Mating allocations in Holstein combining genomic information and linear programming optimization at the herd level.

In this study, we explored mating allocation in Holstein using genomic information for 24,333 Holstein females born in Denmark, Finland, and Sweden. We used 2 data sets of bulls: the top 50 genotyped bulls and the top 25 polled genotyped bulls on the Nordic total merit scale. We used linear programming to optimize economic scores within each herd, considering genetic level, genetic relationship, semen cost, the economic impact of genetic defects, polledness, and ß-casein. We found that it was possible to reduce genetic relationships and eliminate expression of genetic defects with minimal effect on the genetic level in total merit index. Compared with maximizing only Nordic total merit index, the relative frequency of polled offspring increased from 13.5 to 22.5%, and that of offspring homozygous for ß-casein (A2A2) from 66.7 to 75.0% in one generation, without any substantial negative impact on other comparison criteria. Using only semen from polled bulls, which might become necessary if dehorning is banned, considerably reduced the genetic level. We also found that animals carrying the polled allele were less likely to be homozygous for ß-casein (A2A2) and more likely to be carriers of the genetic defect HH1. Hence, adding economic value to a monogenic trait in the economic score used for mating allocation sometimes negatively affected another monogenetic trait. We recommend that the comparison criteria used in this study be monitored in a modern genomic mating program.

Emphasis on resilience in dairy cattle breeding: Possibilities and consequences.

This study aimed to investigate dairy cattle breeding goals with more emphasis on resilience. We simulated the consequences of increasing weight on resilience indicators and an assumed true resilience trait (TR). Two environments with different breeding goals were simulated to represent the variability of production systems across Europe. Ten different scenarios were stochastically simulated in a so-called pseudogenomic simulation approach. We showed that many modern dairy cattle breeding goals most likely have negative genetic gain for TR and promising resilience indicators such as the log-transformed, daily deviation from the lactation curve (LnVAR). In addition, there were many ways of improving TR by increasing the breeding goal weight of different resilience indicators. The results showed that adding breeding goal weight to resilience indicators, such as body condition score and LnVAR, could reverse the negative trend observed for resilience indicators. Loss in the aggregate genotype calculated with only current breeding goal traits was 12 to 76%. This loss was mainly due to a reduction in genetic gain in milk production. We observed higher genetic gain in beef production, fertility, and udder health when breeding for more resilience, but from an economical point of view, this was not high enough to compensate for the reduction in genetic gain in milk production. The highest genetic gain in TR was obtained when adding the highest breeding goal weight to LnVAR or TR, both with 0.29 genetic standard deviation units. The indicators we used, body condition score and LnVAR, can be measured on a large scale today with relatively cheap methods, which is crucial if we want to improve these traits through breeding. Economic values for resilience have to be estimated to find the most optimal breeding goal for a more resilient dairy cow in the future.

Mating allocations in Nordic Red Dairy Cattle using genomic information.

In this study, we compared mating allocations in Nordic Red Dairy Cattle using genomic information. We used linear programming to optimize different economic scores within each herd, considering genetic level, semen cost, the economic impact of recessive genetic defects, and genetic relationships. We selected 9,841 genotyped females born in Denmark, Finland, or Sweden in 2019 for mating allocations. We used 2 different pedigree relationship coefficients, the first tracing the pedigree 3 generations back from the parents of the potential mating and the second based on all available pedigree information. We used 3 different genomic relationship coefficients, 1 SNP-by-SNP genomic relationship and 2 based on shared genomic segments. We found high correlations (≥0.83) between the pedigree and genomic relationship measures. The mating results showed that it was possible to reduce the different genetic relationships between parents with minimal effect on genetic level. Including the cost of known recessive genetic defects eliminated expression of genetic defects. It was possible to reduce genomic relationships between parents with pedigree measures, but it was best done with genomic measures. Linear programming maximized the economic score for all herds studied within seconds, which means that it is suitable for implementation in mating software to be used by advisors and farmers.

Dairy cattle farmers' preferences for different breeding tools.

