Collagen (Coll), as the basic material of matrix scaffolds for cell growth, has been widely used in the field of tissue engineering and regenerative medicine. In this study, collagen protein was modified by L-lysine (Lys), and cross-linked by genipin (GN) to prepare the L-lysine-modified collagen (Lys-Coll-GN) scaffolds. Microstructure, pore size, porosity, stability and biocompatibility of Lys-Coll-GN scaffolds were observed. The results showed that the bond between L-lysine and collagen protein molecule was formed by generating amide linkage, and mouse embryo fibroblasts proliferation was not inhibited in the Lys-Coll-GN scaffolds. In the multiple comparisons of Coll-scaf- folds, Coll-GN scaffolds and Lys-Coll-GN scaffolds, Coll-scaffolds was the worst in mechanical characteristics while the highest in biodegradation rate. Compared to Coll-GN scaffolds, Lys-Coll-GN scaffolds had more fiber structure, higher interval porosity (P<0. 01). Although the tensile stress of Lys-Coll-GN scaffolds reduced significantly, its e- longation length extended when the scaffolds was fractured (P<0. 01). The percentage of Lys-Coll-GN scaffolds residual weight was lower than that of Coll-GN scaffolds after all the scaffolds were treated by collagenase for 5 days (P<0. 01). This study suggested that Lys-Coll-GN scaffold had good biocompatibility, and it improved the mechanical property and degradation velocity for collagen-based scaffold. This study gave a new predominant type of tissue engineering scaffold for the regenerative medicine.
Animals ; Biocompatible Materials ; chemistry ; Cell Proliferation ; Collagen ; chemistry ; Cross-Linking Reagents ; Fibroblasts ; cytology ; Iridoids ; chemistry ; Lysine ; chemistry ; Mice ; Porosity ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVE To investigate the effect and mechanism of low concentrations of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) on colorectal adenocarcinoma SW620 cell proliferation and apoptosis. METHODS SW620 cells were exposed to low concentrations of p, p′-DDT ranging from 1×10-12 to 1×10-6 mol.L-1 for 48 and 96 h. MTT assay was employed to examine the effect of p,p′-DDT on SW620 cell viability. Different cell stages of cycle and apoptosis rate were determined by flow cytometry after SW620 cells were exposed to 1×10-10 , 1×10-9 and 1×10-8 mol.L-1 for 96 h. Western blotting was used to determine the protein expression of Wnt/ β-catenin signaling components 〔β-catenin, phospho-β-catenin and phospho-glycogen synthase kinase ( GSK) 3β〕, their downstream target proteins ( c-Myc and cyclin D1)and apoptosis related proteins (Bcl-2, Bax, procaspase 8 and procaspase 3). RESULTS The viability of colorectal adenocarcinoma SW620 cells was significantly increased after exposure to low concentrations of p,p′-DDT ranging from 1×10-12 to 1×10-7 mol.L-1 for 96 h. p,p′-DDT 1×10-10 , 1×10-9 and 1×10-8 mol.L-1 exposure led to a decreased percentage of SW620 cells in G1 stage(P<0.01) along with an increased percentage of cells in S stage(P<0.01). Meanwhile, the apoptosis rate was signifi-cantly decreased compared with control group ( P < 0. 01). Exposure to p, p′-DDT from 1 × 10-10 to 1×10-8 mol.L-1 induced upregulation of phospho-GSK3β ( Ser9), β-catenin, c-Myc and cyclin D1 in SW620 cells( P <0.01). Moreover, apoptosis related proteins Bcl-2, procaspase 8 and procaspase 3 were unregulated(P<0.01), and Bax level and caspase 3 activity were decreased in p,p′-DDT-stimulated cells(P < 0.01). CONCLUSION Low concentrations of p, p′-DDT exposure activates Wnt/ β-catenin signaling and affects apoptosis-related proteins, which may be involved in p,p′-DDT-induced cell prolifer-ation as well as suppression of cell apoptosis in SW620 cells.

Objective To identify features of antibodies in the supernatants of cultured Castleman's disease cells.Methods Lymphocytes of Castleman's disease were isolated and cultured.Immunofluorescence and immunoblot assays were performed with IgG extracted from culture supernatants.The immunoglobulin heavy chaingene of cultured tumor B cells was analyzed by RT-PCR,cloning and sequencing.ResultsIg Gextracted from culture supernatant scouldattachtotheepithelialcellsurfacesofmousebladdertissues.Theantibodycouldalsoidentifytwoantigencomponents,210000and190000,ofnormalhumanepidermaltis-sues.ThesequencesimilaritywasfoundinimmunoglobulinheavychaingeneofculturedtumorBcellscom-paredwiththatof6patientswithCastleman'sdiseasepreviouslyreported.Conclusions Castleman's tumor associated with paraneoplastic pemphigus can secret autoantibody with similar features to that found in patients'sera.

