Occupational risks for uveal melanoma results from a case-control study in nine European countries

Objective Uveal melanoma is a rare disease with poor prognosis and largely unknown etiology. We studied potential occupational risk factors.Methods A population based case-control study was undertaken during 1995–1997 in nine European countries using population and colon cancer controls with personal interviews. Occupational exposure to sunlight and artificial UV radiation was assessed with a job exposure matrix. In total, 320 uveal melanoma cases were eligible at pathology review, and 292 cases were interviewed, participation 91%. Out of 3357 population controls, 2062 were interviewed, 61%, and out of 1272 cancer controls 1094 were interviewed, 86%.Results Using population controls, occupational exposure to sunlight was not associated with an increased risk (RR=1.24, 95% CI=0.88−1.74), while an excess risk found with use of colon cancer controls was attributed to confounding factors. An excess risk in welders was restricted to the French part of the data. Cooks, RR=2.40; cleaners, RR 2.15; and laundry workers, RR=3.14, were at increased risk of uveal melanoma.Conclusion Our study does overall not support an association between occupational sunlight exposure and risk of uveal melanoma. The finding of an excess risk of eye melanoma in cooks in several European countries is intriguing.     

Evidence for a single-step mechanism in the origin of hyperdiploid childhood acute lymphoblastic leukemia

High hyperdiploidy (>50 chromosomes) in childhood acute lymphoblastic leukemia (ALL) is characterized by nonrandom multiple trisomies and tetrasomies involving in particular chromosomes X, 4, 6, 8, 10, 14, 17, 18, and 21. This characteristic karyotypic pattern, the most common in pediatric ALL, may arise via a tetraploid state with subsequent loss of chromosomes, by sequential gains of chromosomes in consecutive cell divisions, or by simultaneous gain of chromosomes in a single mitosis. These alternatives may be distinguished by investigation of the allelic ratios of loci on the tetrasomic and disomic chromosomes. Previous studies of tetrasomy 21 and of the occurrence of uniparental disomies (UPDs) have suggested that the most likely mechanism is simultaneous gain. However, the other pathways have not been definitely excluded because complete analyses of all disomies and tetrasomies have never been performed. In the present study, we investigated 27 hyperdiploid ALLs by using 58 polymorphic microsatellite markers mapped to 23 of the 24 human chromosomes. Twenty-six tetrasomies were analyzed (involving chromosomes X, 8, 10, 14, 18, and 21), and the frequency of UPDs was determined in 10 cases. In total, 200 chromosomes were studied. Equal allele dosage was observed in 24 of 26 tetrasomies, and only 7 UPDs were found. These data strongly suggest that hyperdiploidy in childhood ALL generally arises by a simultaneous gain of all additional chromosomes in a single abnormal mitosis.     

Endogenous surfactant metabolism in newborn infants with and without respiratory failure

Studies using stable isotopically labeled glucose and palmitate as precursors of pulmonary surfactant synthesis have demonstrated slow surfactant turnover in premature infants with respiratory distress syndrome (RDS). However, only limited data about surfactant turnover are available for term infants. Because acetate is a direct precursor of de novo synthesized surfactant fatty acid, we measured [1-13C1]acetate incorporation into surfactant of term infants without respiratory dysfunction (control group), preterm infants with RDS, and term infants with primary respiratory failure to determine whether stable isotopically labeled acetate would yield similar results to previous studies of preterm infants with RDS and, furthermore, would distinguish normal from abnormal surfactant turnover. Despite similar amounts of phospholipids and acetate precursor enrichment, the control group had higher fractional synthetic rate and shorter half-life of clearance than preterm infants with RDS, (fractional synthetic rate, 15.4 +/- 2.4 versus 2.2 +/- 0.4%/d, p < 0.001; half-life of clearance, 27 +/- 3 versus 105 +/- 11 h, p < 0.001). Term infants with severe respiratory failure had a lower fractional synthetic rate than those with mild disease (2.9 +/- 0.6 versus 13.8 +/- 3.5%/d, p = 0.014) and a reduced amount of phospholipids recovered from tracheal aspirates (54 +/- 17 versus 300 +/- 28 nmol, severe versus mild disease, respectively, p < 0.001). The amount of phospholipids in tracheal aspirates correlated inversely with disease severity, (r = -0.75, p = 0.01). We conclude that normal surfactant turnover in term infants is faster than in preterm infants with RDS. Surfactant turnover in term infants with severe respiratory failure is similar to that of preterm infants with RDS, suggesting either delayed maturity of the surfactant system or disruption from the underlying disease process.     

Induced abortion in the Nordic countries: special emphasis on young women

BACKGROUND: To analyze the trends in legally induced abortions among women younger than 30 years in the five Nordic countries, Denmark, Finland, Iceland, Norway and Sweden, since the liberalized abortion laws came into force. METHODS: Data stem from national registrations of vital events. Some have been published in the national vital statistics while others have been retrieved for this study. General and age-specific abortion rates are used to analyze the trends. Further, an index has been calculated by dividing the age-specific abortion rates by the Nordic average. RESULTS: The analysis reveals an overall reduction in the general abortion rates in the Nordic countries, apart from Iceland. The rates have been highest in Denmark and Sweden and lowest in Finland since the early 1980s. In the mid-1980s, the abortion rates increased among 15-19-year-old women in Sweden and among 20-24-year-old women in Denmark, Norway and Sweden, followed by a reduction. In Iceland the very low age-specific abortion rates for all age groups under 30 years at the beginning of the study period increased and Iceland had the highest rate for 15-19-year-old women in the late-1990s. CONCLUSIONS: The relatively low abortion rates in Finland demonstrate effective preventive efforts, although the recent increase challenges further studies on the relationship between abortion rates and counseling activities. The rise in abortion rates in Iceland indicate a need for improved sex education, contraceptive services and availability of contraceptive methods for young people.     

