Upper limits on a stochastic background of gravitational waves

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Synovial haemangioma of the knee: a case report

Synovial haemangioma is a rare but important cause of knee symptoms, which, when undiagnosed, can lead to significant morbidity. Diagnosis is frequently difficult and delayed. We report on a case of synovial haemangioma, which demonstrates the difficulties inherent in diagnosis and the morbidity associated with diagnostic delay, in a young woman. Magnetic resonance imaging (MRI) is a useful tool for diagnosis, but detection on MRI can also be problematic, as shown by this case, demonstrating the need for greater awareness of this condition by both clinicians and radiologists. Arthroscopy is important in both the diagnosis and treatment of these lesions.

Genome wide significant linkage in schizophrenia conditioning on occurrence of depressive episodes

BACKGROUND

Schizophrenia shows substantial clinical heterogeneity. One common important clinical variable in presentation is the occurrence of episodes of major depression.

METHODS

We undertook analyses in an attempt to detect loci that influence susceptibility to, or modify the clinical expression of, schizophrenia according to the occurrence of episodes of major depression. We used a logistic regression framework in which lifetime presence/absence of major depression was entered as a covariate in the linkage analysis of our UK schizophrenia affected sibling pair series (168 affected sibling pairs typed for a 10 cM map of microsatellite markers).

RESULTS

Inclusion of presence/absence of depression as a covariate detected a genome wide significant linkage signal on chromosome 4q28.3 at 130.7 cM (LOD = 4.59; p = 0.038; increase in maximum LOD over univariate analysis (ILOD) = 3.62). Inclusion of the depression covariate also showed suggestive evidence of linkage on 20q11.21 (LOD = 4.10; expected to occur by chance 0.093 times per genome scan, ILOD = 2.83).

CONCLUSIONS

Our findings identify loci that may harbour genes that play a role in susceptibility to, or modify the risk of, episodes of major depression in people with schizophrenia.

Factors affecting progression of knee cartilage defects in normal subjects over 2 years

OBJECTIVES

Cartilage defects are present in subjects with knee osteoarthritis (OA). Although they are often present in healthy subjects, there is little data on the natural history of cartilage defects. The aim of this study was to examine the change in cartilage defects over 2 yr and to identify factors associated with this change.

METHODS

One hundred and twenty-four healthy subjects underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at five sites. Bone size was determined at medial and lateral tibial plateau and patella. Height, weight, body mass index and physical activity were measured by standard protocols.

RESULTS

Eighty-six subjects completed the study. The mean cartilage defect score of each tibiofemoral compartment increased over time. However, medial and lateral tibiofemoral defect score decreased in 5% of the subjects. Cartilage defects were more likely to progress in males than females in each individual compartment (P<0.001 for medial tibiofemoral, P=0.005 for lateral tibiofemoral and P=0.01 for patellar cartilage). Baseline cartilage defect score was negatively associated with the progression of cartilage defects in each compartment (all P<0.001).

CONCLUSION

Although knee cartilage defects progressed over time in the majority of normal subjects, those of the highest severity tended to regress. Male gender and baseline cartilage defect score were the main factors associated with the progression of cartilage defects. Larger studies will be required to identify factors associated with the progression and regression of lesions.

Comparison of processes and intermediate outcomes between South Asian and European patients with diabetes in Blackburn, north-west England

BACKGROUND

Diabetes and its complications are more prevalent among South Asians than people of European origin and there is some evidence that patients of South Asian origin with diabetes receive poorer quality care.

METHODS

Longitudinal study of patients with diabetes in Blackburn, UK. Processes of care indicators [measurement of blood pressure (BP), cholesterol and glycosolated haemoglobin (HbA1c)] and values of these intermediate outcomes were extracted for all patients registered on a diabetes information system for the period 1995-2001. Differences in processes of care indicators and intermediate outcomes between ethnic groups were estimated after adjusting for the potential confounding factors of sex, age and socioeconomic status (SES). Generalized estimating equations were used to model trends and to test for differences in trends over time.

