Association between hepatitis C virus and hepatocellular carcinoma using assays based on structural and nonstructural hepatitis C virus peptides

Stored sera from 181 Greek patients with hepatocellular carcinoma (HCC), 35 patients with metastatic liver cancer, and 416 hospital controls with diagnoses other than malignant neoplasm or liver disease were examined with first and second generation hepatitis C virus (HCV) enzyme immunoassays as well as with five HCV supplemental assays based on structural and nonstructural HCV peptides. Second generation HCV enzyme immunoassays were more sensitive than first generation assays. However, both assays had suboptimal specificity using the standard reactivity criterion (absorbance of sample to cutoff greater than or equal to 1.0). Specificity was improved by centrifugation and by using a sample's optical density to cutoff ratio greater than or equal to 3.0 or supplemental assays; in this instance the prevalence of antibodies to HCV was 13.3% (24 of 181), 0 (0 of 35), and 1.4% (6 of 416) in HCC, metastatic liver cancer, and hospital controls, respectively. A similar estimation of prevalence of antibody to HCV in HCC (12.5% or 4 of 32) was obtained when the recombinant immunoblot assay, second generation, was used to screen a random sample of HCC patients. The relative risk linking HCV to HCC was estimated as 10.4 (95% confidence interval, 4.2-26.0; P less than 0.0001). These data suggest that the prevalence of antibodies to HCV in HCC using stored sera has been previously overestimated even though the evidence of a causal association of HCV with HCC persists.

Meconium peritonitis-antenatal diagnosis by ultrasound

Meconium peritonitis is usually the result of prenatal bowel obstruction with subsequent perforation, then the contents spread into the peritoneal cavity, which results in a sterile inflammatory reaction. The incidence ranges from 1/1500 to 1/2000, if without prenatal diagnosis and planned postnatal treatment, the mortality rate is as high as 62%. We describe three children, two with surgically, one with autoptically confirmed meconium peritonitis. All had abnormally prenatal ultrasonographic examinations. The first fetus showed a large 10 x 11 cm intra-abdominal mass with floating echogenic substances inside and with an echogenic rim. The second showed increased echogenicity with dilated bowel in abdominal cavity in one of the twin, and the third had an intra-abdominal cyst with several echogenic bands inside, fetal ascites was also noted. It is remarkable that the ultrasonographic findings were different in the three children. Two of the three children survived postoperation, one died 3 hours later after induction out at 31 weeks of gestational age due to multiple congenital anomalies.

Strategies for blood screening for the hepatitis C virus and for the human immunodeficiency virus in high risk groups

For many infectious agents, seroprevalence rate is low but has serious consequences and must therefore be kept out of donated blood supplies. However, screening to ensure the safety of blood supplies has an associated very high cost. For example, in blood banks, detection of all the harmful items in a large number of samples is an expensive and tedious process. The laboratory and statistical approaches to obtain significant savings by the pooling method were discussed from 1943, recently, there have been further discussions of pooling sera as a means to determining the HIV seroprevalence rate in the general population or the weed out all HIV-positive individuals in blood screening. Here we describe a simple mathematical method to weed out all HIV, and HCV seropositive units. The method is designed to maximize possible savings. Two examples illustrate the application of this method in determining the number to be pooled in each stage, and the resulting savings. When the prevalence rate is lower than 2 percent. our method offers savings of over 80 percent.

Successful use of pooled sera to estimate HIV antibody seroprevalence and eliminate all positive cases

Pooling specimens when testing them in large numbers can save scarce resources and several earlier reports have indicated this to be a feasible strategy. In an HIV antibody mass screening test carried out in our laboratory, we used Dorfman's two-stage model. We sought to establish the optimal number of specimens in a pool, and to achieve maximum efficiency while maintaining both sensitivity and specificity. Before testing for HIV antibody, five positive samples were placed in a set of 1012 sera in a double blind manner, one positive sample into a second set of 1012 sera and none in a third set. The positive rate was assumed to be 0.2% for each set of 1012 sera. As indicated by our model, 22 individual serum samples were placed into each of 46 pools which, when tested by particle agglutination assays, lead to the identification of all positive samples. We concluded that the prevalence rate can be estimated in the first stage, 95% confidence intervals were given, and the efficiency rate could be calculated for the identification of all infected specimens in a large number of samples showing low prevalence rates.

High protein, saturated fat and cholesterol diet, and low levels of serum lipids in colorectal cancer

In a case-control study probing the role of diet on the occurrence of colorectal cancer and undertaken in Athens, Greece, sera were collected from 100 cases and 100 controls, and serum total cholesterol, high-density-lipoprotein (HDL) cholesterol and triglycerides were determined. The biochemical results were analyzed in conjunction with nutrient intakes and a dietary score that summarizes in a linear way the dietary contrast between high-risk (high protein, saturated fat and dietary cholesterol; low vegetable) and low-risk (low protein, saturated fat and cholesterol; high vegetable) patterns. Cases with colorectal cancer had significantly (p less than 0.001) and substantially lower values of serum total cholesterol and particularly HDL cholesterol, but these associations did not reflect dietary practices, since protein intake and, to a lesser (and nonsignificant) extent, saturated fat and dietary cholesterol intake were higher among cases than among controls. In absolute terms, the dietary effect (as summarized in the linear dietary score) is more evident among persons with low serum total cholesterol and HDL cholesterol than among those with high levels of these serum lipids. These results indicate that a diet beneficial with respect to the risk of coronary heart disease is also likely to reduce the risk of colorectal cancer, even though low levels of serum total cholesterol and particularly HDL cholesterol represent important independent correlates of clinically overt colorectal cancer.

