22 research outputs found

    Cactus pear: a natural product in cancer chemoprevention

    Get PDF
    BACKGROUND: Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. Although chemoprevention has shown promise in some epithelial cancers, currently available preventive agents are limited and the agents are costly, generally with side effects. Natural products, such as grape seed, green tea, and certain herbs have demonstrated anti-cancer effects. To find a natural product that can be used in chemoprevention of cancer, we tested Arizona cactus fruit solution, the aqueous extracts of cactus pear, for its anti-cancer effects in cultured cells and in an animal model. METHOD: Aqueous extracts of cactus pear were used to treat immortalized ovarian and cervical epithelial cells, as well as ovarian, cervical, and bladder cancer cells. Aqueous extracts of cactus pear were used at six concentrations (0, 0.5, 1, 5, 10 or 25%) to treat cells for 1, 3, or 5 days. Growth inhibition, apoptosis induction, and cell cycle changes were analyzed in the cultured cells; the suppression of tumor growth in nude mice was evaluated and compared with the effect of a synthetic retinoid N-(4-hydroxyphernyl) retinamide (4-HPR), which is currently used as a chemoprevention agent. Immunohistochemistry staining of tissue samples from animal tumors was performed to examine the gene expression. RESULTS: Cells exposed to cactus pear extracts had a significant increase in apoptosis and growth inhibition in both immortalized epithelial cells and cancer cells in a dose- and time-dependent manner. It also affected cell cycle of cancer cells by increasing G1 and decreasing G2 and S phases. Both 4-HPR and cactus pear extracts significantly suppressed tumor growth in nude mice, increased annexin IV expression, and decreased VEGF expression. CONCLUSION: Arizona cactus pear extracts effectively inhibited cell growth in several different immortalized and cancer cell cultures, suppressed tumor growth in nude mice, and modulated expression of tumor-related genes. These effects were comparable with those caused by a synthetic retinoid currently used in chemoprevention trials. The mechanism of the anti-cancer effects of cactus pear extracts needs to be further studied

    Regulation of squamous cell differentiation in human head and neck carcinoma cells by retinoids

    No full text
    Retinoids have been found to be effective in the prevention of premalignant lesions and second primary cancers in the upper aerodigestive tract. Further development of retinoids for prevention and therapy of head and neck squamous cell carcinoma (HNSCC) requires a better understanding of their mechanism of action on the growth and differentiation of such cells. I have chosen to employ cultured HNSCC cell lines as a model system for investigating the mechanism underlying the effects of retinoids. These cells are useful because all-trans retinoic acid (ATRA) inhibits their proliferation. Furthermore, two HNSCC cell lines were found to express three squamous differentiation (SqD) markers characteristic of normal keratinocytes and ATRA suppressed the expression of these markers as reported for normal keratinocytes. It is thought that nuclear retinoic acid receptors (RARs and RXRs), which act as DNA-binding transcription modulating factors, mediate the effects of retinoids on the growth and differentiation of normal and tumor cells. I found that all four cell lines examined expressed RAR-α,\alpha , RAR-τ,\tau , and RXR-α\alpha and three of four expressed RAR-β.\beta . ATRA treatment increased the level of RAR-α,\alpha , -β,\beta , and -τ\tau in four cell lines. Two HNSCC cell lines that exhibited a progressive increase in the expression of SqD markers during growth in culture also showed a concurrent decrease in RAR-β\beta level. Moreover, increasing concentrations of RA suppressed the SqD marker while inducing RAR-β\beta mRNA. Several synthetic retinoids which exhibit a preference for binding to specific nuclear RARs showed a differential ability to inhibit cell proliferation, transactivate transcription of the reporter genes (CAT and luciferase) from the RA response element (RARE) of the RAR-β\beta gene, and induce RAR-β\beta expression. Those retinoids that were effective inducers of RAR-β\beta also suppressed SqD effectively, indicating an inverse relationship exists between the expression of RAR-β\beta and SqD. This inverse relationship suggests a role for RAR-β\beta in the suppression of SqD.

