Akihiko Suyama

Prognostic significance of serum anti-p53 antibody in patients with hepatocellular carcinoma

BACKGROUND/AIMS Abnormalities of the p53 gene can lead to the production of anti-p53 antibody in the serum of cancer patients. We evaluated the prognostic significance of anti-p53 antibody in 86 patients with hepatocellular carcinoma (HCC) in comparison with clinicopathological factors: age, sex, etiology, smoking and drinking habits, history of blood transfusion, presence of encephalopathy and ascites, Child classification, Pugh score, bilirubin, albumin, prothrombin time, indocyanine green retention time at 15 min (ICG), underlying liver disease, alpha-fetoprotein (AFP), tumor size, number of tumors, differentiation degree of HCC, presence of extrahepatic metastasis and therapy for HCC. METHODS The serum anti-p53 antibody in 86 patients with HCC, 20 with chronic hepatitis (CH) and 20 with liver cirrhosis (LC) was measured by an enzyme-linked immunosorbent assay (ELISA). A single-strand conformation polymorphism-polymerase chain reaction (SSCP-PCR) analysis and loss of heterozygosity (LOH) study of the p53 gene were performed using 8 tissue samples of 8 HCC from four antibody-positive and four antibody-negative patients. The survival probabilities were assessed by the Kaplan-Meier technique, and a Cox regression analysis was used to identify the independent factors for prognosis. RESULTS Anti-p53 antibody was positive in 32% (28 of 86) of the sera from patients with HCC, but in none of the 20 with CH and 20 with LC. p53 antibody positivity was associated with bilirubin and the number of tumors (p=0.027 and p=0.018, respectively). Overall survival was shorter in the HCC patients with p53 antibody than in those without p53 antibody (p<0.02). Bilirubin, p53 antibody, AFP and ICG were found to be significant prognostic factors by univariate analysis. A Cox multivariate analysis showed that bilirubin and p53 antibody were independent prognostic variables (p<0.0001 and p=0.003, respectively). In four antibody-positive patients, mutation and LOH of the p53 gene were detected in one patient and two patients, respectively. In contrast, only one of four antibody-negative patients exhibited LOH of the p53 gene. CONCLUSIONS Serum anti-p53 antibody could be a useful prognostic factor in patients with HCC.

Mortality and Cancer Incidence in Misasa, Japan, a Spa Area with Elevated Radon Levels

A historical cohort study was conducted in Misasa town, Tottori prefecture, Japan, where radon spas have been operating for a long time. Misasa town was divided into an elevated radon level area and a control area, with mean indoor radon levels of about 60 and 20 Bq/m3, respectively. In total, 3,083 subjects in the elevated radon level area and 1,248 in the control area, all aged 40 or older on January 1, 1976, were followed up until December 31, 1993, for a mean period of 14 years. The mortality rates from all causes exhibited no difference between the elevated radon level area and the control area for both sexes. No difference was observed in the incidence of all‐site cancers (age, period‐adjusted rate ratios by Poisson regression, RR=1.06, 95% confidence interval (CI) 0.79–1.42 for males, RR=0.90, 95% CI 0.65–1.24 for females), while stomach cancer incidence seemed to decrease for both sexes (RR=0.70, 95% CI 0.44–1.11 for male, RR=0.58, 95% CI 0.34–1.00 for female) and lung cancer incidence for males only seemed to increase (RR=1.65, 95% CI 0.83–3.30 for male, RR=1.07, 95% CI 0.28–4.14 for female) in the elevated radon level area. Caution is needed in the interpretation of these findings, however, since the individual exposure level was not measured and major confounding factors, such as smoking and diet, could not be controlled in this study.

Cross-sectional study on risk factors of HIV among female commercial sex workers in Cambodia

To describe epidemiological features on HIV prevalence among female commercial sex workers (CSWs), a cross-sectional study on sexual behaviour and serological prevalence was carried out in Cambodia. The CSWs were interviewed on their demographic characters and behaviour and their blood samples were taken for testing on sexually transmitted diseases, including HIV, Chlamydia trachomatis, syphilis, and hepatitis B. Associations between risk factors and HIV seropositivity were analysed. High seroprevalence of HIV and Chlamydia trachomatis IgG antibody (CT-IgG-Ab) was shown among the CSWs (54 and 81.7%, respectively). Univariate logistic regression analyses showed an association between HIV seropositivity and age, duration of prostitution, the number of clients per day and CT-IgG-Ab. Especially, high-titre chlamydial seropositivity showed a strong significant association with HIV prevalence. In multiple logistic regression analyses, CT-IgG-Ab with higher titre was significantly independently related to HIV infection. These suggest that existence of Chlamydia trachomatis is highly related to HIV prevalence.

Development of an instrument to measure postmortem lividity and its preliminary application to estimate the time since death

A degree of postmortem lividity was related to a subcutaneous hemoglobin concentration, which can be measured by using light absorption. On the basis of this theory, the authors have developed an instrument utilizing a light to measure the degree of postmortem lividity. By using 42 corpses whose postmortem intervals were known, the authors examined the relationship between the actual postmortem intervals and the measurements, and found that there was significant correlation between them.

Application of a computer based education system for aged persons and issues arising during the field test

We plan to apply a computer-based multimedia text-book system for health education in the future. To do this, the computer system should be manageable to any person regardless of age or computer experience. We developed a multimedia text-book system and field-tested it to survey the reaction of aged persons. The system offers information about obesity prevention, such as a guide for eating and exercise. All contents are presented by text, image and voice. Also, a guide for exercise is shown by a movie. In this investigation we found that there were many considerations for aged persons using a computer. They seemed to have a strong aversion toward computers. They had the feeling that computers are difficult to use; actually 22 persons among 65 could not use it. Improvements in user interface seems to be the most important thing to make computers accessible to aged persons. On the other hand, question-and-answer programs for diagnosing ones health status were well accepted. Such a function is useful for attracting the interest of aged persons when we design a computer-based education system.