Clinical risk factors but not bone density are associated with prevalent fractures in prepubertal children

OBJECTIVE

The aim of this study was to investigate the association of clinical risk factors and bone density with prevalent fractures in prepubertal children.

METHODS

Bone mineral density (BMD) in lumbar spine, femoral neck and total body bone was assessed by dual-energy X-ray absorptiometry. Clinical data on risk factors were collected by measurement and questionnaires.

RESULTS

Of 324 children, 32 (10%) had a prevalent fracture (upper limb 69%). Most fractures were due to low-energy falls at home (69%). Children with fractures were older (P = 0.04), had higher levels of sports participation (P = 0.03), lower levels of breastfeeding (P = 0.05) and tended towards higher usage of inhaled corticosteroids in the previous year (P = 0.05). However, both BMD and apparent BMD did not differ between those with and without prevalent fracture. No differences were observed in the proportion of maternal fractures, maternal smoking during pregnancy, asthma history and oral prednisolone in last year (all P > 0.05). A final model incorporating age, weight, height, breastfeeding history, sports participation and inhaled corticosteroid usage accounted for 10% of the variability in the odds of fracture (P = 0.03).

CONCLUSION

These results suggest that BMD may be less important than clinical risk factors for total fracture risk in prepubertal children. However, sample size limitations mean that further investigation in larger populations with less heterogeneity in fracture types is warranted.

Falsely elevated serum tobraycin levels in a patient receiving nebulised tobramycin

It is common when treating patients with respiratory exacerbations of cystic fibrosis to use both nebulised and intravenous antibiotics. Aminoglycoside drug levels are often measured from finger-prick blood samples. We describe a case of a 14-year-old girl treated simultaneously with IV and nebulised tobramycin in whom drug levels, measured from finger prick blood samples, were erroneously high due to finger contamination by the nebulised drug. Special precautions or direct venepuncture is essential when assessing antibiotic levels in such patients.

Symptomatic fracture incidence in those under 50 years of age in southern Tasmania

OBJECTIVE

To document symptomatic fracture incidence in those aged under 50 years of age.

METHODS

Fractures were ascertained from X-ray reports containing the word 'fracture' from all radiology providers for the geographically defined population of southern Tasmania (n = 165 175) for the period 1 July 1997 to 30 June 1999.

RESULTS

In the 2-year study frame there were 2943 fractures in 164 730 person years in males and 1348 fractures in 165 620 person years in females. This represents a fracture incidence of 1787 per 100 000 person years in males and 819 per 100 000 person years in females. Peak fracture incidence was 10-14 years in females and 15-19 years in males although different fracture types had varying peak incidence suggesting different fracture-specific causes. The most common fractures were those of the hand (24%), forearm (17%), wrist (10%) and foot (9%). All fractures (including vertebral) were more common in males with relative risks ranging from 1.34 to 4.50. The estimated probability of at least one fracture between birth and 50 years of age was 59% for males and 34% for females.

CONCLUSION

There are threefold as many fractures in this age group compared to those due to osteoporosis in the elderly in any given year. More research priority needs to be given to understanding the causes of these fractures so that preventive strategies can be formulated.

Consumer acceptance of vegetarian sweet potato products intended for space missions

Sweet potato is one of the crops selected for NASA's Advanced Life Support Program for potential long-duration lunar/Mars missions. This article presents recipes of products made from sweet potato and determines the consumer acceptability of products containing from 6% to 20% sweet potato on a dry weight basis. These products were developed for use in nutritious and palatable meals for future space explorers. Sensory evaluation (appearance/color, aroma, texture, flavor/taste, and overall acceptability) studies were conducted to determine the consumer acceptability of vegetarian products made with sweet potato using panelists at NASA/Johnson Space Center in Houston, TX. None of these products including the controls, contained any ingredient of animal origin with the exception of sweet potato pie. A 9-point hedonic scale (9 being like extremely and 1 being dislike extremely) was used to evaluate 10 products and compare them to similar commercially available products used as controls. The products tested were pancakes, waffles, tortillas, bread, pie, pound cake, pasta, vegetable patties, doughnuts, and pretzels. All of the products were either liked moderately or liked slightly with the exception of the sweet potato vegetable patties, which were neither liked nor disliked. Mean comparisons of sensory scores of sweet potato recipes and their controls were accomplished by using the Student t-test. Because of their nutritional adequacy and consumer acceptability, these products are being recommended to NASA's Advanced Life Support Program for inclusion in a vegetarian menu plan designed for lunar/Mars space missions.

