It has recently been demonstrated by three independent research groups including ours that interleukin 1 (IL-1), a polypeptide hormone produced by activated monocytes or macrophages, or both, stimulates the release of hypothalamic corticotropin-releasing factor (CRF). Since CRF acts centrally in the brain to reduce food intake, we hypothesized that IL-1 might induce anorexia through this central action of CRF. The present study was carried out to examine the hypothesis, using male Wistar rats. Based on three lines of evidence, we report here that IL-1, both endogenously released and exogenously administered, induces the suppression of food intake in rats and that endogenous CRF in the brain is involved in the IL-1-induced anorexia. First, lipopolysaccharide (LPS), a potent stimulant of the release and production of endogenous IL-1, caused anorexia in a dose-related manner, and this effect was significantly blocked by pretreatment with glucocorticoid hormones, which have been shown to inhibit the production of endogenous IL-1 by LPS. Second, intraperitoneal injection of IL-1 resulted in a dose-related suppression of food intake. Third, anorexia induced by IL-1 was diminished by the immunoneutralization of endogenous CRF in the brain. These results provide further evidence of the existence of bidirectional communication between the immune and neuroendocrine systems. Furthermore, this connection between IL-1 and CRF may represent a mechanism by which anorexia results from the activation of the immune system by such immunological challenges as acute infectious diseases.
Mass screening for liver cancer based mainly on abdominal ultrasound was begun in major cities of Hokkaido, Japan, in November 1981, to enable early detection and treatment of hepatocellular carcinoma (HCC). Serum alpha-fetoprotein levels were also measured to minimize false negative studies. Examinees included those who sought liver disease screening as well as high risk individuals: hepatitis B surface antigen carriers and those with a past or current liver disease, history of blood transfusion, family history of liver cancer, and more recently those with positive anti-hepatitis C antibodies. The examination was carried out on each Saturday and Sunday as one round, and by February 1992 48 rounds had been performed. A total of 8090 individuals were investigated, and HCC was detected in 91 with a detection rate of 1.12%. This rate was 1.6% among 5684 individuals who were selected for high risk. Cumulative rates of survival among these patients were 79.0% at 1 year, 43.8% at 3 years, 19.3% at 5 years and 15.4% at 7 years. These survival rates were comparable with those for the patients with HCC diagnosed during follow-up of chronic liver disease and treated at our hospital. The cost for detecting one HCC patient in this programme was 2,660,000 yen (approximately US$25,000), which was less than those for some other types of cancer in a similar setting. Considering the high detection rate in this programme, we feel that similar programmes should be encouraged and supported.
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