Hypoxia Informed RBE-Weighted Beam Orientation Optimization for Intensity Modulated Proton Therapy Using [18F]-FMISO-PET Estimation of pO2

PURPOSE/OBJECTIVE(S)

Variable relative biological effectiveness (RBE) models have previously informed proton therapy dose optimization algorithms, but few models have incorporated hypoxia's increase on radioresistance. Here, we obtain voxel-based estimation of partial oxygen pressure to weigh RBE values in a single biologically informed beam orientation optimization (BOO) algorithm.

MATERIALS/METHODS

Four brain cancer patients with [18F]-FMISO-PET/CT images were selected from an HCP database. Oxygen values were derived from tracer uptake using a non-linear least squares curve fitting. RBE dose was then weighted using oxygen enhancement ratios (OER) for each structure and substituted into the dose fidelity term of our BOO algorithm. The nonlinear optimization problem was solved using a split-Bregman approach, with FISTA as the solver. This method (HypRBE) was compared dose fidelity terms using the Rorvik RBE model (RegRBE), without OER. Tumor homogeneity index (HI), Dmax, and D95% were evaluated along with worst-case statistics after normalization to normal tissue isotoxicity.

RESULTS

Compared to RegRBE, HypRBE increased tumor [HI, Dmax, D95%] on average by [0.5%, 2.0%, 2.5%] and improved worst-case tumor [HI, Dmax, D95%] by [5.3%, 16.2%, 9.6%]. HypRBE shows an increase in therapeutic ratio, and is notably robust against uncertainty scenarios.

CONCLUSION

We have developed an optimization algorithm whose dose fidelity term is weighted by hypoxia informed RBE values. We have shown that HypRBE selects beams that are better suited to protect low RBE, well-oxygenated normal tissue while maintaining high dose to high RBE, hypoxic tumor cells.

Towards Automated Dosimetric Analysis of the Bladder Trigone: Deep-Learning-Based Joint Segmentation and Landmark Localization

PURPOSE/OBJECTIVE(S)

The bladder trigone dosimetry is hypothesized to have a stronger correlation with post-SBRT urinary toxicity than that of the entire bladder. However, the trigone tends to move significantly between simulation and daily treatment. Its small size, large daily motion, and proximity to the target lead to potentially consequential but unaccounted-for dosimetric uncertainties. Manual segmentation of the structure can be inconsistent and time-consuming, even with MR-guided RT. Here, we propose and demonstrate a deep-learning-based framework for joint segmentation and landmark localization to support deformable registration and comprehensive dosimetric analysis.

MATERIALS/METHODS

A total of 30 patients were randomly selected for training, and 20 were held out for testing. Each patient had 1 simulation and 5 daily pre-treatment images obtained from a clinical 0.35T MR Linac. The trigone is defined as the triangular bladder section among three landmarks (2 ureteral orifices and the internal urethral orifice). In the manual contouring process, the 3 landmarks were identified first, followed by trigone segmentation. The proposed joint method uses a modified 3D nnU-Net with 2 decoders, one for segmentation and the other for landmark localization. The shared encoder is expected to extract features useful for both tasks. The joint framework was compared with a baseline method using two separate 3D nnU-Nets for landmark localization and trigone segmentation, respectively. Since the trigone is small (∼2% of the bladder volume), we further experimented with a second-stage prediction mimicking the human contouring process. The predicted landmarks from the first stage were used to crop the trigone region, and a second network was trained on cropped images. Evaluation metrics included the Dice score, 95% Hausdorff distance (HD95), and average surface distance (ASD) for segmentation, and Euclidean distance (ED) between the predicted and ground truth landmarks for localization.

RESULTS

The quantification metrics are summarized in the table below. The joint approach shows similar Dice performance to the baseline method but markedly better HD95 by 13%. For landmark localization, the proposed method is similar to the baseline, but the integration of the segmentation task stabilizes the training process. The two-stage approach further improves HD95, ASD, and ED by 27%, 24%, and 19%.

CONCLUSION

Combining segmentation and landmark localization exhibits a synergistic effect. The proposed two-stage approach provided additional improvement. Future studies will explore the deformable registration of the trigone based on the segmentation and landmark detection, as well as analyze cumulated dose distribution.

Comparative study of outcomes between allograft intervertebral disc transplantation and anterior cervical discectomy and fusion: a retrospective cohort study at least 5 years of follow-up

PURPOSE

Adjacent segment degeneration (ASDeg) after anterior cervical discectomy and fusion (ACDF) seriously affects the long-term efficacy of the operation. Therefore, our team has done a lot of research on allograft intervertebral disc transplantation (AIDT) to prove its feasibility and safety. This study will compare the efficacy between AIDT and ACDF in the treatment of cervical spondylosis.

METHODS

All patients who received ACDF or AIDT in our hospital from 2000 to 2016 and followed up for at least 5 years were recruited and divided into ACDF and AIDT groups. The clinical outcomes including functional scores and radiological data of both groups were collected and compared preoperatively and postoperatively at 1 week, 3 months, 6 months, 12 months, 24 months, 60 months and last follow-up. Functional scores included Japanese Orthopedic Association score (JOA), Neck Disability Index (NDI), Visual Analog Scale of Neck (N-VAS) and Arms (A-VAS) pain, the Short Form Health Survey-36 (SF-36) and imaging dates including digital radiographs in the lateral, hyperextension and flexion positions to assess the stability, sagittal balance and mobility of the cervical spine and magnetic resonance imaging (MRI) scans to assess the degeneration of adjacent segment.

RESULTS

There were 68 patients with 25 in AIDT group and 43 in ACDF group. Satisfactory clinical results were obtained in both groups, but the long-term NDI score and N-VAS score in the AIDT group were better. The AIDT obtained the same stability and sagittal balance of the cervical spine as fusion surgery. The range of motion of adjacent segments can be restored to the preoperative level after transplantation, but this increases significantly after ACDF. There were significant differences in the superior adjacent segment range of motion (SROM) between two groups at 12 months (P = 0.039), 24 months (P = 0.035), 60 months (P = 0.039) and the last follow-up (P = 0.011). The inferior adjacent segment range of motion (IROM) and SROM had a similar trend in the two groups. The ratio value of the greyscale (RVG) of adjacent segments showed a downward trend. At the last follow-up, the RVG decreased more significantly in the ACDF group. At the last follow-up, there was a significant difference in the incidence of ASDeg between the two groups (P = 0.000). And the incidence of adjacent segment disease (ASDis) is 22.86% in the ACDF group.

CONCLUSION

The allograft intervertebral disc transplantation may be as an alternative technique to traditional anterior cervical discectomy and fusion for the management of cervical degenerative diseases. For the more, the results showed it would improve cervical kinematics and reduce the incidence of adjacent segment degeneration.

Comparative finite element analysis of posterior short segment fixation constructs with or without intermediate screws in the fractured vertebrae for the treatment of type a thoracolumbar fracture

Six-screw short-segment posterior fixation for thoracolumbar fractures, which involves intermediate screws at the fractured vertebrae has been proposed to reduce the rates of kyphosis recurrence and implant failure. Yet, little is known about the mechanisms and biomechanical responses by which intermediate screws at the fracture vertebrae enhance fixation strength. The objective of this study was to investigate the biomechanical properties that are associated with the augmentation of intermediate screws in relation to the severity of type A thoracolumbar fracture using finite element analysis. Short-segment stabilization models with or without augmentation screws at fractured vertebrae were established based on finite element model of moderate compressive fractures, severe compressive fractures and burst fractures. The spinal stiffness, stresses at the implanted hardware, and axial displacement of the bony defect were measured and compared under mechanical loading conditions. All six-screw stabilization showed a decreased range of motion in extension, lateral bending, and axial rotation compared to the traditional four-screw fixation models. Burst thoracolumbar fracture benefited more from augmentation of intermediate screws at the fracture vertebrae. The stress of the rod in six-screw models increased while decreased that of pedicle screws. Our results suggested that patients with more unstable fractures might achieve greater benefits from augmentation of intermediate screws at the fracture vertebrae. Augmentation of intermediate screws at the fracture vertebrae is recommended for patients with higher wedge-shaped or burst fractures to reduce the risk of hardware failure and postoperative re-collapse of injured vertebrae.

