Pelvic bone tumor segmentation fusion algorithm based on fully convolutional neural network and conditional random field

Background and objective

Pelvic bone tumors represent a harmful orthopedic condition, encompassing both benign and malignant forms. Addressing the issue of limited accuracy in current machine learning algorithms for bone tumor image segmentation, we have developed an enhanced bone tumor image segmentation algorithm. This algorithm is built upon an improved full convolutional neural network, incorporating both the fully convolutional neural network (FCNN-4s) and a conditional random field (CRF) to achieve more precise segmentation.

Methodology

The enhanced fully convolutional neural network (FCNN-4s) was employed to conduct initial segmentation on preprocessed images. Following each convolutional layer, batch normalization layers were introduced to expedite network training convergence and enhance the accuracy of the trained model. Subsequently, a fully connected conditional random field (CRF) was integrated to fine-tune the segmentation results, refining the boundaries of pelvic bone tumors and achieving high-quality segmentation.

Results

The experimental outcomes demonstrate a significant enhancement in segmentation accuracy and stability when compared to the conventional convolutional neural network bone tumor image segmentation algorithm. The algorithm achieves an average Dice coefficient of 93.31 %, indicating superior performance in real-time operations.

Conclusion

In contrast to the conventional convolutional neural network segmentation algorithm, the algorithm presented in this paper boasts a more intricate structure, proficiently addressing issues of over-segmentation and under-segmentation in pelvic bone tumor segmentation. This segmentation model exhibits superior real-time performance, robust stability, and is capable of achieving heightened segmentation accuracy.

Dehydrocostus lactone (DHC) promotes osteoblastic differentiation and mineralization through p38/RUNX-2 signaling

Dysregulation of osteoblastic differentiation is an important risk factor of osteoporosis, the therapy of which is challenging. Dehydrocostus lactone (DHC), a sesquiterpene isolated from medicinal plants, has displayed anti-inflammatory and antitumor properties. In this study, we investigated the effects of DHC on osteoblastic differentiation and mineralization of MC3T3-E1 cells. Interestingly, we found that DHC increased the expression of marker genes of osteoblastic differentiation, such as alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Additionally, DHC increased the expressions of collagen type I alpha 1 (Col1a1) and collagen type I alpha 2 (Col1a2). We also demonstrate that DHC increased ALP activity. Importantly, the Alizarin Red S staining assay revealed that DHC enhanced osteoblastic differentiation of MC3T3-E1 cells. Mechanistically, it is shown that DHC increased the expression of Runx-2, a central regulator of osteoblastic differentiation. Treatment with DHC also increased the levels of phosphorylated p38, and its blockage using its specific inhibitor SB203580 abolished the effects of DHC on runt-related transcription factor 2 (Runx-2) expression and osteoblastic differentiation, suggesting the involvement of p38. Based on these findings, we concluded that DHC might possess a capacity for the treatment of osteoporosis by promoting osteoblastic differentiation.

Bone tumor examination based on FCNN-4s and CRF fine segmentation fusion algorithm

Background and objective

Bone tumor is a kind of harmful orthopedic disease, there are benign and malignant points. Aiming at the problem that the accuracy of the existing machine learning algorithm for bone tumor image segmentation is not high, a bone tumor image segmentation algorithm based on improved full convolutional neural network which consists fully convolutional neural network (FCNN-4s) and conditional random field (CRF).

Methodology

The improved fully convolutional neural network (FCNN-4s) was used to perform coarse segmentation on preprocessed images. Batch normalization layers were added after each convolutional layer to accelerate the convergence speed of network training and improve the accuracy of the trained model. Then, a fully connected conditional random field (CRF) was fused to refine the bone tumor boundary in the coarse segmentation results, achieving the fine segmentation effect.

Results

The experimental results show that compared with the traditional convolutional neural network bone tumor image segmentation algorithm, the algorithm has a great improvement in segmentation accuracy and stability, the average Dice can reach 91.56%, the real-time performance is better.

Conclusion

Compared with the traditional convolutional neural network segmentation algorithm, the algorithm in this paper has a more refined structure, which can effectively solve the problem of over-segmentation and under-segmentation of bone tumors. The segmentation prediction has better real-time performance, strong stability, and can achieve higher segmentation accuracy.

[Current situation and trend of medical laboratory results homogeneity management]

Medical test results are indispensable and important tools in diagnosis and treatment services. It is necessary to promote the homogenization of test results first, because homogenization is the basis for mutual recognition of test results. Mutual recognition of medical test results can help share resources among medical institutions, provide more reliable test results for early prevention, screening and treatment of diseases, and reduce repeated tests, thus improving people's medical experience. In recent years, with the deepening of medical system reform and the promotion of graded diagnosis and treatment, governments have continuously introduced policies of mutual recognition of test results around country. However, homogenization is a prerequisite for mutual recognition of test results, with the emergence of intelligent medicine in the era of internet big data, opportunities and challenges coexist in the development of homogeneity management. In the future, the homogeneity of medical test results will present a trend of digitalization, automation, informatization and intelligence.

Femoral image segmentation based on two-stage convolutional network using 3D-DMFNet and 3D-ResUnet

OBJECTIVE

The femur is a typical human long bone with an irregular spatial structure. Femoral fractures are the most common occurrence in middle-aged and older adults. The structure of human bone tissue is very complex, and there are significant differences between individuals. Segmenting bone tissue is a challenging task and of great practical significance.

