Osteoarthritis prevalence in retired national football league players with a history of ankle injuries and surgery

Context: Ankle injuries are common at all levels of American football, and retired National Football League (NFL) players have a high prevalence of osteoarthritis (OA), but little is known about how ankle injuries influence OA prevalence and daily activities in this population or how surgical interventions for such injuries alter the risk of OA. Objective: To examine (1) the association of ankle-injury history with OA prevalence, (2) the association of surgical intervention after ankle injury with OA prevalence, and (3) the relationships among ankle injuries, reported OA, and daily activities in retired NFL players. Design: Case-control study. Setting: Survey. Patients or Other Participants: Data from the Retired NFL Players General Health Survey. Main Outcome Measure(s): We created a 7-category main exposure variable that differentiated respondents by football-related ankle injury and surgical intervention. Multivariable binomial regression models were used to estimate prevalence ratios and 95% confidence intervals. Among those reporting OA, we examined the distribution of responses regarding whether OA affected daily activities. Results: Among the 2446 respondents, 920 participants experienced OA in any joint during their lifetime. Compared with those reporting no ankle injuries, the prevalence of OA was higher among those with a history of ankle injury. Also, the prevalence of OA was higher among those who had undergone surgery versus those who had not. The number of retired NFL players who reported that OA often affected their daily activities increased with the number of ankle injuries. Conclusions: Among former NFL players, a history of ankle injury increased the prevalence of OA. More ankle injuries increased the probability that OA negatively affected daily activities. Future prospective research is needed to better determine the influence of surgical intervention at the ankle or foot on OA

Talar and Subtalar T1ρ Relaxation Times in Limbs with and without Chronic Ankle Instability

Objective: The primary aim was to determine differences in talocrural and subtalar joint (STJ) articular cartilage composition, using T1ρ magnetic resonance imaging (MRI) relaxation times, between limbs in individuals with unilateral chronic ankle instability (CAI) and compare with an uninjured control. Our secondary purpose was to determine the association between talocrural and STJ composition in limbs with and without CAI. Design: T1ρ MRI relaxation times were collected on 15 CAI (11 females, 21.13 ± 1.81 years, body mass index [BMI] = 23.96 ± 2.74 kg/m2) and 15 uninjured control individuals (11 females, 21.07 ± 2.55 years, BMI = 24.59 ± 3.44 kg/m2). Talocrural cartilage was segmented manually to identify the overall talar dome. The SJT cartilage was segmented manually to identify the anterior, medial, and posterior regions of interest consistent with STJ anatomical articulations. For each segmented area, a T1ρ relaxation time mean and variability value was calculated. Greater T1ρ relaxation times were interpreted as decreased proteoglycan content. Results: Individuals with CAI demonstrated a higher involved limb talocrural T1ρ mean and variability relative to their contralateral limb (P 0.05), talocrural and posterior STJ composition measures were positively associated. Conclusions: Individuals with CAI have lower proteoglycan content in both the talocrural and posterior STJ in their involved limbs relative to the contralateral and a healthy control limb. Cartilage composition findings may be consistent with the early development of posttraumatic osteoarthritis

Role of vortices in magnetization reversal of rectangular NiFe elements

Vortices are seen in the magnetization distributions of rectangular magnetic elements in both experiments and micromagnetic simulations, To investigate the role of vortices during magnetization reversal Ni80Fe20 elements 100 nm and 200 nm wide and 5-60 nm thick were fabricated by electron beam lithography and studied by high-resolution magnetic imaging in the transmission electron microscope. During reversal, vortices appeared near the ends of the elements, grew under an increasing reverse field, and disappeared after rapid switching. Maximum switching fields of 400 Oe for 100 nm wide elements and 200 Oe for 200 nm wide elements occurred for film thicknesses of 25-30 nm and above. Simulations showed that reversal in these elements always occurred by means of vortices, however the simulated switching fields were much higher than the experimentally observed values. Lower switching fields were obtained in the simulations when vortex creation was assisted by 'defects' at the edges of the elements. However, to successfully simulate the magnitude and thickness dependence of the switching fields, it was necessary to start from an initial magnetic state which already contained a vortex