    Nutritional and Medicinal Use of Cactus Pear (Opuntia Spp.) Cladodes and Fruits

    No full text
    Natural products and health foods have recently received a lot of attention both by health professionals and the common population for improving overall well-being, as well as in the prevention of diseases including cancer. In this line, all types of fruits and vegetables have been reevaluated and recognized as valuable sources of nutraceuticals. The great number of potentially active nutrients and their multifunctional properties make cactus pear (Opuntia spp.) fruits and cladodes perfect candidates for the production of health-promoting food and food supplements. Although traditionally appreciated for its pharmacological properties by the Native Americans, cactus pear is still hardly recognized because of insufficient scientific information. However, recent studies on Opuntia spp. have demonstrated cactus pear fruit and vegetative cladodes to be excellent candidates for the development of healthy food. Therefore, this review summarizes current knowledge on the chemical composition of Opuntia cacti with particular emphasis in its use as food and medicine

    A Settlement Landscape Reconstruction Approach Using GIS Analysis with Integrated Terrain Data of Land and Water: A Case Study of the Panlongcheng Site in the Shang Dynasty (Wuhan, China)

    No full text
    The landscape of ancient sites has changed greatly with the passage of time. Among all of the factors, human activities and the change in natural environment are the main factors leading to the change in site landscape. The Panlongcheng site, which is located in Hubei Province, China, has a history of 3500 years with the most abundant relics in the Yangtze River Basin during the Shang Dynasty. As a near-water site, the landscape of the Panlongcheng site is greatly affected by water level changes and water conservancy activities. In this paper, by using spatial information technology, the data obtained from land and underwater archaeological exploration were integrated to restore landscapes of Panlongcheng sites in different periods. After removing modern artificial features and topsoil, the landscapes of the sites before the Shang Dynasty, in the Shang Dynasty and modern time were reconstructed. Combining historical records of water level changes, the landscape and water–land distribution of the Panlongcheng site were compared. The analysis results reflect the interaction between water level changes and human activities in this region for thousands of years, and support the archaeological findings in the near-water area of the Panlongcheng site, which provides a new idea for the landscape reconstruction and analysis of near-water sites

    Clinical utilization of methylprednisolone in conjunction with tranexamic acid for accelerated rehabilitation in total hip arthroplasty

    No full text
    Abstract Purpose This study aimed to evaluate the efficacy and safety of combined methylprednisolone (MP) and tranexamic acid (TXA) in promoting accelerated rehabilitation following total hip arthroplasty (THA). We further investigated effective strategies for rapid rehabilitation post-THA. Methods Conducted as a randomized controlled trial involving 80 patients, the study allocated subjects into two groups. The control group received saline and TXA, whereas the experimental group was administered with an additional dose of MP. Several clinical parameters, including markers of inflammation, pain, nausea, and coagulation factors, were meticulously assessed in both groups. Results It was observed that the group receiving the MP + TXA treatment showcased significant reductions in postoperative levels of CRP and IL-6, as well as an alleviation in pain scores. Furthermore, this group demonstrated lower incidences of postoperative nausea and fatigue, facilitating enhanced hip joint mobility. Interestingly, this group did exhibit blood glucose fluctuations within the first 24 h postoperatively. However, there was no notable difference between the groups concerning transfusion rate, postoperative hospital stay duration, and coagulation profile, and no severe complications were reported. Conclusion The findings suggest that the combined administration of MP and TXA can appreciably enhance postoperative recovery, by reducing inflammatory markers, alleviating pain, reducing nausea and fatigue, and improving hip mobility, without leading to an increased risk of severe perioperative complications. This highlights the potential role of this combined therapy in facilitating improved postoperative patient experiences

    CAD AND CAE TECHNOLOGIES OF A NOVEL PLANE SIX-BAR SWAYING MACHINE

    No full text

    Advances in second-generation high-temperature superconducting tapes and their applications in high-field magnets

    No full text
    Second-generation high-temperature superconducting (2G-HTS) tapes based on REBa2Cu3O7-x (REBCO, RE: rare earth) materials enable the energy-efficient and high-power-density delivery of electricity, thereby promoting the development of clean energy generation, conversion, transmission, and storage. To overcome the weak grain-boundary connection and poor mechanical properties of these superconductors, a thin-film technology for epitaxy and biaxial textures based on flexible substrates has been developed. In recent years, high-quality 2G-HTS tapes have been produced at the kilometer scale and used in superconducting demonstration projects. This review first summarizes the development of HTS materials and briefly expounds the properties of REBCO superconducting materials. Subsequently, the structural characteristics, preparation methods, and current research progress of 2G-HTS tapes are given. In addition, the applications of REBCO tapes in constructing high-field magnets are also briefly reviewed
    corecore