The association between the diversity of online activities on smartphones and cognitive function among middle-aged and elderly Chinese adults.

BACKGROUND: Many studies have shown that using smartphones can improve cognitive function, but no studies have shown the effect of the diversity of online activities on cognitive function. Therefore, this study explores the association between the diversity of online activity on smartphones and cognitive function among middle-aged and elderly Chinese adults. METHODS: A total of 13,347 Chinese middle-aged and elderly participants were used in the final analysis. Multivariate linear regression models were used to explore the relationships among the frequency of smartphone use, number of online activities, various activities, and cognitive function. RESULTS: We found that 2,143 respondents (16.1%) used smartphones, and the top three online activities were watching news (80.3%), posting moments (72.4%), and chatting (68.0%) among all smartphone users to access the internet. After adjusting for all covariates, we found that the increase in the frequency of smartphone use and the number of online activities were correlated with a higher cognitive score. Moreover, some online activities, such as watching news (ß:0.5, 95% CI:0.2-0.8), posting moments (ß:0.4, 95% CI:0.2-0.7) playing games (ß:0.3, 95% CI:0.03-0.6) and making mobile payments (ß:0.3, 95% CI:0.1-0.5) were independently associated with good cognitive function. DISCUSSION: In the middle-aged and elderly population, smartphone use plays an important role in cognitive function. Considering the increasing prevalence of smartphones among middle-aged and elderly individuals, this study can provide references and insights for health education and in-depth scientific research related to internet usage.

Research hotspots and trends regarding microRNAs in hypertension: a bibliometric analysis.

To investigate the research levels, hotspots, and development trends regarding microRNAs in hypertension, this study conducted a visual analysis of studies on miRNA in hypertension based on the Web of Science core collection database using CiteSpace and VOSviewer analysis software along with literature from 2005-2023 as information data. Using citation frequency, centrality, and starting year as metrics, this study analyzed the research objects. It revealed the main research bodies and hotspots and evaluated the sources of literature and the distribution of knowledge from journals and authors. Finally, the potential research directions for miRNAs in hypertension are discussed. The results showed that the research field is in a period of vigorous development, and scholars worldwide have shown strong interest in this research field. A comprehensive summary and analysis of the current research status and application trends will prove beneficial for the advancement of this field.

Molecular mechanism of α-Hederin in tumor progression.

α-Hederin is a monosaccharide pentacyclic triterpene saponin compound derived from the Chinese herb, Pulsatilla. It has garnered considerable attention for its anti-tumor, anti-inflammatory, and spasmolytic pharmacological activities. Given the rising incidence of cancer and the pronounced adverse reactions associated with chemotherapy drugs-which profoundly impact the quality of life for cancer patients-there is an immediate need for safe and effective antitumor agents. Traditional drugs and their anticancer effects have become a focal point of research in recent years. Studies indicate that α-Hederin can hinder tumor cell proliferation and impede the advancement of various cancers, including breast, lung, colorectal, and liver cancers. The principal mechanism behind its anti-tumor activity involves inhibiting tumor cell proliferation, facilitating tumor cell apoptosis, and arresting the cell cycle process. Current evidence suggests that α-Hederin can exert its anti-tumor properties through diverse mechanisms, positioning it as a promising agent in anti-tumor therapy. However, a comprehensive literature search revealed a gap in the comprehensive understanding of α-Hederin. This paper aims to review the available literature on the anti-tumor mechanisms of α-Hederin, hoping to provide valuable insights for the clinical treatment of malignant tumors and the innovation of novel anti-tumor medications.

[The experimental study of tissue engineered autologous cartilage using chitosan-gelatin complex scaffolds].