Breeding technologies play a significant role in improving dairy cattle production. Scientifically proven tools for improved management and genetic gain in dairy herds, such as sexed semen, beef semen, genomic testing, dairy crossbreeding, and multiple ovulation embryo transfer (MOET), are readily available to dairy farmers. However, despite good accessibility, decreasing costs, and continuous development of these tools, their use in Sweden is limited. This study investigated Swedish dairy farmers' preferences for breeding tools through a survey including a discrete choice experiment. The survey was distributed online to 1 521 Swedish farmers and by an open link published through a farming magazine. In total, the study included 204 completed responses. The discrete choice experiment consisted of 10 questions with two alternative combinations, which gave 48 combinations in total. Utility values and part-worth values were computed using a conditional logit model based on the responses in the discrete choice experiment for nine groups of respondents: one group with all respondents, two groups based on respondents using dairy crossbreeding or not within the past 12 months, two based on herd size, two based on respondent age, and two based on whether respondents had used breeding advisory services or not. The strongest preferences in all groups were for using sexed semen and beef semen. Genomic testing was also significantly preferred by all groups of respondents. Except in large herds, MOET on own animals was significantly and relatively strongly disfavoured by all groups. Buying embryos had no significant utility value to any group. Dairy crossbreeding had low and insignificant utility values in the group of all respondents, but it was strongly favoured by the group that had used dairy crossbreeding within the past 12 months, and it was disfavoured by the group that had not. Part-worth values of combined breeding tools showed that combinations of sexed and beef semen, alone or with genomic testing without dairy crossbreeding, were the most preferred tools. Compared with the most common combinations of breeding tools used in the past 12 months, the part-worth values indicated that Swedish dairy farmers may prefer to use breeding tools more than they do today. Statements on the different breeding tools indicated that the respondents agreed with the benefits attributed to the breeding tools, but these benefits may not be worth the cost of genomic testing and the time consumption of MOET. These valuable insights can be used for further development of breeding tools.

Sinonasal outcome test-22 and peak nasal inspiratory flow - valuable tools in obstructive sleep apnoea.

BACKGROUND: Sinonasal complaints contribute to low adherence to continuous positive airway pressure (CPAP) treatment. We aimed to investigate sinonasal health in obstructive sleep apnoea (OSA) patients, using the sinonasal outcome test-22 (SNOT-22), and to analyse whether SNOT-22 is affected by CPAP adherence. We also aimed to investigate whether peak nasal inspiratory flow (PNIF) was able to predict adherence to CPAP. METHODS: The study population comprised 197 OSA patients (60 females) initiating CPAP treatment. The SNOT-22, PNIF and the Epworth Sleepiness Scale were assessed at baseline and follow-up. One-night polygraphy, the Hospital Anxiety and Depression Scale, peak expiratory flow and health-related issues were assessed at baseline. At follow-up, the patients were categorised into adherent (more than 4 hours/night) and non-adherent (less than 4 hours/night) to CPAP treatment. RESULTS: The average time for following up CPAP treatment was (mean plus or minus SD) 24.0 plus or minus 23.9 days and it did not differ significantly between the groups. The SNOT-22 score was elevated among all OSA patients, 36.1 plus or minus 19.4. There was a larger improvement in the SNOT-22 score at follow-up among adherent CPAP users compared with non-adherent users (-10.4 plus or minus 13.9 vs. -3.2 plus or minus 15.4). A PNIF value of less than 100 litres/min increased the risk of non-adherence to CPAP with an adjusted odds ratio (OR) of 2.40 ((95% CI 1.16-5.00)). CONCLUSIONS: The SNOT-22 was elevated in patients with OSA, indicating a considerable sinonasal disease burden. The SNOT-22 improved with good CPAP adherence. A low PNIF value was able to predict poor CPAP adherence. Both the SNOT-22 and PNIF can be valuable tools in the evaluation of OSA patients and in the management of CPAP treatment.

Association of genomically enhanced and parent average breeding values with cow performance in Nordic dairy cattle.

This study compared the abilities of virgin heifer genomically enhanced breeding values (GEBV) and parent average breeding values (PA) to predict future cow performance. To increase confidence in genomic technology among farmers, a clear demonstration of the relationship between genomic predictions and future phenotypes is needed. We analyzed 12 different traits in first parity, including production, conformation, fertility, and other functional traits. Phenotype data were obtained from national milk recording schemes and breeding values from the Nordic Cattle Genetic Evaluation. Direct genomic breeding values were calculated using genomic BLUP and combined with traditional breeding values, using bivariate blending. The data covered 14,862 Red Dairy Cattle, 17,145 Holstein, and 7,330 Jersey genotyped virgin heifers born between 2013 and 2015 in Denmark, Finland, and Sweden. Phenotypes adjusted for systematic environmental effects were used as measures of cow performance. Two methods were used to compared virgin heifer GEBV and PA regarding their ability to predict future cow performance: (1) correlations between breeding values and adjusted phenotypes, (2) ranking cows into 4 quartiles for their virgin heifer GEBV or PA, and calculating actual cow performance for each quartile. We showed that virgin heifer GEBV predicted cow performance significantly better than PA for the vast majority of analyzed traits. The correlations with adjusted phenotypes were 38 to 136% higher for GEBV than for PA in Red Dairy Cattle, 42 to 194% higher for GEBV in Holstein, and 11 to 78% higher for GEBV in Jersey. The relative change between GEBV bottom and top quartiles compared with that between PA bottom and top quartiles ranged from 9 to 261% for RDC, 42 to 138% for Holstein, and 4 to 90% for Jersey. Hence, farmers in Denmark, Finland, and Sweden can have confidence in using genomic technology on their herds.

