Cross-sectional associations between adipose tissue depots and areal bone mineral density in the UK Biobank imaging study.

The relationship between obesity and osteoporosis is poorly understood. In this study, we assessed the association between adiposity and bone. The fat-bone relationship was dependent on sex, body mass index classification, and menopausal status. Results highlight the importance of accounting for direct measures of adiposity (beyond BMI) and menopause status. INTRODUCTION: Assess the relationship between direct measures of adiposity (total body fat mass, visceral adipose tissue, and abdominal subcutaneous adipose tissue) with the whole body and clinically relevant bone sites of the lumbar spine, and femoral neck areal bone mineral density (aBMD) in men and women. METHODS: This cross-sectional analysis was conducted utilizing de-identified data from the UK Biobank on participants (n = 3674) with available dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) data. Sex-stratified multiple linear regression was used to assess the relationship between adiposity measures and aBMD outcomes, controlling for age, race, total body lean mass (DXA), height, BMI class, physical activity, smoking, menopausal status (women), and hormone use (women). RESULTS: In men, significant interactions were observed between measures of adiposity and BMI on aBMD for the whole body and lumbar spine. Interactions indicated a positive relationship between adiposity and aBMD in men classified as normal weight, but an inverse relationship in men with elevated BMI. In women, significant interactions between adiposity measures and menopausal status were observed primarily for the whole body and femoral neck aBMD bone outcomes which indicated a negative relationship between adiposity and aBMD in premenopausal women, but a positive relationship in postmenopausal women. CONCLUSION: Total body adiposity, abdominal subcutaneous adipose tissue, and visceral adipose tissue were all significantly associated with aBMD in both men and women. The strength and direction of association were dependent on sex, BMI classification, and menopausal status (women).

Association of objectively measured physical activity and bone health in children and adolescents: a systematic review and narrative synthesis.

The influence of day-to-day physical activity on bone in adolescence has not been well characterized. Forty articles were identified that assessed the relationship between accelerometry-derived physical activity and bone outcomes in adolescents. Physical activity was positively associated with bone strength in peri-pubertal males, with less consistent evidence in females. Physical activity (PA) is recommended to optimize bone development in childhood and adolescence; however, the influence of day-to-day PA on bone development is not well defined. The aim of this review was to describe the current evidence for objectively measured PA on bone outcomes in healthy children and adolescents. MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, CINAHL, PsycInfo, and ClinicalTrials.gov were searched for relevant articles up to April 2020. Studies assessing the relationship between accelerometry-derived PA and bone outcomes in adolescents (6-18 years old) were included. Two reviewers independently screened studies for eligibility, extracted data, and rated study quality. Forty articles met inclusion criteria (25 cross-sectional, 15 longitudinal). There was significant heterogeneity in accelerometry methodology and bone outcomes measured. Studies in males indicated a significant, positive relationship between moderate to vigorous PA (MVPA) and bone outcomes at the hip and femur, particularly during the peri-pubertal years. The results for MVPA and bone outcomes in females were mixed. There was a paucity of longitudinal studies using pQCT and a lack of data regarding how light PA and/or impact activity influences bone outcomes. The current evidence suggests that objectively measured MVPA is positively associated with bone outcomes in children and adolescents, especially in males. However, inconsistencies in methodology make it difficult to determine the amount and type of PA that leads to favorable bone outcomes. Given that the majority of research has been conducted in Caucasian adolescents, further research is needed in minority populations.

Physical activity, sedentary time, and longitudinal bone strength in adolescent girls.

