A multicentre study of the precision and accuracy of the TruSlice and TruSlice Digital histological dissection devices.

BACKGROUND: Five key factors enabling a good surgical grossing technique include a flat uniformly perpendicular specimen cutting face, appropriate immobilisation of the tissue specimen during grossing, good visualisation of the cutting tissue face, sharp cutting knives and the grossing knife action. TruSlice and TruSlice Digital are new innovative tools based on a guillotine configuration. The TruSlice has plastic inserts whilst the TruSlice Digital has an electronic micrometre attached: both features enable these dissection factors to be controlled. The devices were assessed in five hospitals in the UK. MATERIAL AND METHODS: A total of 267 fixed tissue samples from 23 tissue types were analysed, principally the breast (n = 32) skin (30), rectum (28), colon (27) and cervix (17). Precision and accuracy were evaluated by measuring the defined thickness, and the consistency of achieving the defined thickness of tissue samples taken respectively. Both parameters were expressed as a total percentage of compliance for the cohort of samples accessed. RESULTS: Overall, the mean (standard deviation) score for precision was 81 (11) % whilst the accuracy score was 82 (11) % (both p < 0.05, chi-squared test), although this varied with type of tissue. Accuracy and precision were strongly correlated (rp = 0.83, p < 0.001). CONCLUSION: The TruSlice Digital devices offer an assured precision and accuracy performance which is reproducible across an assortment of tissue types. The use of a micrometre to set tissue slice thickness is innovative and should comply with laboratory accreditation requirements, alleviating concerns of how to tackle issues such as the 'measurement of uncertainty' at the grossing bench.

Physical activity, calcium intake and childhood bone mineral: a population-based cross-sectional study.

UNLABELLED: In a free-living cohort of 4-year old children, mean daily time in moderate-vigorous physical activity and daily calcium intake at 3 years, were positively related to hip bone size and density. Relationships between physical activity and bone indices were stronger when calcium intake was above compared with below median (966 mg/day). INTRODUCTION: We examined the cross-sectional relationships between childhood physical activity, dietary calcium intake and bone size and density. METHODS: Children aged 4 years were recruited from the Southampton Women's Survey. They underwent measurement of bone mass by DXA (Hologic Discovery). Physical activity was assessed by accelerometry (Actiheart, Cambridge Neurotechnology Ltd, Cambridge, UK) for seven continuous days. RESULTS: Four hundred twenty-two children (212 boys) participated. In a cross-sectional analysis, after adjusting for gender, daily mean time(minutes per day) spent in moderate to very vigorous activity (MVPA) was positively related to hip BA (R(2) = 3%, p < 0.001), BMC (R(2) = 4%, p < 0.001), aBMD (R (2) = 3%, p = 0.001) and estimated vBMD (R(2) = 2%, p = 0.01), but not height (r (s) = 0.04, p = 0.42) or weight (r(s) = 0.01, p = 0.76). Mean daily calcium intake (assessed at 3 years old) positively predicted bone indices in those with a calcium intake below the median (966 mg/day), but there was a much attenuated relationship in those above this. These associations persisted after inclusion of total energy, protein and phosphorus in multivariate models. The relationships between MVPA and bone indices were stronger in children with calcium intakes above the median. Thus, for aBMD, the variance explained by MVPA when daily calcium intake was below the median was 2% (p = 0.1) and above median was 6% (p = 0.001). CONCLUSIONS: These results support the notion that adequate calcium intake may be required for optimal action of physical activity on bone development and that improving levels of physical activity and calcium intake in childhood may help to optimise accrual of bone mass.

Increased fat mass is associated with increased bone size but reduced volumetric density in pre pubertal children.