Hemograma de bovinos (Bos indicus) sadios da raça nelore no primeiro mês de vida, criados no estado de São Paulo Hemogram of healthy nelore breed (Bos indicus) calf at the first month of life, raised in São Paulo state, Brazil

Avaliou-se as mudanças nos constituintes do hemograma de bovinos da raça Nelore, 71 machos e 56 fêmeas, no primeiro mês de vida, criados no Estado de São Paulo. Foram utilizadas 127 amostras de sangue de bezerros criados a pasto, divididos em cinco grupos: de 0-3, 3-7, 7-14 , 14-21 e 21-30 dias de idade. Os valores médios encontrados foram: número de hemácias 8,31 &plusmn; l,84 x 10(6)/ mi l; Volume globular 39 &plusmn; 6%; taxa de hemoglobina 12,89 &plusmn; 2,04g/dl; Volume Corpuscular Médio 48,19 &plusmn; 5,68fl; Concentração de Hemoglobina Corpuscular Média 32,81 &plusmn; 1,84; reticulócitos 0,27 &plusmn; 0,54% e eritroblastos 214 &plusmn; 594/mil; número de leucócitos/mil 10593 &plusmn; 3008, neutrófilos bastonetes 97 &plusmn; 165; neutrófilos segmentados 4837 &plusmn; 2201; linfócitos 5222 &plusmn; 1909; eosinófilos 86 &plusmn; 139; monócitos 346 &plusmn; 221; basófilos 4 &plusmn; 24. Os fatores sexuais não apresentaram influência significativa sobre o hemograma, com exceção dos reticulócitos e eritroblastos. Os fatores etários apresentaram influência significativa (p&le;0,03) sobre as curvas de regressão do hemograma, com o volume globular, hemácias e hemoglobina diminuindo e o CHCM e reticulócitos aumentando até os 3 a 7 dias, havendo uma inversão desta variação dos sete até os 30 dias. A curva de regressão do percentual de linfócitos aumentou e de neutrófilos diminuiu gradativamente após o nascimento. O encontro destas curvas ocorreu entre o sétimo e o décimo quarto dia de vida.<br>Changes on the hemogram parameters were evaluated for healthy Nelore purebreed bovines at the first month age, with 71 male and 56 female, and raised in São Paulo State, Brazil. For this purpose, 127 samples of blood were collected, and divided in five groups ; 0-3 , 3-7 . 7-14 , 14-21 and 21-30 days of age. The mean values were: erithrocyte counts 8.31&plusmn; 1.84 x 10(6)/ mu l; Package Cell Volume 39 &plusmn; 6%: hemoglobin 12.89 &plusmn; 2.04g/dl; Mean Corpuscular Volume 48.19 &plusmn; 5.68fl; Mean Corpuscular Hemoglobin Concentration 32.81 &plusmn; 1.84 ; Reticulocytes 0.27 &plusmn; 0.54%; erythroblast 214 &plusmn; 594/mul; leukocytes (mu l): 10593 &plusmn; 3008; band neutrophils 97 &plusmn; 165; segmented neutrophils 4837 &plusmn; 2201; lymphocytes 5222 &plusmn; 1909; eosinophils 86 &plusmn; 139: monocytes 346 &plusmn; 221; basophils 3 &plusmn; 24. Sex had no influencing the hemogram values except to reticulocytes and erythroblast that were higher in females. Age significantly influenced the leucogram and eritrogram values (p&le;0.0 3). The Package Cell Volume, erythrocytes, and hemoglobin decreasing and the Mean Corpuscular Hemoglobin Concentration and reticulocytes increasing until the thirth to seventh days. There was an subsequent inversion of this variation in this period until the thirtieth day. The lymphocyte percentage regression curve increasing and neutrophils decreasing after birth. The intersection between the two leukocytes curves occurred between the seventh and the fourteenth day of life