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Nicholas J Bishop

Publications and source records attributed to Nicholas J Bishop.

4 recordsLinked to original sources
PubMed2006

Association between bone mass and fractures in children: a prospective cohort study.

UNLABELLED: This is the first prospective cohort study of the association between bone mass and fracture risk in childhood. A total of 6213 children 9.9 years of age were followed for 24 months. Results showed an 89% increased risk of fracture per SD decrease in size-adjusted BMC. INTRODUCTION: Although previous case-control studies have reported that fracture risk in childhood is inversely related to bone mass, this has not been confirmed in prospective studies. Additionally, it remains unclear which constituent(s) of bone mass underlie this association. We carried out a prospective cohort study to examine the relationship between DXA measures in children 9.9 years of age and risk of fracture over the following 2 years. MATERIALS AND METHODS: Total body DXA scan results obtained at 9.9 years of age were linked to reported fractures over the following 2 years in children from a large birth cohort in southwest England. DXA measures consisted of total body less head (TBLH) BMD, bone area, and BMC, and results of subregional analysis of the humerus. Analyses were adjusted for age, sex, ethnicity, and social position. RESULTS: Complete data were available on 6213 children. There was a weak inverse relationship between BMD at 9.9 years and subsequent fracture risk (OR per SD decrease = 1.12; 95% CI, 1.02-1.25). In analyses examining the relationship between fracture risk and volumetric BMD, fracture risk was inversely related to BMC adjusted for bone area, height, and weight (OR = 1.89; 95% CI, 1.18-3.04) and to estimated volumetric BMD of the humerus (OR = 1.29; 95% CI, 1.14-1.45). Fracture risk was unrelated to both TBLH and humeral bone area. However, in analyses of the relationship between fracture risk and bone size relative to body size, an inverse association was observed between fracture risk and TBLH area adjusted for height and weight (OR = 1.51; 95% CI, 1.17-1.95). CONCLUSIONS: Fracture risk in childhood is related to volumetric BMD, reflecting an influence of determinants of volumetric BMD such as cortical thickness on skeletal fragility. Although bone size per se was not related to fracture risk, we found that children who fracture tend to have a smaller skeleton relative to their overall body size.

Body Height↗
PubMed2005

Oscillatory motion induces change blindness.

Change blindness is the relative inability of normally sighted observers to detect large changes in scenes when the low-level signals associated with those changes are either masked or of extremely low magnitude. Change detection can be inhibited by saccadic eye movements, artificial saccades or blinks, and 'mud splashes'. We now show that change detection is also inhibited by whole image motion in the form of sinusoidal oscillations. The degree of disruption depends upon the frequency of oscillation, which at 3 Hz is equivalent to that produced by artificial blinks. Image motion causes the retinal image to be blurred and this is known to affect object recognition. However, our results are inconsistent with good change detection followed by a delay due to poor recognition of the changing object. Oscillatory motion can induce eye movements that potentially mask or inhibit the low-level signals related to changes in the scene, but we show that eye movements promote rather than inhibit change detection when the image is moving.

Adolescent↗
PubMed2004

Intravenous pamidronate treatment in children with moderate to severe osteogenesis imperfecta: assessment of indices of dual-energy X-ray absorptiometry and bone metabolic markers during the first year of therapy.

Bisphosphonates are now widely used to treat children with osteogenesis imperfecta (OI). However, there are few published data following the initial evolution of changes in bone mass with such treatment. The purpose of the present study was to assess indices of skeletal size and total and regional bone mass in children with OI during the first year of their pamidronate therapy. Twenty-six children [11 males, age median 10.6 (range 3.2-15.5) years] with type III (n=9) or type IV (n=17) OI received intravenous pamidronate 1.0 mg/kg/day on 3 consecutive days, 3-monthly over a 1-year period. Bone mass assessed by dual energy X-ray absorptiometry, serum alkaline phosphatase (ALP) and urine type I collagen N-terminal telopepetide (NTX) were measured at each cycle. Lumbar (L2 to L4) vertebral height increased by median (interquartile range) 4.5% (7.3), area by 11.3% (19.3), bone mineral content (BMC) by 73.7% (50.4), and bone mineral density (BMD) by 48.7% (34.7), P<0.0001 during the first year of therapy. Total body bone area increased by 26.7% (26.3), total body BMC by 41.4% (44.5), and total body BMD by 8.8% (8.3), P<0.0001. Head bone area remained constant whilst head BMC and BMD increased. Pre-infusion U-NTX and S-ALP levels decreased progressively during the follow-up indicating reducing bone turnover rate during pamidronate therapy. Increased bone area and mineral mass were observed during the first year of intravenous pamidronate therapy in children with OI. Increased head bone mass implies a direct effect of pamidronate on skeletal mass accretion, rather than an indirect effect mediated through increased physical activity.

Absorptiometry, Photon↗