The Inhibitory Effect of RADKPS on Pyroptosis of Nucleus Pulposus-Derived Mesenchymal Stem Cells

Intervertebral disc (IVD) degeneration (IDD) is a primary cause of low-back pain in people, which is associated with nucleus pulposus-derived mesenchymal stem cells (NPMSCs). In this study, the involvement of lipopolysaccharide (LPS) in the pyroptosis of NPMSCs was investigated. The effect of RADKPS on the pyroptosis of NPMSCs and the underlying mechanism behind the impact of RADKPS on the proliferative capacity of NPMSCs were also studied. Pyroptosis of NPMSCs was induced with 10 μg/mL LPS and its effects on the downstream signaling pathways were explored. The protective effect of RADKPS on NPMSCs under the action of LPS and its possible mechanism were explored, using different techniques such as immunohistochemical analysis, cell proliferation assay, quantitative real-time polymerase chain reaction (qPCR), and Western blot analysis. Accordingly, caspase1/p20/p10, a protein associated with pyroptosis, was found to be overexpressed in LPS-challenged NPMSCs, Furthermore, the qPCR results demonstrated that LPS promoted the expression of pyroptosis-related gene IL-1β (p < 0.0001), while downregulating the expression of Sox-9 (p < 0.001), which was a gene associated with the extracellular matrix. The immunohistochemical results identified lowered extracellular signal-regulated kinase 1/2 (ERK1/2) expression and phosphorylated (p-)ERK1/2 in the degenerated IVD tissues. In this study, the influence of RADKPS on the proliferative ability of NPMSCs was evaluated using two-dimensional (2D) and three-dimensional (3D) cultures. It was noted that RADKPS promoted the proliferation of NPMSCs in 2D and 3D cultures. The findings of the Western blot experiments revealed that RADKPS inhibited the expression of pyroptosis-related proteins, while it upregulated the p-ERK1/2 (p < 0.001), RhoA (p < 0.01), collagen II (p < 0.01), and Sox-9 (p < 0.01), whereas ERK inhibitor PD98059 and RhoA signaling pathway inhibitor CCG-1423 inhibited their expression. These findings reveal to us that RADKPS hydrogel may protect NPMSCs from pyroptosis. It was also noted that cell proliferation-related signaling pathways may promote the proliferation of NPMSCs. The results revealed that RADKPS hydrogel could be used as a potential therapeutic approach for IDD. Impact Statement RADKPS inhibits the pyroptosis of NPMSCs and promotes the production of extracellular matrix, which has the potential of intervertebral disc biotherapy.

Growth differentiation factor 5 inhibits lipopolysaccharide-mediated pyroptosis of nucleus pulposus mesenchymal stem cells via RhoA signaling pathway

BACKGROUND

Degenerative disc disease(DDD)is one of the most important causes of low back pain (LBP). Programmed death of human nucleus pulposus mesenchymal stem cells (NPMSCs) plays an important role in the progression of DDD. Growth differentiation factor-5 (GDF-5) is a protein that promotes chondrogenic differentiation, and has been reported to slow the expression of inflammatory factors in nucleus pulposus cells. Compared with those in normal rats, MRI T2-weighted images show hypointense in the central nucleus pulposus region of the intervertebral disc in GDF-5 knockout rats.

METHODS AND RESULTS

We aimed to evaluate the role of GDF-5 and Ras homolog family member A (RhoA) in NPMSCs. We used lipopolysaccharide (LPS) to simulate the inflammatory environment in degenerative disc disease, and performed related experiments on the effects of GDF-5 on NPMSCs, including the effects of pyroptosis, RhoA protein, and the expression of extracellular matrix components, and the effects of GDF-5, on NPMSCs. In addition, the effect of GDF-5 on chondroid differentiation of NPMSCs was included. The results showed that the addition of GDF-5 inhibited the LPS-induced pyroptosis of NPMSCs, and further analysis of its mechanism showed that this was achieved by activating the RhoA signaling pathway.

CONCLUSION

These findings suggest that GDF-5 plays an important role in inhibiting the pyroptosis of NPMSCs and GDF-5 may have potential for degenerative disc disease gene-targeted therapy in the future.

Dietary isoleucine supplementation enhances growth performance, modulates the expression of genes related to amino acid transporters and protein metabolism, and gut microbiota in yellow-feathered chickens

This study investigated the effects of dietary isoleucine (Ile) on growth performance, intestinal expression of amino acid transporters, protein metabolism-related genes and intestinal microbiota in starter phase Chinese yellow-feathered chickens. Female Xinguang yellow-feathered chickens (n = 1,080, aged 1 d) were randomly distributed to 6 treatments, each with 6 replicates of 30 birds. Chickens were fed diets with 6 levels of total Ile (6.8, 7.6, 8.4, 9.2, 10.0, and 10.8 g/kg) for 30 d. The average daily gain and feed conversion ratio were improved with dietary Ile levels (P < 0.05). Plasma uric acid content and glutamic-oxalacetic transaminase activity were linearly and quadratically decreased with increasing dietary Ile inclusion (P < 0.05). Dietary Ile level had a linear (P < 0.05) or quadratic (P < 0.05) effect on the jejunal expression of ribosomal protein S6 kinase B1 and eukaryotic translation initiation factor 4E binding protein 1. The relative expression of jejunal 20S proteasome subunit C2 and ileal muscle ring finger-containing protein 1 decreased linearly (P < 0.05) and quadratically (P < 0.05) with increasing dietary Ile levels. Dietary Ile level had a linear (P = 0.069) or quadratic (P < 0.05) effect on the gene expression of solute carrier family 15 member 1 in jejunum and solute carrier family 7 member 1 in ileum. In addition, bacterial 16S rDNA full-length sequencing showed that dietary Ile increased the cecal abundances of the Firmicutes phylum, and Blautia, Lactobacillus, and unclassified_Lachnospiraceae genera, while decreased that of Proteobacteria, Alistipes, and Shigella. Dietary Ile levels affected growth performance and modulated gut microbiota in yellow-feathered chickens. The appropriate level of dietary Ile can upregulate the expression of intestinal protein synthesis-related protein kinase genes and concomitantly inhibit the expression of proteolysis-related cathepsin genes.

Fisetin regulates the biological effects of rat nucleus pulposus mesenchymal stem cells under oxidative stress by sirtuin-1 pathway

BACKGROUND

Excessive oxidative stress has been accepted as one of the critical factors for intervertebral disc degeneration (IDD), which is associated with low back pain (LBP). Fisetin (Fis) is a bioactive flavonoid that possesses strong bioactive activity. In present study, we aimed to illuminate the role of Fis on nucleus pulposus mesenchymal stem cells (NPMSCs).

METHODS

NPMSCs were isolated and cultured from rat NP tissues and identified by flow cytometry and multilinear differentiation. The cytotoxicity of Fis, EX-527, and hydrogen peroxide (H₂ O₂ ) on NPMSCs was validated using Cell Counting Kit-8 tests. Cell apoptosis was tested by flow cytometry and TUNEL assay. Inflammatory mediators were assessed by Elisa tests, RT-PCR. Extracellular matrix (ECM) metabolism was measured by Western blot analysis and RT-qPCR. The expression of the SIRT1 was evaluated by Western blot analysis.

RESULTS

NPMSCs were successfully isolated and cultured from rat NP tissues, and it has been identified by flow cytometry and multilinear differentiation. The results showed that Fis attenuated H₂ O₂ -induced apoptosis, inflammation, and ECM degradation of NPMSCs. Moreover, the above protective effects of Fis can be inhibited by EX-527, a unique SIRT1 inhibitor, indicating that SIRT1 may involve in the mechanism of Fis in protecting NPMSCs from oxidative stress.

CONCLUSIONS

As a natural compound with little cytotoxicity on NPMSCs, Fis alleviate H₂ O₂ -induced apoptosis, inflammation, and ECM degradation by suppressing oxidative stress, this finding may add the theoretical basis for research on new treatment of IDD based on NPMSCs.