Sweet potato in a vegetarian menu plan for NASA's Advanced Life Support Program

Sweet potato has been selected as one of the crops for NASA's Advanced Life Support Program. Sweet potato primarily provides carbohydrate--an important energy source, beta-carotene, and ascorbic acid to a space diet. This study focuses on menus incorporating two sets of sweet potato recipes developed at Tuskegee University. One set includes recipes for 10 vegetarian products containing fom 6% to 20% sweet potato on a dry weight basis (pancakes, waffles, tortillas, bread, pie, pound cake, pasta, vegetable patties, doughnuts, and pretzels) that have been formulated, subjected to sensory evaluation, and determined to be acceptable. These recipes and the other set of recipes, not tested organoleptically, were substituted in a 10-day vegetarian menu plan developed by the American Institute of Biological Sciences (AIBS) Kennedy Space Center Biomass Processing Technical Panel. At least one recipe containing sweet potato was included in each meal. An analysis of the nutritional quality of this menu compared to the original AIBS menu found improved beta-carotene content (p<0.05). All other nutrients, except vitamin B6, and calories were equal and in some instances greater than those listed for NASA's Controlled Ecological Life Support Systems RDA. These results suggest that sweet potato products can be used successfully in menus developed for space with the added benefit of increased nutrient value and dietary variety.

The relationship of circulating insulin-like growth factor 1, its binding protein-3, prostate-specific antigen and C-reactive protein with disease stage in prostate cancer

OBJECTIVE

To assess the relationships among circulating insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3), prostate-specific antigen (PSA) and C-reactive protein (an indicator of inflammatory systemic response) in patients with prostate disease and cancer of different stages.

PATIENTS AND METHODS

Circulating IGF-1, IGFBP-3, PSA and C-reactive protein concentrations were measured in patients with BPH (17) or stages T1/T2 (15), T3/T4 (16) and metastatic prostate cancer (12 patients).

RESULTS

IGF-1 and IGFBP-3 concentrations were similar between patients with BPH and those with cancer, and there was no difference between the groups with cancer. In the latter patients there was a significant correlation between age and IGFBP-3 concentrations (r = -0.400, P = 0.008) but not with IGF-1 concentrations. Controlling for age, there were significant partial correlations between C-reactive protein and IGF-1 (r = -0.412, P = 0.008) and IGFBP-3 (r = -0.277, P = 0.05).

CONCLUSIONS

These results indicate that circulating IGF-1 and IGFBP-3 concentrations do not change with disease stage in prostate cancer, but that they decrease with an increase in the systemic inflammatory response.

Uterine artery resistance and anxiety in the second trimester of pregnancy

OBJECTIVE

To investigate the association between maternal anxiety and uterine artery resistance index (RI) at 20 weeks of gestation.

METHODS

Uterine artery blood flow was assessed using color Doppler ultrasound and maternal anxiety was measured using the Hospital Anxiety and Depression (HAD) scale in 96 healthy primigravid women attending consecutively for their routine 20-week anomaly scan.

RESULTS

The mean uterine artery RI was 0.54 (95% confidence interval, 0.52-0.56) and the median HAD anxiety score was 6 (range, 0-20). There was no association between RI and anxiety scores (r = 0.09, P = 0.36). Women scoring as definite cases of anxiety did not have a significantly elevated uterine artery RI or increased frequency of waveform notching compared to women with doubtful or no anxiety.

