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Journal ArticleDOI

Plasma Melatonin Levels in Patients Suffering From Colorectal Carcinoma

01 May 1988-Journal of Pineal Research (Blackwell Publishing Ltd)-Vol. 5, Iss: 3, pp 251-258
TL;DR: Plasma melatonin was determined in samples of patients with colorectal carcinoma and in controls using an iodinated radioimmunoassay and during the night, melatonin concentration in cancer patients was significantly lower than in controls.
Abstract: Plasma melatonin was determined in samples of patients with colorectal carcinoma and in controls using an iodinated radioimmunoassay Both groups showed large individual variability in absolute melatonin levels However, during the night, melatonin concentration in cancer patients was significantly lower than in controls
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Journal ArticleDOI
TL;DR: It is suggested that working a rotating night shift at least three nights per month for 15 or more years may increase the risk of colorectal cancer in women.
Abstract: Exposure to light at night suppresses the physiologic production of melatonin, a hormone that has antiproliferative effects on intestinal cancers. Although observational studies have associated night-shift work with an increased risk of breast cancer, the effect of night-shift work on the risk of other cancers is not known. We prospectively examined the relationship between working rotating night shifts and the risk of colorectal cancers among female participants in the Nurses' Health Study. We documented 602 incident cases of colorectal cancer among 78 586 women who were followed up from 1988 through 1998. Compared with women who never worked rotating night shifts, women who worked 1-14 years or 15 years or more on rotating night shifts had multivariate relative risks of colorectal cancer of 1.00 (95% confidence interval [CI] = 0.84 to 1.19) and 1.35 (95% CI = 1.03 to 1.77), respectively (P(trend) =.04). These data suggest that working a rotating night shift at least three nights per month for 15 or more years may increase the risk of colorectal cancer in women.

748 citations


Cites background from "Plasma Melatonin Levels in Patients..."

  • ...Furthermore, the finding that colorectal cancer patients had lower plasma levels of melatonin than healthy control subjects suggests a possible link between low melatonin levels and the enhanced development of colorectal cancer in humans (22, 23 )....

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Journal ArticleDOI
TL;DR: The radioprotective effects of melatonin against cellular damage caused by oxidative stress and its low toxicity make this molecule a potential supplement in the treatment or co-treatment in situations where the effects of ionizing radiation are to be minimized.
Abstract: Ionizing radiation is classified as a potent carcinogen, and its injury to living cells is, to a large extent, due to oxidative stress. The molecule most often reported to be damaged by ionizing radiation is DNA. Hydroxyl radicals (*OH), considered the most damaging of all free radicals generated in organisms, are often responsible for DNA damage caused by ionizing radiation. Melatonin, N-acetyl-5-methoxytryptamine, is a well-known antioxidant that protects DNA, lipids, and proteins from free-radical damage. The indoleamine manifests its antioxidative properties by stimulating the activities of antioxidant enzymes and scavenging free radicals directly or indirectly. Among known antioxidants, melatonin is a highly effective scavenger of *OH. Melatonin is distributed ubiquitously in organisms and, as far as is known, in all cellular compartments, and it quickly passes through all biological membranes. The protective effects of melatonin against oxidative stress caused by ionizing radiation have been documented in in vitro and in vivo studies in different species and in in vitro experiments that used human tissues, as well as when melatonin was given to humans and then tissues collected and subjected to ionizing radiation. The radioprotective effects of melatonin against cellular damage caused by oxidative stress and its low toxicity make this molecule a potential supplement in the treatment or co-treatment in situations where the effects of ionizing radiation are to be minimized.

339 citations

Journal ArticleDOI
TL;DR: There is a need for extensive studies on the use of melatonin in order to improve the quality of life in advanced age, and currently available data do not allow us to conclude that melatonin may have a role in extending normal longevity.

305 citations

Journal ArticleDOI
TL;DR: Current knowledge indicates that sleep/wake disturbances are prevalent in cancer populations and little is known regarding use of pharmacologic and herbal and complementary supplements and potential adverse outcomes or interactions with cancer therapies.
Abstract: Purpose/objectives To review the state of the science on sleep/wake disturbances in people with cancer and their caregivers. Data sources Published articles, books and book chapters, conference proceedings, and MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and the Cochrane Library computerized databases. Data synthesis Scientists have initiated studies on the prevalence of sleep/wake disturbances and the etiology of sleep disturbances specific to cancer. Measurement has been limited by lack of clear definitions of sleep/wake variables, use of a variety of instruments, and inconsistent reporting of sleep parameters. Findings related to use of nonpharmacologic interventions were limited to 20 studies, and the quality of the evidence remains poor. Few pharmacologic approaches have been studied, and evidence for use of herbal and complementary supplements is almost nonexistent. Conclusions Current knowledge indicates that sleep/wake disturbances are prevalent in cancer populations. Few instruments have been validated in this population. Nonpharmacologic interventions show positive outcomes, but design issues and small samples limit generalizability. Little is known regarding use of pharmacologic and herbal and complementary supplements and potential adverse outcomes or interactions with cancer therapies. Implications for nursing All patients and caregivers need initial and ongoing screening for sleep/wake disturbances. When disturbed sleep/wakefulness is evident, further assessment and treatment are warranted. Nursing educational programs should include content regarding healthy and disrupted sleep/wake patterns. Research on sleep/wake disturbances in people with cancer should have high priority.