The Impact of COVID-19 Pandemic among Cancer Patients

Purpose/Objective(s)

Clinical visits play an important role in disease management among cancer patients. The Covid-19 pandemic has hindered patients from seeking care and has changed treatment recommendations. We evaluated how the Covid-19 pandemic affected patients’ health outcomes, related to the changing choice of treatment, and the association with demographic variables.

Materials/Methods

17,062 cancer patients who received routine care at our institution between January 1, 2019 and March 31, 2021 were studied. As the Covid-19 outbreak was declared to be a public health emergency within the United States on January 31, 2020, a binary Covid variable is defined as pre- or post-Covid based on whether the cancer was diagnosed prior to/on this date or after this date and treatment variable as radiation, other or no therapy being given. Age within the pre- and post-Covid cohorts was compared via two-sample t-test and the association between gender, partnership status, treatment, and Covid was assessed via chi-squared tests. The relationship between time from the date of diagnosis to death (the primary outcome), and Covid, adjusted for covariates (age, gender, partnership status, and treatment) was evaluated via the Cox proportional hazards (Cox PH) model. The impact of Covid on the treatment effect to overall survival was further assessed by including interactions between Covid and treatment.

Results

Among 17,062 cancer patients, 11,477 (67.3%) and 5,585 (32.7%) were diagnosed within pre- and post-Covid cohorts. Age was found to be different between the pre- and post-Covid (mean±SD: 64.6±15.1 vs 63.7±15.7; p<0.001). Gender, partnership status, and treatment were also found to be associated with Covid (all p<0.002); while a lower percentage of patients received radiation therapy within the post-Covid (26.6%) than the pre-Covid (34.7%), a greater percentage received other therapy within the post-Covid (60.7%) than the pre-Covid (51.7%). Both Covid cohorts included more females (51.3% pre vs 53.8% post) and partnered patients (62.3% pre vs 61.5% post). All covariates, including the interaction term, in the Cox PH model were significant predictors of overall survival, with older, non-partnered, male, post-Covid, and no therapy patient having a greater hazard to death (all p<0.007). Patients within the post-Covid had a greater hazard to death regardless of the given treatment, compared to the pre-Covid (Hazard Ratio: 1.18, 1.09, 2.35 for radiation, other and no therapy).

Conclusion

Covid-19 impacts patient care in multiple aspects. This impact is associated with age, gender and partnership status. Treatment choices also differed between patients who had a cancer diagnosis within pre- vs post-Covid cohorts. With different impact of Covid-19 on the treatment effect to overall survival, patients within the post-Covid had a greater hazard to death regardless of the given treatment. Further study is needed to better understand these observations.

Functionalized self-assembling peptide RADKPS hydrogels promote regenerative repair of degenerated intervertebral discs

Objective: the aim of this study was to investigate whether the functionalized self-assembling peptide hydrogel RADKPS is safe and effective for regenerative repair of degenerative intervertebral discs. Methods: an in vitro degenerative model of human nucleus pulposus cells was constructed by serum starvation culture, and their proliferation, apoptosis and viability were examined after three-dimensional culture with the RADKPS hydrogel. An in vivo degenerative model of the rabbit intervertebral disc was constructed by annulus fibrosus puncture, and the degeneration of the intervertebral disc was evaluated by imaging, histology, immunohistochemistry, and biomechanics after RADKPS hydrogel intervention. Results: through in vitro cell experiments it is shown that human degenerated nucleus pulposus cells after three-dimensional culture with the RADKPS hydrogel still exhibited better proliferation, viability, and low apoptosis rate. Through in vivo animal experiments we found that rabbit degenerated intervertebral discs intervened with the RADKPS hydrogel had higher water content, better histological morphology, more extracellular matrix synthesis, and better biomechanical properties. It is demonstrated that the RADKPS hydrogel may initiate the endogenous repair process through the sustained recruitment and enrichment of nucleus pulposus progenitor cells. Conclusion: it is verified from both in vitro cellular experiments and in vivo animal experiments that the regenerative repair effect of RADKPS, a functionalized self-assembling peptide hydrogel, on degenerated intervertebral discs is safe and effective. It is shown that it would be a new therapeutic approach for the regenerative repair action of intervertebral discs.

OUP accepted manuscript

The treatment of intervertebral disc degeneration (IVDD) is still a huge challenge for clinical updated surgical techniques and basic strategies of intervertebral disc regeneration. Few studies have ever tried to combine surgery and cell therapy to bridge the gap between clinical and basic research. A prospective clinical study with a 72-month follow-up was conducted to assess the safety and feasibility of autologous discogenic cells transplantation combined with discectomy in the treatment of lumbar disc herniation (LDH) and to evaluate the regenerative ability of discogenic cells in IVDD. Forty patients with LDH who were scheduled to have discectomy enrolled in our study and were divided into the observed group (transplantation of autologous discogenic cells after discectomy) and control group (only-discectomy). Serial MRI and X-ray were used to evaluate the degenerative extent of index discs, and clinical scores were used to determine the symptomatic improvement. No adverse events were observed in the observed group, and seven patients in the control group underwent revisions. Both groups had significant improvement of all functional scores post-operatively, with the observed group improving more considerably at 36-month and 72-month follow-up. The height and water content of discs in both groups decreased significantly since 36 months post-op with the control group decreased more obviously. Discectomy combined with autologous discogenic cells transplantation is safe and feasible in the treatment of LDH. Radiological analysis demonstrated that discogenic cells transplantation could slow down the further degeneration of index discs and decrease the complications of discectomy.

Effects of maternal and progeny dietary selenium supplementation on growth performance and antioxidant capacity in ducklings

This study evaluated the effects of selenium (Se) supplementation in maternal and offspring diets on performance and antioxidant capacity of ducklings aged from 0 to 2 wk. A total of 144 female Longyan duck breeders aged 22-wk were allotted into 2 treatments and fed a control diet or a 0.16 mg Se/kg supplemented diet. At 40-wk, 120 offspring from each treatment were divided into 2 groups, with 6 replicates of 10 birds. Using a 2 × 2 factorial design, ducklings from each maternal dietary treatment were assigned to a control diet or a 0.16 mg Se/kg supplemented diet from hatch to 2-wk. Compared with Se-deficient diet, maternal diet supplemented with 0.16 mg Se/kg increased the BW of hatchlings (P < 0.01). There were interactions between maternal and progeny diet with 0.16 mg Se/kg in BW of ducklings aged 2 wk and BW gain (BWG) as ducklings from maternal Se/progeny none treatment had the lightest BW and BWG (P < 0.01). Maternal diet with 0.16 mg Se/kg decreased plasma concentration of uric acid and insulin-like growth factor 1 (P < 0.01), and progeny diet supplemented with 0.16 mg Se/kg increased the activities of glutathione peroxidase 3 (GPx3) in plasma and glutathione peroxidase 1 in erythrocyte (P < 0.01). Maternal diet with 0.16 mg Se/kg increased (P < 0.05) the hepatic activity of total superoxide dismutase (T-SOD). Progeny diet supplemented with 0.16 mg Se/kg increased (P < 0.01) hepatic activity of GPx3 and decreased (P < 0.01) the hepatic concentration of malondialdehyde. Interactions were detected between maternal and progeny diet with 0.16 mg Se/kg in hepatic activity of T-SOD and maternal and progeny diet supplemented with Se displayed the highest hepatic activity of T-SOD (P < 0.05). Overall, Se supplementation in the diet of duck breeders and offspring increased the antioxidant capacity of ducklings. Maternal Se supplementation increased the BW of hatchlings, whereas maternal and progeny dietary Se supplementation did not affect the BWG of ducklings aged from 0 to 2 wk. Se supplementation with additional 0.16 mg/kg in the diet of duck breeders and offspring displayed beneficial effects particularly on the antioxidant capacity in ducklings.