METHODS

Our research is based on segmenting and the three-dimensional reconstruction of femoral images using X-ray imaging. The currently commonly used two-dimensional fully convolutional network Unet has the problem of ignoring spatial position information and losing too much feature information. The commonly used three-dimensional fully convolutional network 3D Unet has the problem of ignoring spatial position information and losing too much feature information. For the problem of many model parameters, we proposes a two-stage network segmentation model composed of 3D-DMFNet and 3D-ResUnet networks and trains the network in stages to segment the femur. One stage is used to detect the coarse segmentation of the femur range, and one stage is used for the fine segmentation of the femur so that the training speed is fast and the segmentation accuracy is moderate, which is suitable for detecting the femur range.

RESULTS

The experimental dataset used in this paper is from The Second Affiliated Hospital of Fujian Medical University, which consists of 30 sets of femur X-ray images. The experiment compares the accuracy and loss value of Unet and the two-stage convolutional network. The image shows that the two-stage convolutional network has higher accuracy. At the same time, this paper shows the effect of the two-stage coarse segmentation and fine segmentation of medical images. Subsequently, this paper applies the model to practice and obtains the model's Dice, Sensitivity, Specificity and Pixel Accuracy values. After comparative analysis, the experimental results show that the two-stage network segmentation model composed of 3D-DMFNet and 3D-ResUnet network designed in this paper has higher accuracy, intuitiveness, and more application value than traditional image segmentation algorithms.

CONCLUSION

With the continuous application of X-ray images in clinical diagnosis using femoral images, the method in this paper is expected to become a diagnostic tool that can effectively improve the accuracy and loss of femoral image segmentation and the three-dimensional reconstruction.

Recent advances in cell-based and cell-free therapeutic approaches for sarcopenia

Sarcopenia is a progressive loss of muscle mass and function that is connected with increased hospital expenditures, falls, fractures, and mortality. Although muscle loss has been related to aging, injury, hormonal imbalances, and diseases such as malignancies, chronic obstructive pulmonary disease, heart failure, and kidney failure, the underlying pathogenic mechanisms of sarcopenia are unclear. Exercise-based interventions and multimodal strategies are currently being considered as potential therapeutic approaches to prevent or treat these diseases. Although drug therapy research is ongoing, no drug has yet been proven to have a substantial safety and clinical value to be the first drug therapy to be licensed for sarcopenia. To better understand the molecular alterations underlying sarcopenia and effective treatments, we review leading research and available findings from the systemic change to the muscle-specific microenvironment. Furthermore, we explore possible mechanisms of sarcopenia and provide new knowledge for the development of novel cell-free and cell-based therapeutics. This review will assist researchers in developing better therapies to improve muscle health in the elderly.

[Percutaneous biliary stent combined with brachytherapy for malignant obstructive jaundice: a multicenter retrospective controlled study]

Objective: To investigate the efficacy, safety and prognostic factors of percutaneous biliary stent combined with iodine-125 seed chain brachytherapy (radiotherapy) in the treatment of malignant obstructive jaundice. Methods: Data of 107 cases with malignant obstructive jaundice treated with percutaneous biliary stent implantation from January 2017 to December 2020 were retrospectively analyzed. Among them, 58 cases received biliary stent combined with iodne-125 seed chain brachytherapy (study group), and 49 cases received biliary stent implantation (control group). The changes of bilirubin, stent patency time, complications, overall survival (OS) and prognostic factors were analyzed in both groups. Results: The incidence of complications in the study group and the control group were 17.2% and 18.3% respectively, and the difference was not statistically significant (P=0.974). Serum total bilirubin levels were decreased significantly in both groups at one month after surgery (P<0.001). Postoperative stent patency time was significantly better in the study group (10.0±1.6 months) (95% CI: 8.2～12.5) than that in the control group (5.2±0.4 months) (95% CI: 4.1～6.0, P<0.001). The median OS was longer in the study group (11.2±1.8 months) (95% CI: 9.2～12.8) than that in the control group (8.0±1.1 months) (95% CI: 8.0～12.8, P<0.001). Multivariate analysis result showed that stent combined with brachytherapy (HR=0.08, 95% CI:0.04～0.15, P<0.001) and receiving further anti-tumor therapy after surgery (HR=0.27, 95% CI:0.15~0.49, P<0.001) were independent risk factors affecting the patency of biliary stents. Preoperative percutaneous transhepatic biliary drainage (HR=0.46, 95%CI:0.28～0.74, P=0.002), stent combined with brachytherapy (HR=0.23, 95%CI:0.14～0.39, P<0.001) and receiving further anti-tumor therapy after surgery (HR=0.37, 95%CI:0.22～0.61, P<0.001) were independent risk factors affecting OS. Conclusion: Percutaneous biliary stent combined with brachytherapy is safe and effective in the treatment of malignant obstructive jaundice, which can significantly prolong the patency time of biliary stent and the survival time of patients.

