Selection from fixed term to permanent employment: prospective study on health, job satisfaction, and behavioural risks

STUDY OBJECTIVE

To examine health, job satisfaction, and behavioural risks as antecedents of selection from fixed term to permanent employment.

DESIGN

Prospective cohort study of change in employment contract during a two year period. Self reported health, recorded sickness absence, job satisfaction, behavioural risks, demographics, and occupational characteristics were assessed at baseline.

SETTING

Hospital staff in two Finnish hospital districts.

PARTICIPANTS

A cohort of 526 hospital employees (54 men, 472 women) aged 20 to 58 years with a fixed term job contract at baseline.

MAIN RESULTS

During the follow up period, 137 became permanently employed. Men, employees in higher positions, full time workers, and those with five to eight years in the employ of the hospital were more likely to become permanently employed. After adjusting for these factors, obtaining a permanent job contract was predicted by self rated good health (odds ratio (OR) 3.90; 95% confidence intervals (CI) 1.34 to 11.36), non-caseness of psychological distress (OR 1.80; 95% CI 1.01 to 3.20), high job satisfaction (OR 1.86; CI 1.17 to 2.94), and non-sedentary life style (OR 2.64; CI 1.29 to 5.41), compared with the rest of the cohort.

CONCLUSIONS

Investigation of fixed term employees yields new information about selective mechanisms in employment mobility. Good health seems to promote the chances for a fixed term employee to reach a better labour market status. These results correspond to earlier research on selective mechanisms in other forms of employment mobility and provide a partial explanation for the socioeconomic gradient of health.

Dietary and serum alpha-tocopherol, beta-carotene and retinol, and risk for colorectal cancer in male smokers

OBJECTIVE

To study the association between dietary and serum antioxidant vitamins and carotenoids and risk for colorectal cancer in male smokers.

DESIGN

A prospective cohort study within a randomised, double-blind, placebo-controlled trial testing supplementation with alpha-tocopherol (50 mg/day), beta-carotene (20 mg/day) or both in preventing cancer.

SUBJECTS AND METHODS

Participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study with complete dietary data and serum samples available from baseline. These included 26,951 middle-aged male smokers among whom 184 colorectal cancer cases were diagnosed during 8 y of follow-up. Relative risks were calculated with Cox proportional hazards models adjusting for trial supplementation, age, body mass index, serum cholesterol, cigarettes smoked per day and physical activity.

RESULTS

There was no significant association between dietary vitamin C or E, alpha-or gamma-tocopherol, retinol, alpha- or beta-carotene, lycopene or lutein+zeaxanthin and risk for colorectal cancer. Serum alpha-tocopherol, beta-carotene or retinol was also not associated with the risk, neither did the season when baseline blood was drawn modify the relationship between serum beta-carotene and colorectal cancer risk.

CONCLUSIONS

Our data support the results from previous studies in which no association between dietary antioxidant vitamins and carotenoids and risk for colorectal cancer has been observed. Likewise, no association between baseline serum antioxidant concentrations and colorectal cancer risk was evident.

SPONSORSHIP

The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study was supported by a contract with the US National Cancer Institute (N01-CN-45165).

Estimating the distribution of usual dietary intake by short-term measurements

OBJECTIVE

To estimate the habitual dietary intake distribution in a population on the basis of repeated short-term measurements, especially of multiple 24 h diet recalls.

METHODS

Six different statistical methods were evaluated and compared. The comparison referred to theoretical assumptions, admitted data transformations, statistical foundations, available software packages, and applications to real data of dietary intake.

RESULTS

The Nusser method and a simplified version of it proposed in the paper have proved to be universally applicable methods for estimating the usual intake distribution for food groups and nutrients. Also, the Buck method seemed to be a robust estimation procedure suitable for the description of food consumption data, whereas the other considered methods were only applicable for log-normally distributed intake data or required a comprehensive data simulation. Characteristics of the estimated usual intake distribution were a decreased standard deviation, increased lower percentiles, and decreased upper percentiles compared to the observed sample distribution of individual means. Empirical results concerning total fat and vegetable intake in three different European consumption surveys showed that the estimated percentiles of the usual intake distribution did not depend markedly on the number of sampling days.

CONCLUSIONS

Repeated short-term measurements like 24 h diet recalls can be used to describe the habitual dietary intake distribution in food consumption surveys. Recommended is a sampling design of two non-consecutive sampling days. The sampling days of all participants should be selected in such a way that they cover all seasons and days of the week.

