Pattern of gp120 sequence divergence linked to a lack of clinical progression in human immunodeficiency virus type 1 infection

Differential rates of AIDS development and/or T4 lymphocyte depletion in HIV-1-infected individuals remain unexplained. The hypothesis that qualitative differences in selection pressure in vivo may account for different rates of disease progression was addressed in nine eligible study participants from a cohort of 315 homosexual men who have been followed since 1985. Disproportionately fewer changes in variable regions and more in C3 of gp12O were found to be significantly associated with slower disease progression. Our finding provides the first example to demonstrate that differential selection pressure related to the emergence of HIV-1 variants is associated with long term nonprogression. Candidate vaccines that elicit strong selection pressure on C3 of gp120 are likely to provide better protection than those targeting variable regions.

Regulation of the acute phase response genes alpha 1-acid glycoprotein and alpha 1-antitrypsin correlates with sensitivity to thermal injury

BACKGROUND

The response to thermal injury is a complex physiologic process requiring communication between sites of injury and distal target organs. The liver, one of these target organs, synthesizes a family of secretory proteins, the acute phase reactants (APRs), that carries out specific protective functions. This study investigates the response of positively regulated (alpha 1-acid glycoprotein and alpha 1-antitrypsin) and negatively regulated (albumin) APR genes to severe thermal injury in three rat strains with differing abilities to survive thermal stress.

METHODS

Age and weight matched male Buffalo, Sprague-Dawley, and Fischer 344, 12- to 16-week-old rats (275 to 325 gm) received a 40% total body surface area scald burn. Total RNA was isolated from livers at 0, 2, 5, 12, 24, and 48 hours. Northern blot hybridization was performed with 32P-labeled rat alpha 1-glycoprotein, rat albumin, and mouse alpha 1-antitrypsin cDNAs. Relative amounts of alpha 1-glycoprotein, alpha 1-antitrypsin, and albumin mRNAs were determined by means of densitometric analyses.

RESULTS

All three strains elicit both a positive and negative acute phase (AP) response. Significant differences were observed in the degree and kinetics between strains. Those more sensitive to thermal injury exhibited a more intense positive AP response and possibly a delayed recovery. The AP response between these strains correlates with the variation in ability to survive severe trauma.

CONCLUSIONS

The differences in the kinetics and intensity of induction of APR genes between Buffalo, Sprague-Dawley, and Fischer rat strains suggest that the least intense AP response and its timely recovery correlated with the ability to survive a severe thermal injury and that, conversely, the more intense and prolonged response correlated with sensitivity to severe thermal injury. We propose that this may be a basis for variation in survival to thermal injury.

Effect of thermal injury on the expression of transcription factors that regulate acute phase response genes: the response of C/EBP alpha, C/EBP beta, and C/EBP delta to thermal injury

BACKGROUND

Eukaryotic organisms possess natural defense mechanisms that protect against stress stimuli. One such mechanism is the activation of families of stress response genes (e.g., the acute phase response). Transcription of many of these genes is regulated by the leucine zipper or bZIP proteins (CCAAT binding/enhancer binding proteins [C/EBPs]). The aim of this study was to show that the C/EBP transcription factor genes respond to thermal injury.

METHODS

Age- and weight-matched male Buffalo, Sprague-Dawley, and Fischer 344 12- to 16-week-old rats (275 to 325 gm) received a 40% total body surface area scald burn. Total RNA was isolated from livers at 0, 2, 5, 12, 24, and 48 hours. Northern blot hybridization was performed with 32P-labeled C/EBP alpha, C/EBP beta, and C/EBP delta cDNAs. Relative amounts of each mRNA were determined by densitometric analyses. For Western analyses liver nuclear and cytoplasmic protein extracts were prepared from burned and control rats. Nuclear protein extracts were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted onto a PVDF membrane, and detected by using an enhanced chemiluminescence detection kit.

RESULTS

Expression of C/EBP genes is regulated in response to 40% total body surface area scald burn. A simultaneous decrease in C/EBP alpha and an increase in C/EBP beta and C/EBP delta mRNA levels occur in response to thermal injury. Western analyses detect changes in C/EBP alpha and C/EBP beta pool levels that suggest a differential regulation of these genes in response to thermal injury.

CONCLUSIONS

The responses of C/EBP alpha, C/EBP beta, and C/EBP delta are similar in Buffalo, Sprague-Dawley, and Fischer rats. The induced level, however, of C/EBP beta mRNA was highest in the Sprague-Dawley strain and lowest in the Buffalo strain and correlates well with the mortality of these strains. Because C/EBP beta is associated with the transactivation of stress response genes, this may explain the intensity of the response in the susceptible strains. This agrees with our hypothesis that the higher degree of sensitivity of the Sprague-Dawley rat to stress relative to the Buffalo strain may be due to inherently higher levels of factors such as C/EBP whose functions are associated with activation of stress response genes.

A case-control study of oral cancer in Changhua County, Taiwan

Forty oral cancer patients identified consecutively in Changhua Christian Hospital between 1990 and 1992 were compared with 160 population-based controls, matched for sex, age, area of residence, and educational background. Betel quid chewing was positively associated with the risk of oral cancer with adjusted odds ratio of 58.4 (95% CI: 7.6-447.6). The greater the number of years of chewing betel quid, the higher the risk of oral cancer; the adjusted odds rations were 12.9, 93.7 and 397.5 for < 21, 21-40, and > 40 years of betel chewing as compared with the non-users. The risk also increased with the quantity chewed per day; the odds ratios for those chewing < 10, 10-20 and > 20 quids/day were 26.4, 51.2 and 275.6, respectively. These odds ratio estimates were all statistically significantly different from the null value of unity.

Dietary factors and the risk of endometrial cancer: a case--control study in Greece

In a hospital-based case-control study of endometrial cancer undertaken in Athens (1992-94), 145 women residents of Greater Athens with confirmed cancer of the endometrium were compared with 298 control patients with orthopaedic diseases. Personal interviews were conducted in the hospital setting, and diet was assessed using a validated semiquantitative food frequency questionnaire. Nutrient intakes for individuals were calculated by multiplying the nutrient intake of a typical portion size for each specified food item by the frequency at which the food was consumed per month and summing these estimates for all food items. Data were modelled through logistic regression, controlling for demographic, reproductive and somatometric risk factors for endometrial cancer as well as for total energy intake. No macronutrient was significantly associated with endometrial cancer risk, but increasing intake of monounsaturated fat, mostly olive oil, by about one standard deviation was associated with a 26% risk reduction (odds ratio = 0.74; 95% confidence interval 0.54-1.3). Among micronutrients, only calcium intake was significantly inversely associated with endometrial cancer risk, whereas there was evidence against retinol and zinc imparting protection against the disease. With respect to food groups, there was weak and non-significant evidence that vegetables are protective, whereas consumption of pulses was positively associated with disease possibly because they contribute substantially in Greece to energy intake in excess of physical activity-dependent requirements.