Regional differences regarding risk of developing rheumatoid arthritis in Stockholm County, Sweden: results from the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study.

OBJECTIVES: Rheumatoid arthritis (RA) is a complex disease that is associated with genetic and environmental factors. We have investigated geospatial variation in the risk of developing RA within Stockholm County, Sweden, with respect to established environmental risk factors for RA, as well as serologically defined subgroups of RA. METHOD: Information regarding geographical location for 1432 cases and 2529 controls from the Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study, living in Stockholm County at RA symptom onset, or matched date for controls, was used to estimate geospatial variation in risk. We used generalized additive models (GAMs) to create a risk surface, calculate odds ratios (ORs), and adjust for potential confounding by smoking, education level, and RA within family. We performed a stratified analysis based on the presence/absence of anti-citrullinated peptide antibodies (ACPA). RESULTS: We found significant spatial variation in the odds of developing RA in Stockholm County. After adjustment for smoking, education level, and family history of RA, this geospatial variation remained. The stratified analysis showed areas with higher ORs for ACPA-positive RA and ACPA-negative RA, after adjusting for smoking, education level, and having a family history of RA. Living in the city of Stockholm was associated with decreased risk of RA. CONCLUSIONS: The risk of developing RA in Stockholm County is not distributed evenly and there are areas of increased risk that could not be explained by known factors. Further investigations of local exposures or social factors are warranted.

Group housing of male CD1 mice: reflections from toxicity studies.

Owing to their naturally aggressive behaviour, male mice are often housed individually in toxicity studies. However, several publications advocate group-housing of mice to enable normal social behaviour and interactions between the animals. This refinement project aimed at facilitate group-housing in toxicity studies. A handling procedure, including key factors such as allocation into groups before sexual maturation, transfer of used nesting material into clean cages and avoidance of external changes, that makes group-housing of male CD-1 mice possible in long-term toxicity studies has been developed at Safety Assessment within AstraZeneca, Sweden. Observations on the effect on aggression/fighting in group-housed male mice following different procedures performed in toxicity studies have shown that temporary removal of animals from the group for blood or urine sampling does not affect the group dynamics. However, temporary removal of animals for mating leads to fighting if the animals are taken back to the original group. Treatment with test compound might affect the general condition of the animals and the social hierarchy could be changed. In such cases aggression/fighting might occur and the animals have to be separated. Our experience clearly indicates that group housing of male mice in long-term studies leads to more easily handled animals, as compared with individually housed mice.

Cardiovascular event in systemic lupus erythematosus in northern Sweden: incidence and predictors in a 7-year follow-up study.

INTRODUCTION: An increased rate of cardiovascular disease (CVD) has been suggested in patients with systemic lupus erythematosus (SLE). The risk for myocardial infarction (MI), coronary artery disease and stroke has been reported as particularly prevalent in younger females compared with the reference population. This study was performed to analyse the standard incidence ratio (SIR) of and predictors for cardiovascular events (CVEs) in patients with SLE from northern Sweden, with a fairly homogenous population. METHODS: In 2000 all prevalent patients with SLE (≥4 American College of Rheumatology [ACR] criteria; n = 277) from the four northern-most counties of Sweden were assessed with clinical and laboratory analyses. Seven years follow-up data concerning MI and stroke were extracted from the national registers of hospitalization and death in Sweden. The incidence ratio among the patients was compared with that for the general population from the same catchment area using data from the same register and Statistics Sweden. To identify time to event and CVE predictors, two matched controls for each patient were used and disease related variables as CVD predictors. RESULTS: The SIR for a CVE was 1.27 (95% CI 0.82-1.87) and for females separately aged 40-49 years was 8.00 (95% CI 1.65-23.38). The overall SIR for MI was 2.31 (95% CI 1.34-3.7), for females overall was 1.75 (95% CI 0.84-3.22) and for females aged between 40 and 49 years was 8.7 (95% CI 1.1-31.4). The time to an event was significantly shorter among SLE patients (p < 0.001) and was predicted by hypertension adjusted for smoking and disease. High SLEDAI and anti-cardiolipin IgG antibodies predicted an event in Cox proportional hazards regression models adjusted for age and previous MI. Diabetes, smoking ever and sex did not affect the prediction models. CONCLUSION: The risk of a CVE, or MI, was eight- or nine-fold greater among middle-aged female SLE patients. Time to event was significantly shorter and CVE was associated with SLE-related factors including hypertension and age.

