Currently, as the key raw material of artificial biological heart valve, bovine pericardium is mainly depend on import and has become a “bottleneck” challenge, greatly limiting the development of domestic biological heart valve. Therefore, the localization of bovine pericardium is extremely urgent. In this study, the pericardium of Sichuan yak was compared with that of Australian cattle in terms of fundamental properties and anti-calcification performance. The results demonstrated that the appearance and thickness of yak pericardium were more advantageous than the Australian one. Sichuan yak pericardium and Australian cattle pericardium had comparable performance in shrinkage temperature, mechanical test and anti-calcification test. This study preliminarily verifies the feasibility of substitution of Australian cattle pericardium by Sichuan yak pericardium and promotes the progression of bovine pericardium localization with data support.
Sclerostin, as a bone-derived secreted glycoprotein, is a suppressor of Wnt signaling pathway. Recently, adverse cardiovascular events in the treatment of osteoporosis with sclerostin inhibitors have raised concerns about the association of sclerostin with atherosclerotic heart disease. Whether the role of sclerostin in atherosclerotic heart disease is harmful or beneficial is not clear. This article reviews the progress of the mechanisms of sclerostin in vascular calcification and atherosclerotic heart disease, focusing on the relationship between sclerostin and vascular calcification, the impact of its concentration changes on atherosclerotic heart disease, and the effect of sclerostin inhibitor on cardiovascular events.
Calcific aortic valve disease has been the most common heart valve disorder in western world, accompanying with the increase of morbidity in our country year by year. Several molecules and mechanisms are involved in the progression of aortic valve calcification, which intensify the complexity of this pathological process. It is known that inflammation, a key factor in many diseases, has its own role in the development of aortic valve calcification. It has been demonstrated that inflammation, one of the most important participants in this disorder, which may accelerate the local lesions in aortic valve via promoting the expression of osteogenic differentiation of associated factors or decreasing the level of protective molecules. Dyslipidemia is a traditional risk factor of cardiovascular events. However, it may induce or enhance the inflammatory response whereby facilitates the calcific lesions in aortic valve. Recently, several researches have illustrated that non-coding RNAs, a stimulative factor in the progression of malignant tumor, might play a role in the development of aortic valve calcification. MiRNA and lncRNA, the non-coding RNAs which regulate the expression of genes involved in inflammatory and osteogenic differentiation, are undeniable regulators of aortic valve calcification.
ObjectiveTo analyze the expression profile changes of osteogenic-related genes during spontaneous calcification of rat bone marrow mesenchymal stem cells (BMSCs). MethodsBMSCs were isolated from 3-day-old healthy Sprague Dawley rats;cells at the 4th generation were used to establish the spontaneous calcification model in vitro. Spontaneous calcification process was recorded by inverted phase contrast microscope observation and alizarin red staining after 7 and 14 days of culture. For gene microarray analysis, cell samples were collected at 0, 7, and 14 days after culture; the differentially expressed genes were analyzed by bioinformatics methods and validated by real-time quantitative PCR (RT-qPCR) assay. ResultsRat BMSCs calcified spontaneously in vitro. When cultured for 7 days, the cells began to aggregate and were weakly positive for alizarin red staining. After 14 days of culture, obvious cellular aggregation and typical mineralized nodules were observed, the mineralized nodules were brightly positive for alizarin red staining. A total of 576 gene probe-sets expressed differentially during spontaneous calcification, corresponding 378 rat genes. Among them, 359 gene probe-sets expressed differentially between at 0 and 7 days, while only 13 gene probe-sets expressed differentially between at 7 and 14 days. The 378 differentially expressed genes were divided into 6 modes according to their expression profiles. Moreover, according to their biological functions, differentially expressed genes related to bone cell biology could be classified into 7 major groups:angiogenesis, apoptosis, bone-related genes, cell cycle, development, cell communication, and signal pathways related to osteogenic differentiation. In cell cycle group, 12 down-regulated genes were linked with each other functionally. Matrix metalloproteinase 13 (Mmp13), secreted phosphoprotein 1 (Spp1), Cxcl12, Mmp2, Mmp3, Apoe, and Itga7 had more functional connections with other genes. The results of genes Spp1, Mgp, Mmp13, Wnt inhibitory factor 1, Cxcl12, and cyclin A2 by RT-qPCR were consistent with that of gene microarray. ConclusionThe first 7 days after rat BMSCs were seeded are a key phase determining the fate of spontaneous calcification. Multiple genes related with cell communication, bone-related genes, cell cycle, transforming growth factor-β signaling pathway, mitogen-activated protein kinase signaling pathway, and Wnt signaling pathway are involved during spontaneous calcification.
Abstract: Objective To evaluate a new type of treatment that reduces calcification of glutaraldehydetreated bovine jugular venous conduit (BJVC). Methods Fresh bovine jugular veins were treated with glutaraldehyde, followed by Triton X-100 and epoxy chloropropane (EC+Tr group). We compared the group’s appearance, histology, shrinkage temperature, tensile strength, and elongation at break with those of a fresh group, and with a group treated with glutaraldehyde only (GA group). We then implanted the EC+Tr and GA group BJVCs subcutaneously into the backs of SD rats and left them for eight weeks (n=8). The morphologic properties and inflammatory response of the test specimens were evaluated by HE staining. The tissue calcium content was determined by atomic absorption spectrophotometer. Results The shrinkage temperature, tensile strength, and elongation at break of the EC+Tr group were significantly higher than those of the fresh group (86.15±0.92 ℃ vs. 69.94±0.92 ℃,t=35.239, P=0.000; 5.31±0.14 mPa vs.3.15±0.95 mPa,t=6.362, P=0.000; 265.11%±27.80% vs. 16521%±25.06%,t=7.550, P=0.000) and of the GA group (86.15±0.92 ℃ vs. 82.73±1.28 ℃, t=6.137, P=0.000; 5.31±0.14 mPa vs. 4.52±0.56 mPa,t=3.871, P=0.002; 265.11%±27.80% vs.237.85%±17.41%,t=2.351,P=0.034). The tissue structure of the subcutaneously implanted EC+Tr veins remained intact;degradation was slight and they contained few inflammatory cells. The calcium content of the EC+Tr group was lower than that of the GA group (51.22±2.69 μg/mg vs. 73.24±3.82 μg/mg, t=11.545，P=0.000). Conclusion Treatment with Triton X-100 and epoxy chloropropane modification with glutaraldehydetreated bovine jugular venous conduit was an effective way to prepare BJVC that avoided calcification.