Evidence for posttranscriptional regulation of C/EBPalpha and C/EBPbeta isoform expression during the lipopolysaccharide-mediated acute-phase response

The mRNAs of the CCAAT/enhancer-binding trans-activator proteins (C/EBPalpha and C/EBPbeta) serve as templates for the differential translation of several isoforms which have specific transcriptional regulatory functions. By using an oligonucleotide corresponding to the C/EBP binding site of the mouse alpha1-acid glycoprotein promoter, we detected multiple forms of C/EBPalpha and C/EBP++ beta proteins in the mouse liver that have DNA-binding activity. By using specific antisera, we detected C/EBPalphas with molecular masses of 42, 38, 30, and 20 kDa that have DNA-binding activity. The pool levels of the 42- and 30-kDa isoforms were high in control nuclear extracts and decreased significantly after lipopolysaccharide (LPS) treatment. The binding activity and protein levels of the 20-kDa isoform are low in controls and increase dramatically after LPS treatment. C/EBPbeta isoforms with molecular masses of 35, 20, and 16 kDa were also detected. The 35-kDa pool level did not change whereas the 20-kDa isoform was strongly induced in response to LPS. Western (immunoblot) and Southwestern (DNA-protein) analyses show that p42 C/EBPalpha forms specific complexes with the alpha1-acid glycoprotein oligonucleotide in control nuclear extract and that p20 C/EBP beta forms complexes in LPS-treated liver. Our studies suggest that synthesis of specific C/EBPalpha and C/EBPbeta isoforms occurred in the normal liver in vivo and that LPS mediated a differential initiation and inhibition of translation at specific AUG sites within each mRNA. The qualitative and quantitative changes in C/EBPalpha and C/EBPbeta isoform pool levels suggest that LPS or an LPS-stimulated factor can regulate the selection of AUG start sites for both activation and repression of translation. This regulation appears to involve an LPS-mediated down-regulation of initiation at the first AUG codon of the 42-kDa C/EBPalpha and dramatic translational up-regulation at the fifth AUG codon of the 20-kDa C/EBPalpha and the third AUG codon of the 20-kDa C/EBPbeta. These regulatory events suggest the existence of proteins that may act as translational trans-acting factors.

[A randomized clinical trial for the evaluation of head and neck squamous cell carcinoma treating with traditional Chinese medicine]

This paper described the research design,research process and statistical analysis of randomized clinical trial by treatment with traditional Chinese medicine in patients with squamous cell carcinoma of the head and neck.At first we found there was no significant difference between treating group and contral group(P>0.05) using log-rank test on Kaplan-Meier survival curves. With further multivariate analysis Cox model and after adjusting for sex,age,legth of taking the assigned medication,grade of tumor differentiation and using of chemotherapy,the rate of tumor-related death for control group was significantly higher than that for treating group :hazards ratio estimate was 1.939(95% confidence interval 1.008-3.729,(P<0.05).The length of taking Chinese medicine was one of the most important prognostic factors(P<0.001).The results suggest that the prescribed medication contributed to the improved survival,and it was an independent prognostic factor.

Characterization of somatic cell hybrids exhibiting extinction of AFP, albumin and an AFP-HPRT transgene

We utilized an AFP-HPRT transgene, i.e. the HPRT coding sequences under the regulation of AFP enhancer and promoter sequences, to localize the AFP extinguisher locus in intertypic somatic cell hybrids (hepatoma X fibroblast). This hybrid gene construct, which directly links AFP regulation to a reversibly selective gene, enabled the selection of stably transfected cells which express AFP, as well as cells showing extinction of AFP. Mouse hepatoma cells stably transfected with and expressing the transgene were fused to human fibroblasts, and the resulting somatic cell hybrids were characterized using Southern, Northern and karyotypic analyses. That several hybrids exhibited the proper extinction of AFP, AFP-HPRT and albumin suggests coregulation of these genes by an extinguisher. Segregant lines derived from these hybrids were selected for the loss of extinguisher activity and for reexpression of the transgene. Karyotypic analysis of hybrid and segregant lines, exhibiting proper AFP, albumin and AFP-HPRT phenotypes, revealed that the presence of human chromosome 7 was most closely associated with the AFP-extinguished state. The hybrids generated in these studies now make it possible to isolate the sequences responsible for AFP and albumin extinction.

Breast size and mammographic pattern in relation to breast cancer risk

The relation of Wolfe's parenchymal patterns and radiographically-assessed breast size with breast cancer risk was evaluated in a population-based nested case-control study in Uppsala, Sweden. All women who attended a mammographic screening programme in Uppsala county starting in 1988 have been followed for the occurrence of breast cancer through 1993. The analysis was based on 295 cases and 589 age-matched controls, whose mammograms were blindly evaluated for parenchymal pattern and breast size. Women with P2 or DY pattern had a significantly elevated risk of breast cancer compared with women with N1 or P1 (OR = 2.09; 95% CI = 1.52-2.86). There was an inverse association of breast size with breast cancer risk, which disappeared after adjusting for parenchymal pattern, because breasts of smaller size tended to have high-risk parenchymal patterns. It is concluded that in Swedish women, and perhaps in Caucasian women in general, small breast size is associated with increasing breast risk through its association with high-risk parenchymal pattern. This is in contrast to the fact that Asian women, who in general have breasts of smaller size, have low prevalence of high-risk parenchymal pattern as well as low rates of breast cancer.

Does age at the last birth affect breast cancer risk?

We studied the relative importance of age at first and age at last full-term pregnancy (FTP) in a large data set of 3950 cases and 11,510 controls, of whom 2263 cases and 7359 controls had two or more FTPs. We found that a 5-year delay in age at first FTP is associated with an odds ratio of 1.17 (95% confidence interval of 1.05-1.29), whereas a 5-year delay in the age of last FTP is associated with an odds ratio of 1.05 (95% confidence interval 0.96-1.14). Misleading results concerning the relative importance of age at first and last FTP may be obtained when parity is only adjusted in broad categories, uniparous women whose FTP is, simultaneously, both the first and the last are not excluded from the analysis, and age at any FTP between the first and last is not controlled for.