Functional analysis of the mouse alpha-fetoprotein enhancers and their subfragments in primary mouse hepatocyte cultures

We have compared the activities of mouse alpha-fetoprotein (AFP) enhancers I, II, and III with their minimal enhancer fragments (Mers) I, II, and III and with the entire 7-kilobase pair enhancer domain by transient expression assay in primary fetal mouse liver cells. The level of expression directed by the AFP promoter [p(-1009)AFPcat] alone is stimulated at least 10-fold by the entire AFP enhancer domain (-1009 to -6983). Enhancer I can drive the level of chloramphenicol acetyltransferase activity equivalent to that of the entire enhancer domain, whereas the increase in activity by enhancers II and III is significantly lower (1.5-fold). MersI, II, and III all mediate a greater increase in activity than their corresponding enhancer regions. The increase with MerI is 16-fold. Using DNase I protection analyses we identified 3 protein-binding regions in MerI; site Ia binds liver and brain nuclear proteins; site Ib binds liver, kidney, and brain nuclear proteins as well as purified C/EBP; site Ic binds liver and kidney nuclear proteins. Site-specific mutation of Ia, Ib, or Ic showed a 10-25% reduction in chloramphenicol acetyltransferase expression; deletion of the C/EBP-binding site in Ib showed a 45% reduction in activity and mutation of all 3 sites (Ia, Ib, and Ic) resulted in a 75% reduction in activity. Our studies indicate no single trans-acting factor is absolutely essential for enhancer activity, and that the enhancer activity of MerI is mediated via a combinatorial and additive mechanism.

Non-mosaic trisomy 20 in cultures of amniotic fluid from a fetus with serious congenital malformation

We present a case of non-mosaic trisomy 20 in amniotic fluid associated with major congenital anomalies. A detailed prenatal ultrasonic examination was performed, and revealed dilatation of the cisterna magna and the fourth ventricle with hypoplasia of the vermis of the cerebellum. Fetal echocardiography showed overriding aorta and ventricular septal defects with pulmonary atresia. However, the karyotype of the lymphocyte in the cord blood was normal female 46, XX. The occurrence of the Dandy-Walker malformation in non-mosaic trisomy 20 has not been reported before, and the clinical significance of this major defect for prenatal diagnosis is discussed.

Birth order and risk of testicular cancer

To explore the etiology of testicular cancer, cases of testicular cancer were identified among members of a cohort of Danish boys born between 1941 and 1957 (inclusive), who had attended schools in Copenhagen and Gentofte and whose school health records were contained in an archive under the supervision of the Danish Cancer Registry. One hundred and eighty-three cases of testicular cancer diagnosed before 31 December 1984 were identified; 366 controls, matched to cases by sex and age, were selected from the same cohort. Information on potential risk factors and confounders was obtained from two sources: school health records and midwife protocols, both of which were recorded prior to the diagnosis of testicular cancer in cases. Relative risks (RR) approximated by the odds ratios were calculated and, in logistic regression analyses, adjustments were done for known or suspected confounders. A decreasing risk of testicular cancer with increasing birth order was observed (P = 0.020). Compared with being firstborn, being number four or more in birth order was associated with a significantly decreased RR for all testicular cancers (RR = 0.3, 95 percent confidence interval [CI] = 0.3-0.8) and testicular seminoma (RR = 0.1, CI = 0.02-0.9). No association was observed between high social class and the risk of testicular cancer (RR = 1.4, CI = 0.8-2.3); neither was age at which the study subjects had mumps or measles related to risk of testicular cancer. No cases of mumps orchitis were observed before or during school years. A slightly increased RR for testicular cancer among boys from small families could be explained by the association between family size and birth order.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripartum cardiomyopathy

Peripartum cardiomyopathy is a relatively rare complication of pregnancy, characterized by heart failure of obscure etiology during the antepartal or postpartal period. During a 10-year period in our hospital, of 36,882 women who delivered, 6 were diagnosed as having peripartum cardiomyopathy. The incidence in our hospital was estimated as 1:6,147 deliveries. Among these 6 patients, 2 cases with fulminating courses died 1 month after treatment. Two other cases had cardiomyopathy and multiple congestive heart failure and died after 3 years and 6 years. Only one case, whose cardiac size returned to normal within 4 months, completely recovered from this disease. Another survivor with persistent cardiomegaly was followed for 5 years and remained clinically stable. In addition to congestive heart failure, the occurrence of complications such as sepsis, hepatorenal failure, and arrhythmia were the major causes of death. According to the results of our study, return of cardiac chamber size to the normal range indicated a good prognosis. We concluded that the prognosis of peripartum cardiomyopathy depends upon the degree of cardiac dysfunction and the response to therapy.

Time trends in physical activity among college alumni, 1962-1988

Little direct evidence exists in the epidemiologic literature to support the widely held belief that an individual's physical activity behavior varies over the years. To provide data, the authors prospectively studied patterns of physical activity among 6,092 Harvard College alumni (average age at the start of follow-up, 43 years) who responded to questionnaires in 1962 or 1966, 1977, and 1988, and who declared themselves free of cardiovascular disease and cancer throughout that period. The median energy expenditure increased between 1962 or 1966 and 1977, but stabilized between 1977 and 1988. However, rank correlation coefficients between estimates of energy expenditure in 1977 and 1988 ranged from 0.36 to 0.41 for the various age groups (compared with 0.81-0.84 for the Quetelet index, and 0.60-0.65 for the current number of cigarettes smoked per day), implying that physical activity at the individual level was not constant. For 4,238 alumni for whom data on collegiate sports participation were available, the rank correlation coefficients between collegiate activity and alumni activity 1-7 decades later were even lower, ranging from 0.05 to 0.17 (compared with 0.31-0.58 for the Quetelet index). Thus, physical activity assessed over a short time period in an individual may not be a valid proxy for activity over the long term. The characteristics that distinguished alumni who consistently expended less than 1,000 kcal/week (in climbing stairs, walking, and playing sports) in 1962 or 1966, 1977, and 1988 from those who consistently expended greater than 2,500 kcal/week were as follows: at baseline, older age, overweight, and cigarette smoking; and during college, not having been a varsity athlete and fewer hours playing sports.

[The relationship between weights of fetuses with autosomal trisomies and low maternal serum alpha-fetoprotein]

An association between low maternal serum alpha-fetoprotein (MSAFP) and fetal trisomy has now been thoroughly documented. The mechanisms resulting in low MSAFP are still unclear. In order to determine whether the low values of MSAFP in autosomal trisomies are associated with smaller fetal weights, we compared 11 fetuses with Down syndrome (trisomy 21), 4 with trisomy 18, with 45 normal fetuses. All of them are aborted in the second trimester of pregnancy. No significant difference in the weight distribution between fetuses with Down syndrome and control fetuses was found. In contrast, as compared with the control fetuses, fetuses with trisomy 18 had a significant lower weight distribution. The mean value of MSAFP was 0.72 +/- 0.26 MoM for those with Down syndrome and 0.51 +/- 0.33 MoM for fetuses with trisomy 18; both results being significantly lower than that of normal control (1.01 +/- 0.28). The mean value of amniotic fluid AFP was 0.63 +/- 0.23 MoM for fetuses with Down syndrome. This value was significantly lower than those of the fetuses with trisomy 18 and normal controls (1.02 +/- 0.09 and 1.02 +/- 0.30). A linear relationship between MSAFP and fetal weight was found in normal fetuses at a given gestational age but was not found in trisomy pregnancy. Fetal weight cannot be used to explain the reason for low MSAFP in Down syndrome pregnancy but may partially account for the lower levels noted in fetuses with trisomy 18.

