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find Keyword "calcification" 14 results
  • A New Type of Anticalcification Bovine Jugular Venous Conduit

    Abstract: Objective To evaluate a new type of treatment that reduces calcification of glutaraldehydetreated 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. 16521%±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 glutaraldehydetreated bovine jugular venous conduit was an effective way to prepare BJVC that avoided calcification.

    Release date:2016-08-30 05:57 Export PDF Favorites Scan
  • EXPRESSION PROFILE OF OSTEOGENIC-RELATED GENES DURING SPONTANEOUS CALCIFICATION OF RAT BONE MARROW MESENCHYMAL STEM CELLS

    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.

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  • Developmental mechanism for calcific aortic valve disease

    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.

    Release date:2018-01-31 02:46 Export PDF Favorites Scan
  • Surgical resection of space occupying with extensive calcification of pancreatic head

    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.

    Release date:2019-01-16 10:05 Export PDF Favorites Scan
  • Extraction of calcification in ultrasonic images based on convolution neural network

    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.

    Release date:2018-10-19 03:21 Export PDF Favorites Scan
  • Soft tissue calcifications and ossifications observed by means of panoramic radiography

    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.

    Release date:2019-06-25 09:50 Export PDF Favorites Scan
  • Single-center retrospective analysis of 125 donor hearts from brain death donation and to explore the use of marginal donor hearts

    ObjectiveTo analyze the assessment and maintenance of 125 donor hearts from brain death donation and explore the use of marginal donor hearts.MethodsA retrospective analysis was conducted on the evaluation, maintenance, operation and follow-up results of 125 donor hearts from April 2016 to August 2019. There were 98 males and 27 females at age of 6-50 (36.0±2.4) years.ResultsTwelve donor hearts were discarded due to unqualified evaluation after heart harvest. 113 patients of heart transplantation were performed with a double lumen venous anastomosis manner. The mean time of cold ischemia was 220.1±6.7 min. Four patients died within 30 days after operation. Postoperative right ventricular assist circulation was performed in 4 patients, intra-aortic balloon counterattack (IABP) in 12 patients and extracorporeal membrane oxygenation (ECMO) in 12 patients. Marginal donors included 15 hepatitis B antigen positive donor hearts, 2 tricuspid regurgitation, 1 mitral regurgitation, 5 coronary calcification, 4 myocardial stunning and 2 severe weight mismatch. The results of follow-up (2 years) after marginal donor heart transplantation were satisfactory.ConclusionImproving the assessment and maintenance of donor hearts can improve the utilization rate of the heart, and the marginal donor heart transplantation needs long-term follow-up.

    Release date:2019-10-12 01:36 Export PDF Favorites Scan
  • A case of perivalvular leakage and attempt of closure operation after transcatheter aortic valve replacement

    This paper reported a 75-year-old female patient. She was admitted to our hospital for “repeated chest pain, shortness of breath for more than 5 years, and syncope 3 times”. The CT scan of the patient showed severe aortic valve stenosis, bicuspid valve, and severe calcification; then she underwent transcatheter aortic valve replacement in our hospital. After the prosthesis was implanted, there was a significant paravalvular leak. Considering the triangular area formed between the calcified clumps, the valve was not fully dilated. Paravalvular leak closure was performed during the operation, attempted through the valve stent mesh to closuring. A rare incarceration of the transmitter occurred. An attempt was made to pull out the incarcerated transmitter through a pull-up technique, which resulted in the prosthesis prolapse. The patient was eventually transferred to surgery aortic valve replacement.

    Release date:2020-05-26 02:34 Export PDF Favorites Scan
  • Transcatheter aortic valve replacement for severe aortic valve stenosis via carotid approach: a case report

    This case was an elderly male patient with symptomatic aortic valve calcification and severe aortic valve stenosis. Before the operation, the heart valve team had fully evaluated the patient’s suitability for transcatheter aortic valve replacement and approach. This patient had severe stenosis and plaques in the iliac artery, femoral artery, descending aorta, so the carotid artery approach transcatheter aortic valve replacement was chosen. After the operation, the patient’s symptoms improved significantly. So far, the patient was generally in good condition, without chest tightness, shortness of breath and other symptoms in daily activities. The current clinical application of the transcarotid approach is relatively small, but it is believed that with the publication of more clinical research results, the application of the transcarotid approach in transcatheter aortic valve replacement will become more and more common.

    Release date:2020-10-26 03:00 Export PDF Favorites Scan
  • Detection of microcalcification clusters regions in mammograms combining discriminative deep belief networks

    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.

    Release date:2021-06-18 04:50 Export PDF Favorites Scan
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