RESULTS

Process of care was similar in South Asian and European patients. Mean BP and cholesterol concentration fell during the study period. South Asians had a higher level of HbA1c throughout the study period. South Asians had lower levels of BP and cholesterol in 1995 but the differences diminished or were abolished over time. SES did not explain differences between ethnic groups. Analyses stratified by baseline levels of intermediate outcomes (above or within target) demonstrated improvements among above target patients were greater among European patients.

CONCLUSIONS

Processes of care indicators are similar in diabetic patients of South Asian and European origin, irrespective of SES. However, there are worrying differences in improvements over time in the intermediate outcomes, and glycaemic control remained poorer among patients of South Asian origin patients throughout.

Comparison of conventional standing knee radiographs and magnetic resonance imaging in assessing progression of tibiofemoral joint osteoarthritis

OBJECTIVE

Although the current recommendation is to measure radiographic joint space width (JSW) to assess structural change in osteoarthritis (OA), there is increasing interest in direct measurement of cartilage volume from magnetic resonance imaging (MRI). We performed a longitudinal study to compare change in both JSW and articular cartilage volume in subjects with symptomatic knee OA.

METHODS

JSW was measured in 28 subjects with knee OA (57% females, mean age 62.8+/-9.8 years) who had standing radiographs in full extension, where both radiographs had satisfactory alignment. Each subject had femoral, tibial and combined femoral and tibial cartilage volumes determined from T1-weighted fat saturated sagittal knee MRI. All subjects had a repeat of the knee radiograph and MRI 1.96+/-0.4 years later.

RESULTS

At baseline there was a moderate, but statistically significant, correlation between JSW and femoral and tibial cartilage volumes in the medial tibiofemoral joint, which was strengthened by adjusting for medial tibial bone size (R=0.58-0.66, P=0.001). Although we observed a reduction in JSW and femoral and tibial cartilage volumes over the study period, there was no significant association between reduction in JSW and cartilage volume (R<0.13). There was a trend towards a significant association between change in medial tibiofemoral cartilage volume and joint replacement at 4 years (OR=9.0, P=0.07) but not change in medial tibiofemoral JSW (OR=1.1, P=0.92).

CONCLUSIONS

Although there was a modest correlation between cartilage volume and JSW in the medial tibiofemoral compartment, there was no correlation between longitudinal change in these measures. Change in cartilage volume appears to be a better predictor of joint replacement. Further work in larger samples over a longer period of time will be needed to confirm these findings.

Polymorphisms within the PHF11 gene at chromosome 13q14 are associated with childhood atopic dermatitis

Atopic dermatitis is an increasingly common and debilitating childhood disorder that is often accompanied by asthma and allergic rhinitis. Although the pathology of these disorders is distinct, the majority of cases are atopic, typified by elevated serum IgE. A new locus at chromosome 13q14 centred on the genes SETDB2 and PHF11 and associated with increased total serum IgE has recently been identified. Although the precise functions of SETDB2 and PHF11 are not known, both proteins are expressed in cells of the immune system and include conserved domains that suggest a role in chromatin remodelling or transcriptional regulation, respectively. In a family-based association study across the SETDB2 and PHF11 genes, we have identified two single-nucleotide polymorphisms in the PHF11 gene significantly associated with childhood atopic dermatitis in an Australian cohort. These results provide further evidence that this locus is a novel and important regulator of human atopic disease.

Sociodemographic factors associated with calcium intake in premenopausal women: a cross-sectional study

OBJECTIVE

To describe associations between sociodemographic factors and calcium intake in premenopausal women.

DESIGN

Cross-sectional study.

SETTING

Population-based.

SUBJECTS

A total of 467 randomly selected, predominantly Caucasian Tasmanian women aged 25-44 y, response rate 63%.

MAIN OUTCOME MEASURES

calcium intake, sociodemographic factors, anthropometrics, osteoporosis knowledge and self-efficacy.

RESULTS

Education level, calcium-specific osteoporosis knowledge and self-efficacy were all independently associated with calcium intake (P<0.05). The odds of achieving the recommended dietary intake for calcium increased with higher levels of calcium-specific self-efficacy and knowledge, and decreased in smokers or if the household's main financial provider was unemployed (P<0.05).