Topical retinoic acid alters the expression of cellular retinoic acid-binding protein-I and cellular retinoic acid-binding protein-II in non-lesional but not lesional psoriatic skin

Therapeutic retinoids have profound effects on psoriatic skin pathology but their interactions with various retinoid-binding proteins in lesional vs non-lesional skin have not been investigated. Using quantitative real-time PCR the mRNA expression of cellular retinol-binding protein I (CRBPI) and retinoic acid-binding protein I/II (CRABPI/CRABPII) was studied in psoriatic and healthy control (=normal) skin after 4 days of occlusive RA/vehicle treatment (n=6). Untreated psoriatic lesions showed a markedly elevated CRABPII/CRABPI ratio, while the CRBPI level was reduced in lesional and non-lesional skin as compared to normal skin. In RA-treated normal and non-lesional skin, the mRNA expression of CRBPI was unaltered while that of CRABPI and CRABPII was reduced by approximately 80% and increased approximately 5-fold, respectively, as compared to vehicle-treated skin. In contrast, lesional skin exposed to RA showed an almost 90% increase in CRBPI transcripts but unaltered expression of CRABPI and CRABPII, yet, the mRNA expression of several inflammatory mediators, e.g. inducible nitric oxide synthase, interferon-gamma and interleukin-1beta, was clearly reduced. Immunohistochemistry localized CRABPII to suprabasal keratinocytes in normal skin and revealed markedly elevated levels in lesional skin. RA treatment induced CRABPII protein expression in normal and non-lesional skin, to similar levels as in untreated lesions. The results indicate that the effects of RA differ in normal/non-lesional psoriatic skin and lesional skin. Whether the high expression of CRABPII in psoriatic skin lesions is due to increased amounts of endogenous retinoids in lesional skin or reflects an abnormal regulation of the CRABPII gene in psoriasis remains to be studied.

Contingent employment, health and sickness absence

OBJECTIVES

This study explored the health and sickness absences of contingent employees.

METHODS

Analyses of self-reported health and recorded spells of sickness absence were based on a cohort of 5650 employees (674 men, 4976 women) in 10 Finnish hospitals.

RESULTS

After adjustment for demographic and work-related characteristics, contingent employees had a better self-rated health status [odds ratio 0.76, 95% confidence interval (95% CI) 0.62-0.94 of poor or average health status]. There were no differences in the prevalence of diagnosed chronic diseases and minor psychiatric morbidity between the groups. After adjustment for self-rated health and confounding, female, but not male, contingent employees had a lower rate of self-certified (1-3 days) sickness absences than permanent employees (rate ratio 0.90, 95% CI 0.85-0.95). Contingent employees, irrespective of gender, had a 0.77 (95% CI 0.71-0.84) times lower rate of medically certified (>3 days) sickness absence than permanent employees. Poor self-rated health status, reported diagnosed chronic diseases, and minor psychiatric morbidity were associated with medically certified absences to a less extent among contingent employees than among permanent employees.

CONCLUSIONS

These findings suggest better self-rated health and a lower sickness absence rate for contingent employees than for permanent employees. The difference in sickness absence between the groups seems not only to be associated with actual differences in health, but also with different thresholds of taking sick leave or working while ill.

Phenotypic/genotypic correlations in patients with epidermolytic hyperkeratosis and the effects of retinoid therapy on keratin expression

Dominant-negative mutations in the KRT1 and KRT10 genes cause epidermolytic hyperkeratosis, a rare form of ichthyosis sometimes associated with palmoplantar keratoderma. Although there is no permanent cure, some patients improve on retinoid therapy. More knowledge is needed, however, about the mechanism of action of retinoids and the genotypic/phenotypic correlations in this disease. Thirteen patients from 10 families with generalized disease and 2 sporadic patients with nevoid lesions were studied, probably representing most of the patients in Sweden and Norway. All patients, except one nevoid case, were known to have KRT1 or KRT10 mutations. Those with mutated keratin 1 (K1) invariably had associated keratoderma (n=6). In contrast, only 1 of 7 patients with K10 mutations had this problem (p = 0.0047). Five out of 6 patients with KRT10 mutations benefited from treatment with oral acitretin (5-25mg/day) or topical tretinoin/tazarotene, but none of the patients with KRT1 mutations derived any benefit. Quantitative analysis of K1 and K10 mRNA in skin biopsies obtained before and after retinoid therapy (n=8) showed no consistent down-regulation of mutated keratin that would explain the therapeutic outcome. Instead, the mRNA expression of K2e (a normal constituent of the upper epidermis) diminished especially in nonresponders. In contrast, K4 mRNA and protein (marker of retinoid bioactivity in normal epidermis) increased in almost all retinoid-treated patients. In conclusion, our study confirms a strong association between KRT1 mutations and palmoplantar keratoderma. Retinoid therapy is particularly effective in patients with KRT10 mutations possibly because they are less vulnerable to a down-regulation of K2e, potentially functioning as a substitute for the mutated protein in patients with KRT1 mutations.

A national short-term follow-Up study of extremely low birth weight infants born in Finland in 1996-1997

OBJECTIVES

The aims of this prospective nationwide investigation were to establish the birth rate, mortality, and morbidity of extremely low birth weight (ELBW) infants in Finland in 1996-1997, and to analyze risk factors associated with poor outcome.