[Safety and efficacy of TIPS combined with iodine-125 seed strands in the treatment of patients with hepatocellular carcinoma combined with portal vein tumor thrombosis]

Objective: To study the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) combined with iodine-125 (¹²⁵Ⅰ) seed strands implantation in patients with hepatocellular carcinoma combined with portal vein tumor thrombosis. Methods: 25 cases with diffuse intrahepatic tumor combined with tumor thrombus type Ⅲ/Ⅳ requiring TIPS were simultaneously implanted with ¹²⁵Ⅰseed strand. Tumor thrombus was controlled with ¹²⁵I seed implantation brachytherapy to keep the TIPS pathway unobstructed, reduce the portal vein pressure, and observe the changes in the cause of death of the patients. During the same period, 30 cases without TIPS and seed strand implantation were used as controls. Data between groups were compared using t-test, Chi-Squared test or Fisher's exact test. Results: TIPS combined with ¹²⁵Ⅰ seed strand implantation was safe in patients with diffuse hepatocellular carcinoma combined with type III/IV portal vein tumor thrombus, and 92.0% (23/25) of the patients maintained unobstructed TIPS pathway. Compared with the control group, patients in the treatment group died of fewer lead-related complications, and most died from chronic liver failure (84.0% vs. 56.7%, χ² = 4.771, P=0.029). The incidence of upper gastrointestinal bleeding was significantly decreased (12.0% vs. 46.7%, χ² =7.674, P=0.006) and ascites severity was significantly improved (mild 40.0% vs. 16.7%, moderate 52.0% vs. 20.0%, severe 8.0% vs. 46.7%, χ² =13.246 , P=0.001). Conclusions: TIPS combined with ¹²⁵Ⅰ seed strand implantation is safe and feasible in patients with diffuse intrahepatic tumor combined with tumor thrombus type Ⅲ/Ⅳ. Moreover, it can effectively keep the shunt patency and reduce portal vein pressure, thereby reducing the incidence of upper gastrointestinal bleeding and improving the degree of ascites. TIPS combined with ¹²⁵Ⅰ seed strand implantation may be used as a standard treatment modality for patients requiring TIPS therapy combined with tumor thrombus type Ⅲ/Ⅳ.

Long non-coding RNA plasmacytoma variant translocation 1 and growth arrest specific 5 regulate each other in osteoarthritis to regulate the apoptosis of chondrocytes

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and growth arrest specific 5 (GAS5) have opposite functions in the apoptosis of chondrocytes, which are involved in the pathogenesis of osteoarthritis (OA). The opposite roles of PVT1 and GAS5 in OA may indicate the existence of crosstalk between them in OA. This study aimed to explore the possible interaction between PVT1 and GAS5 in OA. Accumulation of PVT1 and GAS5 in OA and control synovial fluid samples was measured by RT-qPCR. The interaction between PVT1 and GAS5 in chondrocytes was explored by overexpression experiments. Dual-luciferase reporter assay was performed to analyze the binding of PVT1 and GAS5 to each other’s promoter regions. Regulatory roles of PVT1 and GAS5 in the apoptosis of chondrocytes were studied with cell apoptosis assay. PVT1 was upregulated in OA, and GAS5 was downregulated in OA. An inverse correlation between PVT1 and GAS5 was observed across OA samples. Under lipopolysaccharides (LPS) treatment, PVT1 was upregulated and GAS5 was downregulated. Interestingly, PVT1 and GAS5 overexpression downregulated each other in chondrocytes. Cell apoptosis analysis showed that PVT1 overexpression promoted cell apoptosis, while GAS5 overexpression suppressed cell apoptosis induced by LPS. Co-transfection of PVT1 and GAS5 failed to significantly affect cell apoptosis. PVT1 and GAS5 directly bound to each other’s promoter regions. Our study characterized the interaction between PVT1 and GAS5 in OA. Their interaction regulated the apoptosis of chondrocytes, which play a critical role in OA. PVT1 and GAS5 may form a negative feedback loop in OA.

MicroRNA-455-3p regulates proliferation and osteoclast differentiation of RAW264.7 cells by targeting PTEN

Background

Macrophages are one of the important cells in immune system. In this article, we aim to explore the regulatory role of miR-455-3p on proliferation and osteoblast differentiation of RAW264.7 cells.

Methods

Expression levels of genes and proteins in cells were tested via qRT-PCR and western blot. The targeted correlation between miR-455-3p and PTEN was identified by luciferase analysis. MTT assay and flow cytometry were applied to detect the proliferation and apoptosis of cells. Osteoclastogenesis was completed by stimulating RAW 264.7 cells with RANKL. Tartrate-resistant acid phosphatase (TRAP) activity in different groups of cells were assessed.

Results

Firstly, we determined that up-regulation of miR-455-3p promoted the proliferation and inhibited apoptosis of RAW 264.7 cells. MiR-455-3p deficiency played opposite effect in RAW 264.7 cells. Additionally, osteoclastogenesis-related factors (TRAP, CTSK and NFATc1) expression levels were remarkably up-regulated in miR-455-3p-mimic group of RAW264.7 cells treated with RANKL, but decreased in inhibitor group. Luciferase assay proved that miR-455-3p targeted PTEN. We took a further step and found overexpression of PTEN significantly inhibited the increased proliferation and osteoblast differentiation of RAW264.7 cells induced by miR-455-3p.