Hyperglycemia induced activation of type-1 protein phosphatase activator (kinase FA) in perfused human placenta

We report the identification of type-1 protein phosphatase activating factor (kinase FA), a unique biologic mediator for both insulin and epidermal growth factors in the human placenta. The activity of kinase F, was found to be extremely labile in the unperfused placenta. Fresh term placentas lost more than 50% of the total kinase FA activity within 6 hours when exposed to air of incubated in medium but not perfused. In contrast, the activity of kinase FA was stable when the human term placenta was dually perfused. This indicates that placental dual perfusion is a useful method for studying protein phosphorylation-dephosphorylation involved in signal transduction. When fresh placentas were perfused with media containing glucose at 141 +/- 10, 242 +/- 12 and 436 +/- 20 mg/dL, kinase FA activity was stimulated several-fold in a glucose concentration-dependent manner when compared with control levels at delivery. The results suggest that hyperglycemia-mediated activation may represent a previously unknown control mechanisms for the regulation of protein kinase FA. The results also suggest that human placental perfusion is a good in vitro system for studying signal transduction mechanisms involved in hormonal actions and metabolic regulation.

Prenatal diagnosis of major congenital cardiovascular malformations

This prospective study was designed to determine whether there would be a higher incidence of congenital cardiovascular malformation (CCVM) in pregnant women with certain risk factors. Fetal echocardiography, from second trimester of term, was performed in 1,659 pregnant women with risk factors for CCVMs and 826 pregnant women without risk factors from March 1990 to April 1995. Two-dimensional imaging, fetal M mode measurements, Doppler waveform velocity and Doppler color flow mapping were used for fetal heart examination. During this period, 70 fetuses with major cardiovascular malformations were found. The prenatal detection rate was determined as 2.8% (70/2,485) in our study. The rate in the high-risk group, however, was 3.7% (61/1,659). Of all indications, fetal risk factors had the highest rate (9.3%, 46/494) of detected CCVMs. Maternal and familial indications could be excluded from the high-risk group as they did not show any increased incidence over the low-risk group. We suggest that fetal echocardiography is mandatory in the high-risk group, especially in cases with fetal and placental risk factors. Fetal cardiac screening in the hands of first-line sonographers has a major role in prenatal diagnosis of CCVMs in the low-risk group.

Green-tea consumption and risk of stomach cancer: a population-based case-control study in Shanghai, China

The effect of drinking Chinese green tea on the risk of stomach cancer was evaluated in a population-based case-control study conducted in Shanghai, China, from October 1991 to December 1993. Eligible cases were incident cases of primary stomach cancer diagnosed during the study period among residents of Hongkou district and Nanhui county aged under 80 years. Controls were selected from the same street or commune where the case resided and were matched to the cases on age (within three years) and gender. A total of 711 cases and 711 matched controls, more than 90 percent of the eligible subjects, completed the interview. Information was obtained on the types of tea used, age when habitual tea drinking started, frequency of new batches of tea leaves used per day, number of cups brewed from each batch, total duration of drinking for each batch, strength and temperature of the tea consumed. Statistical analysis was based on modelling through conditional logistic regression. After adjusting for age, gender, place of residence, education, birthplace, alcohol consumption, and cigarette smoking, the odds ratio (OR) comparing drinkers of green tea with nondrinkers was 0.71 (95 percent confidence interval = 0.54-0.93). The adjusted OR decreased with increasing number of new batches of the green tea consumed each day (P value trend = 0.006). With the largest series of stomach cancer cases to date, this study found green-tea consumption associated with lower risk of stomach cancer. Among drinkers of green tea, the risk of stomach cancer did not depend on the age when habitual green-tea drinking started. Green tea may disrupt gastric carcinogenesis at both the intermediate and the late stages.

Organochlorine compounds and estrogen-related cancers in women

The organochlorines, a diverse group of some 15,000 compounds, have been implicated increasingly as being harmful to humans. Some congeners of DDT and PCB elicit very weak estrogenic responses in animals, while the dioxin TCDD and related compounds have antiestrogenic properties. This review summarizes the evidence regarding whether certain organochlorine compounds, usually as persistent food-chain contaminants, increase the risk of breast and endometrial cancers through their estrogenic potential. In humans, neither ecologic data nor occupational studies provide clear support for an association between organochlorine exposure and the occurrence of these cancers. In our summary analysis of occupational exposure, the rate ratio of breast cancer for exposed cf unexposed women was 0.84 (95 percent confidence interval [CI] = 0.50-1.33) for PCBs and 1.08 (CI = 0.68-1.58) for TCDD. Similarly, effect estimates close to unity were found in summary analysis of breast cancer case-control studies regarding levels of DDE and PCB in adipose tissue or serum. In two recent nested case-control studies using stored specimens, the odds ratio per standard deviation increase in serum p,p'-DDE was 1.27 (CI = 0.95-1.69). Although estrogenic effects of certain organochlorine compounds should be easier to detect on the endometrium, we know of no analytic epidemiologic studies of endometrial cancer published to data. We conclude that available data do not indicate that organochlorines will affect the risk of these two cancers in any but the most unusual situation.

Collagen biosynthesis in human oral submucous fibrosis fibroblast cultures

To investigate the mechanism of collagen accumulation in oral submucous fibrosis (OSF) tissues, we examined the biosynthesis of collagen in fibroblast cultures established from OSF lesions. Fibroblasts obtained from four of ten OSF specimens showed more than a 1.5-fold increase in the production of collagens compared with fibroblasts from age-, sex-, and passage-matched normal controls (p < 0.05). When the relative amounts of collagen synthesis were estimated by SDS polyacrylamide gel electrophoresis, it was found that both OSF and control cells produced about 85% type I collagen and 15% type III collagen. The ratio of alpha 1(I) to alpha 2(I) chains was about 3:1 in OSF cells instead of the 2:1 expected for type I collagen. The excess alpha 1(I) chains could mean that collagen type I trimer was synthesized by the fibroblasts. These findings suggest that collagen overproduction and a reduced degradation of the structure-stable collagen type I trimer synthesized by OSF fibroblasts might contribute to the accumulation of collagen in OSF lesions in vivo. The mechanism(s) of increased procollagen production were analyzed by Northern blot, slot blot, and Southern blot. The OSF fibroblast strains with elevated collagen production also contained higher-than-normal levels of procollagen mRNA, and the ratios of alpha 1(I), alpha 2(I), and alpha 1(III) procollagen mRNAs were compatible with the results of corresponding procollagen alpha chains. The gene copy number of pro alpha 2(I) collagen gene in OSF fibroblasts was about 1.05. No gene amplification was found. These results indicate that expression of these procollagen genes in cultured fibroblasts is regulated at the transcriptional level.