Comparison of mini-open repair system and percutaneous repair for acute Achilles tendon rupture

Background

To reduce incision complications, minimally invasive operative approaches for treatment with acute Achilles tendon rupture have been developed, such as Mini-open repair and percutaneous repair. Which technique is the better surgical option? In the present study, we compared the two surgical procedures— modified Mini-open repair versus percutaneous repair—in the treatment of acute Achilles tendon rupture.

Methods

From January 2016 to November 2018, 68 matched patients with acute Achilles tendon rupture were divided into treatment group (Mini-open with modified Ma-Griffith technique) and control group (the Ma–Griffith technique). The patients were then treated with different surgical techniques and followed up for no less than 24 months, and the functional outcome scores and complications were retrospectively evaluated.

Results

The mean follow-up time in Mini-open repair group was 29.0±2.9 months, and that in control group was 27.9±2.9 months (P=0.147). The Mini-open repair group showed reliably higher American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score and Achilles tendon Total Rupture Score (ATRS) than the control group in functional assessment (95.0±3.8 vs. 92.3±5.3, P=0.000; 93.8±3.8 vs. 90.9±4.5,P=0.000). There was no cases of sural nerve injury in Mini-open repair group, whereas the percutaneous repair group had 5 cases of the same (P=0.027). No significant differences were found in the calf circumference (32.3±3.9 vs. 31.8±3.6) (P=0.564), range of motion of the ankle (51.3±4.8 vs. 50.5±4.2, P=0.362), or wound complications (34/0 vs. 34/0) (P=1.000) between the two groups at the end of the follow-up time. However, the percutaneous repair group had a shorter average operating time (23.1±5.2 min) than that of the Mini-open repair group (27.7±4.3 min) (P=0.000).

Conclusions

Acute Achilles tendon ruptures may be treated successfully with a new Mini-open repair system or percutaneous repair technique. However, the Mini-open repair system may represent a superior surgical option, since it offers advantages in terms of direct visual control of the repair, AOFAS Ankle-Hindfoot Score, Achilles tendon Total Rupture Score and risk of sural nerve palsy.

Study design

Case-control studies, Level of evidence, 3.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04802-8.

Estimation of dietary tryptophan requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, reproductive organ and ovarian follicle development and serum biochemical indices

This study aimed to determine the dietary tryptophan (Trp) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 22 wk were randomly allocated to 6 treatments, each with 6 replicates of 14 ducks. During the next 16 wk, birds were fed the basal diet with total Trp contents of 1.00, 2.00, 3.00, 4.00, 5.00 and 6.00 g/kg, respectively. Dietary Trp levels increased egg production, egg mass and feed intake of duck breeders from 22 to 37 wk (P < 0.05), and there were linear and quadratic effects of Trp level (P < 0.05). The feed conversion ratio (FCR) quadratically decreased with dietary Trp levels (P < 0.05). Dietary Trp levels decreased (P < 0.05) egg albumen height and Haugh unit at wk 8 or 12, and the responses were linear and quadratic (P < 0.05). The body weight of breeders, absolute and relative weight of oviduct, number and total weight of preovulatory follicles (POF), and its proportion relative to ovarian weight were increased (P < 0.05), and the responses were linear (P < 0.01) and quadratic (P < 0.001). Ovarian weight increased quadratically (P < 0.05), and the mean weight of POF increased (P < 0.05), linearly and quadratically. The proportion of small yellow follicles relative to ovary weight decreased (P < 0.01) linearly and quadratically. At wk 16 of the trial period, the serum albumin content and alanine aminotransferase activity decreased (P < 0.05) and the creatinine content increased (P < 0.01) linearly and quadratically. The Trp requirements were estimated to be 3.14 g/kg for optimizing egg production, 2.93 g/kg for egg mass, and 2.92 g/kg for FCR. Overall, dietary Trp levels (1 to 6 g/kg) affected productive performance, egg quality, reproductive organ and ovarian follicle development, and serum biochemical indices of layer duck breeders, and a diet containing 2.9 to 3.1 g Trp per kg feed was adequate during the laying period (22 to 37 wk of age).

Cluster phenomenon of vertebral refractures after posterior pedicle screw fixation in a patient with glucocorticosteroid-induced Kümmell's disease: a treatment dilemma

INTRODUCTION

Surgical treatments are usually preferred in patients with Kümmell's disease since it represents a failure of conservative treatment for osteoporotic vertebral compression fracture without evidence of spontaneous healing. However, the risk of postoperative refractures is much higher in patients with glucocorticosteroid-induced osteoporosis (GIOP) than in those with primary osteoporosis, possessing a therapeutic challenge and dilemma to orthopaedic surgeons.

CASE REPORT

We described a rare cluster phenomenon of vertebral refractures in a patient with GIOP subsequent to segmental internal fixation for the initial management of glucocorticosteroid-induced Kümmell's disease, and a review of the literature.

CONCLUSION

Our patient illustrates that clinicians should be aware of the significant management dilemma and possible disastrous outcome after surgical interventions for glucocorticosteroid-induced Kümmell's disease and, thus, pay much more attention to comprehensive perioperative antiosteoporotic medications for patients with GIOP in current medical treatment.

The application of reduced dietary crude protein levels supplemented with additional amino acids in laying ducks

This study was aimed at studying use of reduced dietary crude protein (CP) level supplemented with additional amino acids in laying ducks. A total of 720 Jingjiang ducks (50 wk) were randomly assigned to 5 treatments and fed 5 basal diets with CP levels at 17.5, 16.5, 15.5, 14.5, or 13.5%, with additional amino acids added to each diet for 12 wk. Each treatment had 6 replicates of 24 ducks each. Dietary CP levels affected (P < 0.05) egg production and mass of laying ducks, and there was a linear and quadratic decrease with decreasing CP levels (P < 0.05). Dietary CP levels did not affect egg weight and feed conversion ratio (FCR), but egg weight decreased linearly (P < 0.05); FCR increased linearly and quadratically (P < 0.05) with decreasing CP levels. There were no significant differences in egg quality among the different CP levels (P > 0.05). Ovarian weight, total and mean weight of preovulatory follicles, and total weight of small yellow follicles (SYF) were decreased by dietary CP levels (linear, P < 0.01 and quadratic, P < 0.05). The oviductal weight decreased linearly (P < 0.05), and the number of SYF decreased linearly and quadratically with decreasing CP levels (P < 0.05). The serum estradiol content decreased linearly with dietary CP levels (P < 0.05). The serum contents of luteinizing hormone, prolactin, and progesterone decreased (P < 0.05), linearly and quadratically (both P < 0.01) with decreasing CP levels. The serum contents of creatinine (CRE), triglycerides (TG), total cholesterol (TC), and alanine aminotransferase (ALT) activity were affected (P < 0.05) by different dietary CP levels. The total protein content increased linearly (P < 0.05), TC content increased quadratically (P < 0.05), and contents of albumin, CRE, TG, and phosphorus, and activities of aspartate aminotransferase and ALT increased linearly and quadratically (both P < 0.05) with decreasing CP levels. Overall, reduced dietary CP levels with addition of amino acids affected the laying performance, the development of reproductive organs and ovarian follicles, serum hormones, and biochemical indices of laying ducks. Dietary CP levels can be reduced to 14.5% with additional amino acid supplementation for 12 wk in laying ducks without negative effect on laying performance and egg quality.

