Somatic and psychological characteristics of noise-sensitive adults in Finland

The authors examined the relationship of noise sensitivity with health status and psychological factors in individuals <70 yr of age in Finland. Subjects (n = 1,355) were selected from a 1988 case-control study, based on the Finnish Twin Cohort, that assessed noise sensitivity, lifetime noise exposure, and hypertension. Other health status and psychological factors were obtained from a questionnaire that had been administered to the same individuals in 1981. Statistical analysis showed that noise sensitivity was associated significantly with hypertension, emphysema, use of psychotropic drugs (i.e., sleeping pills, tranquilizers, and pain relievers), stress, smoking, and hostility, even after adjustment for lifetime noise exposure. These results indicate that noise sensitivity has both psychological and somatogenic components.     

Concomitant vinorelbine and radiation in head and neck squamous cell carcinoma in vitro

Concomitant chemoradiotherapy has been used for locally advanced head and neck squamous cell carcinoma (HNSCC) particularily with cisplatin, 5-FU, methotrexate, bleomycin and taxanes. Vinorelbine is a semisynthetic vinca alcaloid, which causes a block in the G2/M phase of the cell cycle. HNSCC cell lines have previously been reported to be sensitive to vinorelbine in nanomolar concentrations. In the current study the effect of vinorelbine as a radiosensitizer in vitro was studied and eight recently established head and neck SCC cell lines of the UT-SCC-series were tested. Vinorelbine concentrations of 0.4-1.6 nM were used, corresponding to the IC70, IC50 and IC30 values of each cell line, resulting in 30%, 50% and 70% inhibition in clonogenic survival. The desired concentrations of vinorelbine were added to the medium and the cells were plated in 96-well culture plates in this solution. The plated cells were irradiated 24 h later with 4MeV photons generated by a linear accelerator and incubated at 37 degrees C with 5% CO2 for 4 weeks. Thereafter, the number of wells containing coherent, living colonies, consisting of 32 cells or more, was counted. The plating efficiency was calculated and the fraction survival data were fitted to the linear quadratic model [F = exp[-(alphaD + betaD2)]]. An additive effect of combining vinorelbine and irradiation could be demonstrated. The dose-dependent decrease in survival was seen at vinorelbine doses of 0.4-1.6 nM in all cell lines tested.     

Life satisfaction and depression in a 15-year follow-up of healthy adults

OBJECTIVE: The aim of this study was to investigate the cross-sectional and longitudinal relationship between life satisfaction and depressive symptoms in healthy adults. METHOD: This is a 15-year prospective cohort study with a nationwide sample of healthy Finnish adults (N = 9679), aged 18-45, who responded to postal questionnaires in 1975, 1981 and 1990 including a 4-item life satisfaction (LS) scale (range 4-20) and, in 1990, the 21-item Beck Depression Inventory (BDI). RESULTS: A strong linear association was found between concurrent LS and BDI scales (r = 0.6). With an LS cut-off point of 11/12, moderate/severe depression (BDI > or = 19) was detected with 87% sensitivity, 88 % specificity and a 94% area under the ROC curve. Longitudinally, a strongly increased risk of moderate/severe depression in 1990 was observed among the dissatisfied (LS 12-20) compared with the satisfied (LS 4-6) in 1975 (OR = 6.7; 95 %CI 4.2-10.9) and in 1981 (OR = 10.4; 6.1-17.6). CONCLUSION: The 4-item LS scale can identify a group of healthy people from the general population with a high risk of having or developing depressive symptoms. Since low life satisfaction also indicates an elevated risk of other adverse health outcomes, the assessment of subjective well-being should be encouraged both in surveys and in clinical practice.     