Liveborn children and risk of hepatocellular carcinoma

Clinical, animal, and epidemiologic evidence indicates that exogenous steroids influence the risk of hepatocellular carcinoma (HCC) and a recent study suggested that parity also may increase the risk of this tumor in women. The latter hypothesis was evaluated in the data from a case-control study which was carried out in Athens and covered 166 male and 19 female cases of HCC, and 381 male and 51 female hospital controls. Among males, there was no association between the number of liveborn children and risk of HCC, whereas among women, there was a suggestive positive association. Compared with women with one or two children, the relative risk for HCC was 0.6 among nulliparous women, 1.3 among those with three or four children and 1.7 among those with five or more children. The association of parity with risk of HCC was limited to women who were positive for hepatitis-B surface antigen (HBsAg) and was not confounded by hepatitis-C virus infection or tobacco smoking. The small number of HCC cases does not permit firm conclusions. If confirmed, however, these results would provide the foundation for a practical preventive advice that could be given to women who are positive for HBsAg.

Physical activity and risk of prostatic cancer among college alumni

Clinical observations and laboratory experiments have suggested a role for testosterone in the development of prostatic cancer. Since physical training may act to lower testosterone levels, men who are very active may have a reduced risk of this cancer. To test this hypothesis, the authors prospectively followed 17,719 Harvard alumni (aged 30-79 years) from 1965 or 1969 to 1977, and 1980 to 1988 for the occurrence of prostatic cancer (n = 419). Physical activity was assessed in either 1962 or 1966, and again in 1977, based on self-reported stair climbing, walking, and sports played. Alumni who expended greater than 4,000 kcal/week at both assessments were at reduced risk of developing prostatic cancer (age-adjusted rate ratio, 0.12; 95% confidence interval 0.02-0.89) compared with their inactive counterparts who expended less than 1,000 kcal/week at both assessments. These results should be interpreted cautiously, since only one case of prostatic cancer was identified among alumni highly active at both assessments, who contributed 4% of total person-years to the analysis. Among alumni aged 70 years and older, those who extended greater than 4,000 kcal/week at either assessment had about half the risk of those who expended less than 1,000 kcal/week at either assessment (age-adjusted rate ratio, 0.53; 95% confidence interval 0.29-0.95). The authors attribute these findings to the increased precision with which physical activity could be measured when combining two activity assessments. Alternatively, long-term maintenance of a high level of physical activity may be necessary for further reduction of risk. There was no evidence of a dose-response relation.

Diet, pregnancy estrogens and their possible relevance to cancer risk in the offspring

Total estrogens, estradiol and estriol were determined by radioimmunoassay in the blood of 141 pregnant women during their 26th and 31st weeks of pregnancy, and the results were correlated with dietary patterns and nutrient intakes during pregnancy, assessed through a semiquantitative food frequency questionnaire. No food group or nutrient showed a significant (p less than 0.05) association with any of the examined hormones at both the 26th and the 31st week of pregnancy. Relatively more consistent were a positive association between consumption of starchy roots (potatoes) and all the indicated hormones, and a negative association between vitamin A and estradiol and total estrogens; however, the multitude of comparisons hinders a biologic interpretation at this time. There was suggestive evidence that weight gain up to the 31st week of pregnancy was positively associated with both total estrogens (p = 0.09) and estradiol (p = 0.11). The present study has limitations reflecting the relatively small sample size and the problems inherent in epidemiologic methods assessing nutritional intakes. However, the findings suggest that quantitative aspects of diet, as reflected in pregnancy weight gain, may be more important than dietary composition in influencing levels of pregnancy estrogens and in affecting the occurrence of gonadal germ cell tumors and other conditions that may be associated with them.

Epidemiologic assessment of interactions of hepatitis-C virus with seromarkers of hepatitis-B and -D viruses, cirrhosis and tobacco smoking in hepatocellular carcinoma

A recently introduced enzyme immunoassay procedure for antibodies against the hepatitis-C virus (HCV) was used to test samples from 185 cases with hepatocellular carcinoma (HCC) and 432 hospital controls. The anti-HCV results were examined in conjunction with previously reported data from this study concerning hepatitis-B virus (HBV) serology, hepatitis-D virus (HDV) antibodies, presence of cirrhosis and tobacco smoking. There was evidence for interaction between HBV and HCV in the causation of HCC: as previously reported, the rate ratio (RR) linking the presence of anti-HCV to HCC among subjects positive for hepatitis-B surface antigen (HBsAg) was substantially higher than the corresponding RR among those negative for this marker; furthermore, among HCC patients positive for HBsAg, a high proportion (33/61) of those who were positive for hepatitis-Be antigen (HBeAg) or its antibody were positive for anti-HCV, whereas among HBsAg-positive controls who were also positive for HBeAg or its antibody, none was positive for anti-HCV (0/18; p less than 10(-4)). The anti-HCV-related RR for HCC was also higher among HCC patients with cirrhosis than among those without evidence of co-existing cirrhosis (RR 11.4 vs. 4.4; p = 0.06). In addition, there was some evidence of interaction between tobacco smoking and HCV in the origin of HCC; after controlling for age, sex and HBsAg status, the RR for subjects positive for anti-HCV was 6.8 among smokers but only 3.2 among non-smokers (p = 0.26). By contrast, there was no suggestion of an interaction between anti-HCV and anti-HDV, in agreement with the presumed minimal role, if any, of HDV in HCC etiology. These results support the notion that HCV is involved in the etiology of HCC by advancing, through a chronic liver disease process, carcinogenesis initiated by other factors.

