45 research outputs found

    The mechanisms by which polyamines accelerate tumor spread

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    Increased polyamine concentrations in the blood and urine of cancer patients reflect the enhanced levels of polyamine synthesis in cancer tissues arising from increased activity of enzymes responsible for polyamine synthesis. In addition to their de novo polyamine synthesis, cells can take up polyamines from extracellular sources, such as cancer tissues, food, and intestinal microbiota. Because polyamines are indispensable for cell growth, increased polyamine availability enhances cell growth. However, the malignant potential of cancer is determined by its capability to invade to surrounding tissues and metastasize to distant organs. The mechanisms by which increased polyamine levels enhance the malignant potential of cancer cells and decrease anti-tumor immunity are reviewed. Cancer cells with a greater capability to synthesize polyamines are associated with increased production of proteinases, such as serine proteinase, matrix metalloproteinases, cathepsins, and plasminogen activator, which can degrade surrounding tissues. Although cancer tissues produce vascular growth factors, their deregulated growth induces hypoxia, which in turn enhances polyamine uptake by cancer cells to further augment cell migration and suppress CD44 expression. Increased polyamine uptake by immune cells also results in reduced cytokine production needed for anti-tumor activities and decreases expression of adhesion molecules involved in anti-tumor immunity, such as CD11a and CD56. Immune cells in an environment with increased polyamine levels lose anti-tumor immune functions, such as lymphokine activated killer activities. Recent investigations revealed that increased polyamine availability enhances the capability of cancer cells to invade and metastasize to new tissues while diminishing immune cells' anti-tumor immune functions

    Anti-inflammatory Components from Functional Foods for Obesity

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    Obesity, defined as excessive fat accumulation that may impair health, has been described throughout human history, but it has now reached epidemic proportions with the WHO estimating that 39% of the world’s adults over 18 years of age were overweight or obese in 2016. Obesity is a chronic low-grade inflammatory state leading to organ damage with an increased risk of common diseases including cardiovascular and metabolic disease, non-alcoholic fatty liver disease, osteo-arthritis and some cancers. This inflammatory state may be influenced by adipose tissue hypoxia and changes in the gut microbiota. There has been an increasing focus on functional foods and nutraceuticals as treatment options for obesity as drug treatments are limited in efficacy. This chapter summarises the importance of anthocyanin-containing fruits and vegetables, coffee and its components, tropical fruit and food waste as sources of phytochemicals for obesity treatment. We emphasise that preclinical studies can form the basis for clinical trials to determine the effectiveness of these treatments in humans

    Production of Microcytospheres

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    Do Young Hepatocellular Carcinoma Patients Have Worse Prognosis? The Paradox of Age as a Prognostic Factor in the Survival of Hepatocellular Carcinoma Patients

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    Background/Aims: Our previous study showed that male hepatocellular carcinoma (HCC) patients below 40 years of age had the worst survival in the initial several years, but had the best prognosis thereafter. Thus, it seems that age has a paradoxical influence on the prognosis. To further clarify the issue of age on HCC prognosis, we initiated this study. Methods: A total of 11 312 HCC cases from seven medical centers from 1986 to 2002 were included. We analyzed the 1-year survival and survival after 1 year. Results: Male gender, age younger than 40 years old and hepatitis B virus (HBV) were associated with worse 1-year survival. In contrast, male gender, age younger than 40 years old and HBV were associated with better survival after 1 year. Higher percentage of the young HCC patients had a tumor size larger than 3 cm. 83.7% of HCC patients below 40 years of age were male and 89.8% of them were HBV carriers. Conclusions: If we encountered a young HCC patient, the patient will probably be a male HBV carrier. He would probably have larger tumor and is more likely to expire within 1 year than the older HCC patients. However, if the young HCC patient can survive for more than 1 year, he would probably have better survival in the following years than the older patients
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