Purification and characterization of Streptococcus mutans glucosyltransferase (GtfC) expressed in Escherichia coli

Streptococcus mutans constitutively expresses three glucosyltransferases, i.e., GtfB, GtfC, and GtfD; which synthesize glucan polymers from sucrose. To obtain individual GTF without complexing with one another, a purification strategy was developed to recover recombinant GTF expressed from Escherichia coli. The recombinant GtfC was aggregated and associated with the insoluble fraction in E. coli homogenates. GtfC was solublized with the 8M urea, renatured to its biologically active form by serial dialysis against sodium phosphate buffer, and subsequently purified to homogeneity by DEAE-Sephacel and hydroxylapatite column chromatography. The GtfC enzyme preparation was purified 16.3-fold and the molecular weight was estimated to be 140 kDa. GtfC synthesized water insoluble glucan in a primer independent manner and its enzymatic activities could be enhanced by dextran. Purified GtfC had a pH optimum of 6.5, a K(m) of 9.26 mM for sucrose and a pI of 5.5. Distinct from the previous reports, results from this study offers an alternative for the purification of the recombinant GTFs free from any detergent contamination to make it more suitable for utilization in vivo.

Prenatal diagnosis of tetralogy of fallot by Doppler color flow mapping

The prenatal diagnosis of tetralogy of Fallot (TOF) can be difficult, as the routine sonographic four-chamber view may be normal before birth. Unlike the normal fetus, in which blood flows adjacent to the left side of the interventricular septum, on color Doppler mapping a fetus with TOF also demonstrates antegrade flow along the right side of the interventricular septum. This Y-shaped ventricular outflow passing through the dilated aortic tract is confluent at the level of the ventricular septal defect during the systolic phase. In the past 3 years, three cases of TOF have been diagnosed prenatally at the Chang Gung Memorial Hospital. In each case, the above picture was demonstrated. 2-Dimensional Doppler color flow mapping may be helpful in the prenatal diagnosis of TOF.

Human and canine cardiac troponin T and creatine kinase-MB distribution in normal and diseased myocardium. Infarct sizing using serum profiles

OBJECTIVE

Cardiac troponin T (cTnT) has been suggested as a new, more specific marker of myocardial cellular damage. The objectives of this study were to examine the distribution of cTnT and creatine kinase (CK)-MB in normal and diseased heart tissue of dogs and humans, and to assess the use of serum cTnT for the estimation of infarct size in dogs.

DESIGN

Serial serum specimens over 7 days were obtained from normal dogs (controls, n = 3) and dogs that underwent surgical coronary artery occlusion (n = 6). Heart muscle samples were obtained from the controls and after 3 weeks of occlusion in experimental dogs. Diseased human heart muscle samples were obtained at autopsy from patients who had died of acute myocardial infarction (n = 3). Normal heart muscle samples (n = 3) were obtained at autopsy from patients who died of non-cardiac-related illnesses. Tissues were sectioned and homogenized to harvest both cytosolic and myofibril-bound proteins. Serum samples and tissue homogenates were assayed for cTnT, CK-MB, and myoglobin (humans only). Total protein was assayed on homogenate samples and results were reported as milligrams per gram of total protein.

RESULTS

The distributions of cTnT, CK-MB, and myoglobin were equivalent across 14 sites within normal human heart. Creatine kinase-MB and myoglobin were more than 99% cytosolic. Cardiac troponin T was 92% myofibril bound and 8% cytosolic. In the control dog hearts, cTnT was higher and CK-MB was lower in the right ventricle than in the left ventricle. While CK-MB and myoglobin were more than 99% cytosolic, cTnT was 98% myofibril bound and 2% cytosolic. Infarct sizing in dog hearts initially did not correlate well with serum cTnT or CK-MB concentrations. However, when the data were separated by infarct location (right coronary artery; left circumflex coronary artery), the correlations improved dramatically. Differences in tissue concentrations of cTnT and CK-MB between the left and right ventricle might explain the change in correlations. Coronary artery occlusion in dogs and humans resulted in decreased cytosolic and myofibril cTnT and increased CK-MB and myoglobin in diseased myocardial tissue.

CONCLUSIONS

Our observed biochemical alterations suggest that the energy-producing proteins CK-MB and myoglobin are upregulated following cellular damage, while the structural and regulatory protein cTnT does not have a mechanism for replacement of lost protein following cell injury and necrosis.

Establishment of in vivo hepatoma models in rat and mouse from rodent hepatoma cell lines

BACKGROUND

Hepatoma is one of the most common cancers in Southeast Asia and African countries. In Taiwan, it is the leading cause of death in male cancer patients. In order to examine the effect of various factors on the growth of hepatoma, in vivo hepatoma models such as carcinogen-induced hepatoma and subcutaneous implantation of hepatoma in nude mice have been used. However, there are disadvantages in these models.

METHODS

Rats and mice were anesthetized by ketamine or ether, respectively. After a midline incision was made, N1S1 rat hepatoma cells were injected intrasplenically to partially hepatectomized or sham-operated rats, while BALB/c mice received intrasplenic injection of ML-2 and ML-3 mouse hepatoma cells. For direct tumor implantation, a 1mm3 N1S1 tumor piece was implanted in liver of Sprague-Dawley (SD) rat using a trocar. Animals were sacrificed at specific times after tumor implantation. Tumor incidence and the number of tumor nodules on the liver surface were recorded. Tumor samples were fixed and embedded for histological examination.

RESULTS

After intrasplenic implantation of ML-2 cells, no tumor was observed on the liver in any of the 10 mice 40 days later. In comparison, rapid growth of hepatic ML-3 tumors was observed in all animals. Rat hepatoma cells RH-35, McA-RH7777 and McA-RH8994 cells did not form tumors in SD rats. The tumorigenicity of N1S1 cells in SD rats was dose-dependent on implanted tumor cells. In addition, hepatic N1S1 tumors could be obtained within a few weeks by homograft.

CONCLUSIONS

We have successfully established in vivo hepatoma models in both the rat and the mouse. The murine ML-3 cells generated hepatoma in syngeneic BALB/c mice while the tumorigenicity of N1S1 cells in partially hepatectomized SD rats was dose-dependent on implanted tumor cells. These in vivo rodent models will be valuable tools for future studies of hepatoma.

Exercise intensity and longevity in men. The Harvard Alumni Health Study

OBJECTIVE

To examine the independent associations of vigorous (> or = 6 resting metabolic rate [MET] score) and nonvigorous (< 6 MET score) physical activity with longevity.

DESIGN

Prospective cohort study, following up men from 1962 or 1966 through 1988.

SETTING/PARTICIPANTS

Subjects were Harvard University alumni, without self-reported, physician-diagnosed cardiovascular disease, cancer, or chronic obstructive pulmonary disease (n = 17,321). Men with a mean age of 46 years reported their physical activities on questionnaires at baseline.

MAIN OUTCOME MEASURE

All-cause mortality (3728 deaths).