OBJECTIVE: To investigate whether man-made porous chitosan-gelatin complex scaffold was a appropriate scaffold for tissue engineering cartilage. METHODS: Chondrocytes isolated from Changfeng crossbred swines' auricular cartilage were seeded onto chitosan- gelatin scaffolds to be cultured in a three dimensional environment. The chondrocyte- polymer constructs were implanted into the subcutaneous tissue of the swines' abdomenal wall. Specimens were harvested and analyzed by gross observation, histology, type II collagen immunohistochemistry and biochemistry after 10 and 16 weeks in vivo respectively. RESULTS: H.E staining showed cartilage was formed, and chondrocytes were enclosed in lacuna with histological characteristics similar to natural cartilage. Some clusters of neocartilage surrounded by fibrous tissues were observed. Elastic fibres were observed in the mesenchyma of cartilage 16 weeks after by Vehoeff's staining. Immunohistochemical staining of the neocartilage with anti- type II collagen showed the presence of type II collagen in the ECM of tissue engineered cartilage. The proteoglycans content in tissue engineered cartilage was close to that of natural swine's auricular cartilage. CONCLUSION: The experiments demonstrated that using chitosan-gelatin complex scaffold we can generate autologous cartilage on animals with normal immune system. Porous chitosan- gelatin complex scaffolds may be a suitable scaffolds for tissue engineered cartilage.

Repression of allo-cell transplant rejection through CIITA ribonuclease P+ hepatocyte.

AIM: Allo-cell transplant rejection and autoimmune responses were associated with the presence of class II major histocompatibility complex (MHC II) molecules on cells. This paper studied the effect of Ribonuclease P (RNase P) against CIITA, which was a major regulator of MHCII molecules, on repressing the expression of MHCII molecules on hepatocyte. METHODS: M1-RNA is the catalytic RNA subunit of RNase P from Escherichia coli. It were constructed that M1-RNA with guide sequences (GS) recognizing the 452, 3408 site of CIITA by PCR from pTK117 plasmid, then were cloned into the EcoRI/BglII or EcoR//SalIsite of vector psNAV (psNAV-M1-452-GS, psNAV-M1-3408-GS) respectively. The target mould plate (3176-3560) of CIITA was obtained from Raji cell by RT-PCR, and then inserted into the XhoI/EcoRIof pGEM-7zf(+) plasmid (pGEM-3176). These recombinant plasmids were screened out by sequence analysis. psNAV-M1-452-GS, psNAV-M1-3408-GS and its target RNA pGEM-3176 were transcribed and then mixed up and incubated in vitro. It showed that M1-3408-GS could exclusively cleave target RNA that formed a base pair with the GS. Stable transfectants of hepatocyte cell line with psNAV-M1-3408-GS were tested for expression of class II MHC through FCM, for mRNA abundance of MHCII, Ii and CIITA by RT-PCR., for the level of IL-2 mRNA on T cell by mixed lymphocyte reaction. RESULTS: When induced with recombinant human interferon-gamma (IFN-gamma), the expression of HLA-DR, -DP, -DQ on psNAV-M1-3408-GS(+) hepatocyte was reduced 83.27 %, 88.93 %, 58.82 % respectively, the mRNA contents of CIITA, HLA-DR, -DP, -DQ and Ii decreased significantly. While T cell expressed less IL-2 mRNA in the case of psNAV-M1-3408-GS(+) hepatocyte. CONCLUSION: The Ribonuclease P against CIITA-M1-3408-GS could effectively induce antigen-specific tolerance through cleaving CIITA. These results provided insight into the future application of M1-3408-GS as a new nucleic acid drug against allo-transplantation rejection and autoimmune diseases.

Study of novel chitosan-gelatin artificial skin in vitro.

A novel absorbable scaffold composed of chitosan and gelatin was fabricated by freezing and lyophilizing methods, resulting in an asymmetric structure. This bilaminar texture is suitable for preparing a bilayer skin substitute. The methods employed to confirm the applicability of this chitosan-gelatin scaffold as an ideal skin substitute were a water uptake ability test, in vitro fibroblast proliferation, and scaffold tests in which fibroblasts were co-cultured with keratinocytes. The chitosan-gelatin scaffolds were more wettable and adsorbed more water than did chitosan alone. In static cell culture the thinner scaffold is better than the thicker one, and because of diffusion limitations in the scaffold, culture time must be within 3 weeks before transplantation to living tissues. Keratinocytes were co-cultured with fibroblasts in chitosan-gelatin scaffolds to construct an artificial bilayer skin in vitro. The artificial skin obtained was flexible and had good mechanical properties. Moreover, there was no contraction observed in the in vitro cell culture tests. The data from this study suggest that chitosan-gelatin scaffolds are suitable for skin tissue engineering goals.

