ABSTRACT
At present, acellular matrix is an effective replacement material for the treatment of skin damage, but there are few systematic evaluation studies on its performance. The experimental group of this study used two decellularization methods to prepare the matrix: one was the acellular matrix which sterilized with peracetic acid first (0.2% PAA/4% ethanol solution) and then treated with hypertonic saline (group A), the other was 0.05% trypsin/EDTA decellularization after γ irradiation (group B); and the control group was soaked in PBS (Group C). Then physical properties and chemical composition of the three groups were detected. Hematoxylin eosin (HE) staining showed that the acellular effect of group B was good. The porosity of group A and B were both above 84.9%. In group A, the compressive modulus of elasticity was (9.94 ± 3.81) MPa, and the compressive modulus of elasticity was (12.59 ± 5.50) MPa in group B. There was no significant difference between group A or B and group C. The total content of collagen in acellular matrix of group A and B was significantly lower than that of group C (1. 662 ± 0.229) mg/g, but there was no significant difference in the ratio of collagen Ⅰ/Ⅲ between group B and group C. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that there was no significant difference in microstructure. Qualitative detection of fibronectin and elastin in each group was basically consistent with that in group C. Therefore, acellular matrix of group B had better performance as scaffold material. The experimental results show that the acellular matrix prepared by γ-ray sterilization and decellularization of 0.05% Trypsin enzyme/EDTA could be used for the construction of tissue-engineered skin. It could also provide reference for the preparation and mounting of heterogeneous dermal acellular matrix. It was also could be used for electrostatic spinning or three-dimensional printed tissue engineered skin scaffold which could provide physical and chemical parameters for it.
Subject(s)
Acellular Dermis , Cells, Cultured , Extracellular Matrix , Porosity , Tissue Engineering , Tissue ScaffoldsABSTRACT
Objective To establish a finite element model of cell perfusion culture, and study the effect of different perfusion speeds on the movement of suspended cells. Methods The two-dimensional (2D) model of cell and microchannels was established using COMSOL Multiphysics and meshed. Three groups were established according to the perfusion speed, namely, u0=0.196 mm/s, u1=0.117 mm/s, u2=0.04 mm/s. The fluid-structure interaction module was used for calculation. Results The flow field distribution in the microchannel was relatively uniform. During the equal period of time, the ratio of cell suspension perfusion speed was u0∶u1∶u2=5∶3∶1, and the ratio of cell displacement in the microchannel was D0∶D1∶D2=4.1∶ 2.9∶1. When the speed was proportional, the displacement of cells also roughly followed the corresponding proportional change. With the increase of perfusion speed, stress concentration in cells during movement would occur. The stress and fluid shear force (FSS) of cells during movement were within the safe value range, and cell destruction would not occur. Conclusions The suspended cells can enter into the microchannel without injury at a certain perfusion speed. Perfusion techniques can be used in cell implantation of in vitro tissue engineering products.
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Objective To analyze the diagnostic value of features of mammographic mass edge in digital three dimensional tomography, and to discuss the correlations between the mammographic mass edge features and pathological features and molecular biological indicators, in order to provide evidence for early and accurate diagnosis and treatment of breast cancer and prognosis evaluation. Methods A retrospective analysis was made in 392 cases of breast cancer confirmed by operation and pathology in the People ' s Hospital of Shanxi Province from August 2017 to June 2018. These patients were examined by digital breast tomography (DBT) and full-field digital mammography (FFDM) before operation. Postoperative specimens were stained by immunohistochemical SP method to measure the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67. The correlation between the mammographic mass edge features and pathological features and molecular biological indicators were analyzed by usingχ2 test and Fisher exact probability method. Results In 392 patients, 352 cases (89.80％) were invasive ductal carcinoma, 6 cases (1.53％) were ductal carcinoma in situ with microinvasion, 7 cases (1.79％) were invasive lobular carcinoma, 17 cases (4.34％) were papillary carcinoma, 8 cases (2.04％) were mucinous carcinoma, 1 case (0.26％) was medullary carcinoma, and 1 case (0.26％) was metaplastic carcinoma. DBT were significantly better than FFDM in the detection rate [93.6％ (367/392) vs. 77.8％ (305/392)] and the diagnostic coincidence rate [88.2％(345/392) vs. 76.8％(278/392)] for breast cancer and judging the marginal features of tumor. The DBT imaging features of mucinous carcinomas were mostly regular in shape and clear in margin. The DBT imaging features of invasive ductal carcinomas were marginal burr sign or burr with lobulation sign. Immunohistochemical detection displayed the positive expression rates of ER and PR were highest, the positive expression rates of HER2 and Ki-67 were the lowest in marginal burr masses;the positive expression rates of ER and PR were high, the positive expression rates of HER2 and Ki-67 were low in marginal lobulated masses; the positive expression rate of HER2 was highest in borderline masses or partial borderline masses; the positive expression rates of HER2 and Ki-67 were highest in clear margin masses. Conclusions Breast DBT can reduce or eliminate the tissue overlap in FFDM examination, and improve the detection rate, the diagnostic coincidence rate and the specificity of breast cancer. It can also indirectly provide evidence for preoperative judgment of biological behavior of tumors, guide clinical treatment and assess the prognosis through the morphological and marginal features of breast masses. Breast DBT is worthy of a wide clinical application in breast examination.
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Bartter′s syndrome(BS) is a rare renal tubular diseases and an autosomal recessive hereditary disease. The characteristic findings are hypokalemia, metabolic alkalosis, and raised serum renin and aldosterone levels. Combination of metabolic syndrome with Bartter′s syndrome has not been reported so far. Here in, we report a case in order to call attention to the diagnosis and treatment of typical Bartter′s syndrome combined with metabolic syndrome.
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Objective To observe the changes in serum High Sensitive C-reactive Protein(hs-CRP)in newly dignosed type 2 diabetic patients after treament with short-term intensive insulin aspart and investigate the relationship of inflammatory factors with insulin resistant.Methods30 newly dignosed ty 2 diabetic were treated by 14 d intensive aspart treament,the levels of fasting plasma glucose(FPG),2hours postprandial glucose(2hPG),insulin and C-peptide,hs-CRP,the mean area under the curve(AUC)of insulin and C-peptide,insulin resistance index(HOMA-A),insulin secretion index(HOMA-B)were compared before and after transient intensive nsulin aspart treament.ResultsAfter the treament,FPG,2hPG,hs-CRP and HOMA-A were significantly decreased(P