RESULTS

Total energy expenditure and energy expenditure from vigorous activities, but not energy expenditure from nonvigorous activities, related inversely to mortality. After adjustment for potential confounders, the relative risks of dying associated with increasing quintiles of total energy expenditure were 1.00 (referent), 0.94, 0.95, 0.91 and 0.91, respectively (P [trend] < .05). The relative risks of dying associated with less than 630, 630 to less than 1680, 1680 to less than 3150, 3150 to less than 6300, and 6300 or more kJ/wk expended on vigorous activities were 1.00 (referent), 0.88, 0.92, 0.87, and 0.87, respectively (P [trend] = .007). Corresponding relative risks for energy expended on nonvigorous activities were 1.00 (referent), 0.89, 1.00, 0.98, and 0.92, respectively (P [trend] = .36). Analyses of vigorous and nonvigorous activities were mutually adjusted. Among men who reported only vigorous activities (259 deaths), we observed decreasing age-standardized mortality rates with increasing activity (P = .05); among men who reported only nonvigorous activities (380 deaths), no trend was apparent (P = .99).

CONCLUSIONS

These data demonstrate a graded inverse relationship between total physical activity and mortality. Furthermore, vigorous activities but not nonvigorous activities were associated with longevity. These findings pertain only to all-cause mortality; nonvigorous exercise has been shown to benefit other aspects of health.

Perinatal characteristics and adult mammographic patterns

We retrieved breast mammograms for 370 women 40 to 74 years old with no history of breast cancer, for whom birth weight, birth length, placental weight and other birth characteristics were indicated in their standard birth records at the Uppsala University Hospital. Blind evaluation of the mammograms allowed these to be classified according to Wolfe's pattern. Logistic regression analysis was applied using as independent variables the recorded birth characteristics and as outcome variable, high risk (P2 and DY) versus low risk (N1 and P1) mammographic parenchymal pattern. After controlling for all the recorded variables, the odds ratio for a high-risk pattern (P2 or DY) increased consistently and significantly (P for trend 0.02) with the weight of the placenta, i.e. the main estrogen-producing organ during pregnancy. There were weak and non-significant positive associations with increasing birth weight (P for trend 0.53) and birth length (P for trend 0.52). These results are compatible with hypotheses suggesting that pregnancy estrogens or other perinatal characteristics may play a risk-modulating role influencing breast cancer in the offspring.

Congenital malformation in newborns. Analysis of 501 cases

Over a 14-year period in Chang Gung Memorial Hospital, 510 out of 44, 362 newborns were found to have birth defects. Maternal age, gestational age, parity, infant sex and birth weight were analyzed for each anomaly and compared to normal newborns. The average maternal age and parity for newborns with congenital anomalies were not significantly different from normal newborns. Mothers giving birth to babies with chromosomal aberrations, however, had a significantly older maternal age than the normal population. The gestational age at delivery was significantly shorter for all except craniofacial anomaly. In addition, there was a high percentage of intrauterine growth retardation in congenital anomalies. The central nervous system, the musculoskeletal system and craniofacial systems were the most commonly involved. The leading anomalies included cleft lip, cleft palate, anencephaly, polydactyly, hydrops fetalis, trisomy 21 and cystic hygroma. With improved ultrasound equipment and other prenatal diagnostic procedures, many defects of the fetus can now be identified. If the fetus is diagnosed with a surgically correctable lesion like cleft lip, it can be kept to term, delivered, then managed postnatally. If life-incompatible malformations have been detected before the 24th week, physicians are in a good position to counsel the parents. After the 24th week termination is proscribed by law. Therefore, physicians must take special care to detect fetal abnormalities early.

Purification of glucosyltransferases (GtfB/C and GtfD) from mutant strains of Streptococcus mutans

Streptococcus mutants constitutively expresses three glucosyltransferases (GTFs), i.e., GtfB, GtfC, and GtfD, which synthesize glucan polymers from sucrose. Two genetically constructed mutants of S. mutans which stably expressed either the cell-associated or the extracellular GTFs were selected for purification and characterization of these enzymes. The cell-associated GtfB and GtfC from strain GS-5DD lacking the gtfD gene expression were extracted by urea, renatured by dialysis in sodium phosphate buffer and then separated from the other wall-associated components by column chromatography. The extracellular GtfD was purified from the culture supernatant of strain NHS1 lacking gtfB and gtfC gene expression. The molecular weights of the purified GTFs was similar (150-160 kDa), as determined by SDS-polyacrylamide gel electrophoresis. The GtfB/C preparation synthesized primarily water-insoluble glucan in a primer independent manner. However, the presence of the dextran enhanced the enzymatic activities of the GtfB/C. GtfD synthesized water-soluble glucan exclusively in a primer dependent manner. Purified GtfD had a pH optimum of 5.5, and a K(m) value of 4.35 mM for sucrose. These results indicated that the mutated strains served as an efficient and specific host to obtain native GTFs.

Organochlorine compounds in relation to breast cancer, endometrial cancer, and endometriosis: an assessment of the biological and epidemiological evidence

There is an increasing public and scientific concern that certain chlorinated compounds, recognized as environmental pollutants, may cause estrogen-related neoplastic disease in humans. The main hypothesis has been that certain organochlorines, through their estrogenic actions, might cause breast cancer. From experimental studies, both in vitro and in vivo, there is evidence that certain organochlorine compounds may cause estrogenic effects, whereas others may cause antiestrogenic effects. In limited studies, some of these compounds in high doses have also been shown to increase and reduce the frequency of estrogen-related tumors in animals. The epidemiological findings regarding the association between organochlorines and breast cancer are inconclusive. However, the largest and best designed study has been interpreted as negative with respect to DDT and polychlorinated biphenyls (PCB) in relation to breast cancer. Associations between organochlorine exposure and endometrial cancer or endometriosis have even more limited empirical basis. The hypothesis that human exposure to environmental levels or organochlorines would favor an estrogenic overactivity leading to an increase in estrogen-dependent formation of mammary or endometrial tumors is not supported by the existing in vitro, animal and epidemiological evidence. It can, however, not be conclusively rejected on the basis of available data.