Conclusions

Our findings supported basic to explore the molecular mechanism of proliferation and osteoblast differentiation of RAW264.7 cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05266-0.

Single-cell rna seq analysis identifies the biomarkers and differentiation of chondrocyte in human osteoarthritis

BACKGROUND

Single-cell RNA sequencing (scRNA-seq) was recently adopted for exploring molecular programmes and lineage progression patterns of pathogenesis of important diseases. In this study, scRNA-seq was used to identify potential markers for chondrocytes in osteoarthritis (OA) and to explore the function of different types of chondrocytes in OA.

METHODS

Here we aimed to identify the biomarkers and differentiation of chondrocyte by Single-cell RNA seq analysis. GeneOntology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to identify the function of candidate marker genes in chondrocytes. Protein-protein interaction (PPI) network was constructed to find the hub genes in 3 types of chondrocyte respectively. We also used qRT-PCR to detect the expression level of the candidate marker genes in different types of chondrocyte.

RESULTS

In this study, we characterized the single-cell expression profiling of 480 chondrocyte samples and found hypertrophic chondrocyte (HTC), homeostatic chondrocyte (HomC) and fibrocartilage chondrocyte (FC) respectively. The results of GO and KEGG analysis showed the candidate marker genes made specific function in these chondrocytes to regulate the development of OAs respectively. We further revealed the differential expression of top 10 marker genes in 3 types of chondrocyte. The marker genes of HTC and FC were mainly expressed in their cell subset respectively. The marker genes of HomC did not have obviously differential expression among different types of chondrocyte. Last, we predicted the key genes in each cell subset. CD44, JUN and FN1 were predicted tightly related to the proliferation and differentiation of chondrocytes in OAs and could be regarded as biomarkers to estimate the development of OA.

CONCLUSION

Our results provide new insights into exploring the roles of different types of chondrocyte in OA. The biomarkers of chondrocyte were also valuable for estimating OA progression.

Do we need to suture the pronator quadratus muscle when we do open reduction and internal fixation for fracture of the distal radius

BACKGROUND

Open reduction and internal fixation is often used for the treatment of distal radius fracture. Opening the pronator quadratus muscle during the process of open reduction and internal fixation is necessary to achieve sufficient exposure. Therefore, knowledge on how to suture the pronator quadratus muscle will be of essence.

AIM

The aim of the present study was to determine if suturing the pronator quadratus during the treatment of the distal radius fracture can enhance limb function .

METHODS

A total of 126 patients were enrolled for the study. The patients underwent open reduction and internal fixation. During the procedure, the pronator quadratus was cut open to allow insertion of the plate. The pronator quadratus muscles of the patients were stitched together before the surgery was completed. After the fracture healed, the patients underwent surgery to remove the internal fixations. Patients received wrist function scores prior to removal of the internal fixations. Healing of the pronator quadratus was during surgery. Patients were grouped according to the healing of the pronator quadratus. Functional scores between the two groups were compared.

RESULTS

Muscle healing was observed in 23 patients during surgery. However, the PQ muscles of these patients were remarkably atrophic, with scar hyperplasia and fibrosis. The muscle fibers were loose, thin, and had decreased in number. The remaining muscle fibers presented different degrees of adhesion with radial carpal flexor muscles, steel plates and interosseous membrane. A total of 23 patients were included in group A and 103 patients in group B based on the intraoperative condition. No statistically significant differences was observed in age and type of fracture between group A and group B. In addition, no statistically significant differences was observed in the isokinetic forearm pronation strength and clinical outcomes including grip strength, wrist ROM, and PRWE scores between the two groups.

CONCLUSION

This study demonstrates that healing of the PQ muscle does not affect the outcomes of volar plating for distal radius fractures with reference to the isokinetic forearm rotation strength, grip strength, wrist ROM, and PRWE scores. The results of this study support our current practice of PQ muscle incision.

[Effectiveness analysis of modified tarsal sinus approach for Sanders - type calcaneal fractures]

Objective

To investigate the short-term effectiveness of modified tarsal sinus approach and traditional tarsal sinus approach in the treatment of Sanders Ⅱ-Ⅲ type calcaneal fractures.

Methods

Between January 2015 and August 2017, 53 patients with Sanders Ⅱ-Ⅲ type calcaneal fractures were selected and divided into observation group (21 cases, using modified tarsal sinus approach for fracture reduction after exposure of the subtalar joint below the long and short fibular tendon) and control group (32 cases, using traditional tarsal sinus approach) by random number method. There was no significant difference between the two groups in terms of gender, age, side, cause of injury, fracture type, injury to operation time, and preoperative Böhler angle, Gissane angle, visual analogue scale (VAS) core ( P>0.05), which were comparable. The operation time, postoperative drainage volume, postoperative Böhler angle, Gissane angle, and postoperative angle improvement values of the two groups were recorded and compared. VAS score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and short-form 36 health survey scale (SF-36) score were used to evaluate the effectiveness.