CONCLUSIONS

The data of this study do not suggest a significant association between maternal anxiety and uterine artery RI at 20 weeks of gestation in healthy primigravid women with normally developing pregnancies. A prospective cohort study would be useful to determine the nature of the relationship between maternal anxiety, alteration in uterine artery blood flow and abnormal pregnancy outcome.

Symptomatic fracture incidence in southern Tasmania: does living in the country reduce your fracture risk?

There are limited data describing urban-rural differences in fracture incidence and the overall effect remains controversial. The aim of this study was to compare symptomatic fracture incidence occurring in geographically defined rural (n = 34619) and urban (n = 194974) populations of Southern Tasmania from July 1, 1997 to June 30, 1999. Fractures were ascertained by reviewing reports from all the radiology providers within the area. In the 2-year study time frame there were 3644 fractures in males and 2657 fractures in females. Fracture incidence was significantly higher in urban compared with rural populations in both sexes (male: RR 1.60, 95% CI 1.47-1.75; female: RR 1.77, 95% CI 1.58-1.98). This higher urban fracture incidence was present across all age groups and all fracture types with the exception of knee and pelvis fractures in males (although not all were statistically significant). In addition, urban men >50 years old had a higher fracture incidence than rural women >50 years old (RR 1.25, 95% CI 1.05-1.50), suggesting that in later life the factors responsible for the urban-rural difference are able to offset completely the effect of gender. While some of the reduced fracture incidence in the rural population may be explained by urban drift and underreporting of minor fractures such as foot fractures, the overall pattern of higher fracture risk was very consistent, suggesting a real difference in whole-of-life symptomatic fracture incidence. Further research at an individual level is required to determine what factors account for these large urban-rural differences, as they imply a substantial potential for fracture prevention.

Effect of acoustic clutter on prey detection by bats

Bats that capture animal prey from substrates often emit characteristic echolocation calls that are short-duration, frequency-modulated (FM) and broadband. Such calls seem to be suited to locating prey in uncluttered habitats, including flying prey, but may be less effective for finding prey among cluttered backgrounds because echoes reflecting from the substrate mask the acoustic signature of prey. Perhaps these call designs serve primarily for spatial orientation. Furthermore, it has been unclear whether the acoustic image conveyed by FM echoes enables fine texture discrimination, or whether gleaning bats that forage in echo-cluttering environments must locate prey by using other cues, such as prey-generated sounds. Here we show that two species of insectivorous gleaning bats perform badly when compelled to detect silent and immobile prey in clutter, but are very efficient at capturing noisy prey items among highly cluttered backgrounds, and both dead or live prey in uncluttered habitats. These findings suggest that the short, broadband FM echolocation calls associated with gleaning bats are not adapted to detecting prey in clutter.

Azole-linked coumarin dyes as fluorescence probes of domain-forming polymers

The binding of 7-aminocoumarins, substituted in the 3-position with heterocyclic benzimidazole or benzothiazole groups by domain-forming polymers in water has been studied. The acrylic polyelectrolyte, poly(methacrylic) acid (PMAA) was used as a solubilizing agent for coumarin dyes 6, 7, and 30 in water. The acid-base properties of these bound coumarin dyes were monitored spectroscopically on titration of aqueous solutions. Alterations in the fluorescence wavelength and intensity, quantum yields, lifetimes, and polarization are consistent with the preferential binding of the dyes in compact hydrophobic domains that form at a pH regime in which the polymer is in its protonated (uncharged) state. In this pH range (<4.0), coumarins 7 and 30 are bound as monocations, whereas coumarin 6 remains in its neutral form. Reduced quantum yields and lifetimes of fluorescence for cationic coumarins can be understood in terms of the imposition of a low-lying electron transfer state, an example of a twisted intramolecular charge transfer (TICT) intermediate. Effects of polymer microenvironment on the rate of TICT state decay (a reverse electron transfer) are observed. Coumarins of the azole type may find use as fluoroprobes of the microenvironments of proteins and other biological macromolecules and as agents for pH sensing.