Effects of capsaicin on laying performance, follicle development, and ovarian antioxidant capacity in aged laying ducks

The present study was conducted to evaluate the effects of dietary addition of capsaicin (CAP) on egg production performance, follicular development, and ovarian antioxidant capacity in laying ducks. Three hundred seventy eight 58-wk-old laying ducks were randomly divided into 3 treatments, each treatment consisted 6 replicates, with 12 individually caged laying ducks per replicate. Ducks fed a basal diet served as control, the other 2 groups of ducks were fed the same diet containing 150 mg/kg CAP but in the manner of feed restriction (pair-fed) or ad libitum fed. The experiment lasted for 8 wk. The results showed that the dietary supplementation with CAP under conditions of ad libitum feeding increased feed intake (P < 0.001) and tended (P < 0.1) to increase egg production and egg weight in laying ducks but had no effects on daily egg mass and feed conversion ratio. The relative weight of large yellow follicles from the 2 CAP-supplemented groups at 64 wk of age were significantly higher than that of the controls (P = 0.01). The relative weight of the small yellow follicles in the CAP free-fed group was significantly higher than that of the other 2 groups (P < 0.01). Capsaicin supplementation under ad libitum feding conditions tended to increase the number of dominant follicles in laying ducks (P = 0.06). The ovarian mRNA expression of genes related to calcium signaling (TRPV4, ATP2A2, ITPR1, and CaM) in the CAP ad libitum fed groups were significantly higher than those of the other 2 groups (P < 0.05). The ovarian mRNA expression of CDK1 in CAP free-fed ducks was significantly higher than that of the other 2 groups (P = 0.01). Capsaicin supplementation significantly increased the plasma glutathione peroxidase activity (P < 0.01) in comparison with the control group but reduced the malondialdehyde content in the ovaries of laying ducks (P < 0.01). The results of this study indicates that dietary supplementation of CAP increased feed intake and improved egg production performance probably by activating calcium signaling pathway and improving redox status.

Microstructure, mechanical properties, and in vitro behavior of biodegradable Zn-1Mg-0.1Ca and Zn-1Mg-0.5Ca

In the present study, the microstructure, mechanical properties, corrosion behavior, wettability, haemocompatibility, and cytocompatibility of the as-cast and as-rolled biodegradable Zn-1Mg-0.1Ca and Zn-1Mg-0.5Ca have been systematically investigated to evaluate their feasibility as potential biodegradable materials. The results demonstrated that the Zn-1Mg-0.1Ca have significantly improved mechanical properties, with the yield strength (YS), ultimate tensile strength (UTS), and elongation of as-rolled Zn-1Mg-0.1Ca are (209.04 ± 28.31) MPa, (331.51 ± 40.06) MPa, and (35.43 ± 3.53)%, respectively. Wettability test results demonstrated that the Zn-1Mg-0.1Ca and Zn-1Mg-0.5Ca have hydrophilic surfaces that can enhance cell responses and tissue-implant interactions. The haemocompatibility evaluation showed that the hemolysis ratio of Zn-1Mg-0.1Ca have a low hemolysis ratio of 0.6%; the platelets remain sphere morphology and are not activated. High cell viability indicates the cytocompatibility of the as-rolled Zn-1Mg-0.1Ca alloy. The Zn-1Mg-0.1Ca alloy can be considered as new suitable biodegradable Zn-based alloys for further biomedical applications.

Dietary L-arginine supplementation enhances growth performance, intestinal antioxidative capacity, immunity and modulates gut microbiota in yellow-feathered chickens

This study investigated the effects of dietary Arginine (Arg) on performance, intestinal antioxidative capacity, immunity, and gut microbiota in Chinese yellow-feathered chickens. One thousand two hundred 1-day-old female Qingyuan partridge chickens were randomly assigned to 5 groups with 6 replicates of 40 birds each. Chickens were fed diets with 5 levels of total Arg (8.5, 9.7, 10.9, 12.1, and 13.3 g/kg) without antibiotics for 30 d. The ADFI, ADG, and feed conversion ratio were improved with dietary Arg levels (P < 0.05). The proportions of CD3⁺ and CD4⁺/CD8⁺ lymphocytes responded in a linear (P < 0.05) manner and those of CD4⁺ in a linear or quadratic (P < 0.05) manner as dietary Arg levels increased. Dietary Arg level had a linear (P < 0.05) or quadratic (P < 0.05) effect on the gene expression of glutathione peroxidase 1, heme oxygenase 1, nuclear factor erythroid 2-related factor 2, and the activities of glutathione peroxidase and total antioxidative capacity in the jejunum and ileum. The relative expression of IL-1β, myeloid differentiation primary response 88, and Toll-like receptor 4 decreased linearly (P < 0.05) in the ileum with increasing dietary Arg levels; secretory IgA contents were increased. In addition, sequencing data of 16S rRNA indicated that dietary Arg increased the relative abundance of Firmicutes phylum, Romboutsia and Candidatus Arthromitus genera, while decreased that of Clostridium sensu stricto 1. A diet containing 12.1 g Arg/kg promoted growth performance, intestinal antioxidation, and innate immunity and modulated gut microbiota in yellow-feathered chickens.

RhTSG-6 inhibits IL-1β-induced extracellular matrix degradation and apoptosis by suppressing the p38, and JNK pathways in nucleus pulposus cells

INTRODUCTION

Intervertebral disc degeneration (IDD) is one of the major causes of low back pain (LBP) which seriously affects health and normal physical activity. Recombinant human tumor necrosis factor-a (TNF-a) induced protein 6 (rhTSG-6) has been reported to have therapeutic effects on a variety of inflammatory diseases, but the effect and mechanism of rhTSG-6 action in IDD are not fully understood. The present study was aimed to explore the functional role of rhTSG-6 in interleukin (IL)-1b-induced nucleus pulposus (NP) cell model.

MATERIALS AND METHODS

Experimental human NP cells were isolated from the patients with idiopathic scoliosis and treated with culture medium containing IL-1b (10 ng/mL) for 24 hours to induce extracellular matrix degradation and apoptosis, simulating an IDD model in vitro. The viability of NP cells was analyzed by the CCK-8 assay. The relevant mRNA and protein levels were measured by RT-qPCR and western blot. The apoptosis of NP cells was determined by flow cytometry analysis and western blot.

RESULTS

Compared with the NP cells without IL-1b treatment, IL-1b caused approximately 70% reduction in the viability of NP cells, while RhTSG-6 partly increased the decrease of IL-1b on cell viabilities. Moreover, treatment with rhTSG-6 considerably attenuated the upregulation of extracellular matrix (ECM)-catabolic factors (MMP-3, MMP-13, ADAMTS-4, and ADAMTS-5), and increased the downregulation of ECM-anabolic factor (collagen II) in NP cells induced by IL-1b, indicating that ECM degradation was suppressed. Furthermore, rhTSG-6 also protected NP cells from IL-1b-induced apoptosis. Mechanically, rhTSG-6 inhibited the activation of members of mitogen-activated protein kinase (MAPK) pathway by blocking the phosphorylation of p38, c-Jun N-terminal kinase (JNK) and ERK in IL-1b-induced NP cells.

CONCLUSIONS

RhTSG-6 can attenuate ECM degradation and apoptosis in IL-1b-induced NP cells by inhibiting the p38, JNK and ERK pathways, which may contribute to its potential application in the therapy of IDD.

Magnetic resonance imaging at 7.0 T for evaluation of early lesions of epiphyseal plate and epiphyseal end in a rat model of Kashin-Beck disease

Background

Kashin–Beck disease (KBD) is a disabling osteoarticular disease involving growth and joint cartilage. Early diagnosis can effectively prevent the progress of the disease. However, the early diagnosis of it is still very difficult. Our aim was to study the knee joint lesions of a rat KBD model using ultra-high field magnetic resonance imaging (MRI) and compare it with X-ray imaging to analyze the possible MRI manifestations of KBD, and to further explore ways to determine the pathological damage of KBD in the early stage.

Methods

A total of 96 Wistar rats were selected and randomly divided into 4 groups: normal diet (Group A), KBD-affected diet (Group B), normal diet+T-2 toxin (Group C), and KBD-affected diet+T-2 toxin (Group D). T-2 toxin was administered at a dose of 0.1 mg/kg/day. In the 4th week, 8th week, and 12th week, eight rats randomly selected in each group were sacrificed by cervical dislocation after undergoing X-ray and 7.0 T MRI imaging, and then knee joints were harvested, sliced, and subjected to hematoxylin-eosin (H&E) staining.

Results

Characteristic image changes including of continuity interruption and early closure and fusion of epiphyseal plates were observed on T1WI in rat model of KBD. The total necrosis rates in the H&E stain of group A to group D were 4.35, 52.38, 33.3, and 73.68%, respectively. The positive rate of image change under 7.0 T MRI was 0.833 VS. that under X-ray was 0.33 (P = 0.001).