Occupation and gastric cancer in Spain

The association between occupational exposure and stomach cancer was investigated in a multicenter case-referent study conducted in Spain on 354 histologically confirmed cases and 354 hospital referents, matched by age, gender, and residence. An increased risk of gastric cancer was found for coal mining workers [odds ratio (OR) 11.8], but the number of workers was small, and therefore the 95% confidence interval (95% CI) was wide (95% CI 1.36-103). An increased risk was observed for wood and furniture workers (OR 1.76), construction workers (OR 1.68), and glass and ceramic workers (OR 2.18), but none of these risks were statistically significant. According to an occupation-exposure linkage system an increased risk was found for occupations associated with exposure to silica and mineral dust (OR 1.80, 95% CI 0.90-3.59). All of the OR estimates were adjusted for the confounding factors socioprofessional status and dietary habits. The possibility of a causal association between stomach cancer and coal and mineral dust is supported by the results.

[Emergency obstetric hysterectomy: report of fifteen cases]

From June 1978 to June 1990, there were 41,989 deliveries, 13,396 cesarean sections and 15 emergency obstetric hysterectomies at Taipei Chang Gung Memorial Hospital. The incidence of emergency obstetric hysterectomy is 36/100,000 deliveries. The mean age of patients is 31.7 years old. The indications for hysterectomy were placental disorder (60.0%), uterine atony (26.7%), and uterine rupture (13.3%). The present series showed that 14 cases had total abdominal hysterectomy, while only one case had a subtotal hysterectomy. Total hysterectomy should generally be performed unless maternal instability mandates a more expeditious subtotal hysterectomy. The most common postoperative complication included unknown fever and urinary tract infection. For those four cases of post-cesarean hysterectomy, conservative treatment was tried but failed. All cases presented with hypotension (less than 80/60 mmHg), tachycardia (greater than 100 times/min) and with a mean hemoglobin of 9 mg% during the observation period. In these patients, blood loss, operating time and length of hospitalization was increased when compared with a group of 7 patients undergoing cesarean hysterectomy. In patients with placenta accreta, who are candidates for cesarean hysterectomy, initial hypotension, tachycardia and shock developed during cesarean section. It must be emphasized that conservative aggressive measures to control obstetric hemorrhage remain the mainstay of therapy, but emergency hysterectomy played the life-saving role with which every practitioner of obstetrics must be familiar and keep in mind.

Changing trends of forceps delivery in Chang Gung Memorial Hospital

Two hundred and fifty-five patients underwent forceps deliveries in Chang Gung Memorial Hospital from January 1, 1985 to June 30, 1990. There was neither maternal nor perinatal mortality related to this procedure during this period; and the perinatal outcome was good without sequela. In the past three years, cesarean section took the place of forceps delivery in some cases with acute fetal distress and malposition. As a result, maternal problems became the most common indication for forceps delivery during that period. Fourth degree laceration of the perineum was the major maternal complication, occurring in 22.4% of total forceps deliveries. Postpartum voiding problems continued to be another complication after forceps delivery, accounting for 7.0%. Either fourth degree laceration of the perineum or postpartum voiding difficulty could be prevented to a certain extent if the forceps were handled delicately in an experienced hand and there was early diagnosis with prompt management of voiding dysfunction.

Horizontal transmission of hepatitis B virus from siblings and intramuscular injection among preschool children in a familial cohort

The authors followed 147 children from 113 families who were susceptible to hepatitis B virus infection for a total of 275 person-years. Among these children, 19 became infected with the hepatitis B virus and thus became new subclinical cases. In this cohort study, parents played a minor role in hepatitis B virus horizontal transmission. On the other hand, the estimated incidence rate ratio of hepatitis B virus infection for siblings of a hepatitis B e antigen (HBeAg) carrier was 2.8 (95% confidence interval 1.1-7.4) when compared with those children without a HBeAg sibling carrier as analyzed by multiple logistic regression. The adjusted incidence rate ratio among siblings increased with increased number of HBeAg carriers. In addition, intramuscular injections played an important role in hepatitis B virus transmission in children. It was found that 61.8% (170/275 person-years) of the children had received intramuscular injections. Most of the injections were administered at private clinics over a 2-year period. Hepatitis B virus infection showed a correlation with injection (adjusted incidence rate ratio = 3.3, 95% confidence interval 1.1-9.5) and with frequency of injections. The authors concluded that HBeAg was a valuable marker for infectivity in hepatitis B virus horizontal transmission. Furthermore, the authors found that hepatitis B virus infection is independently transmitted from sibling to sibling, and by iatrogenic injections because improperly sterilized syringes were shared in areas where hepatitis B is prevalent and intramuscular injection is common.

Risk factors for stomach cancer: a population-based case-control study in Shanghai

A population-based case-control study of stomach cancer was conducted among the teachers and staff of primary and middle schools in Shanghai. A total of 84 cases of stomach cancer were identified in all schools and 2,676 controls were drawn from the teachers and staff of a randomly selected sample of 40 primary and 15 middle schools. Data were analyzed by a multivariate logistic regression model. The analysis indicated that a positive family history of stomach cancer, cigarette smoking, low consumption of fruits, and low consumption of strong tea were significantly associated with stomach cancer incidence.

[Three elderly cases of renal cell carcinoma with pancreatic metastasis]

Three elderly patients, (an 80-year-old female, 78-year-old female and 78-year-old male) suffering from renal cell carcinoma with pancreatic metastasis were reported. In all cases, renal cell carcinoma had been diagnosed previously. Pancreatic tumors were revealed by computed tomography and ultrasonic study during subsequent admission in all cases. In the first case, laparotomy and histological examination proved that pancreatic tumor was metastatic from renal cell carcinoma. In the other cases, according to their clinical course and other laboratory data, we considered the pancreatic tumors to be metastatics from renal cell carcinoma though histological diagnosis was not obtained.

Hepatitis B and C viruses and their interaction in the origin of hepatocellular carcinoma

Serum taken from patients in a case-control study in Athens, Greece, was used to examine the interactive roles of hepatitis B virus (HBV) and hepatitis C virus (HCV) in the origin of hepatocellular carcinoma (HCC). An enzyme immunoassay for anti-HCV was used to test serum taken from 185 cases with HCC, 35 cases with metastatic liver cancer (MLC), and 432 hospital controls. Weakly positive anti-HCV results were more strongly related to MLC than to HCC, implying that these anti-HCV results are false positive. By contrast, strongly positive anti-HCV results were significantly related to HCC (relative risk [RR], 6.3), whereas no significant association was evident for MLC (RR, 0.6). The association of anti-HCV with HCC was substantially higher among subjects whose radioimmunoassay was positive for hepatitis B surface antigen (RR, 20.0) than among those whose radioimmunoassay was negative for this marker (RR, 4.8). These findings indicate that HCV infection has an interactive role in the origin of HCC.