Juvenile hormone III-dependent conformational changes of the nuclear receptor ultraspiracle

The identification of potential endogenous or synthetic ligands for orphan receptors in the steroid receptor superfamily is important both for discerning endogenous regulatory pathways and for designing receptor inhibitors. The insect nuclear receptor Ultraspiracle (USP), an ortholog of vertebrate RXR, has long been treated as an orphan receptor. We have tested here the fit of terpenoid ligands to the JH III-binding site of monomeric and homo-oligomeric USP from Drosophila melanogaster (dUSP). dUSP specifically bound juvenile hormone III (JH III), but not control farnesol or JH III acid, and also specifically changed in conformation upon binding of JH III in a fluorescence binding assay. Juvenile hormone III binding caused intramolecular changes in receptor conformation, and stabilized the receptor's dimeric/oligomeric quaternary structure. In both a radiometric competition assay and the fluorescence binding assay the synthetic JH III agonist methoprene specifically competed with JH III for binding to dUSP, the first demonstration of specific binding of a biologically active JH III analog to an insect nuclear receptor. The recombinant dUSP bound with specificity to a DR12 hormone response element in a gel shift assay. The same DR12 element conferred enhanced transcriptional responsiveness of a transfected juvenile hormone esterase core promoter to treatment of transfected cells with JH III, but not to treatment with retinoic acid or T3. The activity of JH III or JH III-like structures, but not structures without JH III biological activity, to bind specifically to dUSP and activate its conformational change, provide evidence of a terpenoid endogenous ligand for Ultraspiracle, and offer the prospect that synthetic, terpenoid structures may be discovered that can agonize or antagonize USP function in vivo.

Arabidopsis genes essential for seedling viability: isolation of insertional mutants and molecular cloning

We have undertaken a large-scale genetic screen to identify genes with a seedling-lethal mutant phenotype. From screening approximately 38,000 insertional mutant lines, we identified >500 seedling-lethal mutants, completed cosegregation analysis of the insertion and the lethal phenotype for >200 mutants, molecularly characterized 54 mutants, and provided a detailed description for 22 of them. Most of the seedling-lethal mutants seem to affect chloroplast function because they display altered pigmentation and affect genes encoding proteins predicted to have chloroplast localization. Although a high level of functional redundancy in Arabidopsis might be expected because 65% of genes are members of gene families, we found that 41% of the essential genes found in this study are members of Arabidopsis gene families. In addition, we isolated several interesting classes of mutants and genes. We found three mutants in the recently discovered nonmevalonate isoprenoid biosynthetic pathway and mutants disrupting genes similar to Tic40 and tatC, which are likely to be involved in chloroplast protein translocation. Finally, we directly compared T-DNA and Ac/Ds transposon mutagenesis methods in Arabidopsis on a genome scale. In each population, we found only about one-third of the insertion mutations cosegregated with a mutant phenotype.

Inhibition of human immunodeficiency virus type 1 gp120 presentation to CD4 T cells by antibodies specific for the CD4 binding domain of gp120

Human immunodeficiency virus (HIV)-specific CD4 T-cell responses, particularly to the envelope glycoproteins of the virus, are weak or absent in most HIV-infected patients. Although these poor responses can be attributed simply to the destruction of the specific CD4 T cells by the virus, other factors also appear to contribute to the suppression of these virus-specific responses. We previously showed that human monoclonal antibodies (MAbs) specific for the CD4 binding domain of gp120 (gp120(CD4BD)), when complexed with gp120, inhibited the proliferative responses of gp120-specific CD4 T-cells. MAbs to other gp120 epitopes did not exhibit this activity. The present study investigated the inhibitory mechanisms of the anti-gp120(CD4BD) MAbs. The anti-gp120(CD4BD) MAbs complexed with gp120 suppressed gamma interferon production as well as proliferation of gp120-specific CD4 T cells. Notably, the T-cell responses to gp120 were inhibited only when the MAbs were added to antigen-presenting cells (APCs) during antigen pulse; the addition of the MAbs after pulsing caused no inhibition. However, the anti-gp120(CD4BD) MAbs by themselves, or as MAb/gp120 complexes, did not affect the presentation of gp120-derived peptides by the APCs to T cells. These MAb/gp120 complexes also did not inhibit the ability of APCs to process and present unrelated antigens. To test whether the suppressive effect of anti-gp120(CD4BD) antibodies is caused by the antibodies' ability to block gp120-CD4 interaction, APCs were treated during antigen pulse with anti-CD4 MAbs. These treated APCs remained capable of presenting gp120 to the T cells. These results suggest that anti-gp120(CD4BD) Abs inhibit gp120 presentation by altering the uptake and/or processing of gp120 by the APCs but their inhibitory activity is not due to blocking of gp120 attachment to CD4 on the surface of APCs.