PARTICIPANTS AND METHODS

The study population included all stillborn and live-born ELBW infants (birth weight: <1000 g; gestational age: at least 22 gestational weeks [GWs]), born in Finland between January 1, 1996 and December 31, 1997. Surviving infants were followed until discharge or to the age corresponding with 40 GWs. National ELBW infant register data with 101 prenatal and postnatal variables were used to calculate the mortality and morbidity rates. A total of 32 variables were included in risk factor analysis. The risk factors for death and intraventricular hemorrhage (IVH) of the live-born infants as well as for retinopathy of prematurity (ROP) and oxygen dependency of the surviving infants were analyzed using logistic regression models.

RESULTS

A total of 529 ELBW infants (.4% of all newborn infants) were born during the 2-year study. The perinatal mortality of ELBW infants was 55% and accounted for 39% of all perinatal deaths. Of all ELBW infants, 34% were stillborn, 21% died on days 0 through 6, and 3% on days 7 though 28. Neonatal mortality was 38% and postneonatal mortality was 2%. Of the infants who were alive at the age of 4 days, 88% survived. In infants surviving >12 hours, the overall incidence of respiratory distress syndrome (RDS) was 76%; of blood culture-positive septicemia, 22%; of IVH grades II through IV, 20%; and of necrotizing enterocolitis (NEC) with bowel perforation, 9%. The rate of IVH grades II through IV and NEC with bowel perforation decreased with increasing gestational age, but the incidence of RDS did not differ significantly between GWs 24 to 29. A total of 5 infants (2%) needed a shunt operation because of posthemorrhagic ventricular dilatation. Two hundred eleven ELBW infants (40% of all and 60% of live-born infants) survived until discharge or to the age corresponding with 40 GWs. The oxygen dependency rate at the age corresponding to 36 GWs was 39%, and 9% had ROP stage III-V. Neurological status was considered completely normal in 74% of the surviving infants. The proportions of infants born at 22 to 23, 24 to 25, 26 to 27, and 28 to 29 GWs with at least one disability (ROP, oxygen dependency, or abnormal neurological status) at the age corresponding to 36 GWs were 100%, 62%, 51%, and 45%, respectively. Birth weight <600 g and gestational age <25 GWs were the independent risks for death and short-term disability. The primary risk factor for IVH grades II through IV was RDS. Low 5-minute Apgar scores predicted poor prognosis, ie, death or IVH, and antenatal steroid treatment to mothers with threatening premature labor seemed to protect infants against these. Some differences were found in the mortality rates between the 5 university hospital districts: neonatal mortality was significantly lower (25% vs 44%) in one university hospital area and notably higher (53% vs 34%) in another area. Furthermore, significant differences were also found in morbidity, ie, oxygen dependency and ROP rates. Differences in perinatal (79% vs 45%) and neonatal (59% vs 32%) mortality rates were found between secondary and tertiary level hospitals.

CONCLUSION

Our study shows that even with modern perinatal technology and care, intrauterine and early deaths of ELBW infants are common. The outcome of infants born at 22 to 23 GWs was unfavorable, but the prognosis improved rapidly with increasing maturity. The clear regional and hospital level differences detected in survival rates and in short-term outcome of ELBW infants emphasizes that the mortality and morbidity rates should be continuously followed and that differences should be evaluated in perinatal audit procedures. (ABSTRACT TRUNCATED)

Intake of flavonols and flavones and risk of coronary heart disease in male smokers

Flavonols and flavones are antioxidant polyphenolic compounds found in tea, vegetables, fruits, and wine. In experimental studies they have been effective free radical scavengers, metal chelators, and antithrombotic agents. In the few epidemiologic studies of these agents, some have suggested an inverse association between intake of flavonols and flavones and the risk of cardiovascular disease. Our study population comprised 25,372 male smokers, 50-69 years of age, with no previous myocardial infarction. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, which was a randomized, double-blind, placebo-controlled trial with daily supplementation of alpha-tocopherol (50 mg per day) and/or beta-carotene (20 mg per day). The men completed a validated dietary questionnaire at baseline. After 6.1 years of follow-up, there were 1,122 nonfatal myocardial infarctions and 815 coronary deaths. In the multivariate model, the relative risk of nonfatal myocardial infarction was 0.77 (95% confidence interval = 0.64-0.93) among men in the highest (median 18 mg per day) compared with the lowest (median 4 mg per day) quintile of flavonol and flavone intake. The respective relative risk for coronary death was 0.89 (95% confidence interval = 0.71-1.11). Thus, intake of flavonols and flavones was inversely associated with nonfatal myocardial infarction, whereas there was a weaker association with coronary death.

Effects of supplemental alpha-tocopherol and beta-carotene on urinary tract cancer: incidence and mortality in a controlled trial (Finland)

OBJECTIVES

Epidemiological studies have suggested a protective effect of vegetables and fruits on urinary tract cancer but the possible protective nutrients are unknown. We studied the effect of alpha-tocopherol (a form of vitamin E) and beta-carotene supplementation on urinary tract cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study.