Results

All the 53 patients successfully completed the operation without serious complications such as vascular and nerve injury and perioperative death. There was no significant difference in operation time and postoperative drainage volume between the two groups ( P>0.05). Patients in both groups were followed up 12-36 months (mean, 17 months). No infection, fracture displacement, failure of internal fixation, and malunion of fracture occurred after operation. None of the patients underwent secondary joint fusion. There was no significant difference in fracture healing time between the two groups ( t=0.30, P=0.77). The postoperative Böhler angle and Gissane angle at 2 days in the two groups were significantly improved when compared with those before operation ( P<0.05); however, there was no significant difference in Böhler angle, Gissane angle, and improvement value between the observation group and the control group at 2 days after operation ( P>0.05). VAS scores at 24 hours and 1 year after operation were significantly improved when compared with that before operation in both groups ( P<0.05). There was no significant difference in VAS scores between the two groups at 24 hours and 1 year after operation ( P>0.05). There was no significant difference in AOFAS scores between the two groups at 1 year after operation ( t=1.46, P=0.15). However, the SF-36 scale score at 1 year after operation was significantly higher than that of the control group ( t=2.08, P=0.04). At last follow-up, 2 patients in the observation group and 8 patients in the control group presented subtalar joint stiffness or pain, and there was no significant difference in the incidence between the two groups ( χ ²=1.98, P=0.16).

Conclusion

The modified tarsal sinus approach for the treatment of Sanders Ⅱ-Ⅲ type calcaneal fractures has the advantages of minimal invasion, clear reduction under direct vision, reliable reduction and fixation, and low incision complications.

[The effect of semimature dendritic cell and the levels of Treg on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cell]

Objective: To investigate the inducing effect and mechanism of semimature dendritic cell (smDCs) on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cells (ESCs), and to study the connections between smDCs and regulatory dendritic cells (regDCs). Methods: ESCs of 129 mouse labelled green fluorescent protein (GFP) were induced to hepatocytes by using previous methods. Meanwhile, bone marrow mononuclear cells of 129 mouse were induced to smDCs and regDCs. Moreover, the hepatocytes differentiated from 129 mouse ESCs were transplanted into liver of BALB/c mouse 3 days after infusing smDCs and regDCs suspension of 129 mouse into BALB/c mouse by tail vein respectively. After that, the growth status and survival time of transplanted cells in the recipient and infiltration of lymphocytes in transplant sites were observed. Furthermore, Foxp3 expression of peripheral blood CD4+ T cells was also tested. Results: In the control group, the transplanted cells in liver of BALB/c mouse survived only about 1 week. In contrast, the transplanted cells of smDC groups and regDCs groups survived about 4 weeks and the transplant sites of smDC groups also had less CD3(+) T cells. The morphology of smDCs were similar with regDCs. The expression of MHC-Ⅱ, CD40, CD80 and CD86 on smDCs and regDCs were moderate. Moreover, the Foxp3 expression of peripheral blood CD4+ T cells in smDC groups was higher than that in the control groups, from 1.11% up to 5.38%. The Foxp3 expression in regDC groups rose to 3.87%. Conclusion: The smDCs could induce transplantation tolerance of hepatocytes differentiated from 129 mouse ESCs in the recipient. The mechanism was associated with high level of Foxp3(+) Tregs, which could be increased by means of smDCs appropriate expression of MHC-Ⅱ, CD40, CD80 and CD86. The smDCs and regDCs were the same type of tolerance dendritic cells.

Characterization and transplantation of enteric neural crest cells from human induced pluripotent stem cells

The enteric nervous system (ENS) is recognized as a second brain because of its complexity and its largely autonomic control of bowel function. Recent progress in studying the interactions between the ENS and the central nervous system (CNS) has implicated alterations of the gut/brain axis as a possible mechanism in the pathophysiology of autism spectrum disorders (ASDs), Parkinson's disease (PD) and other human CNS disorders, whereas the underlying mechanisms are largely unknown because of the lack of good model systems. Human induced pluripotent stem cells (hiPSCs) have the ability to proliferate indefinitely and differentiate into cells of all three germ layers, thus making iPSCs an ideal source of cells for disease modelling and cell therapy. Here, hiPSCs were induced to differentiate into neural crest stem cells (NCSCs) efficiently. When co-cultured with smooth muscle layers of ganglionic gut tissue, the NCSCs differentiated into different subtypes of mature enteric-like neurons expressing nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP), choline acetyltransferase (ChAT) or calretinin with typical electrophysiological characteristics of functional neurons. Furthermore, when they were transplanted into aneural or aganglionic chick, mouse or human gut tissues in ovo, in vitro or in vivo, hiPSC-derived NCSCs showed extensive migration and neural differentiation capacity, generating neurons and glial cells that expressed phenotypic markers characteristic of the enteric nervous system. Our results indicate that enteric NCSCs derived from hiPSCs supply a powerful tool for studying the pathogenesis of gastrointestinal disorders and brain/gut dysfunction and represent a potentially ideal cell source for enteric neural transplantation treatments.