Conclusions

MRI at 7.0 T is highly sensitive to the early pathological changes of the epiphysis, epiphyseal plate, and metaphyseal end, which can improve imaging positive rate of KBD and decrease the rate of missed diagnosis. This imaging modality can be used for research on early joint lesions and for early diagnosis of KBD.

Estimation of dietary manganese requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, tibial characteristics, and serum biochemical and antioxidant indices

This study was aimed at estimating the dietary manganese (Mn) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 17 wk were randomly allocated to 6 treatments. The birds were fed with a basal diet (Mn, 17.5 mg/kg) or diets supplemented with 20, 40, 80, 120, or 160 mg/kg of Mn (as MnSO₄·H₂O) for 18 wk. Each treatment had 6 replicates of 14 ducks each. As a result of this study, dietary Mn supplementation did not affect the productive performance of laying duck breeders in the early laying period (17–18 wk), but affected egg production, egg mass, and feed conversion ratio (FCR) from 19 to 34 wk (P < 0.05), and there was a linear and quadratic effect of supplement level (P < 0.05). The proportion of preovulatory ovarian follicles increased (P < 0.01) linearly and quadratically, and atretic follicles (weight and percentage) decreased (P < 0.05) quadratically with dietary Mn supplementation. The density and breaking strength of tibias increased (quadratic; P < 0.05), the calcium content of tibias decreased (linear, quadratic; P < 0.01), and Mn content increased (linear, quadratic; P < 0.001) with increase in Mn. The addition of Mn had a quadratic effect on serum contents of estradiol, prolactin, progesterone, luteinizing hormone, and follicle-stimulating hormone (P < 0.001). Dietary Mn supplementation decreased serum contents of total protein (linear, P < 0.05), glucose (quadratic, P < 0.05), total bilirubin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and calcium (linear, quadratic; P < 0.05). The serum total antioxidant capacity and total and Mn-containing superoxide dismutase activities increased (linear, quadratic; P < 0.001), and malondialdehyde content decreased (linear, quadratic; P < 0.001) in response to Mn supplemental levels. The dietary Mn requirements, in milligram per kilogram for a basal diet containing 17.5 mg/kg of Mn, for Longyan duck breeders from 19 to 34 wk of age were estimated to be 84.2 for optimizing egg production, 85.8 for egg mass, and 95.0 for FCR. Overall, dietary Mn supplementation, up to 160 mg/kg of feed, affected productive performance, tibial characteristics, and serum biochemical and antioxidant status of layer duck breeders. Supplementing this basal diet (17.5 mg/kg of Mn) with 85 to 95 mg/kg of additional Mn was adequate for laying duck breeders during the laying period.

Activation of SIRT1 promotes cartilage differentiation and reduces apoptosis of nucleus pulposus mesenchymal stem cells via the MCP1/CCR2 axis in subjects with intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a condition involving disruption of the bone tissue distribution. Nucleus pulposus mesenchymal stem cells (NPMSCs) and Sirtuin 1 (SIRT1) play important roles in bone diseases, therefore the aim of the present study was to evaluate the roles of SIRT1 and NPMSCs in IDD. First, NPMSCs were harvested from patients with IDD. Then, the NPMSCs were treated with a SIRT activator, and monocyte chemoattractant protein 1 (MCP1) and chemokine receptor 2 (CCR2) inhibitors. Indices related to NPMSC growth, proliferation, differentiation and apoptosis were measured. Subsequently, IDD rat models were established and were transfected with NPMSCs overexpressing SIRT1. NPMSC apoptosis and cartilage differentiation were detected in the rat IDD model. SIRT1 expression was found to be decreased, and the expression of MCP1 and CCR2 increased in NPMSCs of patients with IDD. The upregulation of SIRT1 and the downregulation of the MCP1/CCR2 axis promoted cartilage differentiation and reduced the number of apoptotic NPMSCs. Furthermore, MCP1 reversed the progression of the cartilage differentiation of NPMSCs and the inhibition of NPMSC apoptosis induced by SIRT1 overexpression. Moreover, the transplantation of rat NPMSCs overexpressing SIRT1 relieved IDD in rats. Therefore, SIRT1 overexpression improved cartilage differentiation and reduced the apoptosis of NPMSCs by inactivating the MCP1/CCR2 axis, thus attenuating IDD in rats.

Lumbar plain radiograph is not reliable to identify lumbosacral transitional vertebra types according to Castellvi classification principle

Background

The anteroposterior view of the lumbar plain radiograph (AP-LPR) was chosen as the original and first radiographic tool to determine and classify lumbosacral transitional vertebra with morphological abnormality (MA-LSTV) according to the Castellvi classification. However, recent studies found that AP-LPR might not be sufficient to detect or classify MA-LSTV correctly. The present study aims to verify the reliability of AP-LPR on detecting and classifying MA-LSTV types, taking coronal reconstructed CT images (CT-CRIs) as the gold criteria.

Methods

Patients with suspected MA-LSTVs determined by AP-LPR were initially enrolled. Among them, those who received CT-CRIs were formally enrolled to verify the sensitivity of AP-LPR on detecting and classifying MA-LSTV types according to the Castellvi classification principle.

Results

A total of 298 cases were initially enrolled as suspected MA-LSTV, among which 91 cases who received CT-CRIs were enrolled into the final study group. All suspected MA-LSTVs were verified to be real MA-LSTVs by CT-CRIs. However, 35.2% of the suspected MA-LSTV types judged by AP-LPR were not consistent with the final types judged by CT-CRIs. Two suspected type IIIa and 20 suspected type IIIb MA-LSTVs were verified to be true, while 9 of 39 suspected type IIa, 9 and 3 of 17 suspected type IIb, and 11 of 13 suspected type IV MA-LSTVs were verified to truly be type IIIa, IIIb, IV and IIIb MA-LSTVs by CT-CRIs, respectively. Incomplete joint-like structure (JLS) or bony union structure (BUS) and remnants of sclerotic band (RSB) between the transverse process (TP) and sacrum were considered to be the main reasons for misclassification.

Conclusion

Although AP-LPR could correctly detect MA-LSTV, it could not give accurate type classification. CT-CRIs could provide detailed information between the TP and sacrum area and could be taken as the gold standard to detect and classify MA-LSTV.

The effects of dietary Se on productive and reproductive performance, tibial quality, and antioxidant capacity in laying duck breeders

This study evaluated the optimal concentrations of dietary Se for the productive and reproductive performance, tibial quality, and antioxidant status in duck breeders aged 23 to 49 wk. In total, 432 Longyan duck breeders aged 22 wk were allotted randomly to 6 treatments, each with 6 replicates of 12 individually caged birds. The experiment lasted for 27 wk, and birds were fed corn-soybean meal-based diets containing 0.11, 0.19, 0.27, 0.35, 0.43, or 0.51 mg Se/kg, respectively. The tested dietary Se levels did not affect egg production and tibial quality of duck breeders. The Se contents of the shell, yolk or albumin, whole egg, and the fertility of set eggs increased in a linear and quadratic manner (P < 0.05) in response to the increased dietary Se level, whereas the yolk malondialdehyde (MDA) and embryonic mortality decreased. The activities of glutathione peroxidase 3 (Gpx3) in plasma and Gpx1 in the erythrocytes and livers of breeder ducks increased in a linear and quadratic manner (P < 0.05) in response to increased dietary Se levels, whereas the total superoxide dismutase (T-SOD) activity increased and the MDA concentration decreased in the liver. The activity of Gpx3 in the plasma and Gpx1 in the erythrocytes and livers of newly hatched ducklings increased linearly (P < 0.01) with the increase in Se level, whereas the T-SOD activity and MDA concentration did not change. In conclusion, diets containing 0.27 mg Se/kg led to the highest egg fertility and hatchability in Longyan duck breeders, and using levels >0.19 mg Se/kg diet enhanced the antioxidant capacity in breeders and their offspring. The regression model indicated that dietary Se levels 0.19, 0.27, 0.28, 0.24, and 0.30 mg/kg are optimal levels to obtain maximum Se deposition efficiency in eggs, egg fertility, Gpx1 activity in erythrocytes and liver in duck breeders, and plasma activity of Gpx3 in newly hatched ducklings, respectively.

