Bone formation in a carbonate-substituted hydroxyapatite implant is inhibited by zoledronate

Carbonate-substituted hydroxyapatite (CHA) is more osteoconductive and more resorbable than hydroxyapatite (HA), but the underlying mode of its action is unclear. We hypothesised that increased resorption of the ceramic by osteoclasts might subsequently upregulate osteoblasts by a coupling mechanism, and sought to test this in a large animal model.

Defects were created in both the lateral femoral condyles of 12 adult sheep. Six were implanted with CHA granules bilaterally, and six with HA. Six of the animals in each group received the bisphosphonate zoledronate (0.05 mg/kg), which inhibits the function of osteoclasts, intra-operatively.

After six weeks bony ingrowth was greater in the CHA implants than in HA, but not in the animals given zoledronate. Functional osteoclasts are necessary for the enhanced osteoconduction seen in CHA compared with HA.

Do female black field crickets Teleogryllus commodus benefit from polyandry?

Female insects that mate multiply tend to have increased lifetime fitness, apparently because of greater access to male-derived resources (e.g. sperm, nuptial gifts) that elevate fertility/fecundity. Experiments that standardize the number of matings per female also show that polyandry can improve aspects of offspring performance, most notably early embryo survival (egg hatching success). This improvement is widely attributed to genetic benefits which would arise if polyandrous females skew paternity to produce fitter offspring. In two separate experiments with field crickets (Teleogryllus commodus) polyandrous females (two, three or four mates) did not have higher egg hatching success than monandrous females (effect sizes: r = 0.03 and 0.08 for the respective experiments), which is consistent with our finding of no sire effect on hatching success. Polyandry also had no effect on post-hatching offspring survival. Polyandrous females' offspring took significantly longer to mature but their sons were not heavier and their daughters were actually significantly smaller than those of monandrous females. Finally, after controlling for relative male size, monandrous females' sons were more successful when directly competing for a mate.

Sounds different: inbreeding depression in sexually selected traits in the cricket Teleogryllus commodus

If male sexual signalling is honest because it captures genetic variation in condition then traits that are important mate choice cues should be disproportionately affected by inbreeding relative to other traits. To test this, we investigated the effect of brother-sister mating on advertisement calling by male field crickets Teleogryllus commodus. We quantified the effect of one generation of inbreeding on nightly calling effort and five finer-scale aspects of call structure that have been shown to influence attractiveness. We also quantified inbreeding depression on six life history traits and one morphological trait. Inbreeding significantly reduced hatching success, nymph survival and adult lifespan but had no detectable effect on hatching rate, developmental rate or adult body mass. The effect of inbreeding on sexually selected traits was equivocal. There was no decline in calling effort (seconds of sound production/night) by inbred males, but there were highly significant changes in three of five finer-scale call parameters. Sexually selected traits clearly vary in their susceptibility to inbreeding depression.

Intravesical atropine compared to oral oxybutynin for neurogenic detrusor overactivity: a double-blind, randomized crossover trial

PURPOSE

We tested the efficacy and side effect profiles of intravesical atropine compared to oxybutynin immediate release when used by individuals with multiple sclerosis.

MATERIALS AND METHODS

We performed a study to determine the most effective dose of atropine. Eight participants used increasing doses of intravesical atropine during a 12-day period. Bladder diary data showed that the instillation of 6 mg atropine 4 times daily was most effective for increasing bladder capacity (voided/catheter volumes). We then did a randomized, double-blind crossover trial. Participants received 14 days of treatment with oral oxybutynin or with intravesical atropine, followed by 14 days of alternative treatment. Participants recorded a bladder diary and rated side effects and quality of life. The primary outcome variable was bladder capacity.

RESULTS

A total of 57 participants with multiple sclerosis completed the study. Average change in bladder capacity was higher in the atropine arm. The mean +/- SD oxybutynin change was 55.5 +/- 67.2 ml, the mean atropine change was 79.6 +/- 89.6 ml and the mean difference between arms was 24.1 ml (95% CI -0.4, 49.7; p = 0.053). Changes in incontinence events and voiding frequency were not statistically different between the arms. Changes in total side effect and dry mouth scores were significantly better in the atropine treatment arm.