CONCLUSIONS

Women who have lower levels of education, who are in households where the main financial provider is unemployed, who are smokers, and those with low levels of calcium-specific self-efficacy and knowledge are at risk of not achieving adequate calcium intake. This information will assist targeting of public health strategies aimed at improving the calcium intake of premenopausal women.

The clinical correlates of articular cartilage defects in symptomatic knee osteoarthritis: a prospective study

OBJECTIVES

To determine whether articular cartilage defects are associated with cartilage loss and joint replacement in subjects with symptomatic knee osteoarthritis (OA).

METHODS

One hundred and seventeen subjects with symptomatic knee OA underwent magnetic resonance imaging of their dominant knee at baseline and 2 yr later. Cartilage defects were identified as prevalent (defect score > or =2) in each knee compartment. Occurrence of joint replacement by 4 yr was documented.

RESULTS

Cartilage defects were present in 81% of medial, 64% of lateral tibiofemoral compartments and 55% of patellar cartilages. Annual patellar cartilage loss was highest in those with defects compared with no defects (5.5% vs 3.2%, P = 0.01). Tibial cartilage loss was not associated with defects in the medial (4.6% vs 5.8%, P = 0.42) or lateral (4.7% vs 6.5%, P = 0.21) tibial cartilages. Higher total cartilage defect scores (8-15) were associated with a 6.0-fold increased risk of joint replacement over 4 yr compared with those with lower scores (2-7) (95% confidence interval 1.6, 22.3), independently of potential confounders.

CONCLUSIONS

Articular cartilage defects are associated with disease severity in knee OA and predict patellar cartilage loss and knee replacement.

Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay

Currently, the beta-neutrino asymmetry has the largest uncertainty (4 %) of the neutron decay angular correlations. Without requiring polarimetry this decay parameter can be used to measure λ (ga/gv ), test Cabibbo-Kobayashi-Maskawa (CKM) unitarity limit scalar and tensor currents, and search for Charged Vector Current (CVC) violation. We propose to measure the beta-neutrino asymmetry coeffcient, a, using time-of-flight for the recoil protons. We hope to achieve a systematic uncertainty of σa / a ≈ 1.0 %. After tests at Indiana University's Low Energy Neutron Source (LENS), the apparatus will be moved to the National Institute of Standards and Technology (NIST) where the measurement can achieve a statistical uncertainty of 1 % to 2 % in about 200 beam days.

Association between age and knee structural change: a cross sectional MRI based study

OBJECTIVE

To describe the associations between age, knee cartilage morphology, and bone size in adults.

METHODS

A cross sectional convenience sample of 372 male and female subjects (mean age 45 years, range 26-61) was studied. Knee measures included a cartilage defect five site score (0-4 respectively) and prevalence (defect score of > or =2 at any site), cartilage volume and thickness, and bone surface area and/or volume. These were determined at the patellar, medial, and lateral tibial and femoral sites using T(1)weighted fat saturation MRI. Height, weight, and radiographic osteoarthritis (ROA) were measured by standard protocols.

RESULTS

In multivariate analysis, age was significantly associated with knee cartilage defect scores (beta = +0.016 to +0.073/year, all p<0.01) and prevalence (OR = 1.05-1.10/year, all p<0.05) in all compartments. Additionally, age was negatively associated with knee cartilage thickness at all sites (beta = -0.013 to -0.035 mm/year, all p<0.05), and with patellar (beta = -11.5 microl/year, p<0.01) but not tibial cartilage volume. Lastly, age was significantly positively associated with medial and lateral tibial surface bone area (beta = +3.0 to +4.7 mm(2)/year, all p<0.05) and patellar bone volume (beta = +34.4 microl/year, p<0.05). Associations between age and tibiofemoral cartilage defect score, cartilage thickness, and bone size decreased in magnitude after adjustment for ROA, suggesting these changes are directly relevant to OA.