Abortion and breast cancer risk in seven countries

Epidemiologic studies have been inconsistent in suggesting an association between abortion and breast cancer risk. Whether the protection provided by a full-term pregnancy also results from a short-term pregnancy or whether a prematurely terminated pregnancy could increase the risk of breast cancer is unclear. Data from a large, international collaborative study were used to evaluate the association between abortions, whether spontaneous or induced, and breast cancer risk. The data from seven countries included 3,958 breast cancer cases and 11,538 hospital controls with information on abortion history obtained through interviews. Compared with nulliparous women with no abortion (baseline), the odds ratios (OR) and 95 percent confidence intervals (CI) were: for nulliparous women with a history of prior abortion, 0.86 (CI = 0.68-1.08); for parous women with no history of abortion, 0.63 (CI = 0.57-0.69); for parous women with abortion before first birth, 0.82 (CI = 0.69-0.97); and, for parous women with abortion only after first birth, 0.70 (CI = 0.63-0.79). When restricting analysis to parous women, those with a history of abortion exhibited an elevated OR suggesting a 29 percent risk increase if the incomplete pregnancy occurred before first birth (CI = 1.16-1.36) and an 11 percent risk increase for abortion only after first birth (CI = 1.02-1.20) compared with women without such history. The associations observed were stronger among the youngest women. These results do not support a large overall association between abortion and breast cancer risk.

Parity, age at first childbirth, and risk of ovarian cancer

Increasing parity is associated with a reduction in the risk of ovarian cancer, but it is not clear whether this association applies to different histopathological types and to borderline tumours. Moreover, the temporal relations are poorly understood, and the possible role of age at first birth remains unequivocal. We have investigated these issues in a case-control study nested in a nationwide cohort of women born between 1925 and 1960 in Sweden. During follow-up until 1984, 3486 invasive ovarian cancers (2992 epithelial, 330 stromal, 149 germ-cell, 15 not classifiable) and 510 tumours of borderline malignant potential were diagnosed. 5 individually age-matched controls (total 19,980) were selected for each case woman. After simultaneous adjustment for parity and age at first birth, increasing parity was associated with a pronounced consistent decrease in relative risk of all invasive cancers (odds ratio for each additional birth 0.81 [95% Cl 0.77-0.85]), epithelial cancer (0.81 [0.77-0.86]), stromal cancer (0.84 [0.72-0.98]), and germ-cell cancer (0.71 [0.48-1.05]), but a less consistent decrease for borderline tumours (0.92 [0.81-1.04]). The risk of ovarian cancer decreased by about 10% for each 5-year increment in age at first childbirth (odds ratios 0.89 [0.84-0.94] epithelial cancer, 0.92 [0.77-1.10] stromal cancer, 0.92 [0.65-1.32] germ-cell cancer, 0.93 [0.80-1.09] borderline tumours). Because our findings cannot be readily explained by theories involving incessant ovulation or high serum concentrations of gonadotropins, new aetiological hypotheses are needed. Pregnancy-dependent clearance from the ovaries of cells that have undergone malignant transformation could explain the reproductive risk factors for ovarian cancer.

Rising incidence rate of esophageal adenocarcinoma and use of pharmaceutical agents that relax the lower esophageal sphincter (United States)

Primary adenocarcinoma of the esophagus, previously considered a rare neoplasm, has shown a dramatic increase in its incidence rate among White men in the United States since 1970. The reason for this increase is unknown. Since the presence of Barrett's esophagus is essential for the development of most esophageal adenocarcinomas, the increasing incidence of esophageal adenocarcinoma may be related to an increasing prevalence of Barrett's esophagus, and its precursor, gastroesophageal reflux. An association between this increasing incidence and an increasing use of pharmaceutical agents that relax the lower esophageal sphincter is proposed. The data on the dollar amount and approximate quantity in milligrams purchased per capita through retail pharmacies and hospitals in the United States from 1957 to 1986 are presented for four categories of such agents. An upward trend is observed for all four categories.

Erythrocyte Ca2+ pump is defective during sepsis

Saturated Ca2+ extrusion rate through the Ca2+ pump of erythrocytes was determined by the cobalt-exposure method in normal subjects and septic patients. From 48 normal subjects, the value of Vmax of erythrocyte Ca2+ pump was 14.83 +/- 0.49 mmol/L cells/hr; from 29 sepsis patients, it was 9.49 +/- 0.59 mmol/L cels/hr, significantly (P < 0.001) lower than that from the erythrocytes of normal subjects. When the severity of sepsis was evaluated by the septic severity score (SSS), a significant correlation (P < 0.0001) was observed between the Vmax of Ca2+ pump and the patient's SSS, indicating that the inhibition of Ca2+ pump depended on the degree of the pathological development of sepsis. Since the ATP-dependent Ca2+ transport in rat liver plasma membrane is also reduced during the late stage of sepsis [Lau et al., Circ Shock 38:238-244, 1992], impairment of the activity of Ca2+ pump appears to have a general pathophysiological significance in the development of severe sepsis.

Epidemiologic correlates of breast cancer laterality (Sweden)

Breast cancer laterality was studied in relation to age in 80,784 cases of invasive and 3,835 cases of pre-invasive breast cancer in women and 548 cases of invasive breast cancer in men reported to the Swedish Cancer Registry, 1970-89. In a subset of 11,274 women with invasive disease, data on parity were available through the Swedish Fertility Registry. Laterality also was evaluated in relation to age and reproductive variables in 3,986 cases from an international study from the 1960s. The overall incidence of pre-invasive and invasive cancer was higher in the left than in the right breast among both women and men. The excess incidence of invasive cancer in the left breast was evident only after the age of 45 years in women; a similar phenomenon may exist with pre-invasive disease in women and in men. The age-dependent laterality pattern did not appear to be confounded by menopausal status. Among women younger than 45 years, nulliparity, right handedness, and late age at menarche was associated with a somewhat higher incidence of cancer in the right breast. The laterality findings are likely to be due to factors operating early in the carcinogenic process, perhaps at the pre-initiation stage.

Reduced rate of disease development after HIV-2 infection as compared to HIV-1

Human immunodeficiency virus type-2 (HIV-2) is a close relative of the prototype acquired immunodeficiency syndrome (AIDS) virus, HIV-1. HIV-2 is biologically similar to HIV-1, but information is lacking concerning clinical outcomes of HIV-2-infected individuals. From 1985 to 1993, a prospective clinical study was conducted in women with HIV-2 and HIV-1 infection to determine and compare rates of disease development. HIV-1-infected women had a 67% probability of AIDS-free survival 5 years after seroconversion in contrast with 100% for HIV-2-infected women. In addition to having significantly less HIV-related disease outcome in HIV-2 enrollees compared to HIV-1 enrollees, the rate of developing abnormal CD4+ lymphocyte counts with HIV-2 infection was also significantly reduced. This natural history study demonstrates that HIV-2 has a reduced virulence compared to HIV-1.