CONCLUSIONS

Intravesical atropine was as effective as oxybutynin immediate release for increasing bladder capacity and it was probably better with less antimuscarinic side effects. We recommend that intravesical atropine should be made available to patients with neurogenic detrusor overactivity and voiding problems requiring intermittent catheterization as an alternative to oral therapy, which often has troublesome side effects.

A multi-centre evaluation of absorbent products for men with light urinary incontinence

AIMS

This study compared the performance of the four main designs of absorbents for men with light incontinence: pouches (shields), leafs (guards), washable pant with integral pad (pantegral), and small disposable pad.

MATERIALS AND METHODS

We did a multiple crossover trial. Men with light urinary incontinence were recruited. All pouches and leafs available in the UK were identified for inclusion. A single pantegral and small pad were selected based on previous evaluations for design comparison. Products were tested in random order for up to 1 week. Performance criteria (e.g., leakage and comfort) were rated using a validated product performance questionnaire. Wet product weights and amount of leakage were recorded in pad leakage diaries. "Overall opinion" for design performance was used as the primary outcome indicator.

RESULTS

Seventy-four men tested six leafs, six pouches, one pantegral, and one small pad. Leakage data was taken from 3,386 wet pads. The pouches generally performed poorly with few significant differences between products. The leafs were more variable with large and significant differences in ratings. Overall the leaf, pantegral, and small pad designs performed significantly better than the pouch (P <or= 0.01) and the pantegral design performed significantly worse than the leaf (P = 0.01). One leaf product was outstanding and performed significantly better than all other designs (P <or= 0.001).

CONCLUSION

This is the first published trial of absorbent products specifically designed for men. Results show that one particular leaf product works best, the pantegral is most suitable only for very light incontinence and the pouches are least successful.

The effect of leg fracture level and vehicle front-end geometry on pedestrian knee injury and response

In this study a MADYMO® (mathematical dynamic modelling) model has been used to identify the influence of leg fracture on the injuries sustained by the pedestrian during front end impact with a vehicle. A factorial study of a MADYMO® pedestrian and vehicle model are used to investigate the effect of different leg fracture tolerances, geometry, and vehicle compliance on the criteria measured in the European Enhanced Vehicle-safety Committee (EEVC) pedestrian safety tests. These criteria include knee bending, knee shear response, and lower leg bone (tibia) acceleration. The main study examines the spread of typical values of lower limb tolerance based on reported literature and contrasts the response of weaker, low-strength bones, normal tolerance, and limbs which do not fracture. Results show that knee bending angles and therefore ligament strains are significantly increased when fracture does not occur, and are decreased in bones exhibiting a low-strength response. Bone fracture tolerance is shown to be a significant parameter influencing knee bending. The parameters are compared to show that knee shear is significantly influenced by vehicle bumper compliance and that both criteria are heavily influenced by bumper height. Vehicles with more aggressive geometry, higher bumpers, and larger bumper lead were considered for comparative purposes.

Ultrasonic treatment to improve anaerobic digestibility of dairy waste streams

The dairy-processing industry generates various types of organic wastes, which are utilised as stock feed, for anaerobic digestion, spread on land or alternatively land-filled at high costs. Owing to the generation of renewable energy, anaerobic digestion is an attractive option for many factories. To enhance the biological degradation process, a mechanical disintegration of various waste dairy streams was undertaken. While the successful application of ultrasonic treatment has been reported for various municipal waste streams, limited information was available for dairy industry applications. The results of this study showed that ultrasonic treatment can improve the digestibility of the more problematic dairy waste streams, such as sludges, by breaking down micro-organisms' cell walls and releasing soluble cell compounds. For more soluble streams, such as dairy factory effluent, an increased gas production was observed and attributed to the reduced particle size of the fat globules.