T1R1/T1R3 Taste Receptor Suppresses Granulocyte-Mediated Neuroinflammation after Spinal Cord Injury

As an active and predominant blood leukocyte population, granulocytes infiltrate into injured spinal cord and produce pro-inflammatory mediators to aggravate neuroinflammation. In the current study, we identify the role of the T1R1/T1R3 receptor in granulocyte-mediated neuroinflammation in a rat spinal cord injury (SCI) model. We found that T1R1 and T1R3 were substantially expressed in both circulating and infiltrating granulocytes. In vitro stimulation of T1R1/T1R3 receptor with L-serine notably reduced production of reactive oxygen species (ROS) and several pro-inflammatory cytokines. To evaluate the role of T1R1/T1R3 receptor in vivo, gurmarin, a selective T1R3 inhibitor, was injected into rats before and after SCI. Gurmarin administration significantly upregulated expression of interleukin (IL)-1β, IL-6, myeloperoxidase, and matrix metallopeptidase 9, as well as production of ROS in infiltrating granulocytes. Signal pathway analysis revealed that gurmarin promoted nuclear factor (NF)-κβ signaling in infiltrating granulocytes. Consistently, cell apoptosis and inflammatory mediator levels at the injury sites were increased by gurmarin, together with higher T lymphocyte recruitment. Our research indicates that the T1R1/T1R3 receptor is an anti-inflammatory receptor for infiltrating granulocytes after SCI. Simulation of T1R1/T1R3 receptor might be a prospective, or at least a supplemental, therapeutic approach to controlling neuroinflammation to promote functional recovery.

Heme oxygenase-1 protects spinal cord neurons from hydrogen peroxide-induced apoptosis via suppression of Cdc42/MLK3/MKK7/JNK3 signaling

The mechanisms by which oxidative stress induces spinal cord neuron death has not been completely understood. Investigation on the molecular signal pathways involved in oxidative stress-mediated neuronal death is important for development of new therapeutics for oxidative stress-associated spinal cord disorders. In current study we examined the role of heme oxygenase-1 (HO-1) in the modulation of MLK3/MKK7/JNK3 signaling, which is a pro-apoptotic pathway, after treating primary spinal cord neurons with H2O2. We found that MLK3/MKK7/JNK3 signaling was substantially activated by H2O2 in a time-dependent manner, demonstrated by increase of activating phosphorylation of MLK3, MKK7 and JNK3. H2O2 also induced expression of HO-1. Transduction of neurons with HO-1-expressing adeno-associated virus before H2O2 treatment introduced expression of exogenous HO-1 in neurons. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7 and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased H2O2-induced neuronal apoptosis and necrosis. Furthermore, we found that exogenous HO-1 inhibited expression of Cdc42, which is crucial for MLK3 activation. In addition, HO-1-induced down-regulation of MLK3/MKK7/JNK3 signaling might be related to up-regulation of microRNA-137 (mir-137). A mir-137 inhibitor alleviated the inhibitory effect of HO-1 on JNK3 activation. This inhibitor also increased neuronal death even when exogenous HO-1 was expressed. Therefore, our study suggests a novel mechanism by which HO-1 exerted its neuroprotective efficacy on oxidative stress.

Heme Oxygenase-1 Inhibits Neuronal Apoptosis in Spinal Cord Injury through Down-Regulation of Cdc42-MLK3-MKK7-JNK3 Axis

The mechanism by which spinal cord injury (SCI) induces neuronal death has not been thoroughly understood. Investigation on the molecular signal pathways involved in SCI-mediated neuronal apoptosis is important for development of new therapeutics for SCI. In the current study, we explore the role of heme oxygenase-1 (HO-1) in the modulation of mixed lineage kinase 3/mitogen-activated protein kinase kinase/cJUN N-terminal kinase 3 (MLK3/MKK7/JNK3) signaling, which is a pro-apoptotic pathway, after SCI. We found that MLK3/MKK7/JNK3 signaling was activated by SCI in a time-dependent manner, demonstrated by increase in activating phosphorylation of MLK3, MKK7, and JNK3. SCI also induced HO-1 expression. Administration of HO-1-expressing adeno-associated virus before SCI introduced expression of exogenous HO-1 in injured spinal cords. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7, and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased SCI-induced neuronal apoptosis and improved neurological score. Further, we found that exogenous HO-1 inhibited expression of cell division cycle 42 (Cdc42), which is crucial for MLK3 activation. In vitro experiments indicated that Cdc42 was essential for neuronal apoptosis, while transduction of neurons with HO-1-expressing adeno-associated virus significantly reduced neuronal apoptosis to enhance neuronal survival. Therefore, our study disclosed a novel mechanism by which HO-1 exerted its neuroprotective efficacy. Our discovery might be valuable for developing a new therapeutic approach for SCI.

Soluble analog of ApoER2 targeting beta2-glycoprotein I in immune complexes counteracts hypertension in lupus-prone mice with spontaneous antiphospholipid syndrome

Essentials (NZWxBXSB)F1 male mice develop antibodies beta2-glycoprotein I (β2GPI) and hypertension. A1-A1 is a soluble analogue of ApoE receptor 2 with a high affinity for β2GPI/antibody complexes. A1-A1 improved blood pressure and arterial elastance in (NZWxBXSB)F1 male mice. A1-A1 had no adverse effects on the hemodynamics of healthy mice.