Objective To investigate the clinical features of skin cancer.Methods Clinical data of skin cancer and precancerous skin lesions confirmed pathologically from 2005 to 2008 in Peking University First Hospital were retrospectively analyzed by using statistical methods.Results A total of 632 cases of skin cancer and precancerous skin lesions were studied.The most common skin cancer was basal cell carcinoma and squamous cell carcinoma (invasive and in situ) which accounted for 29.3%and 24.2%,respectively.The average age at onset was older than 60 years in 55.4%of the patients,between 35 and 59 years in 34.3%,younger than 35 years in 10.3%.The concordance between clinical and pathological diagnosis reached nearly 90.O%for Paget's disease,70.0% for other common skin cancer and precancerous skin lesions.Conclusions Skin cancer and precancerous skin lesions have a predilection for scalp and face.Patients aged from 35 to 59 years account for a significant proportion not only in cutaneous lymphoma but also in melanoma and epithelium-derived nonmelanoma skin cancer.

Objective To review the influence of 131I therapy on bone mineral density (BMD) in patients with hyperthyroidism.Methods Published articles of prospective randomized controlled study,clinical controlled study or case-control study on BMD change in patients with hyperthyroidism after 131I therapy were selected from PubMed,the Excerpta Media Database (Embase),Cochrane library,Chinese Journal Full-text Database,Wanfang Database,Vip Database and Chinese Biomedical Literature Database.Data from the date of database establishment to October 2015 were all reviewed.The languages were restricted to English and Chinese.Meta-analysis was performed with RevMan 5.3.Results Thirteen trials with a total of 668 hyperthyroidism patients were included.The meta-analysis showed that BMD of the lumbar spine,hip joint,femoral neck and osteocalcin were significantly improved after 131I therapy.The weighted mean difference (WMD) for BMD of the lumbar spine was 0.07 (95％ CI:0.04-0.11),P=0.O00 2;that of the hip joint and the femoral neck was 0.13(95％ CI:0.09-0.16) and 0.05(95％ CI:0.03-0.06),respectively(both P＜0.01).The standardized mean difference (SMD) of osteocalcin was-1.20(95％ CI:-1.43--0.97) with P＜0.01.Furthermore,the improvements were time dependent within the 2 years' follow-up.Conclusions 131I therapy improves the BMD and osteocalcin in patients with hyperthyroidism in a time dependent manner within 2 years' follow-up.

Objective To investigate the possibility of utilizing the mixed bacteria liquid and the Escherichia coli ( E.coli) liquid to establish the chronic salpingitis model of New Zealand rabbits, respectively.Methods Taken as the study object, the un-pregnant New Zealand rabbits (4~5 years old) were randomly divided into three groups: the normal group, the mixed bacteria experimental group and the E.coli experimental group.The trans-vaginal intrauterine intubation operation was performed for the injection of the mixed bacteria liquid and the E.coli liquid.Visual observation was to evaluate the gross pathological changes of the salpingitis and the pelvic cavity.HE staining and the light microscope were used to observe the micro-pathological changes of salpingitis.Results On the 15th day after modeling, increased pelvic effusion, dense peritoneal adhesion, interstitial hyperplasia and infiltration of lymphocytes were observed in both experimental groups. Conclusion Through the trans-vaginal intrauterine intubation operation, the chronic salpingitis model of New Zealand rabbits could be successfully established either by using the mixed bacteria liquid or by using the E.coli liquid.

Objective To evaluate the relationship between desmosome-related proteins and epidermal tumors. Methods Using anti-desmoglein 1 and 2 monoclonal antibodies, expression of desmoglein 1 and 2 was examined by an immunohistochem ical staining method in various epidermal tumors such as squamous cell carcinoma (SCC), actinic keratosis(AK), keratoacanthoma(KA) and seborrhoeic keratosis(SK). Results Desmoglein 1 and 2 were strongly expressed in intercellular space of wh ole epidermis in normal human skin. Expression of desmoglein 1 and 2 was markedl y reduced or absent in SCC cells. Compared with normal epidermal cells, expressi on of desmoglein 1 and 2 was equal to or reduced,with complete absence of stain ing in dysplastic areas in AK cells. Extensive pericellur staining of desmoglein 1 and 2 was found in KA and SK cells, similar to that observed in normal epider mis. Conclusion Expression of desmoglein 1 and 2 is markedly reduced or absent i n human malignant epidermal cancers, reduction of these molecules may contribute to invasiveness and metastasis of epidermal carcinomas.