CONCLUSION

The most consistent knee structural changes with increasing age are increase in cartilage defect severity and prevalence, cartilage thinning, and increase in bone size with inconsistent change in cartilage volume. Longitudinal studies are needed to determine which of these changes are primary and confirm their relevance to knee OA.

characterization of bacterial community diversity in cystic fibrosis lung infections by use of 16s ribosomal DNA terminal restriction fragment length polymorphism profiling

Progressive loss of lung function resulting from the inflammatory response to bacterial colonization is the leading cause of mortality in cystic fibrosis (CF) patients. A greater understanding of these bacterial infections is needed to improve lung disease management. As culture-based diagnoses are associated with fundamental drawbacks, we used terminal restriction fragment (T-RF) length polymorphism profiling and 16S rRNA clone data to characterize, without prior cultivation, the bacterial community in 71 sputa from 34 adult CF patients. Nineteen species from 15 genera were identified in 53 16S rRNA clones from three patients. Of these, 15 species have not previously been reported in CF lung infections and many were species requiring strict anaerobic conditions for growth. The species richness and evenness were determined from the T-RF length and volume for the 71 profiles. Species richness was on average 13.3 +/- 7.9 per sample and 13.4 +/- 6.7 per patient. On average, the T-RF bands of the lowest and highest volumes represented 0.6 and 59.2% of the total volume in each profile, respectively. The second through fifth most dominant T-RF bands represented 15.3, 7.5, 4.7, and 2.8% of the total profile volume, respectively. On average, the remaining T-RF bands represented 10.2% of the total profile volume. The T-RF band corresponding to Pseudomonas aeruginosa had the highest volume in 61.1% of the samples. However, 18 other T-RF band lengths were dominant in at least one sample. In conclusion, this reveals the enormous complexity of bacteria within the CF lung. Although their significance is yet to be determined, these findings alter our perception of CF lung infections.

Effects of bone density feedback and group education on osteoporosis knowledge and osteoporosis self-efficacy in premenopausal women: a randomized controlled trial

In this 2-yr randomized controlled trial, we examined the effect of bone mineral density feedback and two different educational interventions (an osteoporosis information leaflet and group-based behavioral education [OPSMC]) on osteoporosis knowledge and self-efficacy in 470 women aged 25-44 yr. Osteoporosis knowledge increased across all intervention groups. Women receiving the OPSMC had a greater increase in both short (beta = +1.33, 95% confidence interval [CI] = 0.72-1.94) and long-term (beta = +0.64, 95% CI = 0.0034-1.25) osteoporosis knowledge, compared to those receiving the leaflet. In contrast, a low T-score was associated with a significant increase in long-term (beta = +0.66, 95% CI = 0.0034-1.25) but not short-term (beta = +0.57, 95% CI = -0.036 to 1.17) osteoporosis knowledge, compared to a normal T-score. Changes in osteoporosis self-efficacy were not associated with either low bone mineral density or receiving the OPSMC but were negatively associated with number of children (beta = -0.9, 95% CI = - 1.4 to -0.3) and working more than 20 h per week (beta = -2.7, 95% CI = -4.6 to -0.8). In conclusion, both the OPSMC and bone density feedback increased osteoporosis knowledge but not self-efficacy over 2 yr. Women with children or who worked full time have decreased osteoporosis self-efficacy, suggesting that this group should be a specific target for future interventional strategies.

Genetic mechanisms of knee osteoarthritis: a population based case-control study

OBJECTIVE

To compare subjects who had at least one parent with a total knee replacement for severe primary knee osteoarthritis with age and sex matched controls who had no family history of knee osteoarthritis

DESIGN

Population based case-control study of 188 matched pairs (mean age 45 years, range 26 to 60).

METHODS

Articular cartilage volume and bone size were determined at the patella and at the medial tibial and lateral tibial compartments by processing images acquired using T1 weighted, fat saturated magnetic resonance imaging. Radiographic osteoarthritis (ROA) was assessed from a standing semiflexed radiograph scored for joint space narrowing and osteophytosis. Knee pain was assessed by questionnaire. Height, weight, body mass index (BMI), lower limb muscle strength, and endurance fitness were measured by standard protocols.

RESULTS

Compared with the controls, index offspring had higher BMI (27.8 v 26.0 kg/m(2), p = 0.02), weaker lower limb muscles (127 v 135 kg, p = 0.006), more knee pain (47% v 22%, p<0.001), and greater medial tibial bone area (17.6 v 17.1 cm(2), p = 0.01). With the exception of BMI, these differences persisted in multivariate analysis. There was a non-significant trend to higher cartilage volume at tibial sites and increased ROA in the offspring in the total and subgroup analyses, but no difference in height and endurance fitness.