SUMMARY

Background Antiphospholipid syndrome (APS) is diagnosed based on the presence of antiphospholipid antibodies and clinical thrombosis or fetal loss during pregnancy. Lupus-prone (NZWxBXSB)F1 male mice are the mouse model of spontaneous APS. They develop anti-β2GPI antibodies, microinfarcts and hypertension. ApoER2 is a receptor that contributes to anti-β2GPI-dependent thrombosis in APS by down-regulating endothelial nitric oxide synthase activation. Objectives A1-A1 is a small protein constructed from two identical ligand-binding modules from ApoER2, containing the binding site for β2GPI. We studied how treatment with A1-A1 affects the development of hypertension in (NZWxBXSB)F1 male mice. Methods We treated (NZWxBXSB)F1 male mice with A1-A1 for up to 4 weeks and examined changes in hemodynamics by left ventricular pressure-volume loop measurements. Results We observed improvements in blood pressure in the A1-A1 treated mice. A1-A1 prevented the deterioration of arterial elastance by decreasing systemic resistance and improving vessel compliance. We did not detect any adverse effects of the treatment in either male mice or in apparently healthy female (NZWxBXSB)F1 mice. Conclusions We demonstrated that A1-A1, which is a soluble analog of ApoER2 that binds pathological β2GPI/anti-β2GPI complexes, has a positive impact on hemodynamics in lupus-prone mice with spontaneous anti-β2GPI antibodies and hypertension.

Nestin regulates proliferation and invasion of gastrointestinal stromal tumor cells by altering mitochondrial dynamics

Nestin is widely expressed in numerous tumors and has become a diagnostic and prognostic indicator. However, the exact mechanism by which nestin contributes to tumor malignancy remains poorly understood. Here, we found marked upregulation of nestin expression in highly proliferative and invasive gastrointestinal stromal tumor (GIST) specimens. Nestin knockdown in GIST cells reduced the proliferative and invasive activity owing to a decrease of mitochondrial intracellular reactive oxygen species (ROS) generation. Furthermore, nestin was co-localized with mitochondria, and knockdown of nestin increased mitochondrial elongation and influenced the mitochondrial function, including oxygen consumption rates, ATP generation and mitochondrial membrane potential and so on. In exploring the underlying mechanism, we demonstrated nestin knockdown inhibited the mitochondrial recruitment of Dynamin-related protein1 and induced the change of mitochondrial dynamics. Thus, nestin may have an important role in GIST malignancy by regulating mitochondrial dynamics and altering intracellular ROS levels. The findings provide new clues to reveal mechanisms by which nestin mediates the proliferation and invasion of GISTs.

Acetazolamide efficacy in hypokalemic periodic paralysis and the predictive role of genotype

OBJECTIVES

Acetazolamide has been the most commonly used treatment for hypokalemic periodic paralysis since 1968. However, its mechanism of efficacy is not fully understood, and it is not known whether therapy response relates to genotype. We undertook a clinical and genetic study to evaluate the response rate of patients treated with acetazolamide and to investigate possible correlations between response and genotype.

METHODS

We identified a total of 74 genotyped patients for this study. These included patients who were referred over a 15-year period to the only U.K. referral center or to a Chinese center and who underwent extensive clinical evaluation. For all genotyped patients, the response to acetazolamide therapy in terms of attack frequency and severity was documented. Direct DNA sequencing of CACNA1S and SCN4A was performed.

RESULTS

Only 46% of the total patient cohort (34 of 74) reported benefit from acetazolamide. There was a greater chance of benefit in patients with mutations in CACNA1S (31 responded of 55 total) than in those with mutations in SCN4A (3 responded of 19 total). Patients with mutations that resulted in amino acids being substituted by glycine in either gene were the least likely to report benefit.

CONCLUSIONS

This retrospective study indicates that only approximately 50% of genotyped patients with hypokalemic periodic paralysis respond to acetazolamide. We found evidence supporting a relationship between genotype and treatment response. Prospective randomized controlled trials are required to further evaluate this relationship. Development of alternative therapies is required.

Effects of electro-acupuncture on the expression of c-jun and c-fos in spared dorsal root ganglion and associated spinal laminae following removal of adjacent dorsal root ganglia in cats

This study evaluated the plastic changes of c-jun and c-fos in the right sixth lumbar dorsal root ganglion (L6 DRG), Rexed's lamina II in representative spinal segments L3, L5, and L6 and in the nucleus dorsalis (ND) at L3 segments after electro-acupuncture (EA) in cats subjected to removal of L1-L5 and L7-S2 DRG. Following dorsal root ganglionectomy, there was a significant increase in the density of c-jun immunoreactivity in the neurons and glia in spinal lamina II and in the ND; there was also marked elevation in the expression of c-fos in ND. In both cases there was no change in the c-jun and c-fos immunoreactivity in the DRG. After EA in the operated animals, there was an up-regulation in the expression of c-jun in the L6 DRG and the associated spinal lamina II; however, increased c-fos expression was detected only in the L6 DRG. Western blot and RT-PCR were also performed to quantitatively explore the mRNA and protein expression changes in the spinal dorsal horn and associated DRG. Following partial deafferentation, there was a significant increase in the protein level of both c-jun and c-fos in the dorsal horn, while, in both cases there was no change in c-jun and c-fos protein and mRNA in the DRG. After EA in the operated animals, both c-jun protein and its mRNA in the L6 DRG as well as the associated dorsal horn of L6 spinal segment were upregulated, but increased c-fos protein and its mRNA was observed only in the L6 DRG. These findings suggested that c-jun and c-fos might be related to the acupuncture promoted spinal cord plasticity as reported previously.