[The cloning of mouse FasL gene and expression in chondrocytes].

AIM: To clone mFasL cDNA, then insert it into retrovirus expression system pLNCX(2), and express mFasL cDNA in chondrocytes to study its function. METHODS: RT-PCR was applied to amplify mFasL cDNA from the total RNA of activated mouse spleen lymphocytes. The cDNA was inserted into a T-cloning vector, then subcloned into pLNCX(2). After transfection of chondrocytes, expression of FasL cDNA was detected by FACS, and activity of expressed product was analyzed by single mixed lymphocyte reaction(SMLC). RESULTS: mFasL cDNA fragment of 0.855 kb was successfully cloned and verified by sequencing. The transfection efficiency of mFasL cDNA in chondrocytes determined by FACS was 60.64%. Expressed product could evidently inhibit SMLC of allogeneic lymphocytes. It's stimulating index (SI) reduced to 11.71% as compare with the untransfected chondrocytes. CONCLUSION: Cloned recombinant pLNCX(2)-FasL can effectively express mFasL in chondrocytes, and can evidently inhibit SMLC of allogeneic lymphocytes.

[Tissue engineered tendon with skin fibroblasts as seed cells, a preliminary study].

OBJECTIVE: To investigate the effect of tissue engineered tendon using autologous dermal fibroblasts in repairing tendon damage. METHODS: Skin tissues were resected from abdomen of 5 pigs. Fibroblasts were isolated from the skin pieces and cultured in vitro. Bundles of polyglycolic acid (PGA) were arranged in parallel and mixed with the suspension of fibroblasts to form a cell-scaffolded construct, which was further cultured in vitro for 1 week. The tendon of musculus flexor digitorum superficialis of pig's right leg was cut with a defect 3 cm long and then bridged with the cultured construct. Six weeks later, specimens of the regenerated tendon of right musculus flexor digitorum superficialis and specimens of corresponding left leg were taken for gross examination, microscopy and biomechanical analysis. RESULTS: After implantation of the fibroblast-biomaterial complex the wounds healed up and the pigs moved well. The histology of the implanted tendon was similar to that of natural tendon. The breaking strength and maximum tensile force were 173.0 +/- 18.2 N and 18.9 +/- 1.9 MPa, reaching 57.4% and 51.9% of those of normal tendon respectively. CONCLUSION: Skin fibroblasts can be used as seed cells to regenerate tendon with normal structure and function.

Fabrication and surface modification of macroporous poly(L-lactic acid) and poly(L-lactic-co-glycolic acid) (70/30) cell scaffolds for human skin fibroblast cell culture.

The fabrication and surface modification of a porous cell scaffold are very important in tissue engineering. Of most concern are high-density cell seeding, nutrient and oxygen supply, and cell affinity. In the present study, poly(L-lactic acid) and poly(L-lactic-co-glycolic acid) (70/30) cell scaffolds with different pore structures were fabricated. An improved method based on Archimedes' Principle for measuring the porosity of scaffolds, using a density bottle, was developed. Anhydrous ammonia plasma treatment was used to modify surface properties to improve the cell affinity of the scaffolds. The results show that hydrophilicity and surface energy were improved. The polar N-containing groups and positive charged groups also were incorporated into the sample surface. A low-temperature treatment was used to maintain the plasma-modified surface properties effectively. It would do help to the further application of plasma treatment technique. Cell culture results showed that pores smaller than 160 microm are suitable for human skin fibroblast cell growth. Cell seeding efficiency was maintained at above 99%, which is better than the efficiency achieved with the common method of prewetting by ethanol. The plasma-treatment method also helped to resolve the problem of cell loss during cell seeding, and the negative effects of the ethanol trace on cell culture were avoided. The results suggest that anhydrous ammonia plasma treatment enhances the cell affinity of porous scaffolds. Mass transport issues also have been considered.

