Cancer patterns among Koreans in Japan, Koreans in Korea and Japanese in Japan in relation to life style factors

Cancer incidences for major sites were compared among Koreans in Osaka, Japan, Koreans in Korea and Japanese in Osaka by calculating standardized proportional incidence ratios (SPIR's), in addition to updating the findings on cancer mortality experiences of Koreans and Japanese in Osaka reported before. Compared with Japanese, Koreans in Osaka had significantly higher mortality rates from cancers of the esophagus, liver and lung in males, and liver in females. Mortality rates among Koreans in Osaka were significantly lower for stomach cancer in both sexes and for breast cancer in females. Compared with Korean counterparts in the homeland, Koreans in Osaka had a reduced risk for cancers of the stomach in males and the uterus in females. On the other hand, an elevated risk was observed for cancers of the esophagus, colon, liver and lung among Korean males in Osaka and for cancers of the colon and liver among Korean females in Osaka. The risk for cancer of the breast in females was similar among Koreans in the host and home countries. These different cancer patterns among Koreans in the host and home countries and Japanese are discussed in relation to their life styles, such as smoking, drinking and dietary habits, which have been investigated by means of questionnaire surveys.

Morphology, growth and reversion in a stable L-form of Escherichia coli K12

An L-form isolated from Escherichia coli K12 by sequential treatment with N-methyl-N'-nitro-N-nitrosoguanidine and lysozyme was adapted to grow in hyperosmolar liquid cultures. It was stable in the absence of antibiotic when cultured in brain heart infusion (BHI) broth containing NaCl and CaCl2, the optimal concentrations being 0.34 M and 1 mM, respectively. No growth of the L-form was observed when CaCl2 was not added to BHI medium containing 0.34 M-NaCl. On the other hand, when KCl replaced NaCl as the osmotic stabilizer, growth of the L-form was repressed in the presence of CaCl2. Electron microscopy of the L-form confirmed the absence of a cell wall. A revertant strain derived from the L-form grew as a stable bacillary form in BHI medium without osmotic stabilizer. The growth characteristics of the revertant strain resembled those of the parent strain. The revertant strain produced L-forms in the presence of NaCl.

Cloning, sequencing, and expression of cDNA for human beta-glucuronidase

We report here the cDNA sequence for human placental beta-glucuronidase (beta-D-glucuronoside glucuronosohydrolase, EC 3.2.1.31) and demonstrate expression of the human enzyme in transfected COS cells. We also sequenced a partial cDNA clone from human fibroblasts that contained a 153-base-pair deletion within the coding sequence and found a second type of cDNA clone from placenta that contained the same deletion. Nuclease S1 mapping studies demonstrated two types of mRNAs in human placenta that corresponded to the two types of cDNA clones isolated. The NH2-terminal amino acid sequence determined for human spleen beta-glucuronidase agreed with that inferred from the DNA sequence of the two placental clones, beginning at amino acid 23, suggesting a cleaved signal sequence of 22 amino acids. When transfected into COS cells, plasmids containing either placental clone expressed an immunoprecipitable protein that contained N-linked oligosaccharides as evidenced by sensitivity to endoglycosidase F. However, only transfection with the clone containing the 153-base-pair segment led to expression of human beta-glucuronidase activity. These studies provide the sequence for the full-length cDNA for human beta-glucuronidase, demonstrate the existence of two populations of mRNA for beta-glucuronidase in human placenta, only one of which specifies a catalytically active enzyme, and illustrate the importance of expression studies in verifying that a cDNA is functionally full-length.

Evaluation of a mass screening program for stomach cancer with a case-control study design

In order to evaluate the effectiveness of a mass screening program for stomach cancer, a case-control study was conducted in Nose town in Osaka, Japan. The case series consisted of all deaths from stomach cancer during the period 1969-1981 (54 in males and 37 in females). For each case, 3 controls of the same sex and from the same precinct as the case, and born within 5 years of the case birth-year, were selected at random from Nose town residents alive at the date of death of the relevant case. We then investigated whether each case and corresponding controls had ever had screening tests before the date of diagnosis of the case. From the matched analysis of the distribution of screening in case-control combination, the odds ratio of screened vs. unscreened among those who died from stomach cancer compared to those who did not was calculated as 0.595 (90% confidence interval: 0.338-1.045) among males and 0.382 (0.185-0.785) among females. When the screening tests conducted within 12 months of diagnosis were ignored on the presumption that they were symptom-related, the odds ratio was calculated as 0.519 (0.297-0.905) among males and 0.486 (0.239-0.986) among females. These data strongly suggest that the mass screening program is effective in reducing stomach cancer mortality.