Effect of carbonate substitution on the ultrastructural characteristics of hydroxyapatite implants

Carbonate ion substitution has been shown to be beneficial for increasing the amount of in vivo osseointegration to hydroxyapatite (HA). Nevertheless, mechanisms by which carbonate ions increase in vivo bioactivity are not fully understood. Sintered granules of HA and carbonate-substituted hydroxyapatite (CHA) were implanted for 6 and 12 weeks in an ovine model. Samples containing the bone-implant interface were prepared for transmission electron microscopy (TEM) and TEM was used to compare the in vivo reactivity of sintered granules of HA and CHA. The current findings demonstrated that CHA (1.2 and 2.05 wt.%) is more soluble than pure HA in vivo. More dissolution was observed from the CHA, at the bone-implant interface and within the implant, when compared to pure HA. A less crystalline phase was formed between the 2.05 wt.% CHA and bone at 12 weeks in vivo. Bone surrounding both the pure HA and 1.2 wt.% CHA was relatively disorganised at 12 weeks. In comparison, bone surrounding the 2.05 wt.% CHA was considerably more organised and in many regions collagen fibrils were present. Despite increased quality of bone surrounding 2.05 wt.% CHA, compared to 1.2 wt.% CHA, the amount of dissolution from both materials was similar.

A multicenter evaluation of absorbent products for children with incontinence and disabilities

OBJECTIVE

To evaluate all disposable pull-up-style pads (pull-ups) designed for children with learning and or physical disabilities and compare these with a representative sample of disposable diapers (diapers).

DESIGN

A multicenter randomized crossover trial where all children evaluated each product. SETTING AND CHILDREN: A total of 61 community dwelling children with disabilities were recruited from 5 areas throughout the United Kingdom. Families were invited by letter to participate through their local clinical nurse specialist for continence care.

INSTRUMENTS

Instruments used included a range of questionnaires (product performance, design performance, and design preference questionnaires) and pad weight and leakage diaries.

METHODS

The children tested 10 products (5 pull-ups and 5 diapers) for up to 1 week per product both at home and at school. Caregivers (parents and guardians) completed the questionnaires after evaluation of individual products and design groups had been completed. They recorded wet product weights and scored pad leakage at each pad change. School staff completed an abbreviated product performance questionnaire for each product.

RESULTS

There was little difference in the overall performance of the pull-ups compared with the diapers. In the pull-up group, one product performed significantly worse than the others for some performance aspects. Pull-ups worked particularly well for children able to assist with toileting and pad changes. Diapers were liked for ease of changing if the child used calipers, adapted footwear, or trousers. Diapers were more popular than pull-ups for night use, when greater absorbency was required. Neither design performed differently for school or home use. Most caregivers expressed a preference for diapers or pull-ups based on a range of individual needs, for example, level of independence in toileting, discreteness in pad change, fit, and product appearance.

CONCLUSIONS

Diapers and pull-ups have different strengths and limitations, and both meet the specific needs of individual children. Although pull-ups are more expensive than diapers, their use is justified if based on a thorough assessment of individual need.

Benefits of interprofessional learning: an interprofessional MSc in child health

This article addresses interprofessional education (IPE) using a case study evaluating a multidisciplinary MSc course in child health. The participants felt that the nature of the course increased their interprofessional working skills and professional confidence. They described benefits, including new insights, a balanced variety of views, development of respect and equality between professionals, improved communication and a holistic approach to child health.

D-2-hydroxyglutaric aciduria and glutaric aciduria type 1 in siblings: coincidence, or linked disorders?

Glutaric aciduria type 1 (GA1) and D-2-hydroxyglutaric aciduria ( D-2-HGA) are cerebral organic acidurias characterized by the excretion of 3-hydroxyglutaric and D-2-hydroxyglutaric acids, respectively. GA1 is caused by a deficiency of glutaryl-CoA dehydrogenase encoded by the GCDH gene; the biochemical and genetic basis of D-2-HGA is unknown. We diagnosed GA1 in the son of consanguineous Palestinian parents, and D-2-HGA in his sister and brother. All three siblings were neurologically and developmentally normal. A small but abnormal increase in excretion of D-2-hydroxyglutaric acid was also found in the sibling with GA1. These observations suggested a possible pathophysiological link between these two disorders. The sibling with GA1 was homozygous whilst his siblings with D-2-HGA were heterozygous for a 1283 C>T missense mutation (T416I) in exon 11 of the GCDH gene. However, sequence analysis of the GCDH gene in 8 additional unrelated patients with D-2-HGA and 3 with combined D/ L-2-HGA did not reveal any pathogenic mutations. The biochemical and genetic basis of D-2-HGA remains to be determined.

