second IP at the midpoint of the ventral side of the superior FJ showed minimal effect on lumbar spine biomechanics compared with all the other IPs during percutaneous transforaminal facetectomy. Thus, it can be considered as the most suitable IP for facetectomy.

Polysaccharide from Angelica sinensis protects chondrocytes from H2O2-induced apoptosis through its antioxidant effects in vitro.

This study aimed to explore the protective effects of Angelica sinensis polysaccharide (ASP) on rat chondrocyte injury induced by hydrogen peroxide (H2O2). Rat chondrocytes were cultured and treated with different concentrations of ASP alone or in combination with H2O2, and they were measured with cell viability, apoptosis, release of inflammatory cytokines, such as interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α), activity of superoxide dismutase (SOD), and catalase (CAT), and levels of malondialdehyde (MDA) production, respectively. In addition, quantitative real-time reverse transcription polymerase chain reaction was used to estimate the relative expression levels of osteoarthritis (OA)-associated genes, such as collagen type II (Col2a1), aggrecan, SOX9, matrix metalloproteinase (MMP)-1, -3, and -9, as well as tissue inhibitor of matrix metalloproteinase (TIMP)-1, respectively. Results indicated that ASP protected chondrocytes from H2O2-induced oxidative stress and subsequent cell injury through its antioxidant, antiapoptotic and anti-inflammatory effects in vitro. Our study suggests that ASP could become a therapeutic supplementation for the treatment of OA.

Application of lamina replantation with ARCH plate fixation in thoracic and lumbar intraspinal tumors.

The aim of the present study was to investigate the clinical effects of lamina replantation with ARCH plate fixation on patients with thoracic and lumbar intraspinal tumors, following laminectomy. Thirteen patients with thoracic and lumbar intraspinal tumors underwent total lamina replantation with ARCH plate fixation and repair of the supraspinous ligaments, following laminectomy and tumor enucleation. To investigate the clinical effect of lamina replantation with ARCH plate fixation, pre- and postoperative visual analog scale (VAS), and Oswestry Disability Index (ODI) scores were determined, and pre- and postoperative X-ray and magnetic resonance imaging (MRI) examinations were conducted. Computed tomography (CT) examinations were also included in the follow-up. No complications were observed pre- or postoperatively. The VAS and ODI results 2 weeks following surgery and at the final follow-up examination demonstrated a significant improvement compared with the corresponding preoperative results. The X-ray examination results indicated a satisfactory internal fixation location, without any characteristics of a fracture, lumbar scoliosis, kyphosis or instability. Following the surgery, the CT and MRI examination results demonstrated that healing of the lamina bone and repair of the supraspinous ligament had occurred without tumor recurrence or spinal epidural scar recompression. Two of the 13 cases were lost to follow-up. The results indicated that in patients with thoracic and lumbar intraspinal tumors, lamina replantation with ARCH plate fixation following total laminectomy is effective and provides thoracolumbar stability. Furthermore, this has been identified to be an effective technique for preventing intraspinal scar proliferation.

Effects of interspinous spacers on lumbar degenerative disease.

The present study aimed to evaluate the early effects of interspinous spacers on lumbar degenerative disease. The clinical outcomes of 23 patients with lumbar degenerative disease, treated using interspinous spacer implantation alone or combined with posterior lumbar fusion, were retrospectively studied and assessed with a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Pre-operative and post-operative interspinous distance, disc space height, foraminal width and height and segmental lordosis were determined. The early effects and complications associated with the interspinous spacers were recorded. The surgical procedures performed with the in-space treatment were easy and minimally invasive. The VAS scores and ODI were improved post-operatively compared with pre-operatively. Significant changes in the interspinous distance, disc space height, foraminal width and height and segmental lordosis were noted. In-space treatment for degenerative lumbar disease is easy and safe, with good early effects. The in-space system provides an alternative treatment for lumbar degenerative disease.

[Study on the physicochemical properties of cultivated soil of genuine crude and no-enuine crude Chinese Angelica].

OBJECTIVE: To provide basis for environmental factors of genuine crude Chinese angelica. METHOD: On-the-spot investigation and indoor chemical analysis were made to study the physicochemical properties of cultivated soil of Chinese angelica. RESULT AND CONCLUSION: The physical properties and the organic matte and mineral nutrition of cultivated soil of Chinese angelica are best in Min County, Gansu Province. The ecological environment is the leading factor in forming genuine crude Chinese angelica.