METHODS

A total of 29,133 male smokers aged 50-69 years from southwestern Finland were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or a placebo daily for 5-8 years (median 6.1 years). Incident urothelial cancers (bladder, ureter, and renal pelvis; n = 169) and renal cell cancers (n = 102) were identified through the nationwide cancer registry. The diagnoses were centrally confirmed by review of medical records and pathology specimens. The supplementation effects were estimated using a proportional hazards model.

RESULTS

Neither alpha-tocopherol nor beta-carotene affected the incidence of urothelial cancer, relative risk 1.1 (95% confidence interval (CI) 0.8-1.5) and 1.0 (95% CI 0.7-1.3), respectively, or the incidence of renal cell cancer, relative risk 1.1 (95% CI 0.7-1.6) and 0.8 (95% CI 0.6-1.3), respectively.

CONCLUSION

Long-term supplementation with alpha-tocopherol and beta-carotene has no preventive effect on urinary tract cancers in middle-aged male smokers.

Day-to-day reactogenicity and the healthy vaccinee effect of measles-mumps-rubella vaccination

OBJECTIVE

Revaccination policies adopted in many countries to control measles have raised various safety issues including those concerning the second vaccine dose. We performed a prospective, double-blind, crossover trial among twins receiving a measles-mumps-rubella (MMR) vaccine.

STUDY DESIGN

The study comprised 1162 monozygous and heterozygous twins, each of whom randomly received placebo and then vaccine, or vice versa, 3 weeks apart, at 14 to 83 months of age. Most of the oldest children had previously been vaccinated against measles, and one half of the remainder of children had had the disease. Symptoms and signs were recorded daily on structured forms. Statistical methods included a complex analysis of the vaccine attributability of the symptoms and conditional logistic regression.

RESULTS

Vaccination-attributable events occurred in 6% overall. At 14 to 18 months of age, reactions developed between days 6 and 14, peaking at day 10. The clearest vaccine-attributable effect was fever exceeding 101.3 degrees F (38. 5 degrees C; odds ratio: 3.28; 95% confidence interval: 2.23-4.82; P <.001), but the same trend was found for rash, arthralgia, conjunctivitis, staying in bed, drowsiness, and irritability. At 6 years of age, systemic reactions occurred 5 to 15 times less frequently, only arthralgia being associated with vaccination. Zygocity, gender, history of allergy, or infections did not modify reactions. Instead, respiratory symptoms developed within days postinjection to a level of 15% to 20% without subsequent decline and with no difference between vaccinees and placebo recipients.

CONCLUSION

Vaccination was avoided during infections, but many small children became mildly ill within a week or so with no relation to vaccination (the healthy vaccinee effect). MMR vaccine was virtually nonreactogenic when given at 6 years of age. vaccine, measles, mumps, rubella, reactogenicity, adverse events, zygocity, healthy vaccinee effect.

Diet and prostate cancer risk in a cohort of smokers, with a specific focus on calcium and phosphorus (Finland)

BACKGROUND

Calcium, phosphorus, fructose, and animal protein are hypothesized to be associated with prostate cancer risk, potentially via their influence on 1,25-dihydroxyvitamin D3. We examined these nutrients and overall diet and prostate cancer risk in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC Study).

MATERIALS AND METHODS

The ATBC Study was a randomized 2 x 2 trial of alpha-tocopherol and beta-carotene on lung cancer incidence conducted among Finnish male smokers; 27,062 of the men completed a food-use questionnaire at baseline, and comprise the current study population. There were 184 incident clinical (stage 2-4) prostate cancer cases diagnosed between 1985 and 1993. We used Cox proportional hazards models to examine associations between dietary intakes and prostate cancer.

RESULTS

We did not observe significant independent associations for calcium and phosphorus and prostate cancer risk. However, men with lower calcium and higher phosphorus intake had a multivariate relative risk of 0.6 (95% CI 0.3-1.0) compared to men with lower intakes of both nutrients, adjusting for age, smoking, body mass index, total energy, education, and supplementation group. Of the other foods and nutrients examined, none was significantly associated with risk.

DISCUSSION

This study provides, at best, only weak evidence for the hypothesis that calcium and phosphorus are independently associated with prostate cancer risk, but suggests that there may be an interaction between these nutrients.

Effects of supplemental alpha-tocopherol and beta-carotene on colorectal cancer: results from a controlled trial (Finland)

BACKGROUND

Some epidemiological investigations suggest that higher intake or biochemical status of vitamin E and beta-carotene might be associated with reduced risk of colorectal cancer.

METHODS

We tested the effects of alpha-tocopherol and beta-carotene supplementation on the incidence of colorectal cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a double-blind, placebo-controlled trial among 29,133 50-69-year-old male cigarette smokers. Participants were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or a placebo daily for 5-8 years. Incident colorectal cancers (n = 135) were identified through the nationwide cancer registry, and 99% were histologically confirmed. Intervention effects were evaluated using survival analysis and proportional hazards models.