The association between baseline physical activity and sedentary time with 2-year longitudinal bone strength was evaluated. The effect of physical activity on bone depended on maturity status. Sedentary time did not negatively impact bone outcomes, regardless of maturity. Maturity should be considered when developing exercise interventions to improve bone outcomes. INTRODUCTION: Physical activity during adolescence is important to obtain peak bone mass; however, adolescents are increasingly sedentary, potentially increasing risk for osteoporosis later in life. The aim of this study was to assess the association of physical activity and sedentary time with 2-year longitudinal bone outcomes in adolescent females (69% Hispanic/31% non-Hispanic). METHODS: Bone strength was assessed at the 66% tibia, 20% femur, and 66% radius of 9- to 12-year-old girls (n = 131) using peripheral quantitative computed tomography at baseline and 2-year follow-up. Physical activity and sedentary time were assessed via accelerometry. Linear regression analyses were used to assess whether baseline vigorous physical activity (VPA), moderate physical activity (MPA), light physical activity (LPA), or sedentary time predict longitudinal bone outcomes, adjusting for relevant confounders. RESULTS: Significant interactions were found between maturity offset and physical activity. In weight-bearing bones, significant interactions were primarily identified between VPA and maturity offset. Interactions indicated that VPA was associated with favorable bone outcomes at the tibia and femur in girls further past the age of PHV. However, this favorable effect was not observed in girls closer to the age of PHV. At the radius, interactions were primarily observed between LPA and maturity offset. Again, LPA was more beneficial for girls further past the age of PHV. Sedentary time did not significantly influence bone outcomes. CONCLUSION: The effects of physical activity on bone may be dependent on maturity. Therefore, physical activity interventions, with attention to maturity status, may be required to optimize bone strength in girls.

Clinical and pathological responses of weaned pigs to atmospheric ammonia and dust.

Nine hundred and sixty weaned pigs were exposed for five weeks to controlled concentrations of atmospheric ammonia and dust in a single, multifactorial experiment. The treatments were a mean dust concentration of either 1.2, 2.7, 5.1 or 9.9 mg/m3 (inhalable fraction) and a mean ammonia concentration of either 0.6, 10.0, 18.8 or 37.0 ppm, concentrations representative of commercial conditions. The experiment was carried out over two years and the pigs were used in eight batches, each consisting of five lots of 24 pigs. Each treatment combination was replicated once, and an additional control lot (nominally 0 mg/m3 dust and 0 ppm ammonia) was included in each batch. The dust concentration was the same in the other four lots in each batch in which the four concentrations of ammonia were used; thus, the split-plot design was more sensitive to the effects of ammonia than dust. The groups of pigs were kept separately in five rooms in a purpose-built facility, and the pollutants were injected continuously into the air supply. Ammonia was supplied from a pressurised cylinder, and the endogenous dust in each room was supplemented by an artificial dust manufactured from feed, barley straw and faeces, mixed by weight in the proportions 5:1:4; its ingredients were oven-dried, milled and mixed, and then resuspended in the air supply. The health of the pigs was assessed in terms of general pathology, respiratory tract pathology, and the microbiology of the nasal cavity, trachea and lung. In each batch, postmortem examinations were carried out on 40 pigs after five weeks' exposure to the pollutants and on 30 pigs two weeks later to test for carryover and recovery--a total of 560 pigs. These examinations revealed minimal gross pathology and widespread minor pathological changes of little significance. The pigs' turbinate and lung scores were low and unaffected by exposure to pollutants. All the putative bacterial pathogens, with the exception of toxigenic Pasteurella multocida type D, were isolated from the respiratory tract of the pigs of both ages, but there were no differences between the effects of the different concentrations of pollutants.

[Granulocyte sarcoma of the pancreas without extra-pancreatic location]. / Sarcome granulocytaire du pancréas sans autre localisation extra-pancréatique.

INTRODUCTION: Granulocyte sarcoma (GS), also known as chloroma, is a localized malignant tumor composed of myeloid cells, the diagnosis of which is difficult. The pancreatic location and recurrence, aside from any context of malignant hemopathy, are exceptional. OBSERVATION: A 31-year-old woman developed an isolated and recurrent granulocyte sarcoma of the pancreas, without any context of a malignant hemopathy. The diagnosis retained on extemporaneous examination was an adenocarcinoma of the pancreas, because of the non-specific necrotic nature of the tumor. The immuno-histochemical exploration corrected the diagnosis. Despite local surgery, an isolated tumor recurred 6 months later. This relapse was treated with radiotherapy followed by heavy chemotherapy, identical to that applied in acute myeloblastic leukemia (AML). Ten months later, remission was stable and complete. COMMENTS: Isolated granulocyte sarcomas located in the pancreas are exceptional and have often led to initial erroneous diagnosis. Immuno-histochemical methods are essential in order to obtain correct diagnosis. Despite the localized nature of the tumor, intensive AML-type chemotherapy is necessary.