Disulfide structure of alfimeprase: a recombinant analog of fibrolase

The disulfide structure of alfimeprase, a recombinant analog of fibrolase, was experimentally determined by a combination of peptide mapping, Edman degradation, and mass spectrometry. The three disulfide bonds were determined to be Cys-116/196, Cys-156 /180, and Cys-158/163 with the residue number system of alfimeprase.

A cross-sectional study of the association between Heberden's nodes, radiographic osteoarthritis of the hands, grip strength, disability and pain

OBJECTIVE

To describe the associations between hand osteoarthritis (OA), pain and disability in males and females and to further validate the Australian/Canadian OA hand index (AUSCAN LK3.0).

DESIGN

Cross-sectional study of 522 subjects from 101 Tasmanian families (males N=174, females N=348). Hand OA was assessed by two observers using the Altman atlas for joint space narrowing and osteophytes at distal interphalangeal and first carpometacarpal joints as well as a score for Heberden's nodes based on hand photography. Hand pain and function were assessed by the AUSCAN LK3.0 and grip strength by dynamometry in both hands on two occasions.

RESULTS

The prevalence of hand OA was high in this sample at 44-71% (depending on site). Pain and dysfunction increased with age while grip strength decreased (all P< 0.001). All three measures were markedly worse in women, even after taking the severity of arthritis into account. Hand OA explained 5.7-10% of the variation in function, grip strength and pain scores, even after adjustment for age and sex. Further adjustment suggested that the osteoarthritic associations with function and grip strength were largely mediated by pain. Severity of disease was more strongly associated with these scores than presence or absence. Lastly, the AUSCAN LK3.0 showed a comparable association to grip strength with structural damage providing further evidence of index validity.

CONCLUSIONS

Hand OA at these two sites makes substantial contributions to hand function, strength and pain. The associations with function and strength measures appear mediated by pain. Gender differences in all three measures persist after adjustment for variation in age and OA severity indicating that factors apart from radiographic disease are responsible.

Aggressive behaviour in patients with schizophrenia is associated with catechol-O-methyltransferase genotype

BACKGROUND

Evidence exists for an association between aggression and schizophrenia. Although the aetiology of aggression is multifactorial, three studies have reported associations between polymorphisms of the catechol-O-methyltransferase (COMT) gene and aggression in schizophrenia.

AIMS

To replicate these findings in a larger sample using the Overt Aggression Scale (OAS).

METHOD

A sample of 180 people with DSM-IV schizophrenia were rated for aggression using the OAS. Kruskal-Wallis and contingency table analyses were applied to the OAS results.

RESULTS

The high-activity homozygotes showed significantly higher scores of aggression, whereas the heterozygotes showed significantly lower scores. The odds ratio for aggression for the high-activity homozygotes was 2.07 (95% Cl=1.03-4.15), whereas that for the heterozygotes was 0.54 (95% Cl=0.30-1.00). CONCLUSIONS; The high-activity COMT homozygote confers a higher risk of recorded aggression in schizophrenia. Heterozygotes had a significantly lower risk, which may represent an example of heterosis/heterozygote advantage.