Brain temperature in volunteers subjected to intranasal cooling.

PURPOSE: Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods. METHODS: Intranasal balloons catheters circulated with saline at 20°C were applied for 60 min in ten awake volunteers. No sedation was used. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects' personal experience were completed after the experiment. RESULTS: Brain temperature decrease measured by MRSI was -1.7 ± 0.8°C and by phase-mapping -1.8 ± 0.9°C (n = 9) at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 ± 0.3°C (n = 5). The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent in the MMSE test. Postcooling nasal examination detected increased nasal secretion in nine of the ten volunteers. Volunteers' acceptance of the method was good. CONCLUSION: Both MR techniques revealed brain temperature reductions after 60 min of intranasal cooling with balloons circulated with saline at 20°C in awake, unsedated volunteers.

Systemic lupus erythematosus and cardiac risk factors: medical record documentation and patient adherence.

This study explores patients' knowledge of cardiac risk factors (CRFs), analyses how information and advice about CRFs are documented in clinical practice, and assesses patient adherence to received instructions to decrease CRFs. Systemic lupus erythematosus (SLE) patients with ≥ 4 ACR criteria participated through completing a validated cardiovascular health questionnaire (CHQ). Kappa statistics were used to compare medical records with the self-reported CHQ (agreement) and to evaluate adherence. Two hundred and eleven (72%) of the known patients with SLE participated. The mean age of the patients was 55 years. More than 70% of the SLE patients considered hypertension, obesity, smoking and hypercholesterolaemia to be very important CRFs. The agreement between medical record documentation and patients' reports was moderate for hypertension, overweight and hypercholesterolaemia (kappa 0.42-0.60) but substantial for diabetes (kappa 0.66). Patients' self-reported adherence to advice they had received regarding medication was substantial to perfect (kappa 0.65-1.0). For lifestyle changes in patients with hypertension and overweight, adherence was only fair to moderate (kappa 0.13-0.47). Swedish SLE patients' awareness of traditional CRFs was good in this study. However, the agreement between patients' self-reports and medical record documentation of CRF profiles, and patients' adherence to medical advice to CRF profiles, could be improved.

Adiposity indicators and dementia over 32 years in Sweden.

BACKGROUND: High midlife and late-life adiposity may increase risk for dementia. Late-life decrease in body mass index (BMI) or body weight within several years of a dementia diagnosis has also been reported. Differences in study designs and analyses may provide different pictures of this relationship. METHODS: Thirty-two years of longitudinal body weight, BMI, waist circumference, and waist-to-hip ratio (WHR) data, from the Prospective Population Study of Women in Sweden, were related to dementia. A representative sample of 1,462 nondemented women was followed from 1968 at ages 38-60 years, and subsequently in 1974, 1980, 1992, and 2000, using neuropsychiatric, anthropometric, clinical, and other measurements. Cox proportional hazards regression models estimated incident dementia risk by baseline factors. Logistic regression models including measures at each examination were related to dementia among surviving participants 32 years later. RESULTS: While Cox models showed no association between baseline anthropometric factors and dementia risk, logistic models showed that a midlife WHR greater than 0.80 increased risk for dementia approximately twofold (odds ratio 2.22, 95% confidence interval 1.00-4.94, p = 0.049) among surviving participants. Evidence for reverse causality was observed for body weight, BMI, and waist circumference in years preceding dementia diagnosis. CONCLUSIONS: Among survivors to age 70, high midlife waist-to-hip ratio may increase odds of dementia. Traditional Cox models do not evidence this relationship. Changing anthropometric parameters in years preceding dementia onset indicate the dynamic nature of this seemingly simple relationship. There are midlife and late-life implications for dementia prevention, and analytical considerations related to identifying risk factors for dementia.

Nuclear expression of mu-opioid receptors in a human mesothelial cell line.