250 citations

Journal ArticleDOI
TL;DR: The results imply that it is feasible to estimate changes in pineal function of prostate cancer patients by means of non-invasive determination using urinary melatonin and aMT6s.

100 citations

References
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Journal ArticleDOI
TL;DR: It was shown that the tumor-specific antibodies were not directed against bacterial contaminants or against the unusually high concentrations of fibrin found in many neoplastic tissues.
Abstract: Two methods were used to demonstrate the presence of tumor-specific antigens in adenocarcinomata of the human colon: (a) rabbits were immunized with extracts of pooled colonic carcinomata, and the antitumor antisera thus produced were absorbed with a pooled extract of normal human colon and with human blood components; (b) newborn rabbits were made immunologically tolerant to normal colonic tissue at birth, and were then immunized with pooled tumor material in adult life. Normal and tumor tissues were obtained from the same human donors in order to avoid misinterpretation of results due to individual-specific antigenic differences. The antisera prepared by both methods were tested against normal and tumor antigens by the techniques of agar gel diffusion, immunoelectrophoresis, hemagglutination, PCA, and immunofluorescence. Distinct antibody activity directed against at least two qualitatively tumor-specific antigens, or antigenic determinants, was detected in the antisera prepared by both methods and at least two additional tumor antigens were detected exclusively in antisera prepared by the tolerance technique. Whether these additional antigens were qualitatively different from normal tissue antigens, or merely present in tumor tissue in higher concentrations than in normal tissue has not as yet been determined. Furthermore, it was shown that the tumor-specific antibodies were not directed against bacterial contaminants or against the unusually high concentrations of fibrin found in many neoplastic tissues. It was concluded from these results that the pooled tumor extracts contained tumor-specific antigens not present in normal colonic tissue. Identical tumor-specific antigens were also demonstrated in a number of individual colonic carcinomata obtained from different human donors.

2,216 citations

Journal ArticleDOI
28 May 1982-Science
TL;DR: Low nocturnal melatonin concentrations may indicate the presence of estrogen receptor positive breast cancer and could conceivably have etiologic significance.
Abstract: Plasma melatonin concentrations were determined over a period of 24 hours in 20 women with clinical stage I or II breast cancer. In ten of the patients, whose tumors were estrogen receptor positive, the nocturnal increase in plasma melatonin was much lower than that observed in eight control subjects. Women with the lowest peak concentration of melatonin had tumors with the highest concentrations of estrogen receptors. A significant correlation was found between the peak plasma melatonin concentration and the tumor estrogen receptor concentration in 19 of the patients. These data suggest that low nocturnal melatonin concentrations may indicate the presence of estrogen receptor positive breast cancer and could conceivably have etiologic significance.

228 citations

Journal ArticleDOI
TL;DR: The data indicate that the elevated daytime serum levels of melatonin in patients with liver cirrhosis are due to decreased clearance, probably related to decreased liver blood flow, lowered activity of 6 beta-hydroxylase, and competition with bilirubin in the intrahepatic transport system.
Abstract: To evaluate the influence of changes in liver function on serum levels of melatonin, we measured serum levels and MCR of the hormone in patients with liver cirrhosis and in healthy control subjects. Daytime (0900-1100 h) serum levels of melatonin in patients with liver cirrhosis were significantly elevated compared to those in healthy subjects. Significant positive correlations of the daytime serum levels of melatonin with the serum retention rate of indocyanine green dye and serum levels of total bilirubin were noted. The clearance of melatonin from blood showed a biphasic first-order kinetic pattern. The half-life of each phase was significantly prolonged in patients with cirrhosis compared to healthy subjects. Our data indicate that the elevated daytime serum levels of melatonin in patients with liver cirrhosis are due to decreased clearance, probably related to decreased liver blood flow, lowered activity of 6 beta-hydroxylase, and competition with bilirubin in the intrahepatic transport system.

156 citations