[The determination and significance of VEGF in the serum of hemangioma patients].

OBJECTIVE: Looking for an objective biomedical index to distinguish types and phases of hemangioma in order to provide an objective basis for selecting clinical treatment to hemangioma. METHODS: ELISA (enzyme-linked immunosorbent assay) was used to determine serum VEGF concentration of 15 patients with proliferative hemangioma, 6 with involuted hemangioma, 6 with vascular malformation and 8 infants of the control group. RESULTS: The serum VEGF concentrations of 15 proliferative hemangioma patients were significantly higher than those of involuted hemangioma patients, vascular malformation patients and control group infants. The serum VEGF concentrations of involuted hemangioma patients were a little bit higher than those of vascular malformation patients and control group infants, but without statistic significance. CONCLUSIONS: ELISA could easily and accurately determine the serum VEGF concentration of different types and different phases of hemangioma. The determination of serum VEGF concentration could provide guidance for selecting a protocol of systemic corticosteroid treatment for proliferative hemangioma. Combined with gene expression and distribution of VEGF and its receptors and some other cytokines, the determination of serum VEGF concentration could help elucidate the mechanism of proliferative hemangioma.

Repairing large porcine full-thickness defects of articular cartilage using autologous chondrocyte-engineered cartilage.

Large full-thickness defects of articular cartilage remain a major challenge to orthopedic surgeons because of unsatisfactory results of current therapy. Many methods, such as chondrectomy, drilling, cartilage scraping, arthroplasty, transplantation of chondrocytes, periosteum, perichondrium, as well as cartilage and bone, have been tried to repair articular cartilage defects. However, the results are far from satisfactory. In this study, we applied a tissue-engineering approach to the repair of articular cartilage defects of knee joints in a porcine model. Using isolated autologous chondrocytes, polyglycolic acid (PGA), and Pluronic, we have successfully in vivo-engineered hyaline cartilage and repaired articular cartilage defects. The surface of the repaired defects appeared smooth at 24 weeks postrepair. Histological examination demonstrated a typical hyaline cartilage structure with ideal interface healing between the engineered cartilage and the adjacent normal cartilage and underlying cancellous bone. In addition, glycosaminoglycan (GAG) levels in the engineered cartilage reached 80% of that found in native cartilage at 24 weeks postrepair. Biomechanical analysis at 24 weeks demonstrated that the biomechanical properties of the tissue-engineered cartilage were improved compared with those at an earlier stage. Thus, the results of this study may provide insight into the clinical repair of articular cartilage defects.

[In vitro chondrogenic phenotype differentiation of bone marrow stem cells].

OBJECTIVE: To investigate the feasibility of chondrogenic phenotype differentiation of adult swine bone marrow stem cells(MSCs) in a defined medium as seeding cells in cartilage tissue engineering. METHODS: A volume of 5 ml bone marrow was aspirated from swine iliac crest and cultured in the complete medium of DMEM-LG for two weeks. The growth and ultrastructure of the cultured MSCs were observed. Immunohistochemistry and in situ hybridization were applied to detect the expression of collagen type II. RESULTS: The MSCs changed from a spindle-like fibroblastic appearance to a polygonal shape when transferred from the complete medium of DMEM-LG to a defined medium. A large amount of endoplasmic reticulum was observed in large Golgi ccmplex and mitochondria. The differentiation of MSCs toward chondrogenic phenotype was verified by the positive result of collagen type II through immunohistochemistry and in situ hybridization respectively. CONCLUSIONS: Bone marrow stem cells obtained from adult swine can differentiate to be chondrogenic phenotype when cultured in vitro. MSCs can likely be served as optimal autogenous cell source for cartilage tissue engineering.

[Repair of porcine full-thickness skin defects with autologous tissue engineered skin].