1 Possibly acting via mu-opioid receptors (MORs), morphine inhibits the formation of experimentally induced postoperative abdominal adhesions in rats. Mesothelial cells may participate in adhesion formation by secreting mediators that interfere negatively with fibrinolysis. Morphine may prevent adhesions by inhibiting the release of pro-adhesion mediators from mesothelial cells. This study aimed to investigate whether human mesothelial cells express MOR-1; if so, such could constitute a site of action for morphine in adhesion prevention. 2 Cells from Met-5A, a human mesothelial cell line were seeded and prepared for immunocytochemistry and Western blotting. 3 Immunocytochemistry showed MOR-1 expression in mesothelial cells, predominantly in the nuclei. Western blotting showed two bands (c. 35 and 50 kDa) which correspond to those obtained with a control lysate from cells known to express MORs. In addition, we found MOR-1 expression with nuclear and cytoplasmatic localization in biopsies from human abdominal adhesions. 4 The current findings may suggest that morphine could interact directly with mesothelial cells via MOR-1 receptors, and thereby modulate adhesion formation, possibly by interfering with the release of pro-adhesion factors from these cells.

Alcohol consumption is associated with decreased risk of rheumatoid arthritis: results from two Scandinavian case-control studies.

OBJECTIVES: To determine the association between risk of rheumatoid arthritis (RA) and alcohol consumption in combination with smoking and HLA-DRB1 shared epitope (SE). METHODS: Data from two independent case-control studies of RA, the Swedish EIRA (1204 cases and 871 controls) and the Danish CACORA (444 cases and 533 controls), were used to estimate ORs of developing RA for different amounts of alcohol consumed. RESULTS: Alcohol consumption was significantly more common in controls (p<0.05) and dose-dependently associated with reduced risk of RA (p for trend <0.001) in both studies. Among alcohol consumers, the quarter with the highest consumption had a decreased risk of RA of the order of 40-50% compared with the half with the lowest consumption (EIRA, OR = 0.5 (95% CI 0.4 to 0.6); CACORA, OR = 0.6 (95% CI 0.4 to 0.9)). For the subset of RA that is seropositive for antibodies to citrullinated peptide antigens, alcohol consumption reduced the risk most in smokers carrying HLA-DRB1 SE alleles. CONCLUSIONS: The observed inverse association between alcohol intake and risk of RA and the recent demonstration of a preventive effect of alcohol in experimental arthritis indicate that alcohol may protect against RA. This highlights the potential role of lifestyle in determining the risk of developing RA, and emphasises the advice to stop smoking, but not necessarily to abstain from alcohol in order to diminish risk of RA. The evidence of potential RA prevention should prompt additional studies on how this can be achieved.

Increased aortic pulse wave velocity in middle aged women with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a connective tissue disease where inflammatory activity affects several organ systems. An increased risk of cardiovascular disease has been identified in these patients, even after correction for traditional risk factors. The aim of the present study was to evaluate arterial stiffness and central hemodynamics in women with SLE in comparison to controls. Arterial tonometry was used to measure aortic (carotid-femoral) and arm (carotid-radial) pulse wave velocity (PWV), reflected pressure waves, and aortic augmentation index (AIx) in 27 women with SLE (52 to 68 years) and 27 controls. Aortic PWV was higher in women with SLE than controls, 9.8 m/s versus 8.2 m/s (P < 0.01), after correction for mean arterial pressure and body mass index, 9.5 m/s versus 8.5 m/s (P < 0.05). Other parameters were similar, arm PWV, 8.4 versus 8.5 m/s, AIx 34 versus 33% and calculated central aortic pulse pressure 48 versus 43 mmHg, in SLE and controls, respectively (NS). Aortic PWV was positively associated to C-reactive protein (CRP) and complement factor 3 (C3). Women with SLE have increased stiffness of their elastic central arteries. This may be one factor contributing to the increased cardiovascular risk seen in this cohort.

Comparison of the performance of serological kits for Helicobacter pylori infection with European and Asian study populations.

Most commercial kits for the detection of Helicobacter pylori were developed and validated with Western populations, and some have been found to perform less well with Asian populations. This study compared the performances of three serological kits with Swedish and Vietnamese peptic ulcer patients and asymptomatic individuals. The Pyloriset EIA-GIII and HM-CAP ELISA kits indicated that Asian populations had lower antibody titres to H. pylori than European populations. Despite the difference, the Pyloriset EIA-GIII kit performed well with Vietnamese peptic ulcer patients and population controls. The HM-CAP ELISA kit had a significantly lower performance with Asian populations that could not be improved by adjustments to the cut-off level. The Helicoblot 2.1 immunoblot kit performed equally well with Vietnamese and Swedish populations, although the response rate to the 35-kDa band was significantly lower with Vietnamese individuals.