Single point mutations affect fatty acid block of human myocardial sodium channel alpha subunit Na+ channels

Suppression of cardiac voltage-gated Na(+) currents is probably one of the important factors for the cardioprotective effects of the n-3 polyunsaturated fatty acids (PUFAs) against lethal arrhythmias. The alpha subunit of the human cardiac Na(+) channel (hH1(alpha)) and its mutants were expressed in human embryonic kidney (HEK293t) cells. The effects of single amino acid point mutations on fatty acid-induced inhibition of the hH1(alpha) Na(+) current (I(Na)) were assessed. Eicosapentaenoic acid (EPA, C20:5n-3) significantly reduced I(Na) in HEK293t cells expressing the wild type, Y1767K, and F1760K of hH1(alpha) Na(+) channels. The inhibition was voltage and concentration-dependent with a significant hyperpolarizing shift of the steady state of I(Na). In contrast, the mutant N406K was significantly less sensitive to the inhibitory effect of EPA. The values of the shift at 1, 5, and 10 microM EPA were significantly smaller for N406K than for the wild type. Coexpression of the beta(1) subunit and N406K further decreased the inhibitory effects of EPA on I(Na) in HEK293t cells. In addition, EPA produced a smaller hyperpolarizing shift of the V(1/2) of the steady-state inactivation in HEK293t cells coexpressing the beta(1) subunit and N406K. These results demonstrate that substitution of asparagine with lysine at the site of 406 in the domain-1-segment-6 region (D1-S6) significantly decreased the inhibitory effect of PUFAs on I(Na), and coexpression with beta(1) decreased this effect even more. Therefore, asparagine at the 406 site in hH1(alpha) may be important for the inhibition by the PUFAs of cardiac voltage-gated Na(+) currents, which play a significant role in the antiarrhythmic actions of PUFAs.

Point mutations in alpha-subunit of human cardiac Na+ channels alter Na+ current kinetics

Dietary polyunsaturated fatty acids (PUFAs) prevent ischemia-induced fatal cardiac arrhythmias in animals and probably in humans. This action results from inhibition of ion currents for Na+, Ca2+, and possibly other ions. To extend understanding of this protection we are seeking a possible binding site for the PUFAs on the alpha-subunit of the human cardiac Na+ channel, hH1alpha, transiently expressed in HEK293t cells. Three mutated single amino acid substitutions with lysine were made in the alpha-subunit at Domain 4-Segment 6 (D4-S6) for F1760, Y1767 and at D1-S6 for N406. These are in the putative sites of binding of local anesthetics and batrachotoxin, respectively. The mutants F1760K, Y1767K, and N406K, separately and to different extents, affected the current density, the steady-state inactivation potential, accelerated inactivation, delayed recovery from inactivation, and affected voltage-dependent block, but did not affect activation of the hH1alpha. It is essential to learn that single point mutations in D1-S6 and D4-S6 alone significantly modify the kinetics of human cardiac hH1alpha Na+ currents. The effects of PUFAs on these mutant channels will be the subject of subsequent reports.

[Optimization of technical parameters for processing radix Aconiti coreani]

Based on the determination of guanfu A, hypaconitine, and total alkaloids, along with the experiment of acute toxicity of sliced Radix Aconiti Coreani and in compliance with the quality standard stipulated in pharmacopeia-surface features cross section colour and odor of sliced Radix Aconiti Co-reani the technology of processing Radix Aconiti Coreani has been optimized to be steaming the drug for four hours.

Regulation of AP-1 expression and activity in antigen-stimulated mast cells: the role played by protein kinase C and the possible involvement of Fos interacting protein

We have recently observed that protein kinase C (PKC) was involved in the regulation of the accumulation of mRNAs of the AP-1 components in cultured Abelson-transformed murine fetal-liver-derived mast cells stimulated by exocytotic stimuli. Here we analyzed the probable regulatory effect of PKC on the synthesis and DNA-binding activity of AP-1 complexes in immunologic stimulated mast cells. In this study we used the interleukin-3--dependent murine fetal-liver--derived mast cells that were not transformed by the Abelson oncogene. Study of PKC-depleted cells showed PKC dependency of c-fos mRNA accumulation and protein expression in IgE-Ag stimulated cells. In contrast, the c-jun mRNA accumulation was unaffected by PKC depletion, whereas its protein expression was dependent on this enzymatic activity. This suggests the involvement of PKC in the regulation of translation of c-Jun, a level of c-Jun regulation that was not previously described. The amount of AP-1 DNA-bound complex was also lowered in PKC-depleted cells. Therefore, PKC plays an important regulatory role in different stages of the signal transduction pathway because of IgE-Ag stimulation. Surprisingly, we have observed that although the amount of total synthesized c-Fos began to increase 15 minutes after immunologic stimulation, the amount of c-Fos associated with Juns did not increase, even after 45 minutes. This association was not affected by PKC. Using a Fos-interacting protein (FIP)-cDNA probe, an expression of 2.9 kb mRNA was detected in these cells. Furthermore, immunologic stimulation caused an increase in the amount of a Fos-containing protein complex that bound to an FIP-binding DNA oligonucleotide. Therefore, we propose that this protein complex that contains most of the immunologically induced c-Fos has an important role in IgE-Ag-stimulated signal transduction.