RESULTS

Colorectal cancer incidence was somewhat lower in the alpha-tocopherol arm compared to the no alpha-tocopherol arm, but this finding was not statistically significant (relative risk (RR) = 0.78, 95% confidence interval (CI) 0.55-1.09; log-rank test p = 0.15). Beta-carotene had no effect on colorectal cancer incidence (RR = 1.05, 95% CI 0.75-1.47; log-rank test p = 0.78). There was no interaction between the two substances.

CONCLUSION

Our study found no evidence of a beneficial or harmful effect for beta-carotene in colorectal cancer in older male smokers, but does provide suggestive evidence that vitamin E supplementation may have had a modest preventive effect. The latter finding is in accord with previous research linking higher vitamin E status to reduced colorectal cancer risk.

Randomized trial comparing natural and synthetic surfactant: increased infection rate after natural surfactant?

The efficacy of a natural porcine surfactant and a synthetic surfactant were compared in a randomized trial. In three neonatal intensive care units, 228 neonates with respiratory distress and a ratio of arterial to alveolar partial pressure of oxygen <0.22 were randomly assigned to receive either Curosurf 100 mgkg-1 or Exosurf Neonatal 5 ml.kg-1. After Curosurf, the fraction of inspired oxygen was lower from 15 min (0.45 +/- 0.22 vs 0.70 +/- 0.22, p = 0.0001) to 6 h (0.48 +/- 0.26 vs 0.64 +/- 0.23, p = 0.0001) and the mean airway pressure was lower at 1 h (8.3 +/- 3.2 mm H20 vs 9.4 +/- 3.1 mm H20, p = 0.01). Thereafter the respiratory parameters were similar. The duration of mechanical ventilation (median 6 vs 5 d) and the duration of oxygen supplementation (median 5 vs 4 d) were similar for Curosurf and Exosurf. After Curosurf, C-reactive protein value over 40 mg l-1 occurred in 45% (vs 12%; RR 3.62, 95%CI 2.12-6.17, p = 0.001), leukopenia in 52% (vs 28%; RR 1.85, 95% CI 1.31-2.61, p = 0.001) and bacteraemia in 11% (vs 4%; RR 3.17, 95% CI 1.05-9.52, p < 0.05). We conclude that when given as rescue therapy Curosurf had no advantage compared with Exosurf in addition to the more effective initial response. Curosurf may increase the risk of infection.

Lifetime alcohol consumption and breast cancer: a case-control study in Finland

OBJECTIVE

To study the association between lifetime alcohol consumption and the risk of breast cancer.

DESIGN AND SETTING

A case-control study carried out in eastern Finland. Information about alcohol consumption was obtained by two methods: a self-administered food frequency questionnaire (FFQ) including alcohol consumption during the previous 12 months, and a lifetime alcohol consumption questionnaire (AQ) which was administered by the study nurse.

SUBJECTS

The study consisted of 301 breast cancer cases (25-75 years old) and 443 population controls.

RESULTS

The subjects reported higher current alcohol consumption in the AQ compared to the FFQ. According to the AQ, premenopausal cases consumed on average 28 g and controls 24 g alcohol week(-1); in postmenopausal women the values were 15 and 14 g, respectively. About 30% of premenopausal and 60% of postmenopausal women were classified as non-drinkers. The correlation for current alcohol consumption between the FFQ and the AQ was 0.80 in premenopausal women but only 0.40 in postmenopausal women. Current alcohol consumption seemed to influence the reporting of total lifetime alcohol consumption. Current alcohol consumption was not associated with the risk of breast cancer either in premenopausal or postmenopausal women; neither were associations found between alcohol consumption at age of first use, use before the age of 30, or total lifetime alcohol consumption and the risk of breast cancer.

CONCLUSIONS

On average, one to three drinks per week did not increase the risk of breast cancer in this study. Consumption levels were, however, too low to exclude increased risk with high regular consumption. Further research is necessary on lifetime alcohol consumption.

Effects of supplemental alpha-tocopherol and beta-carotene on colorectal cancer: results from a controlled trial (Finland)

BACKGROUND

Some epidemiological investigations suggest that higher intake or biochemical status of vitamin E and beta-carotene might be associated with reduced risk of colorectal cancer.

METHODS

We tested the effects of alpha-tocopherol and beta-carotene supplementation on the incidence of colorectal cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a double-blind, placebo-controlled trial among 29,133 50-69-year-old male cigarette smokers. Participants were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), both agents, or a placebo daily for 5-8 years. Incident colorectal cancers (n = 135) were identified through the nationwide cancer registry, and 99% were histologically confirmed. Intervention effects were evaluated using survival analysis and proportional hazards models.

RESULTS

Colorectal cancer incidence was somewhat lower in the alpha-tocopherol arm compared to the no alpha-tocopherol arm, but this finding was not statistically significant (relative risk (RR) = 0.78, 95% confidence interval (CI) 0.55-1.09; log-rank test p = 0.15). Beta-carotene had no effect on colorectal cancer incidence (RR = 1.05, 95% CI 0.75-1.47; log-rank test p = 0.78). There was no interaction between the two substances.