Mortality among Koreans living in Osaka, Japan, 1973-1982

The mortality pattern of Koreans living in Osaka, Japan was surveyed by comparing their age-specific and age-adjusted death rates with those among Japanese during 1973-1982. Cancer was the leading cause of death among Korean males, while cerebrovascular disease was most common among Korean females in Osaka. Mortality rates from tuberculosis, cancer, mental disorder, cerebrovascular disease, chronic obstructive pulmonary diseases (COPD), liver cirrhosis, accidents and suicide were significantly higher for Korean males than for Japanese males. COPD, liver cirrhosis and accidents were more frequent for Korean females than for Japanese females. In cancers, liver cancer was most common among Korean males, followed by stomach and lung cancers. Stomach cancer was most frequent among Korean females, followed by uterine and liver cancers. The ratio of cancer mortality rates for Koreans and Japanese was significantly higher than 1.0 for oesophagus, liver and lung among males, and for liver among females. Koreans had considerably higher levels of liver cancer and liver cirrhosis compared with Japanese. Mortality from stomach cancer was significantly lower in both sexes among Koreans in Osaka and the reduction of this disease among Koreans in Japan occurred more rapidly than among Japanese.

Pathophysiology of hepatic ischemia in cardiogenic shock

The hepatic hemodynamic response to cardiogenic shock was investigated in a porcine model produced by pericardial tamponade to better understand the pathophysiology of postshock hepatic insufficiency. Reductions of cardiac output to 50 percent of baseline levels produced marked hepatic ischemia by causing disproportionate reductions in blood flow through the celiac and hepatic arteries and portal vein. These were due to selective vasoconstriction of the splanchnic resistance vessels that was mimicked without tamponade by the infusion of angiotensin II, ablated by angiotensin-converting enzyme blockade, unaffected by alpha-adrenergic ablation, and correlated closely with levels of plasma renin activity. The ischemic liver injury of cardiogenic shock appears to be largely due to an exquisite responsiveness of the splanchnic vascular smooth muscle to endogenously released angiotensin II.

AccIII, a new restriction endonuclease from Acinetobacter calcoaceticus

A new site-specific restriction endonuclease, AccIII, was isolated from Acinetobacter calcoaceticus. AccIII recognizes T/CCGGA and cleaves at the position shown by the arrow. AccIII activity was inhibited by adenine methylation at the overlapping dam methylase recognition sequence.

Occurrence of second primary cancers among patients with cervical cancer in Osaka, Japan

Using the data accumulated in the Osaka Cancer Registry, we conducted a study on the effect of radiotherapy for cervical cancer in causing second primary cancers. Two groups of patients with cervical cancer, 1,767 who were given radiotherapy and 1,377 who were not, were followed for 7-9 years on average. In the radiotherapy group, 79 women had second primaries, and in the nonradiotherapy group, 23 did. These figures were compared with the expected cancer incidence for all sites. In the radiotherapy group, a significantly high observed-to-expected ratio was noted in cancers of the rectum, lung, and bladder. The nonradiotherapy group showed no site with a significantly high observed-to-expected ratio. Factors causing the increased level of lung cancer were studied. Some evidence indicated the excess was probably not related to smoking but to radiation, although the mechanism is unknown.

[Cancer screening in Japan--a critique from the epidemiological viewpoint]

The present status of cancer screening in Japan has been critically reviewed from an epidemiological point of view. Cancer screening programs for stomach cancer and uterine cervical cancer were introduced in the 1960s on the basis of the naive belief of many clinicians that early diagnosis is beneficial: Many studies now show that this belief unfounded. Therefore, before the introduction of screening programs as a general policy, epidemiological evaluation is essential. The general principles involved in evaluation of cancer screening were discussed. In contrast to stomach cancer and uterine cervical cancer, cancers of the lung, breast and colorectum are increasing in Japan. In the case of lung cancer, primary prevention, i.e., smoking control, should be preferred, because lung cancer screening has not yet been shown to be effective. In the case of breast cancer and colorectal cancer, screening trials should be designed and appropriate evaluations should be conducted before their implementation as cancer control measures.