Season of birth and breast cancer risk in Sweden

Recent research suggests that intrauterine exposures, perhaps factors that influence birth weight and other indicators of fetal growth, may affect future breast cancer risk. Because birth weight shows seasonal variation in Sweden, we assessed whether risk for breast cancer is associated with month of birth. The analyses included all 115,670 women, born between 1858 and 1968, who were reported to the Swedish Cancer Registry in 1958-89 as having breast cancer. Poisson regression models were used to examine the data. After adjustment for seasonality of number of live births in the population at risk, a significant seasonal pattern was identified for women born between 1880 and 1920. Women born in June had a 5% higher risk of breast cancer than those born in December. By contrast, there was no evidence of birth seasonality among 440,948 women with cancer at other sites. Exposures relevant to breast cancer risk later in life are unlikely to be related to month of birth. Thus, prenatal or early post-natal factors influence breast carcinogenesis, but the seasonal variation in these factors must have decreased over time.

Transport of 2-aminoisobutyric acid in cultured endothelial cells

Conflicting reports exist concerning the presence of a Na(+)-coupled amino acid transport system in cultured endothelial cells. We have employed a non-metabolizable analog, 2-aminoisobutyric acid (AIB), to investigate the activity of Na(+)-dependent amino acid transport in cultured human umbilical vein endothelial cells (HUVEC). We found a pronounced saturable, Na(+)-dependent component of AIB uptake in 'fresh' (non-starved) HUVEC. The Na(+)-dependent component accounted for 78% of total AIB uptake with a high sensitivity to external Na+. The accumulation of AIB was inhibited by ouabain preincubation, consistent with the energetics of Na(+)-coupled transport. Amiloride, an epithelial Na+ channel blocker, also inhibited AIB transport at high concentration. The results strongly support the presence of a Na(+)-coupled transport system of amino acid in HUVEC.

Slower heterosexual spread of HIV-2 than HIV-1

Because of the similar virological properties of HIV types 1 and 2, HIV-2 was assumed to be as infectious and capable of inducing AIDS as HIV-1. Seroepidemiological studies have shown significant rates of HIV-2 infection in West Africa, and surveys from other regions of the world indicate that the spread of HIV-2 infection continues. However the pathogenic potential of HIV-2 is considered to be lower than that of HIV-1. It is therefore important to understand the transmission properties of HIV-2 and its contribution to the AIDS pandemic. Since 1985, we have prospectively studied 1452 registered female prostitutes in Dakar, Senegal, with sequential evaluation of their antibody status to HIV-1 and HIV-2. During the study the overall incidence of HIV-1 and HIV-2 was the same (1.11 per 100 person-years of observation [pyo]). However, the annual incidence of HIV-1 increased substantially: there was a 1.4-fold increased risk per year and thus a 12-fold increase in risk over the entire study period. The incidence of HIV-2 remained stable, despite higher HIV-2 prevalence. In our population the heterosexual spread of HIV-2 is significantly slower than that of HIV-1, which strongly suggests differences in the viruses' infectivity potential.

Comparison of physical properties of light-curing and self-curing dental impression materials

A light-curing polyether urethane dimethacrylate impression material was recently developed. Its polymerization reaction is activated by intensified visible light; therefore, the on-demand set allows operators to work at their own pace. Furthermore, its constant viscosity provides a constant flow rate at the critical stages of taking impressions. The purposes of this study were to evaluate the physical properties and accuracy of this light-curing impression material and to compare it with those of self-curing impression materials currently used in our dental clinic. Physical properties such as strain in compression, compression set, dimensional stability, and tear strength of the impression materials were measured according to test methods stipulated in ADA Specification No. 19 for elastomeric impression materials. The template-coping method developed by Lewinstein and Craig was used to evaluate the accuracy of the impression materials. It was found that the strain in compression of the polyether urethane dimethacrylate was higher than that of the condensation silicones, but lower than that of the addition silicones. The compression set of the condensation silicones was more than that of the polyether urethane dimethacrylate, but much less than that of the polysulfides. The dimensional stability showed that all of the impression materials, except the polyether urethane dimethacrylate, had a negative dimensional change 24 hours after mixing. The sequence is: polysulfide < condensation silicone < addition silicone. The expansion rate of the light-curing material was measured under 0.07% one day after curing. The polyether urethane dimethacrylate had extraordinary tear resistance compared to the other impression materials.(ABSTRACT TRUNCATED AT 250 WORDS)

Handedness, age at menarche, and age at menopause

OBJECTIVE

To investigate the relation between handedness and age at menarche or age at menopause, as both handedness and reproductive variables have been suggested to be influenced by the intrauterine endocrine environment.

METHODS

Self-reported information on handedness, age at menarche, age at menopause, and other demographic and reproductive variables was recorded for 10,328 women still menstruating or in natural menopause. These women had been selected as controls in a multicenter case-control study of breast cancer conducted in the 1960s. Left-handedness (including ambidexterity) was modeled as the outcome variable through multiple logistic regression.

RESULTS

After adjusting for center, age, menopausal status, age at menopause, years of schooling, and parity, there was no significant relation of handedness to age at menarche (odds ratio for each year delayed 1.01, 95% confidence interval [CI] 0.97-1.06) or age at menopause (odds ratio 1.00, 95% CI 0.98-1.02).

CONCLUSION

These findings lend no support to the hypothesis that intrauterine endocrine variables associated with handedness also are related to reproductive variables.

Some statistical considerations in the analysis of case-control studies when the exposure variables are continuous measurements

This paper focuses on some statistical considerations in the estimation of dose-response in case-control studies when the exposure variables are continuous measurements. The first point is that the effects of differential variability in the exposure distributions over cases and controls cannot be differentiated from a true quadratic risk model. The second point is that when dealing with variables where zero denotes no exposure, it is important to treat the unexposed subjects separately from those who were exposed. Failure to do so can lead to differential variability among cases and controls and the resulting confounding with a quadratic risk model. Both of these points are illustrated by an example.

Suggestion of concomitant changes of electric power consumption and childhood leukemia in Greece

Over a 14-year period (1976-89) 679 deaths from childhood leukemia were registered in Greece and the corresponding mortality over this period declined by almost 70%, with no evidence of differential reduction by gender or population type. For each of the nine geographical regions of the country, slopes of decreasing mortality from childhood leukemia over the study period were calculated and correlated with the corresponding slopes of increasing electric power consumption over the 16-year period 1970-85 (allowing for a postulated latency of about 5 years). A positive association was noted, which however was not statistically significant (p approximately 0.26). Studies of similar nature conducted in larger countries over more extended periods could contribute to the resolution of the controversy surrounding the role of electric power-generated extremely low frequency electric and magnetic fields in the etiology of childhood leukemia.