High concordance of bipolar I disorder in a nationwide sample of twins

OBJECTIVE: The few studies of bipolar I disorder in twins have consistently emphasized the genetic contribution to disease liability. The authors report what appears to be the first twin study of bipolar I disorder involving a population-based twin sample, in which the diagnoses were made by using structured, personal interviews. METHOD: All Finnish same-sex twins (N=19,124) born from 1940 to 1957 were screened for a diagnosis of bipolar I disorder as recorded in the National Hospital Discharge Register between 1969 and 1991 or self-reported in surveys of the Finnish Twin Cohort in 1975, 1981, and 1990. Thirty-eight pairs were thereby identified and invited to participate in the study; the participation rate was 68%. Lifetime diagnoses were made by using the Structured Clinical Interview for DSM-IV. The authors calculated probandwise and pairwise concordances and correlations in liability and applied biometrical model fitting. RESULTS: The probandwise concordance rates were 0.43 (95% CI=0.10 to 0.82) for monozygotic twins and 0.06 (95% CI=0.00 to 0.27) for dizygotic twins. The correlations in liability were 0.85 and 0.41, respectively. The model with no familial transmission was rejected. The best-fitting model was the one in which genetic and specific environmental factors explained the variance in liability, with a heritability estimate of 0.93 (95% CI=0.69 to 1.00). CONCLUSIONS: The high heritability of bipolar disorder was demonstrated in a nationwide population-based twin sample assessed with structured personal interviews.     

Two prospective studies found that elevated 2-hr glucose predicted male mortality independent of fasting glucose and HbA1c

OBJECTIVE: To quantify the relative contribution of elevated 2-hr glucose, fasting glucose (FPG), and HbA1c to all-cause mortality. STUDY DESIGN AND SETTING: A joint analysis of two prospective studies with baseline glycemia measurements. RESULTS: The multivariate adjusted hazard ratios (HRs) corresponding to a one standard deviation increase in HbA1c were 1.14 (95% CI 1.03-1.25), 1.08 (0.98-1.19) for FPG and 1.15 (1.05-1.27) for 2-hr glucose, respectively. Entering the 2-hr glucose to the model based on the FPG and HbA1c significantly improved the prediction of mortality, whereas neither FPG, nor HbA1c added significant information once 2-hr glucose was in the models. In subjects with FPG <7.0 mmol/L and HbA1c < or = 6.5%, the HR was 1.35 (1.03-1.78) in men with 2-hr glucose > or = 7.8 mmol/L compared with men with 2-hr glucose <7.8 mmol/L. CONCLUSION: Elevated 2-hr glucose was a predictor of mortality independent of the levels of fasting glucose and HbA1c.     

The immunodominant epitope of lipocalin allergen Bos d 2 is suboptimal for human T cells

We have proposed earlier that the poor capacity of the lipocalin allergen Bos d 2 to stimulate highly allergic subjects' peripheral blood mononuclear cells could be ascribed to endogenous lipocalins and could be related to the allergenic potential of the molecule. Here, we have characterized the proliferative and cytokine responses of human T cell clones against the immunodominant epitope of Bos d 2. We observed, for clone F1-9, that a substitution of aspartic acid for asparagine in the core region of the epitope increased the stimulatory capacity of the peptide about 100-fold in comparison with the natural peptide. For clone K3-2, from a different patient, the substitution of lysine for glutamine or isoleucine for leucine in the core region resulted in about 30-fold and 10-fold increases in the stimulatory capacity of the peptides, respectively. The clones also recognized self-protein-derived peptides but not the peptides derived from other lipocalins. We suggest that the poor recognition of the immunodominant epitope of Bos d 2 can be a factor accounting for Bos d 2-allergic subjects' weak cellular responses. Suboptimal recognition of self and allergen epitopes by T cells may be of significance for the allergenicity of proteins.     

Effect of extent of motion and type of load on the wear of polyethylene in a biaxial hip simulator

The most commonly used wear test device for prosthetic hip joints is the so-called biaxial rocking motion (BRM) design. The design has been criticized for its excessive sliding distance per cycle. The design was modified so that the extent of motion was reduced from 46 to 23 degrees, and comparative tests were run with the use of 1-kN static load. The present authors have earlier used 1-kN static load with good results. To further confirm this finding, additional, comparative tests were run with double-peak dynamic load and 46 degrees extent of motion. All three tests (46 degrees /static, 23 degrees /static and 46 degrees /dynamic), were done with conventional ultra-high-molecular-weight polyethylene acetabular cups against polished CoCr femoral heads in diluted calf serum lubricant. In all tests, the principal cup wear mechanism was adhesive, manifested as burnishing. With respect to wear particles, those produced in the 46 degrees /dynamic test showed the lowest resemblance to particles isolated from periprosthetic tissues. The 46 degrees /dynamic test produced a mean wear rate 43% higher than 46 degrees /static, whereas the 46 degrees /static and 23 degrees /static tests produced almost identical values. The results indicated that the 46 degrees extent of motion and dynamic load may not always be the optimal combination in BRM tests.     