Control of gastric vascular resistance in cardiogenic shock

That local splanchnic ischemia is associated with the acute gastric "stress" erosions seen in shock is well established. The hemodynamic mechanism mediating that ischemia is unknown. Pericardial tamponade was produced in anesthetized pigs while hemodynamic parameters were monitored in the systemic circulation as a whole and in the vascular beds of the celiac and left gastric arteries, respectively. Stepwise increases in pericardial pressure produced progressive decreases in arterial pressure and cardiac output (i.e., reproducible, quantitable, and rapidly reversible levels of cardiogenic shock). This produced a profound reduction in blood flow in the celiac and gastric beds that was significantly disproportionate to the reduction in cardiac output. This was due to significant increases in celiac and gastric vascular resistance that were more than twice as great as those seen in the systemic circulation as a whole (i.e., selective splanchnic vasoconstriction). This response was abolished by ablation of the renin-angiotensin axis, whether by bilateral nephrectomy, captopril, or saralasin, and mimicked, without tamponade, by the infusion of angiotensin II. Levels of celiac artery blood flow and resistance correlated significantly with endogenous levels of plasma renin activity. On the other hand, this response was not abolished by confirmed alpha-adrenergic blockade (phenoxybenzamine) or by sympathectomy. In this model, cardiogenic shock produces regional splanchnic ischemia in the celiac and gastric vascular beds by inducing a severe and disproportionate vasospasm that is mediated primarily by the renin-angiotensin axis.

Follow-up study of HBs Ag-positive blood donors with special reference to effect of drinking and smoking on development of liver cancer

In order to confirm the close association between chronic hepatitis B virus (HBV) infection and primary hepatocellular carcinoma (PHC) in Japan, 8,646 male hepatitis B surface antigen (HBs Ag)-positive blood donors (GPT less than or equal to 35 Karmen units) were followed up. Twenty liver cancer cases were observed during the follow-up period (average 6.2 years), the expected number calculated on the basis of age-specific incidence rates among the general population being 3.03. Therefore, the observed to expected ratio of liver cancer was 6.60, that is significantly higher than 1.0. During the same follow-up period, a total of 76 deaths were observed, of which 20 were due to liver cancers and 9 to liver cirrhoses, meaning that nearly 40% of deaths among the study subjects due to chronic liver diseases. Drinking and smoking habits in the liver cancer cases were compared with those observed in healthy male HBV carriers. A strong positive association between drinking habits and liver cancer was observed and there was a significant dose-response relationship after adjustment for cigarette smoking habits. A high risk of liver cancer was also observed among heavy smokers, but a significant dose-response relationship could not be found between smoking habits and liver cancer, partly because of the limited number of the study subjects. These findings suggest that HBV is a major etiologic agent of PHC in Japan where the HBs Ag prevalence rate is about 2%, and alcohol drinking and cigarette smoking may promote the process of HB viral hepato-carcinogenesis.

Prospective study of "early" gastric cancer

In order to elucidate the natural history of early gastric cancer, we followed up non-concurrently certain patients who had been diagnosed endoscopically as having "early' gastric cancer and who had histological evidence of cancer by biopsy, but on whom surgical resection had been delayed or had not been conducted. At the Center for Adult Diseases, Osaka, 56 cases were eligible for this study. Out of these, 27 cases progressed to advanced cancer and 16 remained at the early stage during the follow-up period (6-88 months, mean: 29 months). The remaining 13 cases had had neither surgical resection nor examinations. The survivorship function for the duration of "early" gastric cancer was estimated by the life-table method of Kaplan and Meier. The median of the duration was estimated as 37 months. The 5-year survival rate of the 34 cases on whom surgical resection had not been conducted was estimated as 64.5%. These results suggest that early diagnosis and early treatment may lead to a reduction of mortality from stomach cancer.

Regulation of the phosphatidylethanolamine methylation pathway in Saccharomyces cerevisiae

1. Phosphatidyl-N-methylethanolamine methyltransferase mutants of Saccharomyces cerevisiae were isolated. Genetic analysis showed that phosphatidylethanolamine methyltransferase and phosphatidyl-N-methylethanolamine methyltransferase are coded for by separate genes. Phosphatidyl-N-methylethanolamine methyltransferase activity and phosphatidyl-N,N-dimethylethanolamine methyltransferase activity appeared to be catalyzed by the same enzyme. 2. Phosphatidyl-N-methylethanolamine methyltransferase was found to be repressed by myo-inositol and choline. Both myo-inositol and choline at concentrations of 10 micrograms/ml were required for repression. The decreased enzyme level was restored by the removal of myo-inositol or choline or both. 3. Both myo-inositol and choline were required for the maximum repression of phosphatidylethanolamine methyltransferase in wild-type cells. In contrast, choline was not required for the repression of the enzyme in mutant strain 172. This was due to a single nuclear gene mutation in the genome of strain 172. 4. The activity of the phosphatidylethanolamine methylation pathway in cells decreased with time on incubation of cells with myo-inositol and choline, myo-Inositol could not be replaced by other structurally related compounds, such as scyllo-inositol or mannitol. 5. The physiological significance of the repression of the phosphatidylethanolamine methylation pathway is discussed with respect to the mechanism for maintaining the contents of phosphatidylethanolamine and phosphatidylcholine at normal levels.