Violence against women increases the risk of infant and child mortality: a case-referent study in Nicaragua

OBJECTIVE: To investigate the impact of violence against mothers on mortality risks for their offspring before 5 years of age in Nicaragua. METHODS: From a demographic database covering a random sample of urban and rural households in Le n, Nicaragua, we identified all live births among women aged 15-49 years. Cases were defined as those who had died before the age of 5 years, between January 1993 and June 1996. For each case, two referents, matched for sex and age at death, were selected from the database. A total of 110 mothers of the cases and 203 mothers of the referents were interviewed using a standard questionnaire covering mothers' experience of physical and sexual violence. The data were analysed for the risk associated with maternal experience of violence of infant and under-5 mortality. FINDINGS: A total of 61% of mothers of cases had a lifetime experience of physical and/or sexual violence compared with 37% of mothers of referents, with a significant association being found between such experiences and mortality among their offspring. Other factors associated with higher infant and under-5 mortality were mother's education (no formal education), age (older), and parity (multiparity). CONCLUSIONS: The results suggest an association between physical and sexual violence against mothers, either before or during pregnancy, and an increased risk of under-5 mortality of their offspring. The type and severity of violence was probably more relevant to the risk than the timing, and violence may impact child health through maternal stress or care-giving behaviours rather than through direct trauma itself.     

Canine cutaneous and systemic histiocytosis: reactive histiocytosis of dermal dendritic cells

Canine histiocytic proliferative disorders include reactive diseases such as cutaneous and systemic histiocytosis and neoplastic diseases such as cutaneous histiocytoma and localized and disseminated histiocytic sarcoma (malignant histiocytosis). Their etiology and pathogenesis are unknown. Canine cutaneous and systemic histiocytosis target the skin and subcutis and have similar clinical behavior. Systemic histiocytosis also affects other organ systems. Clinicopathologic and phenotypic features of canine cutaneous and systemic histiocytosis were examined in this study. Canine cutaneous (18 cases) and systemic (26 cases) histiocytosis were characterized by angiocentric, pleocellular accumulations consisting of CD1+, CD11c+, MHCII+, CD4+, and Thy-1+ (CD90) activated dermal dendritic antigen-presenting cells (APC) with admixed CD3+, CD8+, TCRalphabeta+ T lymphocytes, and neutrophils. Hence, canine cutaneous and systemic histiocytosis represent two clinical manifestations of a reactive proliferation of dermal dendritic cells. Cultures and special stains failed to identify infectious agents. Canine reactive histiocytoses respond to immunosuppressive therapy (cyclosporine A or leflunomide). Therefore, immune-dysregulatory mechanisms are likely to be involved. Spontaneous reactive histiocytoses are frequently seen in dogs, and they constitute an excellent model to study pathologic mechanisms involved in reactive proliferations of dermal dendritic APC.     

Hormone receptor regulated proopiomelanocortin gene expression

The activity of the POMC gene is regulated by both stimulatory and inhibitory hormones. Presumably, some balance exists in the influence of these hormones in order to maintain a steady-state level of activity of this gene. Physiological insults, such as stress, may upset this balance and change the rate of production of POMC and its biologically active peptides. The relative strength of these different hormones may therefore determine the long-term expression of this gene. Chronic administration of CRF to rats, primates and humans produces prolonged increases in plasma ACTH levels. This long-term effect is most likely due to an activation of the POMC gene. Interestingly, chronic treatment of anterior pituitary cells with CRF desensitizes CRF receptors. Thus, despite the corticotrophs becoming refractory to the acute stimulatory actions of CRF, the POMC gene remains stimulated. These findings suggest that corticotrophs do not have to be continuously activated by CRF to maintain a long-term increase in POMC gene expression. This contrasts with the actions of glucocorticoids whose effects are abruptly terminated following their removal from the target tissue. The molecular basis of this form of cellular memory to the actions of CRF may involve cAMP regulatory phosphoproteins binding to and activating the POMC gene. If this phenomenon is shown to occur and the phosphorylation state of these nuclear proteins is found to govern their level of interaction with POMC gene, then it would represent a novel mechanism of gene regulation. Proof for this mechanism and the elucidation of how other second messengers such as protein kinase C and calcium regulate the POMC gene will greatly aid our understanding of the precise molecular mechanisms controlling opioid peptide expression.     

Exploring preschool teachers’ professional profiles in Swedish preschool: a latent class analysis

This article explores preschool teachers’ professional profiles in Sweden. Considering various educational policy reforms in Sweden the last decades, this study is grounded in interactionist perspectives and Bronfenbrenner’s bio-ecological model. A set of multiple professional indicators related to preschool teachers’ educational background, personal characteristics and their working context were analysed applying latent class analysis as a person-oriented approach. The sample consists of 698 preschool teachers across different preschools in 46 municipalities in Sweden. The analysis revealed two subgroups of preschool teachers’ professional profiles: (a) late educated (after the introduction of preschool curriculum in 1998) and (b) early educated (before the introduction of preschool curriculum in 1998). The pattern of graduation year, experience, continuous professional development and specified assignment in preschool was the most distinctive pattern across these profiles. Findings add to the ongoing debate on preschool teachers’ professionalization suggesting an alternative analytic approach examining multiple indicators characterizing preschool teachers’ professional profiles.