Serum ferritin and stomach cancer risk among a Japanese population
Article Abstract:
Generally, risk factors for the development of cancer are determined retrospectively. After patients have developed cancer their histories are compared with the general population to glean any differences that might be of medical interest. The authors of the present study have access to a unique resource which permits special tests to be performed on blood samples taken before the patients actually developed symptoms of cancer. A large number of samples of blood serum were collected from 1970 to 1972 and again from 1977 to 1979 from citizens of Hiroshima and Nagasaki who had been exposed to unusually high levels of radioactivity some years previously. These subjects are known to be at an especially high risk for the development of cancer. Two factors of interest in the ongoing study of cancer development are the roles of nutritional iron and copper. Since high levels of serum ferritin, and low levels of serum transferrin are indicators of large body stores of iron, these proteins were measured in the stored serum samples of 233 patients who later developed stomach cancer and 84 patients who later developed lung cancer. Researchers also measured ceruloplasmin, a copper-containing protein, which reflects the body stores of copper. Low levels of ferritin were found to be more common among the patients with stomach cancer. When the levels were grouped into five classes, the patients in the lowest, or fifth, class had three times the risk of stomach cancer as those in the highest quintile of ferritin. Many of the patients in the group had been previously diagnosed with achlorhydria, an absence of stomach acid which indicates atrophy of the stomach lining. Patients with both low ferritin levels and achlorhydria had a 10-fold greater risk of stomach cancer. The risk of stomach cancer was not influenced by the levels of ceruloplasmin, and none of the factors investigated were related to the risk of lung cancer in these subjects. In some cases, the low levels of ferritin were evident five years prior to the onset of cancer, indicating that it is possible to detect some risk factors for stomach cancer years before the actual onset of disease. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Cancer
Subject: Health
ISSN: 0008-543X
Year: 1991
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Sufficient levels of quinine in the serum circumvent the multidrug resistance of the human leukemic cell line K562/ADM
Article Abstract:
Unfortunately, cancer cells sometimes develop resistance to the toxic effects of anticancer drugs. Drug resistance can develop by several different mechanisms. One mechanism results in the simultaneous development of resistance to several drugs and is appropriately called multidrug resistance (MDR). Often patients with acute leukemia or multiple myeloma respond favorably to chemotherapy only to relapse and die because cancer cells have become unresponsive to chemotherapeutic agents. Multidrug resistance seems to result from the expression of a protein in the cancer cell membrane; this protein acts as a pump and pushes many types of chemotherapeutic agents back out of the cancer cell. Insufficient amounts of drug accumulate within the cell, and the cancer cell escapes the toxic effects of treatment. This phenomenon can be studied in vitro, that is, in cells grown under laboratory conditions. Researchers have identified many substances that can block this pumping action, and in principle, render the cancer cells once again susceptible to chemotherapy. However, the amounts of the substances used in the laboratory could never be used inside the human body. More recently, researchers found that the drug quinine, famous as one of the first effective treatments for malaria, may block multidrug resistance. More importantly, quinine appears to block MDR at concentrations practical for medical treatment. An experimental treatment protocol including quinine has begun for patients with leukemia or multiple myeloma refractory (resistant) to treatment. Using cultures of the experimental human leukemic cell designated K562/ADM, researchers found that blood samples taken from the patients contained sufficient quinine to block the MDR in laboratory experiments. This demonstrates that the amount of quinine in the blood of human cancer patients can be sufficient to block multidrug resistance in leukemic cells. However, it remains to be determined if this effect observed in laboratory dishes will affect the leukemic cells in patients' bodies in the same manner. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Cancer
Subject: Health
ISSN: 0008-543X
Year: 1991
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Evaluation of serum levels of soluble interleukin-2 receptor in patients with chronic lymphoproliferative disorders of T-lymphocytes
Article Abstract:
The protein interleukin-2 (IL-2) is involved in the activation and proliferation of T lymphocytes. When IL-2 binds to a cell surface receptor that is specific for IL-2, the cells become stimulated. A soluble form of the receptor (sIL-2R) is present in human blood serum. High levels of sIL-2R have been found in a number of pathological conditions. Levels of sIL-2R have been examined in patients with chronic lymphoproliferative disorders. Chronic lymphoproliferative disorders of T lymphocytes include two major clinical conditions: chronic lymphocytic leukemia of helper T cells (Th-CLL); and lymphoproliferative disease of granular lymphocytes (LDGL). Th-CLL contains both an endemic (commonly occurring but with low mortality) and a non-endemic form of adult T cell leukemia (ATL). The endemic form of ATL is associated with infection with the human T-leukemia virus type 1. Levels of sIL-2R were increased in 12 patients with Th-CLL. When Th-CLL progressed rapidly, patients had significantly higher levels of sIL-2R; levels were approximately 16 times greater when compared with those with a less aggressive disease. The serum concentration of sIL-2R correlated with the number of helper T cells. Twenty-one patients with LDGL also showed an increase of sIL-2R in their serum, but the concentration was lower than levels measured in patients with Th-CLL. The concentration of sIL-2R in the serum of a patient can be used as a clinical marker for Th-CLL and LDGL and can be used to monitor the progression of disease in Th-CLL. The biological significance of this soluble receptor is being studied further. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Cancer
Subject: Health
ISSN: 0008-543X
Year: 1989
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