CONCLUSION

Our study found no evidence of a beneficial or harmful effect for beta-carotene in colorectal cancer in older male smokers, but does provide suggestive evidence that vitamin E supplementation may have had a modest preventive effect. The latter finding is in accord with previous research linking higher vitamin E status to reduced colorectal cancer risk.

Keratin 4 upregulation by retinoic acid in vivo: a sensitive marker for retinoid bioactivity in human epidermis

Retinoids affect keratinocyte differentiation and modulate the expression of many epidermal proteins, among them cellular retinoic acid-binding protein II and the family of cytokeratins. The upregulation of the former protein is a well-known phenomenon, whereas the retinoid-induced regulation of epidermal keratin expression is more complex and only partially understood. We studied the effect of topical retinoids on the expression in healthy skin of cellular retinoic acid-binding protein II, tazarotene-induced genes 1 and 2, several epidermal keratins (K1, K2e, and K10), and two mucous keratins (K4 and K13) known to appear in epidermis under certain abnormal conditions. Reverse transcription-polymerase chain reaction experiments showed that the K4 expression was the one most overtly induced by 2 wk of open treatment with 0.05% of retinoic acid and tazarotene. Using real-time quantitative polymerase chain reaction (TaqMan) and normalization of the mRNA values to beta-actin, the increase in K4 was found to be 100-1000-fold. In comparison, the expression of K13 and cellular retinoic acid-binding protein II was increased 10-50-fold, the K1 and K10 mRNA levels remained unchanged, and the K2e level decreased by a factor of 100-1000. In parallel biopsies, immunohistochemistry showed no change in K1, K2e, or K10 staining, but a strong de novo appearance of K4 in the granular layer after retinoid treatment. In a separate study, occlusive application of 0.025% retinoic acid in four healthy subjects produced a maximal K4 mRNA signal after 48 h and strong K4 staining after 80 h. Finally, a dose-response study showed that the de novo appearance of K4 can be utilized as a sensitive test for retinoid bioactivity in epidermis in vivo.

Toenail selenium and breast cancer-a case-control study in Finland

OBJECTIVE

Low levels of selenium have been associated with a higher risk of cardiovascular diseases and cancer in humans. Since 1984, selenium supplementation through fertilizers has been employed in Finland to increase the very low concentration of selenium in the nation's food supply. As a result, the selenium concentration of Finnish foods became one of the highest in Europe. A decade after selenium supplementation began, the association between toenail selenium and the risk of breast cancer was examined.

DESIGN

Case-control study.

SETTING

Eastern Finland.

SUBJECTS

289 pre- and postmenopausal breast cancer cases and 433 community controls. The diagnosis was unknown at the time the toenail samples were collected.

RESULTS

The mean toenail selenium concentration was 0.80 mg/kg in premenopausal cases and 0.84 mg/kg in premenopausal controls: and 0. 77 mg/kg in postmenopausal cases and 0.80 mg/kg in postmenopausal controls. The odds ratio (OR) comparing the highest with the lowest quintiles of toenail selenium concentration was 1.1 (95% CI 0.4-3.2) in premenopausal women and 0.7 (95% CI 0.3-1.5) in postmenopausal women. The intake of retinol, beta-carotene, vitamin E and vitamin C did not change the association between toenail selenium and breast cancer.

CONCLUSIONS

A decade after selenium supplementation, selenium seems not to be an important factor in the etiology of breast cancer, neither in premenopausal nor postmenopausal women.

SPONSORSHIP

This work was supported by the EVO funds from the Kuopio University Hospital and by research grants from the Academy of Finland, Yrjö Jahnsson Foundation and Juho Vainio Foundation. European Journal of Clinical Nutrition (2000) 54, 98-103

Measles history and atopic diseases: a population-based cross-sectional study

CONTEXT

Many recent cross-sectional studies have suggested that lack of early exposure to communicable diseases, including measles, in affluent countries may have increased rates of atopic disease.

OBJECTIVE

To study the association between natural measles infection and atopy.

DESIGN AND SETTING

Cross-sectional nationwide study in Finland using data gathered between November 1, 1982, and June 30, 1986.

SUBJECTS

A total of 547910 individuals aged 14 months to 19 years who at the time of measles-mumps-rubella (MMR) vaccination had relevant information collected on the occurrence of measles and allergic rhinitis, eczema, and asthma.

MAIN OUTCOME MEASURES

Lifetime occurrence of atopic manifestations in subjects who had had measles compared with those who had not, expressed as age-specific and age-adjusted prevalence ratios.

RESULTS

The age-adjusted prevalence ratio of atopic manifestations among those who had had measles (n = 20 690) compared with those who had not (n = 527 220) was 1.32 (95% confidence interval [CI], 1.27-1.36) for eczema, 1.41 (95% CI, 1.33-1.49) for rhinitis, and 1.67 (95% CI, 1.54-1.79) for asthma. The positive association between measles and atopy was evident at all ages, in both urban and rural dwellers, and among subjects with many or few contacts at home or in day care.