The heritability of depressive symptoms: multiple informants and multiple measures

BACKGROUND: Earlier research suggests large rater differences in heritability estimates of children's depressive symptoms in the context of significant age and sex-limitation effects. METHODS: With data from an ongoing, population-based twin-family study, we estimated genetic and environmental influences on children's depression with models allowing for sex-specific effects. Our assessments of twins included self-reports and ratings made by their classmate peers, their parents and their teachers, allowing estimates of genetic and environmental effects with data from different informants. Model-fitting used maximum likelihood estimation of log-transformed data from a sample of 1,366 11- and 12-year-old twin pairs. RESULTS: Estimates of additive genetic effects were significant for both boys and girls across all four informants, and, standardized to reflect the percentage of phenotypic variance accounted for, those estimates ranged from .28 to .71. Significant effects from common environmental sources were found in ratings of teachers and parents, where, typically, one individual rated both co-twins, but neither in peer nominations nor self-ratings. The correlation of teacher and parent ratings was modest, and bivariate model-fitting found no correlation in either genetic or shared environmental effects between teacher and parental ratings. At this young age, sex-limitation effects were found only in teacher ratings, where genetic effects were greater in girls than in boys. CONCLUSIONS: Results underscore the utility of using multiple informants to measure children's behavior and provide a foundation for follow-up of these twins in later adolescence.     

Effect of mandibular setback surgery on the posterior airway size

Treatment of dentofacial deformities with jaw osteotomies has an effect on airway anatomy, and therefore, mandibular setback surgery has the potential to diminish airway size. The purpose of this study was to evaluate the long-term effect of mandibular setback surgery on the airway size. The material consisted of pre- and postoperative (minimum 1 year) lateral radiograms of 22 individuals (18 females and 4 males) with a mean age of 30 years, who had undergone mandibular setback surgery to correct skeletal Class III discrepancies. Hard and soft tissue points were digitized with a Numonics Accugrid digitizer and analyzed with Xmetrix software. A paired t test was used to evaluate the difference between pre- and postoperative measurements. In addition, Pearson's coefficient correlation was calculated to reveal the possible association between the skeletal change in relation to the change in airway size. The mean value for the initial SNA was 81.3 degrees, 85.4 degrees for SNB, 36.9 degrees for S-Na/MP, and for the posterior airway, 10.5 mm and 12.0 mm retropalatinally and retrolingually, respectively. At the postoperative evaluation, SNB was 80.7 degrees, S-Na/MP 41.0 degrees, and the posterior airway retropalatinally 8.3 mm and retrolingually 9.8 mm. Statistical analysis revealed a highly significant correlation between the change in the ANB angle and in the S-Na/MP angle versus the change in the upper airway size, both retropalatinally and retrolingually. Mandibular setback surgery with posterior rotation may gradually result in increased upper airway resistance in cases where neuromuscular adaptation is insufficient to compensate for the reduction in the airway size. Therefore, large anteroposterior discrepancies should be corrected by combined maxillary and mandibular osteotomies.     

The association between body height and coronary heart disease among Finnish twins and singletons

OBJECTIVE: An inverse association between body height and the incidence of coronary heart disease (CHD) has been observed. However, the mechanisms behind this association are still largely unknown. We will examine the role of genetic and familial factors behind the association in a large twin data set. DESIGN AND SETTING: The data were derived from the Finnish Twin cohort including 2438 singletons, 4073 monozygotic (MZ) twins, and 9202 dizygotic (DZ) twins aged 25-69 years at baseline in 1976. Incident CHD cases were derived from hospital discharge data and cause of death data between 1977 and 1995. Cox regression analysis and conditional logistic regression analysis were used. RESULTS: In population-level analyses no differences in the general risk of CHD between zygosity groups were found. The association between body height and CHD was similar between sexes and zygosity groups. When men and women in all zygosity groups were studied together an increased risk of CHD was found only among the shortest quartile (hazard ratio [HR] = 1.34, 95% CI: 1.14-1.57). Among the twin pairs discordant for CHD a suggestive increased risk for the shorter twin was seen among DZ twins (odds ratio [OR] = 1.19, 95% CI: 0.95-1.48) when men and women were studied together. CONCLUSION: An inverse association between body height and CHD was broadly similar between sexes and twin zygosity groups and was associated with short stature. Among discordant twin pairs we found a weak association among DZ twins but not MZ twins. This may suggest the role of genetic liability behind the association between body height and CHD.