A multicenter comparative evaluation: disposable pads for women with light incontinence

OBJECTIVE

The purpose of this study was to evaluate the current range of disposable pads for women with light incontinence available in the United Kingdom.

SETTING AND SUBJECTS

Sixty community-based women aged 50 years or older were recruited to the study from several locations throughout the United Kingdom.

METHODS

A multiple crossover design was used, which enabled all subjects to test all of the 12 products that were available on the UK market at the time of the evaluation. Two tools were used to evaluate the products: a product performance questionnaire and a pad leakage diary. This incorporated both subjective and objective outcome measures.

RESULTS

Statistically significant differences were found between the products in 13 of the 17 performance aspects, eg, ability to hold urine without leaking and the fit of the pad.

CONCLUSIONS

As a group, all of the products tested performed well in terms of their ability to hold urine without leakage. However, two products performed particularly well and scored highly on most aspects of performance and represented successful "all-round" products; these were the Tena Lady Extra and the Prevail Extra Plus.

Disposable pull-ups versus disposable nappies for children with a disability

Most children are expected to be dry by the age of three years (Lukeman, 1997). However, children with physical and/or learning disabilities may have difficulty achieving continence and will have an ongoing need for absorbent products. Historically these were disposable nappies. In recent years, the disposable pull-up style pad (Fig 1) has proved popular as an alternative design.

N-terminal pro-B-type natriuretic peptide: reference plasma levels from birth to adolescence. Elevated levels at birth and in infants and children with heart diseases

AIM

Determination of plasma levels of N-terminal pro-B-type natriuretic peptide (N-BNP) in infants and children with and without heart diseases.

METHODS

Plasma N-BNP was measured in 78 infants and children without heart disease and in 55 infants and children with heart disease causing volume and pressure overload. Heart diseases included chronic dilated cardiomyopathy, acute left ventricular dysfunction, and congenital cardiac anomalies resulting in left and right ventricular volume or pressure overload. The Mann-Whitney rank-sum test and the ANOVA for ranks test were used to compare two or more groups, respectively.

RESULTS

N-BNP levels were elevated in the first days of life but were not significantly different in children from 4 mo to 15 y old. The upper limit in children older than 4 mo with no heart disease was 349 pg/ml. In patients with heart disease, N-BNP levels were significantly higher than in control children (p < 0.0001).

CONCLUSION

N-BNP levels are elevated in the first days of life and are stable from age 4 mo to adolescence. Elevated N-BNP levels reflect cardiac dysfunction in infants and children.

Mechanical properties of glass-ceramic A–W-polyethylene composites: effect of filler content and particle size

Composites which comprise a bioactive filler and ductile polymer matrix are desirable as implant materials since both their biological and mechanical properties can be tailored for a given application. In the present study three-point bending was used to characterise biomedical materials composed of glass-ceramic apatite-wollastonite (A-W) particulate reinforced polyethylene (PE) (denoted as AWPEX). The effects of filler volume fraction, varied from 10 to 50 vol%, and average particle size, 4.4 and 6.7 microm, on the bending strength, yield strength, mode of fracture, Young's modulus and strain to failure were investigated. HAPEX, a commercially used composite of hydroxyapatite and polyethylene, with a 40 vol% filler content, was used for comparison. Increasing the filler content caused an increase in Young's modulus, yield strength and bending strength, and a decreased strain to failure. When filler particle size was increased, the Young's modulus, yield and bending strengths were found to be slightly reduced. A transition in fracture behaviour from ductile to brittle behaviour was observed in samples containing between 30 and 40 vol% filler.