CONCLUSIONS

Based on our data, measles and atopy occur more frequently together than expected, which does not support the hypothesis that experiencing natural measles infection offers protection against atopic disease.

Improved topical treatment of lamellar ichthyosis: a double-blind study of four different cream formulations

Lamellar ichthyosis (LI) is characterized by generalized scaling of the skin and is often resistant to ordinary emollients. Recently, Locobase(R) fatty cream containing a mixture of 5% lactic acid and 20% propylene glycol (LPL) was found to be markedly effective in a pilot study. To consolidate this finding, a double-blind study comparing LPL with the corresponding mixture in Essex(R) (Diprobase(R)) cream (LPE) and Locobase(R) fatty cream containing either 5% urea or 20% propylene glycol was conducted in 20 patients with LI. Before and after applying the creams twice daily on each of the four extremities for 4 weeks, the following investigations were performed: scoring of xerosis, scaling and erythema, measurements of skin hydration (capacitance) and transepidermal water loss (TEWL), and moulding of the skin surface (replicas). Xerosis was reduced by all four creams, but significantly more so by LPL (P < 0.001) and LPE (P < 0.01). Scaling was only reduced by LPL (P < 0.001) and LPE (P < 0.01), which also caused a slight increase in the erythema score (P < 0.05 for both). The patients' weekly evaluation of symptoms showed that LPL produced the most rapid effect: the response rate after 4 weeks was 63%. Skin hydration and TEWL were both significantly increased by LPL and LPE, whereas skin roughness was reduced most by LPL. Fourteen patients preferred LPL over the other cream formulations. Ten patients continued using LPL for up to 8 weeks with good results and no side-effects other than occasional irritation in the skin folds. LPL is a major advance in the topical treatment of LI that suits most patients. Some patients, however, seem to prefer the more hydrophilic LPE formulation. Both formulations effectively reduce hyperkeratosis and xerosis, but may cause slight irritation and adversely affect the epidermal barrier function.

Diet and risk of colorectal cancer in a cohort of Finnish men

OBJECTIVES

Based on previous epidemiological studies, high fat and meat consumption may increase and fiber, calcium, and vegetable consumption may decrease the risk of colorectal cancer. We sought to address these hypotheses in a male Finnish cohort.

METHODS

We analyzed data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) where 27, 111 male smokers completed a validated dietary questionnaire at baseline. After an average of 8 years of follow-up, we documented 185 cases of colorectal cancer. The analyses were carried out using the Cox proportional hazards model.

RESULTS

The relative risk (RR) for men in the highest quartile of calcium intake compared with men in the lowest quartile was 0.6 (95% CI 0.4-0.9, p for trend 0.04). Likewise, the intake of milk protein and the consumption of milk products was inversely associated with risk of colorectal cancer. However, intake of dietary fiber was not associated with risk, nor was fat intake. Consumption of meat or different types of meat, and fried meat, fruits or vegetables were not associated with risk.

CONCLUSIONS

In this cohort of men consuming a diet high in fat, meat, and fiber and low in vegetables, high calcium intake was associated with lowered risk of colorectal cancer.

Diet and risk of colorectal cancer in a cohort of Finnish men

OBJECTIVES

Based on previous epidemiological studies, high fat and meat consumption may increase and fiber, calcium, and vegetable consumption may decrease the risk of colorectal cancer. We sought to address these hypotheses in a male Finnish cohort.

METHODS

We analyzed data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) where 27, 111 male smokers completed a validated dietary questionnaire at baseline. After an average of 8 years of follow-up, we documented 185 cases of colorectal cancer. The analyses were carried out using the Cox proportional hazards model.

RESULTS

The relative risk (RR) for men in the highest quartile of calcium intake compared with men in the lowest quartile was 0.6 (95% CI 0.4-0.9, p for trend 0.04). Likewise, the intake of milk protein and the consumption of milk products was inversely associated with risk of colorectal cancer. However, intake of dietary fiber was not associated with risk, nor was fat intake. Consumption of meat or different types of meat, and fried meat, fruits or vegetables were not associated with risk.

CONCLUSIONS

In this cohort of men consuming a diet high in fat, meat, and fiber and low in vegetables, high calcium intake was associated with lowered risk of colorectal cancer.

Randomized, placebo-controlled double blind study on the efficacy of influenza immunization on absenteeism of health care workers

BACKGROUND

In healthy adults influenza immunization reduces absenteeism caused by respiratory infections, but data on its efficacy among health care workers are scarce.

OBJECTIVE

To determine the effect of the conventional inactivated influenza A vaccine on reducing absenteeism related to respiratory infections among pediatric health care providers.

STUDY DESIGN

A randomized, placebo-controlled, double blind study on vaccine efficacy was conducted in two pediatric hospitals during the winter season 1996 to 1997. The primary endpoint was days of work lost from the hospital because of respiratory infections. The documentation of absenteeism was based on personal sickness logs.