Peripartum cardiomyopathy: report of a case

Peripartum cardiomyopathy is defined as the development of heart failure during the later part of pregnancy or during the first three to six postpartum months, without an obvious underlying cause or prior evidence of cardiac disease. We present one case of peripartum cardiac failure which occurred in a 25-year-old primigravida with twin gestation. The patient underwent an emergency Cesarean section followed by successful medical treatment. An endomyocardial biopsy was performed 12 days after delivery and the pathological changes were consistent with the diagnosis of peripartum cardiomyopathy.

Analysis of birth weight and gestational age in Taiwan

Appropriate interpretation of monitored fetal growth throughout pregnancy in individual patients and populations is dependent upon the availability of adequate standards. Previously published standards either were based on small samples, data decades old or were characteristic of foreign subpopulations. We have reviewed the data on a series of 46,575 singleton live births at Chang Gung Memorial Hospital from 1979 to 1989. The ratio of males to females was 1.08. The fetal growth pattern in the third trimester of pregnancy approximates a sigmoid curve. Fetal growth was most rapid from the 32nd to the 37th week of gestation with an average increase of 240 g per week. The birth weight declined beyond 42 weeks' gestation. There were significantly greater weight gains amongst male fetuses as compared to female fetuses from the 34th to the 42nd week of gestation. The mean birth weight recorded at 40 weeks' gestation in male and female newborns was 3,381 g and 3,262 g, respectively. Comparing the birth weight of term pregnancies using our data, with those of a previous, two-decade old report (1945-1967) by Chen, we found that birth weight were slightly higher in this study. The derived fetal growth curves are useful for clinical, public health, and investigational purposes.

Birth order and breast cancer risk

It has been hypothesized that prenatal exposure to maternal estrogens may be a risk factor for breast cancer in the offspring. In two recent studies, maternal estradiol levels in the first pregnancy have been compared to those in the second, and in both studies levels were higher in the first pregnancy. If both the hypothesis and the reported findings were true, women born as their mother's second child would be expected to have lower risk for breast cancer than first-born women. Data from 1,468 cases of breast cancer and 4,175 hospital controls from three previously published studies were modelled through multiple logistic regression to evaluate this possibility. The size of the woman's sibship was not related to breast cancer risk. On the other hand, second-born women had, as predicted, lower breast cancer risk than first-born women, although the difference was nominally significant only among premenopausal women. The relative risk for breast cancer, contrasting second-born to first-born women, and the corresponding 95 per cent confidence intervals, were 0.71 (0.54-0.94) among premenopausal women, 0.94 (0.76-1.17) among postmenopausal women, and 0.86 (0.73-1.02) among all women, controlling for menopausal status.

Analysis of quantitative data by quantiles in epidemiologic studies: classification according to cases, noncases, or all subjects?

Quantitative exposure data in epidemiologic studies are frequently analyzed by ordered categories. Categorization by quantiles can be based on the distribution of (1) cases, (2) noncases, and (3) all subjects. The advantages of the three schemes in determining quantiles were compared. They were found to give the same power regarding a test for trend over a wide range of study situations. Considerations on the representativeness and the ease of the analysis implementation could dictate the choice of the categorization scheme.

Endocardial cushion defect in a fetus: with intrauterine cytomegalovirus infection and growth retardation: report of an autopsy case

We describe one case of endocardial cushion defect during the second trimester when a consultative fetal echocardiography was undertaken for fetal intrauterine growth retardation with oligohydramnios. Positive cytomegalovirus IgM in cord blood and cytomegalovirus DNA particles in the amniotic fluid were found incidentally. The relationship between possible intrauterine cytomegalovirus infection and the endocardial cushion defect in this case is not clear.

The effect of non-differential outcome misclassification on estimates of the attributable and prevented fraction

This paper considers the effect of non-differential outcome misclassification on the population attributable fraction and the population prevented fraction. I examine the bias in the attributable and the prevented fraction derived from a risk ratio estimate as a function of the sensitivity and specificity of the outcome classification, the true risk ratio, the prevalence of the exposure, and the baseline disease frequency. With outcome misclassified, disease frequency is an important determinant of the magnitude of the bias; the rarer the disease, the more severe is the bias. For both the attributable and the prevented fraction, the specificity of the outcome classification has a greater influence on the magnitude of the bias than the sensitivity; this is in contrast to the dominant effect of sensitivity in situations of exposure misclassification. Also, unlike the findings in the exposure misclassification, the bias due to outcome misclassification does not increase monotonically with increased prevalence of exposure. For the attributable and prevented fraction derived from an odds ratio estimate, the specificity of the outcome classification does not have a greater influence on bias than the sensitivity, and a perfect specificity alone does not lead to unbiased effect estimates if the sensitivity of the outcome classification is imperfect.

Induced abortions, contraceptive practices, and tobacco smoking as risk factors for ectopic pregnancy in Athens, Greece

A case-control study of the role of induced abortion and other factors on the subsequent occurrence of ectopic pregnancy was undertaken in 1986-1987 in Athens, Greece, where a similar study 20 years ago found a tenfold risk of ectopic pregnancy among women with one or more illegal induced abortions. Seventy women residents of Athens, consecutively admitted to the major state maternity hospital with a diagnosis of ectopic pregnancy, were individually matched with women with a newly diagnosed pregnancy of the same order as the ectopic index pregnancy. Two control women were found for each of 63 cases, but only one control for each of the remaining seven cases. All cases and controls were interviewed by the same qualified obstetrician. Statistical analysis was undertaken with stratification of individual matched triplets and pairs, as well as through conditional multiple regression procedures. The relative risk of recurrence of an ectopic pregnancy was 6.39 with 95% confidence interval (CI) 1.96-21.04. Miscarriages did not increase the risk of ectopic pregnancy. The relative risk for subsequent ectopic pregnancy among women with one or more induced abortion, compared to women without such abortions, was 1.87 (CI 0.84-4.16) controlling only for the matching factors, and 1.71 (CI 0.69-4.27) when marital status (a possible selection factor) was also accounted for in the conditional logistic regression. There was no evidence for increasing risk with increasing number of induced abortions. Past use of an intrauterine device (IUCD) was associated with a relative risk of 3.89 (0.72-21.02); the relative risk increased with the duration of use of the IUCD.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast size, handedness and breast cancer risk