Recent studies have shown that obesity is associated with an increased risk of fracture in both adults and children. It has been suggested that, despite greater bone size, obese individuals may have reduced true volumetric density; however this is difficult to assess using two dimensional techniques such as DXA. We evaluated the relationship between fat mass, and bone size and density, in a population cohort of children in whom DXA and pQCT measurements had been acquired. We recruited 530 children at 6 years old from the Southampton Women's Survey. The children underwent measurement of bone mass at the whole body, lumbar spine and hip, together with body composition, by DXA (Hologic Discovery, Hologic Inc., Bedford, MA, USA). In addition 132 of these children underwent pQCT measurements at the tibia (Stratec XCT2000, Stratec Biomedical Systems, Birkenfeld, Germany). Significant positive associations were observed between total fat mass and both bone area (BA) and bone mineral content (BMC) at the whole body minus head, lumbar spine and hip sites (all p<0.0001). When true volumetric density was assessed using pQCT data from the tibia, fat mass (adjusted for lean mass) was negatively associated with both trabecular and cortical density (ß=-14.6 mg/mm(3) per sd, p=0.003; ß=-7.7 mg/mm(3) per sd, p=0.02 respectively). These results suggest that fat mass is negatively associated with volumetric bone density at 6 years old, independent of lean mass, despite positive associations with bone size.

Secular trends in the incidence of hip and other osteoporotic fractures.

Osteoporosis constitutes a major public health problem through its association with age-related fractures, most notably those of the proximal femur. Substantial geographic variation has been noted in the incidence of hip fracture throughout the world, and estimates of recent incidence trends have varied widely. Studies in the published literature have reported an increase, plateau, and decrease in age-adjusted incidence rates for hip fracture among both men and women. Accurate characterisation of these temporal trends is important in predicting the health care burden attributable to hip fracture in future decades. We therefore conducted a review of studies worldwide, addressing secular trends in the incidence of hip and other fractures. Studies in western populations, whether in North America, Europe or Oceania, have generally reported increases in hip fracture incidence through the second half of the last century, but those continuing to follow trends over the last two decades have found that rates stabilise with age-adjusted decreases being observed in certain centres. In contrast, some studies suggest that the rate is rising in Asia. This synthesis of temporal trends in the published literature will provide an important resource for preventing fractures. Understanding the reasons for the recent declines in rates of hip fracture may help understand ways to reduce rates of hip fracture worldwide.

Early development and osteoporosis and bone health.

Osteoporosis is a skeletal disorder characterized by low bone mass and micro-architectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fracture. Evidence is now accumulating from human studies that programming of bone growth might be an important contributor to the later risk of osteoporotic fracture. Body weight in infancy is a determinant of adult bone mineral content, as well as of the basal levels of activity of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) and hypothalamo-pituitary-adrenal (HPA) axes, and recent work has suggested a central role for vitamin D. Epidemiological studies have shown that maternal smoking and nutrition during pregnancy influence intrauterine skeletal mineralization. Childhood growth rates have been directly linked to the risk of hip fracture many decades later, and now evidence is emerging from experimental animal studies that support these observational data. Recent studies have also highlighted epigenetic phenomena as potential mechanisms underlying the findings from epidemiological studies.

Inhibition by glucocorticoids of the mast cell-dependent weal and flare response in human skin in vivo.

1. This study examines the relative contributions made by inhibition of mast cell degranulation, reduction of mast cell recruitment and maturation, and lowering the responsiveness of the vasculature to histamine, in the inhibition by glucocorticoids of the weal and flare in human skin. 2. One forearm of healthy human volunteers was treated for 24 h (n=6) or daily for 21 days (n=10) with 0.05% clobetasol propionate. The other arm served as control. Weal and flare responses were elicited by intradermal injection of 20 microl of 0.3 mM codeine. The areas of the responses were measured using scanning laser Doppler imaging. Microdialysis was used to assess histamine release. Mast cell numbers and tissue histamine content were assessed in 4-mm punch biopsies. Histamine (20 microl of 1 microM i.d.) was used to assess the status of the vasculature. 3. No significant effects were seen at 24 h. At 21 days, clobetasol reduced the areas of the codeine-induced weal and flare responses by 59 and 58% respectively (both P=0.006). Mast cell numbers were reduced by 47%, (P=0.014) and total tissue histamine content by 52% (P=0.006). Codeine-induced histamine release was reduced by 44% (P=0.022). The weal, but not the flare, induced by histamine was significantly inhibited (P=0.019). Echography revealed a 15% thinning of the skin by clobetasol. 4. These results demonstrate that reduction of the weal and flare responses to codeine following clobetasol treatment, results primarily from reduced mast cell numbers and tissue histamine content rather than inhibition by corticosteroids of mast cell degranulation.