Cancer mortality among Koreans in Osaka, Japan

Using data from the Osaka Cancer Registry, we calculated age-standardized cancer mortality rates among Koreans and Japanese living in Osaka, Japan, during 1968-77. The following points were elucidated: 1) Among Koreans in Osaka, the mortality rate for liver cancer was about twice that among Japanese; 2) Among Koreans in Japan, the mortality rate of stomach cancer has been declining more rapidly than it has among Japanese. The factors involved in the Korean-Japanese difference of liver cancer and those involved in the rapid decrease of stomach cancer among Koreans in Japan are discussed.

Multiple primary cancers following exposure to benzidine and beta-naphthylamine

The incidence of second primary cancers has been ascertained in 3,322 employees who had worked from 1950 to 1978 in industries in Japan that manufactured benzidine and beta-naphthylamine. Of the 244 workers who had suffered from and died of cancer of the genitourinary organs (first primary cancer), 11 (all male) had subsequent primary, histologically confirmed cancers of the liver, gallbladder, bile duct, large intestine, and lung. A control group of 177 male bladder cancer patients, assembled from the Osaka Cancer Registry during 1965-1975, showed eight cases of a second primary, five being stomach cancer. No stomach cancer was observed in the study cohort. A statistically significant excess risk for liver, gall bladder, and bile duct cancer (p less than 0.05) was found The number of observed deaths from respiratory cancer was greater than expected, though not statistically significant. These findings appear to confirm previous clinical data suggesting an increased occurrence of multiple primary cancers in workers exposed to benzidine/beta-naphthylamine, pointing to a pluripotential action of these carcinogens.

Regulation of phosphatidylethanolamine methyltransferase level by myo-inositol in Saccaromyces cerevisiae

1. A conditional choline auxotroph was isolated. The growth of this mutant was markedly inhibited by the addition of a low concentration of myo-inositol to the culture medium. The growth inhibition was completely prevented by the addition of choline. 2. When this mutant cell was grown in the presence of myo-inositol, the intracellular level of phosphatidylethanolamine methyltransferase was very low, whereas in the cell grown in the absence of myo-inositol the enzyme level was normal. The addition of myo-inositol to the cell grown in the absence of myo-inositol caused a marked decrease in the methyltransferase level. 3. The reduction in phosphatidylethanolamine methyltransferase level by myo-inositol also occurred in various wild type strains of Saccharomyces cerevisiae. 4. The decreased methyltransferase activity was restored by the removal of myo-inositol from the culture medium. The restoration of the enzyme level was completely abolished by cycloheximide. Thus, it was shown that protein synthesis was involved in the change of phosphatidylethanolamine methyltransferase level by myo-inositol. 5. These results suggest that the synthesis of phosphatidylcholine from phosphatidylethanolamine by the methylation pathway is regulated by myo-inositol.

Descriptive epidemiology of cancer in Japan: current cancer incidence and survival data

The Research Group for Population-Based Cancer Registration in Japan, which has been collecting cancer incidence and mortality data from participating registries annually since 1974, has also been estimating cancer incidence rates for the whole of Japan by sex, age, and site. Data from the third survey have now been analyzed. Marked changes have been observed by the Osaka Cancer Registry in incidence rates of some sites during this period. Five-year relative survival rates for registered cancer cases have been calculated by the Osaka Registry for the first time in Japan.

Evaluation of a mass screening program for stomach cancer

To evaluate a mass screening program for stomach cancer, we followed 32,789 subjects for 6.1 years by means of a record linkage to a population-based cancer registry. The results show that the mortality from stomach cancer among those studied decreased by 9% as compared with the expected number calculated on the basis of the sex- and age-specific rates among the general population. When the study subjects were limited to those aged 40-59 years, the decrease in stomach cancer deaths became more marked, i.e., a 26% decrease was observed. Because this study is not a controlled trial, the results must be interpreted with the reservation that some biases were present in the study subjects.