Bra cup size and handedness were studied as possible risk factors for breast cancer. Data for 3918 cases and 11,712 controls from 7 centres were used to examine the association of handedness with laterality of breast cancer; data for 2325 cases and 7008 controls from 4 centres were used to assess the relation of bra cup size to breast cancer risk. There was a suggestive (P about 0.10) association of handedness with breast cancer laterality: odds ratio of a left-handed (or ambidextrous) woman having a left-sided cancer 1.22 (95% CI 0.96-1.56). Handedness may affect the lateral occurrence of breast cancer, although this tumour is in general more common in the left breast, possibly because this breast is usually slightly larger. Premenopausal women who do not wear bras had half the risk of breast cancer compared with bra users (P about 0.09), possibly because they are thinner and likely to have smaller breasts. Among bra users, larger cup size was associated with an increased risk of breast cancer (P about 0.026), although the association was found only among postmenopausal women and was accounted for, in part, by obesity. These data suggest that bra cup size (and conceivably mammary gland size) may be a risk factor for breast cancer.

Prevalence of cesarean section in Chang Gung Memorial Hospital, 1984-1989

This study was undertaken to estimate the cesarean delivery rate in Chang Gung Memorial Hospital (CGMH) and to determine whether the reasons for the rising rate have changed during the past 6 years. Since 1984, 43% of the rise in the cesarean rate was due to repeat cesareans, 29% due to dystocia, and 15% due to fetal distress. At the same time, the cesarean delivery rates due to abnormality of position and placentation dropped by 2% in either condition. The rate of cesarean delivery among those with a previous cesarean was 98%. In the future, if the number of vaginal deliveries after cesarean increases, then the overall cesarean delivery rate will decrease or stabilize.

Age at menarche, age at menopause, height and obesity as risk factors for breast cancer: associations and interactions in an international case-control study

The importance of age at menarche, age at menopause, height, and obesity as risk factors for breast cancer, and the possible interactions among these factors in breast cancer causation were investigated in a data set collected in the late 1960's, in an international multicenter case-control study. Multiple logistic regression procedures were used to model data from 3,993 breast cancer cases and 11,783 controls from 7 study centers representing the range of international variation of breast cancer incidence. Height and obesity (measured through the weight/height2 index) were independent risk factors for breast cancer among post-menopausal but not pre-menopausal women; post-menopausal women taller by 10 cm had a 12% higher risk of breast cancer (95% confidence interval, CI, 3-21%) and post-menopausal women of average height (say 158 cm) had an 11% higher risk of breast cancer (CI 7-16%) when they were heavier by 10 kg (and, therefore, more obese by 4 kg/m2). Age at menarche was a risk factor among both pre-menopausal and post-menopausal women, a delay of 2 years corresponding to a 10% reduction in breast cancer risk (CI 6-15%). Age at menopause was also a breast cancer risk factor, women with menopause at each 5 year age difference having a 17% higher risk of breast cancer (CI 11-22%). There is evidence of an interaction (deviation from the logistic regression-postulated multiplicativity) between obesity and age at menarche, implying that the protective effect of late menarche may not apply to overweight women or that late menarche may become detrimental in obese women. The estimated relative risk coefficients, when applied to average risk factor levels observed among control women, can explain only a small fraction of the difference in breast cancer incidence between Boston and Tokyo.

Prevalence of mottled enamel after 12 years of water fluoridation in Chung-hsing New Village

The prevalence of mottled enamel (dental fluorosis) was investigated among children, aged 6 to 15 years, in Chung-hsing New Village and in Tsao-tun Village. The drinking water in Chung-hsing New Village has been fluoridated for 12 years at a level of 0.6 ppm, while the drinking water in Tsao-tun contains a negligible level of 0.08 ppm. The degree of mottled enamel was assessed by using Dean's Index and the Community Fluorosis Index (CFI), the latter being derived from Dean's Index for the purpose of comparison. In Dean's Index, 6 classes based on the severity of the mottling, are identified: normal, questionable, very mild, mild, moderate, and severe. The results showed that children in Chung-hsing had whiter teeth than those in Tsao-tun Village. In the fluoridated group, 5.8% of children fell into the "very mild" mottling category, as compared to 0.9% in Taso-tun, the control area. For the "mild" class, the rate was 1.9% for Chung-hsing New Village and 0.4% for Tsao-tun. With only one exception in Tsao-tun, none of the children in the two groups showed mottling in the "moderate" or "severe" classes. The Community Fluorosis Index (CFI) was 0.15 for the Chung-hsing group, indicating that the occurrence of mottled enamel is very low when compared with data from fluoridation programs in other countries. It is concluded that in Taiwan, a 0.6 ppm fluoride concentration in drinking water, which has previously been reported to be effective in prevention of dental caries, is associated with only negligible mottling of enamel. Even when mottling does occur, the degree is very mild and only small chalky spots can be seen on the teeth.

Epidemiology of pancreas cancer (1988)

This article reviews the epidemiology of cancer of the pancreas, both descriptive and analytical, at all times cognizant of the problems of misdiagnosis, particularly underdiagnosis, of this lethal disease that continue to hinder epidemiological studies. Pancreas cancer is consistently reported to occur more frequently in men than in women, in blacks than in whites, and in urban rather than rural population groups. In some countries, the mortality rates continue to rise, whereas in others, declining levels of disease can be seen among members of younger birth cohorts. Although some of these patterns can be explained by variation in pancreas cancer risk factors, many cannot. Analytical studies consistently demonstrate that cigarette smoking increases the risk of cancer of the pancreas, and this appears, at the present time, to be the only clearly demonstrated risk factor for pancreatic cancer. Although the association with disease risk and coffee consumption, alcohol consumption, occupational exposures, diabetes, pancreatitis, and other factors requires clarification, it appears likely that the most fruitful research area in the coming years may involve exploration of pancreatic cancer risk and nutritional practices.