Effects of ${\rm \small L}$-methionine on growth performance, carcass quality, feather traits, and small intestinal morphology of Pekin ducks compared with conventional ${\rm \small {DL}}$-methionine

The research studied the effects ofl-methionine (l-Met) on growth performance, carcass quality, feather traits, and small intestinal morphology of Pekin ducks compared with conventionaldl-methionine (dl-Met). A total of 1080, 1-day-old male Pekin ducks were randomly allotted to 9 groups with 6 replicate pens of 20 birds each. During the starter phase (1 to 14 d), ducks were fed a basal diet (Met, 0.30%) or that supplemented with dl-Met or l-Met at 0.05, 0.10, 0.15, or 0.20% of feed. During the grower phase (15 to 35 d), ducks were fed a basal diet (Met, 0.24%) or that supplemented with dl- Met or l-Met at 0.04, 0.08, 0.12, or 0.16% of feed. Compared with ducks fed the basal diet, supplementation with either dl- Met or l-Met increased the body weight (BW) of ducks at days 14 and 35, increased average daily gain (ADG) and average daily feed intake (ADFI), decreased F:G at the starter phase, and increased ADG over the whole 35-d period (P < 0.05). The efficacy of l-Met compared to dl- Met was 140.1% for 14-d BW, 137.6% for ADG and 121.0% for F:G for days 1 to 14. Ducks fed diets supplemented with l-Met had greater proportion of leg muscle, higher than in ducks provided with dl- Met (P < 0.05). The breast muscle proportion was enhanced with dl- Met rather than l- Met supplementation (P < 0.01). The back feathers score and fourth primary wing feather length were increased with dl- Met or l-Met supplementation (P < 0.01), and there was increased efficacy of l-Met relative to dl- Met for back feathers score (153.1%). Dietary dl- Met or l- Met supplementation increased villus height of ileal mucosa of ducks at days 14 and 35 (P < 0.01). Overall, dietary l-Met or dl- Met supplementation affected the growth performance of ducks during the starter phase, and improved the feather traits and small intestinal morphology. The efficacy of l-Met to dl- Met ranged from 120 to 140% for growth performance of young ducks (1 to 14 d) and was 153% for the feather traits of ducks (35 d).

Protective effect of curcumin on ochratoxin A-induced liver oxidative injury in duck is mediated by modulating lipid metabolism and the intestinal microbiota

Curcumin has antioxidant functions, regulates the intestinal microbial composition, and alleviates mycotoxin toxicity. The present study aimed to explore whether curcumin could alleviate ochratoxin A (OTA)-induced liver injury via the intestinal microbiota. A total of 720 mixed-sex 1-day-old White Pekin ducklings were randomly assigned into 4 groups: CON (control group, without OTA), OTA (fed a diet with 2 mg/kg OTA), CUR (ducks fed a diet with 400 mg/kg curcumin), and OTA + CUR (2 mg/kg OTA plus 400 mg/kg curcumin). Each treatment consisted of 6 replicates and 30 ducklings per replicate. Treatment lasted for 21 D. Results were analyzed by a two-tailed Student t test between 2 groups. Our results demonstrated that OTA treatment had the highest serum low-density lipoprotein (LDL) level among 4 groups. Compared with OTA group, OTA + CUR decreased serum LDL level (P < 0.05). OTA decreased liver catalase (CAT) activity in ducks (P < 0.05), while addition of curcumin in OTA group increased liver CAT activity (P < 0.05). 16S ribosomal RNA sequencing suggested that curcumin increased the richness indices (ACE index) and diversity indices (Simpson index) compared with OTA group (P < 0.05) and recovered the OTA-induced alterations in composition of the intestinal microbiota. Curcumin supplementation relieved the decreased abundance of butyric acid producing bacteria, including blautia, butyricicoccus, and butyricimonas, induced by OTA (P < 0.05). OTA also significantly influenced the metabolism of the intestinal microbiota, such as tryptophan metabolism and glyceropholipid metabolism. Curcumin could alleviate the upregulation of oxidative stress pathways induced by OTA. OTA treatment also increased SREBP-1c expression (P < 0.05). The curcumin group had the lowest expression of FAS and PPARG mRNA (P < 0.05) and the highest expression of NRF2 and HMOX1 mRNA. These results indicated that curcumin could alleviate OTA-induced oxidative injury and lipid metabolism disruption by modulating the cecum microbiota.

Effects of dietary lysine on productivity, reproductive performance, protein and lipid metabolism-related gene expression in laying duck breeders

This study investigated whether dietary lysine (Lys) affects productive performance and expression of genes related to protein and lipid metabolism in laying duck breeders. Longyan duck breeders (n = 540, 19 wk of age) were randomly assigned to 6 groups with 6 replicates of 15 birds each. Breeders were fed diets with 6 total Lys levels (6.4, 7.2, 8.0, 8.8, 9.6, and 10.4 g/kg) for 26 wk duration. Egg production, egg weight, egg mass, feed conversion ratio, hatchability, hatchling weight, albumen weight, eggshell weight, yolk weight, and yolk proportion increased with dietary Lys levels (P < 0.05). Dietary Lys level had a linear (P < 0.05) and quadratic (P < 0.05) effects on maternal hepatic expression of mechanistic target of rapamycin, eukaryotic translation initiation factor 4E binding protein 1, ubiquitin conjugating enzyme E2K (UBE2K), cathepsin B (CTSB), and quadratically (P < 0.05) increased the concentrations of plasma Lys, leucine, threonine, and tryptophan in duck breeders. In contrast, maternal dietary Lys suppressed expression of proteasome 26S subunit, UBE2K, and CTSB in the liver of hatchlings. Moreover, relative expression of peroxisome proliferator-activated receptors alpha, carnitine palmitoyltransferase 1A, and very low density apolipoprotein-II increased linearly (P < 0.05) and quadratically (P < 0.05), and that of VLDL receptor (VLDLR) decreased quadratically (P < 0.05) in the liver of duck breeders with increasing dietary Lys levels; hepatic triglyceride and cholesterol contents were reduced. Maternal dietary Lys suppressed hepatic expression of VLDLR in the hatchlings. A diet containing 8.6 g Lys/kg promoted protein turnover and lipid metabolism in laying duck breeders, which positively reflected in the productivity and reproductive performance.

Estimation of dietary zinc requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, tibial characteristics, plasma biochemical and antioxidant indices, and zinc deposition

This study evaluated the effects of different dietary zinc (Zn) levels on productive and reproductive performance, egg quality, tibial characteristics, plasma biochemical and antioxidant indices, and zinc deposition in laying duck breeders. A total of 504 Longyan duck breeders aged 21 wk were randomly allocated to 6 treatments and fed a basal diet (Zn, 27.7 mg/kg) or that basal diet supplemented with Zn (as ZnSO₄·H₂ O) at 10, 20, 40, 80, or 160 mg Zn per kg of feed for 20 wk. Each group had 6 replicates of 14 ducks each. Dietary Zn supplementation affected (P < 0.05) the egg production, FCR, and shell thickness of laying duck breeders from 21 to 40 wk, and there was a quadratic (P < 0.05) effect between them. Dietary Zn supplementation affected (P < 0.05) and quadratically (P < 0.001) increased the breaking strength, density, and dry defatted weight of tibias. Alkaline phosphatase, calcium, phosphorus, total superoxide dismutase, glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) activities or content in plasma were affected (P < 0.05), and quadratically (P < 0.01) changed by dietary Zn levels. Dietary Zn supplementation affected (P < 0.01) and increased the Zn deposition in egg yolk (linear, P < 0.05; quadratic, P < 0.001) and tibia (linear, P < 0.05). The dietary Zn requirements, in mg/kg for a basal diet containing 27.7 mg/kg Zn, for Longyan duck breeders from 21 to 40 wk of age were estimated to be 65.4 for optimizing egg production, 68.6 for FCR, 102 for hatchling BW, 94.7 for eggshell thickness, 77.2 for tibial breaking strength, 81.4 for tibial density, 78.9 for tibial dry defatted weight, 69.5 for plasma GSH-Px activity, 72.4 for plasma MDA content, and 94.6 for Zn content in tibia. Overall, dietary Zn supplementation, up to 160 mg/kg feed, affected the productive performance, eggshell thickness, tibial characteristics, plasma antioxidant status, and Zn deposition of layer duck breeders. Supplementing this basal diet (27.7 mg/kg Zn) with 70 to 80 mg/kg additional Zn was adequate for laying duck breeders during the laying period.