RESULTS

Of the 547 randomized vaccinees 427 (78%) persons completed the 4-month follow-up and returned the sickness logs. Immunization failed to reduce episodes of respiratory infections (1.8 episodes/study period among vaccinees vs. 2.0 among controls). Similarly the vaccine failed to affect the total number of days the vaccinees suffered from respiratory infections (13.5 days vs. 14.6 days, respectively). However, days of work lost because of respiratory infections (1.0 days vs. 1.4 days, respectively, P = 0.02) and especially total numbers of days the study persons felt themselves unable to work when either on or off duty (2.5 days vs. 3.5 days, P 0.02) were significantly decreased.

CONCLUSION

Influenza vaccination reduced absenteeism related to respiratory infections by 28%. We therefore believe that routine annual influenza immunizations should be recommended to health care providers working in pediatric settings.

Nutrient intake and use of beverages and the risk of kidney stones among male smokers

High intakes of calcium, potassium, and fluids have been shown to be associated with lowered risk of kidney stones. The authors studied the associations between diet and risk of kidney stones in a cohort of 27,001 Finnish male smokers aged 50-69 years who were initially free of kidney stones. All men participated in the Alpha-Tocopherol, Beta-Carotene Lung Cancer Prevention Study and completed a validated dietary questionnaire at baseline. After 5 years of follow-up (1985-1988), 329 men had been diagnosed with kidney stones. After data were controlled for possible confounders, the relative risk of kidney stones for men in the highest quartile of magnesium intake was 0.52 (95% confidence interval (CI) 0.32-0.85) as compared with men in the lowest quartile. Intake of fiber was directly associated with risk (relative risk (RR) = 2.06, 95% CI 1.39-3.03). Calcium intake was not associated with the risk of kidney stones. Beer consumption was inversely associated with risk of kidney stones; each bottle of beer consumed per day was estimated to reduce risk by 40% (RR = 0.60, 95% CI 0.47-0.76). In conclusion, the authors observed that magnesium intake and beer consumption were inversely associated and fiber intake was directly associated with risk of kidney stones.

The effect of alpha-tocopherol and beta-carotene supplementation on colorectal adenomas in middle-aged male smokers

Epidemiological and experimental studies have indicated that dietary factors such as vitamin C, vitamin E, and beta-carotene are associated with the risk of colorectal cancer. This study was carried out within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study), whose participants were randomly assigned to four supplementation groups: (a) alpha-tocopherol (AT), 50 mg/day; (b) beta-carotene (BC), 20 mg/day; (c) both AT and BC; and (d) placebo. We included the 15,538 ATBC Study participants who had been randomized within the areas of three major cities in southern Finland. Cases of colorectal adenoma (n = 146) were identified by the pathology laboratories in the study areas, and these participants' medical records were collected and reviewed. Alpha-tocopherol supplementation increased the risk for adenomas (relative risk, 1.66; 95% confidence interval, 1.19-2.32), whereas beta-carotene supplementation had no effect on the risk (relative risk, 0.98; 95% confidence interval, 0.71-1.35). Slightly more prediagnosis rectal bleeding and intestinal pain occurred in those adenoma cases who received alpha-tocopherol supplements than in those who did not. Thus, some bias may have resulted, with alpha-tocopherol supplementation leading to more colonoscopies and, thus, to an increased detection of incident polyps in this group. This is further supported by the trial finding that alpha-tocopherol supplementation did not increase the risk of colorectal cancer.

Diet and the risk of breast cancer in a case-control study: does the threat of disease have an influence on recall bias?

It has been suggested that recall bias may explain the discrepant results between case-control and cohort studies on diet and the risk of breast cancer. Two control groups were used for this case-control study of 25 to 75-year-old breast cancer cases (n = 310). The first group consisted of population controls drawn from the Finnish National Population Register (n = 454). The second group consisted of women who were referred to the same examinations as were the cases because of clinical suspicion of breast disease but who were later diagnosed as healthy (referral controls; n = 506). Because the diagnosis was unknown at the time of interview, it was possible to assess by comparing the two control groups whether the self-reporting of diet changed under the threat of disease. Dietary habits were examined using a validated, self-administered food-frequency questionnaire. Premenopausal women misreported their consumption of liquid milk products, tea, and sugar. Reporting bias was also associated with the intake of fat and vitamins. Postmenopausal women misreported consumption of milk products. When recall bias was taken into consideration, milk was associated with increased risk of premenopausal breast cancer, whereas high consumption of poultry or high intake of monounsaturated fatty acids, n-3 fatty acids, n-6 fatty acids, and vitamin E were related to lower risk. The study suggested that oil, milk, cheese, coffee and beta-carotene may act as protective factors in postmenopausal women, whereas butter and cream may be risk factors for breast cancer. In summary, it is possible that some food items may be overreported or underreported under the threat of disease in health-conscious population. However, most of the results in this study were not modified by recall bias.