In order to overcome the shortcomings of high false positive rate and poor generalization in the detection of microcalcification clusters regions, this paper proposes a method combining discriminative deep belief networks (DDBNs) to automatically and quickly locate the regions of microcalcification clusters in mammograms. Firstly, the breast region was extracted and enhanced, and the enhanced breast region was segmented to overlapped sub-blocks. Then the sub-block was subjected to wavelet filtering. After that, DDBNs model for breast sub-block feature extraction and classification was constructed, and the pre-trained DDBNs was converted to deep neural networks (DNN) using a softmax classifier, and the network is fine-tuned by back propagation. Finally, the undetected mammogram was inputted to complete the location of suspicious lesions. By experimentally verifying 105 mammograms with microcalcifications from the Digital Database for Screening Mammography (DDSM), the method obtained a true positive rate of 99.45% and a false positive rate of 1.89%, and it only took about 16 s to detect a 2 888 × 4 680 image. The experimental results showed that the algorithm of this paper effectively reduced the false positive rate while ensuring a high positive rate. The detection of calcification clusters was highly consistent with expert marks, which provides a new research idea for the automatic detection of microcalcification clusters area in mammograms.
Soft tissue opacities are often found by chance during radiographic examinations, especially in panoramic radiography. Because of the diversity of locations and causes, it is easily overlooked by dentists and even radiologists. Even if abnormal calcification is detected, it is difficult to identify its category and clinical relevance. For some soft tissue opacities associated with high-risk diseases, misdiagnosis is likely to delay treatment. Through reviewing the literature and screening the panoramic images from the disease database of West China Hospital of Stomatology, Sichuan University, this review summarizes and classifies the soft tissue opacities appearing in panoramic images, and discusses the clinical correlation to provide the reference for diagnosis, treatment, and prevention of related diseases.
Vascular calcification is an active, adjustable and complex biological process. It is an independent hazard factor for cardiovascular events and there is a lack of effective treatment. As a newly discovered regulated cell death, ferroptosis is closely related to iron metabolism, lipid metabolism, glutathione metabolism and so on. In recent years, studies have shown that ferroptosis may be implicated in the occurrence and progression of vascular calcification. Based on the introduction of ferroptosis, this review will discuss the close relationship between ferroptosis and vascular calcification from intimal calcification, medial calcification and heart valve calcification, in order to provide new ideas for the prevention and treatment of vascular calcification.
Ultrasound is the best way to diagnose thyroid nodules. To discriminate benign and malignant nodules, calcification is an important characteristic. However, calcification in ultrasonic images cannot be extracted accurately because of capsule wall and other internal tissue. In this paper, deep learning was first proposed to extract calcification, and two improved methods were proposed on the basis of Alexnet convolutional neural network. First, adding the corresponding anti-pooling (unpooling) and deconvolution layers (deconv2D) made the network to be trained for the required features and finally extract the calcification feature. Second, modifying the number of convolution templates and full connection layer nodes made feature extraction more refined. The final network was the combination of two improved methods above. To verify the method presented in this article, we got 8 416 images with calcification, and 10 844 without calcification. The result showed that the accuracy of the calcification extraction was 86% by using the improved Alexnet convolutional neural network. Compared with traditional methods, it has been improved greatly, which provides effective means for the identification of benign and malignant thyroid nodules.
ObjectiveTo estimate the prognosis of duodenum-preserving resection of pancreatic head (DPRPH) in the treatment of space occupying with extensive calcification of pancreatic head, and to summarize the key points of surgery.MethodsThe clinical data of a middle-aged woman with rare space occupying with extensive calcification of pancreatic head who underwent surgery in Department of Pancreatic Surgery of West China Hospital in May. 2016 was collected and analyzed.ResultsThe DPRPH operation was successfully completed, with the operative time was 207 min, the intraoperative blood loss was 130 mL, and the hospital stay was 12 d. Removing time of the gastric tube and off-bed activity were on the 3rd day after operation, and the volume of peritoneal drainage per day was decreasing from 30 mL to 10 mL until 7th day after operation. We made examination of serum amylase and fluid amylase for the patient every 2 days, and the examination indexes were within normal level. After removing the peritoneal drainage tube, the pain was obviously relieved on the 12th day after operation, then the patient made hospital discharge. There was no observable pancreatic fistula, duodenal fistula, biliary fistula, delay gastric emptying, peritoneal effusion, pleural effusion, abdominal infection, and abdominal bleeding, neither nor any special discomfort. During the follow-up period of 18 months, we got a good prognosis without any symptom of relapse or discomfort according to the result of CT scans and other examinations.ConclusionDPRPH can make a satisfied prognosis in the treatment of rare space occupying with extensive calcification of pancreatic head.