The influence of gestation feeding strategy on body composition of gilts at farrowing and response to dietary protein in a modified lactation.

Previous experiments have indicated that reproductive function in lean, modern genotypes may be more dependent on body protein mass than, as previously believed, on body lipid reserves. This was investigated in a 3 x 2 factorial arrangement of treatments, involving 60 first-parity sows, comparing three pregnancy feeding strategies and two lactation diets. During pregnancy, sows were fed either a basal diet (5 g lysine/kg, 13 MJ of DE/kg [C]) or the same quantity of basal diet + energy source [E], or additional basal diet supplying both protein and energy [A]. The level of supplement for E and A was adjusted weekly to achieve a backfat thickness measurement (P2 position) of 28 mm at farrowing. Isoenergetic lactation diets were fed to appetite and provided either high (180 g CP/kg, 9 g lysine/kg [H]) or low lysine (120 g CP/kg, 6 g lysine/kg [L]). From d 21 of lactation, sows were separated from their litters and housed next to a boar for 8 h each day; final weaning occurred on d 31. Pregnancy treatment differences in backfat and weight were achieved, with C sows having less backfat on d 1 of lactation than E and A sows (E = 28.1, A = 28.0, C = 22.7 kg, P < 0.001). Sows fed additional basal diet were heavier than E sows, which were heavier than C sows (E = 190, A = 201, C = 178 kg, P < 0.001). Average feed intake over lactation showed a pregnancy feeding effect, with E sows eating less than A or C sows (E = 4.9, A = 5.2, C = 5.4 kg/d, P < 0.005). Total lactation weight loss was affected by pregnancy feeding (E = 18.0, A = 19.0, C = 8.4 kg, P < 0.05) and by lactation diet (L = 19.0, H = 11.3 kg, P < 0.05), whereas total lactation backfat loss was affected only by pregnancy treatment (E = 6.9, A = 6.5, C = 4.6 mm, P < 0.05). No pregnancy treatment or lactation diet effects were observed for litter performance. Lactation diet affected weaning-to-estrus interval, with more sows on the H diet coming into estrus within 6 d of partial weaning (P < 0.05), but there was no pregnancy treatment effect. Therefore, voluntary feed intake during lactation was suppressed by increased fat reserves at a limited body protein mass but not when body protein mass was also increased. Partial weaning-to-estrus interval was increased by reduced dietary protein.

[Formaldehyde fixation in the third millennium]. / La fixation formolée à l'aube du troisième millénaire.

This review deals with the general principles and problems of formaldehyde fixation. After a short description of 1) formaldehyde methods of production, 2) chemical properties of formaldehyde solution, and 3) kinetic of formaldehyde binding in tissue, formaldehyde reactivity with the tissue biopolymers, proteins and cucleic acids mainly, are described. How formaldehyde fixation of tissues adversely affects the reactivity of cellular proteins with their respective specific antibody and the ways the most commonly used retrieval techniques in immunohistochemistry act are, thereafter, discussed. Finally, concerns that need to be dealt with when formalin-fixed specimens are used for genomic analysis and studies of DNA expression are highlighted.

Oncocytoma of the eyelid: an aggressive benign tumor.

OBJECTIVE: The authors report the case of an 83-year-old patient with a benign oncocytoma of the inferior eyelid. DESIGN: INTERVENTIONal case report. INTERVENTION: Treatment consisted of a large orbital exenteration followed by reconstruction with a pedicled temporalis muscle flap. MAIN OUTCOME MEASURES: Histologic evaluation and clinical follow-up were measured. RESULTS: After a year of follow-up, there was no sign of local recurrence. CONCLUSIONS: Oncocytomas, even if benign, must be considered as very aggressive tumors and treated accordingly.