Objectives To identify the COL7A1 gene mutation in a recessive dystrophic epidermolysis bullosa (RDEB) family, and to perform prenatal diagnosis in the patient's offspring. Methods The genomic DNA, obtained from the patient and his wife, was used to screen all 118 exons of the type VII collagen gene (COL7A1) via polymerase chain reaction (PCR) followed by direct DNA sequencing of the PCR products. Fetal DNA was extracted from amniotic fluid of the patient's wife at the 15th week of gestation. PCR, direct DNA sequencing and restriction fragment length polymorphisms (RFLPs) were performed for prenatal diagnosis. Results The patient in this study was a compound heterozygote for a S48P missense mutation in exon 2 and an 11 base pair deletion (3625del11) leading to a premature termination codon (PTC) in exon 27, which are a novel combination of COL7A1 mutations in RDEB. The COL7A1 genotype of his wife was normal. In the fetus, the same deletion of 11 base pair (3625del11) was found in exon 27, but no mutation was found in exon 2. Thus, the fetus was predicted to be a clinically normal child with a carrier genotype. Seven months later, a clinically unaffected male infant was born and the prediction was confirmed. Conclusion We successfully performed the first DNA-based prenatal diagnosis in China in a family with Hallopeau-Siemens RDEB.

Objective:To explore the evaluation of 256 slice spiral computed tomography angiography(CTA)of coronary,serum lipoprotein associated phospholipase A2(Lp-PLA2)and angiopoietin like protein 3(ANGPTL3)on the severity of coronary artery stenosis of patients with coronary heart disease.Methods:A total of 102 patients with coronary heart disease who were diagnosed and treated at Hebei Chest Hospital from July 2022 to March 2023 were selected as the study subjects.According to the Gensini score about the severity of coronary artery stenosis,they were divided into mild stenosis group(0 score≤Gensini score≤20 scores),moderate stenosis group(20 scores60 scores),with 34 cases in each group.The minimum lumen diameter(MLD),percentage of area of stenosis(%AS),percentage of diameter of stenosis(%DS),minimum lumen area(MLA),Lp-PLA2 and ANGPTL3 among three groups were compared.The diagnostic efficiency of the severity of coronary artery stenosis was predicted according to receiver operating characteristic(ROC)curve.Results:The MLA and MLD values in severe stenosis group were significantly lower than those in moderate and mild stenosis groups,while%AS and%DS were significantly higher than those in moderate and mild stenosis groups(t=6.905,4.083,5.871,6.976,3.387,2.198,2.668,3.505,P<0.05),respectively.The Lp-PLA2 and ANGPTL3 values in severe stenosis group were significantly higher than those in moderate and mild stenosis groups(t=4.164,8.220,2.575,3.050,P<0.05),respectively.ROC curve analysis showed that the area under curve(AUC)values of MLA,MLD,%AS,%DS,CCTA comprehensive parameter,LpPLA2 and ANGPTL3 were respectively were 0.838,0.690,0.742,0.801,0.904,0.808 and 0.807 in predicting the severity of coronary artery stenosis.The sensitivities of them were respectively 91.20%,91.20%,64.70%,94.10%,97.10%,70.60%and 88.20%.The specificities of them were respectively 76.50%,57.40%,75.00%,50.00%,70.60%,97.10%and 70.60%.The AUC value of CCTA comprehensive parameter was respectively higher than that of LpPLA2 and ANGPTL3,but the difference was not statistically significant(P>0.05).Conclusion:256 slice spiral CCTA,serum Lp-PLA2 and ANGPTL3 have a certain efficiency in assessing the severity of coronary artery stenosis of coronary heart disease,and 256 slice spiral CCTA has higher predictive efficiency.

Objective To evaluate the performance of desmoglein (Dsg)1 enzyme-linked immunosorbent assay (ELISA) in the detection of serum antibodies in patients with pemphigus foliaceus (PF). Methods Sera were obtained from 80 patients with PF and 132 human controls including 33 patients with bullous pemphigoid, 3 patients with linear IgA bullous dermatosis, 2 patients with acquired bullous epidermolysis, 20 patients with systemic lupus erythematosus (SLE), etc, and subjected to a random and blind test by Dsg1 ELISA and indirect immunofluorescence (IIF) on monkey oesophagus. Results The Dsg1 ELISA was positive in 75 (93.8%) patients with PF and 5 (3.8%) human controls (including 1 case of bullous pemphigoid, 1 case of SLE, 1 case of dermatomyositis, 1 case of eczema and 1 normal human control with indeterminate value), and IIF was positive in 71 (88.8%) patients with PF, but in none of the controls. The sensitivity and specificity was 93.8% (95% CI: 0.85 - 0.98) and 96.2% (95% CI: 0.91 - 0.99) respectively for Dsg1 ELISA in the serodiagnosis of PF, 88.8% (95% CI: 0.82 - 0.96) and 100% (95% CI: 0.96 - 1.00) respectively for IIF. There was no statistical difference in the sensitivities (P= 0.289) or specificities (P= 1.000) between the two test methods.Conclusions Dsg1 ELISA is a simple, sensitive and specific serological detection method, and can serve as an adjunct in the diagnosis of PF.