Extreme polymorphism in a Y-linked sexually selected trait

Males of the livebearing fish, Poecilia parae, exhibit one of the most complex polymorphisms known to occur within populations, whereas females are monomorphic. We describe five distinct male colour morphs and an associated size dimorphism, and demonstrate through pedigree analysis that the locus or loci controlling the male colour polymorphism is linked to the Y-chromosome. Field surveys from 1999 to 2002 of nine populations in Guyana and Suriname, South America, indicate that some morphs are consistently abundant and others are rare, implying that the colour polymorphism has important fitness consequences. By rearing offspring of field-inseminated females, we showed that the common morph is also the most successful morph in terms of reproduction. However, dichotomous choice tests show that two rare morphs are preferred by females over the common morph. These results suggest that alternative male mating strategies, sperm competition, overt male-male competition, or other processes are overriding female preferences in these populations. Furthermore, Y-linkage of the colour polymorphism in P. parae supports the hypothesis that heterogametic sex chromosomes harbour sexually antagonistic traits beneficial to the heterogametic sex.

Management of night-time urinary incontinence in residential settings for older people: an investigation into the effects of different pad changing regimes on skin health

Absorbent pads are the main method of managing urinary incontinence in residential settings for older people. Improvements in technology have resulted in highly absorbent products which may be worn all night, but the effects of prolonged pad wearing on aged skin are unknown. The aim of this study was to examine the effects of two different pad changing regimes on skin health. A cross-over design was used. Subjects from residential settings were randomly allocated to one of two pad changing regimes: a frequent pad changing regime or a less frequent pad changing regime. Each regime lasted 4 weeks and was followed by the alternative regime. Skin measurements were taken twice during each regime using (i) the Diastron Erythema meter, (ii) a visual grading scale, (iii) the Servomed evaporimeter, and (iv) a pH meter. The primary outcome variable was the Diastron Erythema meter index. Eighty-one subjects completed the study. No significant differences were found in the severity of erythema, or skin pH, between regimes. Measurements of trans-epidermal water loss were significantly higher in the less frequent pad changing regime indicating that skin was 'wetter' (P = 0.01; 95% CI: 2.89-21.39). Five subjects developed grade 2 pressure ulcers (abrasions) during the less frequent pad changing regime, but none in the frequent pad changing regime; this result was not significant (P = 0.1; 95% CI: 0-1.09). No evidence was found that a less frequent pad changing regime has an effect on skin erythema or pH. There is evidence that skin is wetter which may make it more vulnerable to friction and abrasion. The statistically non-significant finding of greater incidence of grade 2 pressure ulcers is a cause for concern and merits further investigation because of the clinical significance of loss of skin integrity.

Buccal cells as a source of DNA for comparative animal genomic analysis

The source of DNA of adequate quality and quantity is an important consideration in genome analysis. In many animal and livestock species, easy access to DNA will facilitate the rapid and reliable genotyping of a large number of individual individuals. Here, we describe the use, for the first time, of buccal cells from non-human mammalian species as a source of DNA template for PCR and restriction analysis. The buccal cells from the pig, cow and human, were used to amplify PCR fragments that were scanned SNPs and for comparative genome analysis. The work indicates that buccal cells are also adequate sources of DNA for genome analysis of animals that have been identified as priorities in comparative genomics.

A multicentre comparative evaluation: washable pants with an integral pad for light incontinence

The Continence Product Evaluation Network (CPE network) is funded by the Medical Devices Agency (MDA) of the Department of Health, to undertake comparative evaluations of continence products. There are a wide variety of continence products on the UK market and very little information is available to aid product selection. The aim of this study was to evaluate washable pants with integral pads for women with light incontinence. A randomized multiple cross-over design was used. Seventy-two women tested each of the 10 products that were available on the UK market at the time of the evaluation. Both subjective and objective outcome measures were used to evaluate the products. Products performed similarly in terms of leakage but there were statistically significant differences in other performance aspects, e.g. fit and discreteness. This study should be valuable in enabling purchasers, carers and users to make informed decisions when purchasing products.