Obesity in 70-year-old Swedes: secular changes over 30 years.

OBJECTIVE: Secular increases in obesity have been widely reported in middle-aged adults, but less is known about such trends among the elderly. The primary purpose of this paper is to document the most recent wave of the obesity epidemic in population-based samples of 70-y-old men and women from Göteborg. Additionally, we will investigate the influences of physical activity, smoking and education on these secular trends. POPULATIONS AND METHODS: Five population-based samples of 3702 70-y-olds (1669 men and 2033 women) in Göteborg, Sweden, born between 1901 and 1930, were examined in the Gerontological and Geriatric Population Studies (H70) between 1971 and 2000. Cohort differences in anthropometric measures were the main outcomes studied. Physical activity, smoking habits and education were assessed by comparable methods in all cohorts. Subsamples of the women in the latest two cohorts (birth years 1922 and 1930) were also part of the Prospective Population Study of Women in Göteborg. In these women, it was possible to examine body mass index (BMI) and waist-to-hip circumference ratio (WHR) longitudinally since 1968. RESULTS AND CONCLUSIONS: Significant upward trends were found for height, weight, BMI, waist circumference (WC), WHR, prevalence of overweight (BMI> or =25 kg/m(2)) and obesity (BMI> or =30 kg/m(2)) across cohorts in both sexes. In 2000, 20% of the 70-y-old men born in 1930 were obese, and the largest increment (almost doubling) had occurred between the early 1980s and the early 1990s. In 70-y-old women the prevalence of obesity was 24% in 2000, a 50% increase compared to the cohort born 8 y earlier. BMI increased over time in all physical activity, smoking and education groups, with the exception of never-smoking men. Although 70-y-old women in 2000 were heavier than cohorts examined 8 y previously, data from the women studied longitudinally revealed that these differences were already present in earlier adulthood. In conclusion, the elderly population is very much part of the obesity epidemic, although secular trends in BMI were detected slightly earlier in men than in women. The health implications of these secular trends should be focused on in future gerontological research.

Socioeconomic status and the risk of developing rheumatoid arthritis: results from the Swedish EIRA study.

OBJECTIVE: To study whether formal education and occupational class are associated with incidence of rheumatoid arthritis overall and with the incidence of the two major subgroups of rheumatoid arthritis-seropositive (RF+) and seronegative (RF-) disease. METHODS: 930 cases and 1126 controls participated in a population based case-control study using incident cases of rheumatoid arthritis, carried out in Sweden during the period May 1996 to June 2001. The relative risk (RR) of developing rheumatoid arthritis with 95% confidence interval (CI) was calculated for different levels of formal education compared with university degree and for different occupational classes compared with higher non-manual employees. SUBJECTS: without a university degree had an increased risk of rheumatoid arthritis compared with those with a university degree (RR = 1.4 (95% CI, 1.2 to 1.8)). For manual employees, assistant and intermediate non-manual employees together, the risk of developing rheumatoid arthritis was about 20% more than for non-manual employees. These increased risks were more pronounced for RF+ than for RF- rheumatoid arthritis and were mainly confined to women. Smoking could not of its own explain the observed associations between risk of rheumatoid arthritis in different socioeconomic groups in Sweden. CONCLUSIONS: There was an association between high socioeconomic status and lower risk of rheumatoid arthritis in a population based investigation that was representative for the Swedish population. The study shows that as yet unexplained environmental or lifestyle factors, or both, influence the risk of rheumatoid arthritis, even in the relatively egalitarian Swedish society.

Assessment of the cag pathogenicity island status of Helicobacter pylori infections with serology and PCR.

The serological characterisation of Helicobacter pylori strains has been questioned, e.g., when the presence or absence of the cag pathogenicity island (PAI) is determined. This study compared CagA-reactive serum antibodies, assessed with immunoblot, with cag PAI status, as determined by PCR. CagA serology results were available for 101 individuals contributing 202 bacterial samples for cag PAI PCR. There was a high degree of correlation between the two methods (kappa coefficient, 0.82; 95% confidence interval, 0.68-0.97). Combined with suggested biological explanations for the discrepancies, this finding supports the application of well-evaluated serological assays in the assessment of the cag PAI status of H. pylori infections in clinical and epidemiological studies.