Perinatal outcome of chorionic villus sampling versus amniocentesis

This study assesses the relative risks of first trimester transcervical chorionic villus sampling (CVS) versus midtrimester amniocentesis performed between April 1986 and March 1988. The most common indication for prenatal diagnosis was advanced maternal age. We discovered 5.1% chromosomal aberrations in CVS compared to 1.0% in amniocentesis. Bleeding was the most frequent early complication, and only 1 case had major hemorrhage with subsequent spontaneous abortion. The fetal loss rate (gestational age less than 28 weeks) was 4.5% in CVS versus 1.2% in amniocentesis, which was not significantly different from the background fetal loss rate reported in normal pregnancies after an 8-week gestational age. Three cases of fetal loss after CVS were probably procedure-related; 1 case had spontaneous abortion and 2 cases had chorioamnionitis. Therefore, we considered that the causal relationship between CVS and the infection was highly probable. The clinical pregnancy outcome indicated that there were no differences in overall perinatal mortality, Apgar score, body weight, body length, gestational age at delivery, intrauterine growth retardation, placenta weight and placental disorders between the CVS group and the amniocentesis group. The pregnancies did not reveal any specific effects of the prenatal diagnostic procedure, but a long-term pediatric follow-up is needed.

Association between dental caries prevalence and Streptococcus mutans among 13-year-old children

The prevalence of caries associated prevalence with Streptococcus mutans in saliva and pooled plaque was investigated among 13-year-old Chinese children. In conjunction with saliva sampling simplified greatly by adopting the oral rinse method, an initial threshold value of 10(4) colony forming units (cfu) per ml of rinse was established on the basis of the S. mutans counts from 27 caries-free individuals. The results of the present study showed that, of the total 58 children, 67.3% had S. mutans counts above the threshold value in their saliva, and they developed significantly more decayed surfaces (D) and decayed, missing, filled surfaces (DMFS) than did the children below this value. The association between caries activity and S. mutans counts either in saliva or in pooled plaque samples was even stronger when only decayed surfaces were taken into account. In addition, the detection frequency of S. mutans (81.8%) was higher in saliva than in the pooled plaque samples (43.2%). This may demonstrate that saliva is more sensitive than dental plaque in predicting caries activity. The most prevalent biotypes of the S. mutans strains observed in this study were c and d. The results of this study indicate a significant association of S. mutans levels with caries prevalence. In the estimation of salivary S. mutans levels, the rinse method offered an easy and rapid identification for children with high caries risk and proved to be very practicable for epidemiological study on a larger scale.

Influence of water fluoridation on the eruption of permanent teeth in Chung-Hsing New Village, Taiwan

Along with an evaluation of the effects of 12 years' water fluoridation in the prevention of caries, the present study was conducted to explore the influence of water fluoridation on the eruption of permanent teeth. The survey was carried out in fluoridated Chung-Hsing New Village and the control town of Tsao-Tun from October to December, 1984. Dental examinations were performed on 3,459 children Chung-Hsing New Village and 4,610 in Tsao-Tun, at ages ranging from 3 to 15 years. The results showed that in general, the mean tooth eruption time of girls was earlier than that of boys, and that teeth in the lower jaw emerge sooner than their homologues in the upper jaw, except for premolars. In both fluoridated and control areas the order of tooth eruption was very similar except for the teeth of girls in the upper jaw. The eruption sequence was first premolar, canine then second premolar in the girls of Chung-Hsing New Village, while first premolar, second premolar then canine in those of Tsao-Tun. By comparing the eruption time of permanent teeth in the children of fluoridated and control areas, it was found that they were very alike in general, the only difference being observed in the premolars of the sexes. The premolars of the children in the fluoridated area emerged in the oral cavity 2.5 to 4.5 months later than did their counterparts in the control area.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic gain factors for fractionated radiation treatment of spontaneous murine tumors using fast neutrons, photons plus O2(1) or 3 ATA, or photons plus misonidazole

Therapeutic gain factors (TGFs) have been determined for three spontaneous tumors of the C3H mouse treated by photons + normobaric oxygen (O2(1) ATA), photons + hyperbaric oxygen (O2 3 ATA), photons + misonidazole, or fast neutrons. The tumors were early generation isotransplants of spontaneous tumors: MCaIV, a mammary carcinoma; FSaII, a fibrosarcoma; and SCCVII, a squamous cell carcinoma. The tumors, transplanted to the right leg, were 6 mm at start of treatment. Normal tissue responses studied were acute reaction of normal skin (all treatment modalities) and LD50 following irradiation of the upper abdomen (in test of photons + O2 at 1 or 3 ATA). Thus both the tumor and normal tissues would be classified as "acute responding." All subject tissues were at congruent to 34.5-35 degrees C at irradiation. Treatments were based on d(25)Be or p(43)Be fast neutron beams, 60Co and 137Cs photon beams. Treatments were given in 5 or 15 equal doses in 5 days. For photon treatments, TGFs (air/O2 3 ATA) were substantially and significantly larger than 1 for all three tumor systems treated at small or large doses per fraction when related to skin or abdominal tissue responses. The TGFs (air/O2 1 ATA) were greater than 1 at small doses per fraction for MCaIV and FSaII for skin as the normal tissue; the TGFs for all three tumors and at all doses per fraction would be greater than 1 when related to upper abdominal tissues. TGFs (O2 1 ATA/O2 3 ATA) for photon irradiation greater than 1 were found only for SCCVII and that obtained for both large and small doses per fraction. Misonidazole achieved impressive TGFs (air/air + miso or air/O2 1 ATA + miso); the drug was tested only at 10-12 Gy/fraction and relative to skin. RBEs(FN) for the three tumors were lower at 1.5-2 Gy(FN)/fraction than at 5-6 Gy(FN)/fraction, i.e. the opposite to that reported for normal tissue (RBE increases with decreasing dose per fraction). A TGF (relative to skin reaction) greater than 1 for fast neutron therapy was found only for SCCVII when treated at large doses/fraction; this was true for air or O2 1 ATA conditions.

The effect of non-differential exposure misclassification on estimates of the attributable and prevented fraction

This paper considers the effect of non-differential exposure misclassification on the population attributable fraction and the population prevented fraction as a function of the sensitivity and specificity of the exposure classification, the true relative risk, and the true prevalence of the exposure. Given a certain set of sensitivity, specificity, and prevalence of the exposure, the apparent attributable fraction is a constant proportion of the true attributable fraction regardless of the true relative risk. This observation does not hold for the apparent prevented fraction and the apparent relative risk, both of which vary with the true relative risk. For both the attributable and the prevented fraction, the sensitivity of the exposure classification has a greater influence on the magnitude of the bias than the specificity; also, the higher the prevalence of the exposure, the larger is the bias caused by the imperfect exposure classification.