Dietary curcumin enhances intestinal antioxidant capacity in ducklings via altering gene expression of antioxidant and key detoxification enzymes

The study investigated the effects of dietary curcumin supplementation on tissue distribution of curcumin and its metabolites, intestinal antioxidant capacity, and expression of detoxification-related genes in ducks. A total of 720 one-day-old male Cherry Valley Pekin ducklings (initial BW 58.6 ± 0.1 g) were randomly assigned to 4 dietary groups each with 6 replicates of 30 ducks using a single factorial arrangement design. Ducks in the control group were fed a basal diet and the remainder were fed the basal diet supplemented with 200, 400, or 800 mg/kg curcumin. The experiment lasted for 21 D. Curcumin was present at 13.12 to 16.18 mg/g in the cecal digesta, 75.50 to 575.40 μg/g in jejunal mucosa, 35.10 to 73.65 μg/g in liver, and 7.02 to 7.88 μg/mL in plasma. The jejunal and hepatic contents of curcumin increased significantly (P < 0.05) in response to supplementation with 400 and 800 mg/kg of curcumin respectively, compared with 200 mg curcumin/kg group. There was a linear (P < 0.001) effect of dietary curcumin on relative abundance of SOD1, GPX1, CAT, HO-1, and Nrf2 transcripts, and a quadratic (P < 0.001) increase in the activities of GSH-Px and T-AOC in jejunal mucosa. The expression of CYP1A4, CYP2D17 increased and CYP1B1, CYP2A6 decreased linearly (P < 0.001) with dietary curcumin concentrations. In addition, dietary curcumin increased gene expression of GST, MRP6, and ABCB1 in jejunal mucosa. In conclusion, dietary supplementation with 200 to 800 mg/kg curcumin enhanced the accumulation of curcumin and its metabolites in jejunum as well as increasing the antioxidant capacity and detoxification potential, which play major roles in the protection of duck intestines against damage.

Evaluation of intervertebral disc regeneration with injection of mesenchymal stem cells encapsulated in PEGDA-microcryogel delivery system using quantitative T2 mapping: a study in canines

Intervertebral disc degeneration (IDD), the primary cause of low back pain, is still a great challenge to spinal surgeons and clinicians. T2 mapping, a biochemical magnetic resonance imaging (MRI) technique to calculate relaxation time, has the potential to offer a quantitative assessment of IDD. The aim of the study was to evaluate the regenerative effects of adipose-derived mesenchymal stem cells (MSCs) encapsulated in PEGDA-microcryogels (PMs) reinforced alginate hydrogel (AH) on the degenerative intervertebral disc (IVD) in a canine model using T2 mapping. Four degeneration-induced IVDs (L3-L4 to L6-L7) of 12 adult beagle dogs were injected with phosphate-buffered saline (PBS), MSCs, AH-PMs, and MSCs-laden AH-PMs, respectively. The intact IVD L7-S1 served as the normal control. IVD height change on plain radiograph, Pfirrmann grade and T2 relaxation time on MRI, histological change, and extracellular matrix (ECM)-associated proteins were evaluated during the 24-week follow-up period. Injection of MSCs-laden AH-PMs had the most satisfactory effects, having less decrease of IVD height, lower Pfirrmann grade, milder histological change, and longer T2 relaxation time (P < 0.05). T2 relaxation time was positively correlated with ECM content (proteoglycan: r = 0.85, P < 0.001; collagen II: r = 0.79, P < 0.001) and IVD height (r = 0.81, P < 0.001), but negatively correlated with Pfirrmann grade and histological grade (rho = -0.86, P < 0.001; rho = -0.95, P < 0.001). These results suggest that T2 mapping has the potential to quantitatively evaluate the repairing effects of cell-based engineering treatments on IDD for a long-term follow-up.

The inflammatory cytokine TNF-α regulates the biological behavior of rat nucleus pulposus mesenchymal stem cells through the NF-κB signaling pathway in vitro

Nucleus pulposus (NP) mesenchymal stem cells (NPMSCs) are a potential cell source for intervertebral disc (IVD) regeneration; however, little is known about their response to tumor necrosis factor-α (TNF-α), a critical inflammation factor contributing to accelerating IVD degeneration. Accordingly, the aim of this study was to investigate the regulatory effects of TNF-α at high and low concentrations on the biological behaviors of healthy rat NPMSCs, including proliferation, migration, and NP differentiation. In this study, NPMSCs were treated with different concentration of TNF-α (0-200 ng/mL). Then we used annexin V/propidium iodide flow cytometry analysis to detect the apoptosis rate of NPMSCs. Cell Counting Kit-8, Edu assay, and cell cycle test were used to examine the proliferation of NPMSCs. Migration ability of NPMSCs was detected by wound healing assay and transwell migration assay. Pellets method was used to induce NP differentiation of NPMSCs, and immunohistochemical staining, real-time polymerase chain reaction, and Western blot analysis were used to examine the NPC phenotypic genes and proteins. The cells were further treated with the nuclear factor-κB (NF-κB) pathway inhibitor Bay 11-7082 to determine the role of the NF-κB pathway in the mechanism underlying the differentiation process. Results showed that treatment with a high concentration of TNF-α (50-200 ng/mL) could induce apoptosis of NPMSCs, whereas a relatively low TNF-α concentration (0.1-10 ng/mL) promoted the proliferation and migration of NPMSCs, but inhibited their differentiation toward NP cells. Moreover, we identified that the NF-κB signaling pathway is activated during the TNF-α-inhibited differentiation of NPMSCs, and the NF-κB signal inhibitor Bay 11-7082 could partially eliminate the adverse effect of TNF-α on the differentiation of NPMSCs. Therefore, our findings provide important insight into the dynamic biological behavior reactivity of NPMSCs to TNF-α during IVD degeneration process, thus may help us understanding the underlying mechanism of IVD degeneration.

Radiographic analysis of the correlation between ossification of the nuchal ligament and sagittal alignment and segmental stability of the cervical spine in patients with cervical spondylotic myelopathy

BACKGROUND

Ossification of the nuchal ligament (ONL) caused by chronic injury to the nuchal ligament (NL) is very common in instability-related cervical disorders.

PURPOSE

To determine possible correlations between ONL, sagittal alignment, and segmental stability of the cervical spine.

MATERIAL AND METHODS

Seventy-three patients with cervical spondylotic myelopathy (CSM) and ONL (ONL group) and 118 patients with CSM only (control group) were recruited. Radiographic data included the characteristics of ONL, sagittal alignment and segmental stability, and ossification of the posterior longitudinal ligament (OPLL). We performed comparisons in terms of radiographic parameters between the ONL and control groups. The correlations between ONL size, cervical sagittal alignment, and segmental stability were analyzed. Multivariate logistic regression was used to identify the independent risk factors of the development of ONL.

RESULTS

C2-C7 sagittal vertical axis (SVA), T1 slope (T1S), T1S minus cervical lordosis (T1S-CL) on the lateral plain, angular displacement (AD), and horizontal displacement (HD) on the dynamic radiograph increased significantly in the ONL group compared with the control group. The size of ONL significantly correlated with C2-C7 SVA, T1S, AD, and HD. The incidence of ONL was higher in patients with OPLL and segmental instability. Cervical instability, sagittal malalignment, and OPLL were independent predictors of the development of ONL through multivariate analysis.

CONCLUSION

Patients with ONL are more likely to have abnormal sagittal alignment and instability of the cervical spine. Thus, increased awareness and appreciation of this often-overlooked radiographic finding is warranted during diagnosis and treatment of instability-related cervical pathologies and injuries.