OBJECTIVE: To explore a feasible method to repair full-thickness skin defects with tissue engineered techniques. METHODS: The skin specimens were cut from the Changfeng hybrid swines' abdomen, then keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA and type II collagenase. The cells were seeded in petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with dispase II (keratinocytes) or trypsin (fibroblasts) to separate them from the floor of the tissue culture dishes. A biodegradable material-pluronic F-127 was prefabricated and mixed with these cells, and then the cells-pluronic compounds were seeded evenly into polyglycolic acid (PGA). Tinally the constructs were replanted to autologous animals to repair full-thickness skin defects. Histological changes were observed in 1, 2, 4 and 8 weeks postsurgery. RESULTS: The cells-pluronic F-127-PGA compounds could repair autologous full-thickness skin defects. Histologically, the tissue engineered skin was similar to normal skin with stratified epidermis overlying a moderately thick collageneous dermis. CONCLUSION: Tissue engineered skin can repair autologous full-thickness skin defects with primary-cultured keratinocytes and fibroblasts as seed cells and PGA as a cell carrier.

[Repair of meniscal defects with autologous tissue-engineered fibrocartilage].

OBJECTIVE: To repair critical-sized meniscal defects in an immunocompetent mammal by tissue engineering approach. METHODS: 15 45-day-old Changfeng crossbred pigs were selected as experimental animals. Autologous fibrochondrocytes were obtained from left knee menisci by modified Klagsbrun's method and were proliferated in vitro to a proper amount. A 1-cm-long full-layer defect of right medial meniscus was created anterior to the medial collateral ligament. PGA-fibrochondrocyte-Pluronic complex, fibrochondrocyte-Pluronic complex or PGA only was respectively implanted into the defects. We used intact menisci and untreated meniscal defects as controls. Samples respectively obtained in 9 w, 16 w and 25 w were appraised by general observation, histology, biochemistry and biomechanics. RESULTS: From the sights of general morphology, histological structure and Young's Modulus (59.7% of that in normal meniscus at 25 w), the PGA-cell-Pluronic complex can form the best quality tissue, which can stabilize the GAG ratio (74.5% of that in normal cartilage at 25 w) of femoral entocondyle cartilage. CONCLUSION: Autologous tissue-engineered fibrocartilage is a promising feasible method to regenerate or reconstruct menisci so as to hold back the degenerative changes of the knee.

Blocking transforming growth factor-beta receptor signaling down-regulates transforming growth factor-beta1 autoproduction in keloid fibroblasts.

OBJECTIVE: To study transforming growth factor-beta1 (TGF-beta1) autoproduction in keloid fibroblasts and the regulation effect of blocking TGF-beta intracellular signaling on rhTGF-beta1 autoproduction. METHODS: Keloid fibroblasts cultured in vitro were treated with either rhTGF-beta1 (5 ng/ml) or recombinant adenovirus containing a truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects of regulating gene expression of TGF-beta1 and its receptor I and II were observed with Northern blot. RESULTS: rhTGF-beta1 up-regulated the gene expression of TGF-beta1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated the gene expression of TGF-beta1 and its receptor I, but not receptor II. CONCLUSIONS: TGF-beta1 autoproduction was observed in keloid fibroblasts. Over-expression of the truncated TGFbeta receptor II decreased TGF-beta1 autoproduction via blocking TGF-beta receptor signaling.

[Overexpression of truncated type II transforming growth factor-beta receptor in dermal fibroblasts].

OBJECTIVE: To study the effect of overexpression of truncated type II TGF-beta receptor on transforming growth factor-beta 1(TGF-beta 1) autoproduction in normal dermal fibroblasts. METHODS: In vitro cultured dermal fibroblasts were treated with recombinant human TGF-beta 1(rhTGF-beta 1) (5 ng/ml) or recombinant adenovirus containing truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-beta 1 were observed with Northern blotting. RESULTS: rhTGF-beta 1 up-regulated the gene expression of TGF-beta 1 and type I procollagen. Overexpression of truncated receptor II down-regulated the gene expression of TGF-beta 1. CONCLUSION: Overexpression of the truncated TGF-beta receptor II decreases TGF-beta 1 autoproduction via blocking TGF-beta receptor signal. The results may provided a new strategy for scar gene therapy.