CONCLUSIONS

BMI, muscle strength, knee pain, and medial tibial bone area, but not cartilage volume, appear to play a role in the genetic regulation and development of knee osteoarthritis.

Measurement of the generalized forward spin polarizabilities of the neutron

The generalized forward spin polarizabilities gamma(0) and delta(LT) of the neutron have been extracted for the first time in a Q2 range from 0.1 to 0.9 GeV2. Since gamma(0) is sensitive to nucleon resonances and delta(LT) is insensitive to the Delta resonance, it is expected that the pair of forward spin polarizabilities should provide benchmark tests of the current understanding of the chiral dynamics of QCD. The new results on delta(LT) show significant disagreement with chiral perturbation theory calculations, while the data for gamma(0) at low Q2 are in good agreement with a next-to-leading-order relativistic baryon chiral perturbation theory calculation. The data show good agreement with the phenomenological MAID model.

Soft drink and milk consumption, physical activity, bone mass, and upper limb fractures in children: a population-based case-control study

Carbonated beverages have been reported to increase fracture risk in children but the mechanism is unclear. The aim of this population-based case-control study was to investigate the association between soft drink and milk consumption, physical activity, bone mass, and upper limb fractures in children aged 9-16 years. A total of 206 fracture cases and 206 randomly selected individually matched controls were studied. There were 47 hand fractures; 128 wrist and forearm fractures, and 31 upper arm fractures. An interviewer-administered questionnaire was utilized to retrospectively assess last-year physical activity (including television, computer, and video watching) and to recall the average weekly consumption of milk, colas, and total carbonated drinks. Bone mass at the spine, hip, and total body was assessed by dual-energy X-ray absorptiometry (DXA) and metacarpal morphometry. For total fractures, none of the above drink types was significantly different between cases and controls. For wrist and forearm fractures, there was a positive association between cola drink consumption and fracture risk (OR 1.39/unit, 95% CI: 1.01, 1.91). Cola consumption was significantly correlated with television, computer, and video watching (r = 0.20, P = 0.001) but not bone mineral density or milk drinks. After adjustment for television, computer, and video watching and bone mineral density, the association between cola drinks and fracture risk became nonsignificant (OR 1.31/unit, 95% CI: 0.94, 1.83). No association with other fracture sites was observed. In conclusion, cola, but not total carbonated beverage consumption, is associated with increased wrist and forearm fracture risk in children. However, this association is not independent of other factors and appears to be mediated by television watching and bone mineral density but not by decreased milk intake.

Measurement of Vitamin D metabolites: an international perspective on methodology and clinical interpretation

The International Quality Assessment Scheme for Vitamin D metabolites (DEQAS) was introduced in 1989. Initially, the aim was to improve the reliability of 25-hydroxyvitamin D (25-OHD) assays but the scheme was extended in 1997 to include 1,25-dihydroxyvitamin D (1,25(OH)(2)D). DEQAS has 95 members in 18 countries (January 2003). Five serum samples are distributed quarterly and participants are given up to 6 weeks to return their results for statistical analysis. The majority of participants use commercial kits for both analytes. A performance target was set by an advisory panel in 1997 and, at present, requires participants to get 80% or more of their results within +/-30% of the All-Laboratory Trimmed Mean (ALTM). The performance targets are under continual review. In 2003, 59% of participants met the target (cf. 52% in 2000). A questionnaire, distributed in January 2003, requested information on methods and the interpretation of results. Reference ranges varied but there was reasonable agreement on the 25-OHD concentrations below which Vitamin D supplementation was advised. A minority (22%) of respondents was unsure whether Vitamin D(3) or Vitamin D(2) was used to treat patients in their locality. The majority (52%) of assays for 1,25(OH)(2)D were done 'on demand' and others for apparently spurious reasons. Most respondents thought participation in DEQAS extremely important and the planned introduction of on-line reporting should enhance its value.