Risk factors associated with the prevalence of pulmonary tuberculosis among sanitary workers in Shanghai

The association between potential risk factors and the prevalence of pulmonary tuberculosis was studied in Shanghai Bureau of Sanitation. The study identified a total of 202 cases among 30,289 subjects, and showed that smoking, in particular heavy smoking, had a strong association with tuberculosis after simultaneous adjustment for other factors. Using a multivariate binomial regression, the factors adjusted included the age, sex, history of contact, area of housing and type of work. The relative risk of heavy smokers compared with nonsmokers was 2.17 (95% confidence interval 1.29-3.63). The study showed that although males and old age were associated with a higher risk of tuberculosis than females and young age respectively, these differences were due to the smoking factor. The study also found that the risk of tuberculosis among the subjects with previous patient contacts was twice as high as that among the non-contacts.

Extrahepatic bile duct cancer and smoking, beverage consumption, past medical history, and oral-contraceptive use

Information on potential causal factors in 67 patients with histologically confirmed cancer of the extrahepatic bile ducts was compared with that from 273 patients with other cancers. The control group did not include subjects with tobacco- or alcohol-related cancers. The study subjects were interviewed at 11 large hospitals in eastern Massachusetts and Rhode Island between 1975 and 1979. Among the patients with extrahepatic bile duct cancer, the male-female ratio was 1.5. The use of cigarettes was associated with decreased risk of extrahepatic bile duct cancer. The use of alcohol and coffee was not related to risk of extrahepatic bile duct cancer. Fewer patients than controls reported tea consumption. A statistically significant association between the use of oral contraceptives and extrahepatic bile duct cancer was observed among women under 60 years of age. Patients reported significantly higher frequencies of history of ulcerative colitis or diseases of the gallbladder.

Extrahepatic bile duct cancer and smoking, beverage consumption, past medical history, and oral-contraceptive use

Information on potential causal factors in 67 patients with histologically confirmed cancer of the extrahepatic bile ducts was compared with that from 273 patients with other cancers. The control group did not include subjects with tobacco- or alcohol-related cancers. The study subjects were interviewed at 11 large hospitals in eastern Massachusetts and Rhode Island between 1975 and 1979. Among the patients with extrahepatic bile duct cancer, the male-female ratio was 1.5. The use of cigarettes was associated with decreased risk of extrahepatic bile duct cancer. The use of alcohol and coffee was not related to risk of extrahepatic bile duct cancer. Fewer patients than controls reported tea consumption. A statistically significant association between the use of oral contraceptives and extrahepatic bile duct cancer was observed among women under 60 years of age. Patients reported significantly higher frequencies of history of ulcerative colitis or diseases of the gallbladder.

Death from uveal melanoma. Number of epithelioid cells and inverse SD of nucleolar area as prognostic factors

Criteria for the Callender classification of uveal melanoma are subjective and lead to variations among observers of the same tumor. Two other measures for cell type-the number of epithelioid cells per high-power field (Epi/HPF) and the inverse SD of nucleolar area (ISDNA)-were evaluated as prognostic factors for survival following enucleation for uveal melanoma in 232 patients. Variables significantly related to the number of Epi/HPF were related to ISDNA. Larger, more anteriorly located tumors had a high number of Epi/HPF and a low ISDNA. The two measures were also correlated. Using Kaplan-Meier survival analysis, both measures were related to tumor deaths. Worse prognosis was associated with a higher number of Epi/HPF and a lower ISDNA. Considered together in Cox' proportional hazards analysis, both measures independently predicted outcome. Separately, each measure predicted uveal melanoma-related deaths, in combination with largest tumor dimension, invasion of tumor to the line of transection, and location of the anterior tumor margin. Although ISDNA is the more objective measure of cell type, its practicality compared with other measures of cell type must also be considered.

Tonsillectomy and Hodgkin's disease: results from companion population-based studies

The question of whether persons with a history of tonsillectomy are at increased risk of Hodgkin's disease (HD) in adulthood was evaluated in companion population-based case-control studies conducted in the eastern Massachusetts and the Detroit metropolitan areas. These studies compared the history of tonsillectomy among incident cases with that of all their siblings by matched analysis controlling for confounding by childhood social class, family size, and birth order. Among young adults (15-39 yr) there is substantial evidence that tonsillectomy is not a risk factor and the relative risk (RR) is 1.0 (95% confidence interval, 0.72-1.4). Among middle-aged persons (40-54 yr) the RR is not significantly elevated, 1.5 (0.67-3.3), and the direction of the association differs between the sexes, consistent with the hypothesis of no association. Among older persons, the RR is significantly elevated, 3.0 (1.3-6.9), but the data are sparse. On the basis of these data, it appears unlikely that prior tonsillectomy is a causal factor in the development of HD in young and middle-aged adulthood. Whether it is a risk factor for the malignancy occurring late in life is unclear.

Myoelectric analysis of the paraspinal musculature in relation to automobile driving

In this study, the myoelectric activity of 12 paraspinal muscles of ten men aged 18-24 was recorded to examine the effects of backrest inclination and lumbar support in relation to driving. In total, 24 test conditions were evaluated over a 3.5-hour period in a single day. These tests were then repeated, changing the sequence over the next 4 days. The results indicate a complex interaction between the thoracic and lumbar regions of the back with the lowest myoelectric activity position of 120 degrees backrest inclination, 5 cm of lumbar support, and 13.5-18.5 degrees of seat inclination. Electromyogramatic (EMG) evidence of fatigue was not identified over a 3.5-hour period. The generally low levels of EMG activity and, presumably, disc pressure present in any seating position suggest that the paraspinal muscle activity may not play the predominant role in disc herniation as it relates to automobile driving.

Power calculation in matched case-referent studies. Application and accuracy of the asymptotic power function

Although the asymptotic power function for matched case-referent (case-control) studies has been given, it is not widely applied. One reason for this is that the parameters in the power function do not correspond directly to the usual description of the research situation. When designing a matched case-referent study, the potentially available relevant information concerns the joint distribution of the determinant and matching variate, and the illness rate in relation to those factors, in the study base. Application of the asymptotic power function using these inputs is described. The asymptotic power function is then assessed by use of the Monte Carlo method and is found to be accurate. An example of the application of the asymptotic power function is given.