Prevalence and characteristics of areca nut chewers among junior high school students in Changhua county, Taiwan

Some studies indicate that betel quid and its ingredients chewing can produce cell mutagenicity and tumorigenicity. In Taiwan studies, betel quid chewing is the main cause of submucous fibrosis and oral cancer. Understanding the distribution and characteristics of the areca nut chewing population is one of the first steps in the effort to prevent these oral diseases. A stratified cluster random sample of 2442 junior high school students in Changhua county, Taiwan, were surveyed for the habit of areca nut chewing. Significantly more male students chewed areca nut than female students (9.2% vs 0.9%). The proportion of students who were chewing areca nuts increased with increasing (seventh to ninth) grades. Areca nut was used by junior high school students at a higher rate in village (rural) areas as compared to town (semi-urban) and city (urban) areas (6.4%, 3.7% and 3.0%, respectively). More students in the ordinary achievement classes were chewing areca nuts than those in the high achievement classes (8.4% vs 1.6%). Areca nut chewing students tended to have users in their families. Cigarette smoking and alcohol drinking were positively associated with areca nut chewing. More than half (53.6%) of the areca nut chewing students first experimented with this habit with a family member, most often the father or grandfather.

Risk of extrahepatic bileduct cancer after cholecystectomy

The aetiology of cancer of the extrahepatic bile duct is unknown. Gallstones have been proposed to be a risk factor on the basis of ecological and epidemiological evidence. As gallstones are formed in the gallbladder, the occurrence of extrahepatic bileduct cancer in patients after cholecystectomy is of interest. All patients (62,734) who had had a cholecystectomy during 1965-1983 within the Uppsala Health Care Region, Sweden, were followed up to the end of 1987. Excluding the first year of follow-up, 23 cancers of the extrahepatic bileduct occurred vs 26.3 expected for a standardised incidence ratio (SIR) of 0.88 (95% confidence interval [CI] 0.56-1.31). 10 years or more after operation there was a greater reduction of risk (SIR = 0.27; 95% CI 0.06-0.80). Similar patterns were observed for men and women, and among patients who had undergone cholecystectomy only compared with those who had had their common bileducts explored. To assess surveillance bias the incidence of primary liver cancer was also analysed: SIR = 1.15; 95% CI 0.91-1.44 overall, and 10 years or more after cholecystectomy SIR = 0.98; 95% CI 0.66-1.40. This study shows a reduced risk of extrahepatic bileduct cancer 10 or more years after cholecystectomy, indicating that gallstones may be a cause of this cancer.

Parity and hepatocellular carcinoma. A population-based study in Sweden

The association between parity and hepatocellular carcinoma (HCC) was studied using a data-base generated by linking 2 Swedish nation-wide registries; the Cancer Registry and the Fertility Registry. Among women born between 1925 and 1960, 133 patients with HCC recorded in the Cancer Registry between 1958 and 1984 were compared with 665 age-matched controls. In this nested case-control study there was no positive association between parity, age at first birth or frequency of twinning on the one hand, and risk of HCC on the other. It appears that the positive association between parity and HCC previously reported is limited to cases of HCC caused by chronic infection with hepatitis B virus; these cases represent only a small fraction of HCC cases in Sweden.

Diet and coronary heart disease: a case-control study in Athens, Greece

We conducted a case-control study in Athens, Greece, between January 1990 and April 1991 to examine the association between diet and coronary heart disease. The case series comprised 329 patients with electrocardiographically confirmed first coronary infarct or a first positive coronary arteriogram, or both, who were admitted to a major teaching hospital during a 16-month period. Controls were 570 patients admitted to the same hospital for minor conditions believed to be unrelated to nutrition. Total energy intake was inversely associated with coronary heart disease risk, a quintile energy increase corresponding to a relative risk of 0.96. After controlling for total energy intake, dietary fat was positively related to coronary heart disease, and total carbohydrates were negatively related to coronary heart disease, the nutrient-specific relative risks for a quintile increase being 1.19 (95% confidence interval = 0.96-1.48) and 0.81 (95% confidence interval = 0.67-0.97), respectively. Major fat components (saturated, monounsaturated, and polyunsaturated fat) did not appear to have differential risk implications for coronary heart disease; however, cooking with margarine was associated with an increased relative risk (1.87; 95% confidence interval = 0.82-4.28). Dietary proteins, cholesterol, and vitamin C were not associated with coronary heart disease.

Diet and ovarian cancer: a case-control study in Greece

In a hospital-based case-control study of common malignant epithelial tumors of the ovary, conducted in Athens (1989-1991), 189 cases were compared with 200 hospital visitor controls. Personal interviews were conducted in all cases and diet was ascertained through a semi-quantitative food frequency questionnaire. Nutrient intakes for individuals were estimated by multiplying the nutrient content of a typical portion size for each specified food item by the frequency at which the food was consumed per month and summing these estimates for all food items. Data were analyzed using logistic regression, controlling for non-dietary confounding factors, total energy intake and, among nutrients, mutual confounding influences. Adjusted odds ratios (rate ratios) for ovarian cancer, associated with particular nutritional variables, were expressed in terms of increments approximately equal to the standard deviations of (the residual of) the respective nutrients, on a daily basis. The adjusted odds ratios (and 95% confidence intervals) were 0.80 (0.65-0.99) for mono-unsaturated fat and 0.73 (0.61-0.87) for crude fiber. No substantial, statistically significant or consistent independent associations were noted for total energy, total protein, saturated fat, polyunsaturated fat, dietary cholesterol, total carbohydrates, sucrose, vitamin C, vitamin A, riboflavin or calcium. These associations, if causal, could explain to some extent the relatively low incidence of ovarian cancer in Greece and other Mediterranean countries as well as the increasing incidence trends noted in these countries during the last few decades.

Hair dyes, analgesics, tranquilizers and perineal talc application as risk factors for ovarian cancer

In a hospital-based case-control study of ovarian cancer conducted in Athens (1989-1991), 189 women with histologically confirmed common malignant epithelial tumors of the ovary were compared with 200 hospital visitor controls. All interviews were conducted by personal interview in the 2 participating hospitals and the data were analyzed by modelling through logistic regression, controlling for demographic and reproductive variables. Tranquilizing and hypnotic drugs (mostly diazepam) were not associated with risk of ovarian cancer: the adjusted relative risk (RR) and 95% confidence interval (CI) were 0.96 (0.57 to 1.63), whereas use of analgesics (mostly salicylates) was associated with significantly reduced risk of the disease (RR 0.51; CI 0.26 to 1.02). There was no evidence that perineal application of talc was associated with increased risk (RR 1.05; CI 0.28 to 3.98) but the frequency of reporting talc use was low in the study population. There was a statistically significant (p for trend 0.007) and a dose-dependent association between hair dyeing and risk of ovarian cancer. Compared to never-users, women dyeing their hair up to 4 times per year had a relative risk of 1.74 (0.91 to 3.32) whereas those dyeing their hair 5 or more times per year had a relative risk of 2.16 (1.19 to 3.89).