Hip strength: Ankle proprioceptive threshold ratio predicts falls and injury in diabetic neuropathy

Introduction : We determined lower limb neuromuscular capacities associated with falls and fall‐related injuries in older people with declining peripheral nerve function. Methods : Thirty‐two subjects (67.4 ± 13.4 years; 19 with type 2 diabetes), representing a spectrum of peripheral neurologic function, were evaluated with frontal plane proprioceptive thresholds at the ankle, frontal plane motor function at the ankle and hip, and prospective follow‐up for 1 year. Results : Falls and fall‐related injuries were reported by 20 (62.5%) and 14 (43.8%) subjects, respectively. The ratio of hip adductor rate of torque development to ankle proprioceptive threshold (Hip STR /Ank PRO ) predicted falls (pseudo‐R 2  = .726) and injury (pseudo‐R 2  = .382). No other variable maintained significance in the presence of Hip STR /Ank PRO . Conclusions : Fall and injury risk in the population studied is related inversely to Hip STR /Ank PRO . Increasing rapidly available hip strength in patients with neuropathic ankle sensory impairment may decrease risk of falls and related injuries. Muscle Nerve 50 : 437–442, 2014Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108329/1/mus24134.pd

Topologically Linked Crystals

We discovered a new class of topological crystals, namely linked rings of crystals. Two rings of tantalum triselenide (TaSe3) single crystals were linked to each other while crystal growing. The topology of the crystal form is called a "Hopf link", which is the simplest link involving just two component unknots linked together exactly once. The feature of the crystals is not covered by the conventional crystallography.Comment: 6 pages, 3 figures, to appear in J. Crystal Growt

The relationship between mitochondrial function and walking performance in older adults with a wide range of physical function.

Age related declines in walking performance may be partly attributable to skeletal muscle mitochondrial dysfunction as mitochondria produce over 90% of ATP needed for movement and the capacity for oxidative phosphorylation decreases with age. Participants were from two studies: an ancillary to the Lifestyle Interventions and Independence for Elders (LIFE) Study (n=33), which recruited lower functioning participants (Short Physical Performance Battery [SPPB], 7.8±1.2), and the Study of Energy and Aging-Pilot (SEA, n=29), which enrolled higher functioning (SPPB, 10.8±1.4). Physical activity was measured objectively using the Actigraph accelerometer (LIFE) and SenseWear Pro armband (SEA). Phosphocreatine recovery following muscle contraction of the quadriceps was measured using (31)P magnetic resonance spectroscopy and ATPmax (mM ATP/s) was calculated. Walking performance was defined as time (s) to walk 400m at a usual-pace. The cross-sectional association between mitochondrial function and walking performance was assessed using multivariable linear regression. Participants were 77.6±5.3years, 64.2% female and 67.2% white. ATPmax was similar in LIFE vs. SEA (0.52±0.14 vs. 0.55±0.14, p=0.31), despite different function and activity levels (1.6±2.2 vs.77.4±73.3min of moderate activity/day, p<0.01). Higher ATPmax was related to faster walk-time in SEA (r(2)=0.19, p=0.02,); but not the LIFE (r(2)<0.01, p=0.74) cohort. Mitochondrial function was associated with walking performance in higher functioning, active older adults, but not lower functioning, sedentary older adults

Stable Incretin Mimetics Counter Rapid Deterioration of Bone Quality in Type 1 Diabetes Mellitus.

AIMS: Type 1 diabetes mellitus is associated with a high risk for bone fractures. Although bone mass is reduced, bone quality is also dramatically altered in this disorder. However, recent evidences suggest a beneficial effect of the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) pathways on bone quality. The aims of the present study were to conduct a comprehensive investigation of bone strength at the organ and tissue level; and to ascertain whether enzyme resistant GIP or GLP-1 mimetic could be beneficial in preventing bone fragility in type 1 diabetes mellitus. MATERIALS AND METHODS: Streptozotocin-treated mice were used as a model of type 1 diabetes mellitus. Control and streptozotocin-diabetic animals were treated for 21 days with an enzymatic-resistant GIP peptide ([D-Ala2]GIP) or with liraglutide (each at 25 nmol/kg bw, ip). Bone quality was assessed at the organ and tissue level by microCT, qXRI, 3-point bending, qBEI, nanoindentation and Fourier-transform infrared microspectroscopy. RESULTS: [D-Ala2]GIP and liraglutide treatment did prevent loss of whole bone strength and cortical microstructure in the STZ-injected mice. However, tissue material properties were significantly improved in STZ-injected animals following treatment with [D-Ala(2) ]GIP or liraglutide. CONCLUSIONS: Treatment of STZ-diabetic mice with [D-Ala2]GIP or liraglutide was capable of significantly preventing deterioration of the quality of the bone matrix. Further studies are required to further elucidate the molecular mechanisms involved and to validate whether these findings can be translated to human patients. This article is protected by copyright. All rights reserved

Epidemiology of muay thai fight-related injuries

Combat sports are generally considered more dangerous and risky compared to other athletic activities, as scoring is inextricably linked to inflicting damage on an opponent. This fundamentally unique intent, to injure an adversary in a contest is replete with injury risks from physical exposures. One combat sport increasingly popular among US youth, known as Muay Thai, yields scant epidemiologic study on fighter injuries. To develop a surveillance system to provide magnitude and scope of injury outcomes in order to frame the public health significance. Three surveillance approaches were utilized to identify eligible participants to complete a web survey regarding Muay Thai fight-related injuries. The target population yielded a convenience sample of 195 fighters participating in sanctioned fights across North America and the UK. Regression analyses were conducted to determine whether the injury outcome was related to additional factors such as experience, protection and pre-existing injury. Depending on the approach, contact rates ranged from 83.3-100%; cooperation rates ranging from 44-80%; response rates ranged from 30-60% and 20-55%. Fighters were aged 18 to 47 years old (median 26); predominantly male (85.9%); and white (72.3%). Respondents were professional (n=96, 49.2%) and amateur (n=99, 50.8%) Fighters reported a range of fight experience from 1-111 total fights, with a mean of 15.83. Of the 195 respondents, 108 (55.4%) reported sustaining an injury during the fight. The primary body region that was injured were the extremities (58%). The primary cause or mechanism of the fight injuries was due to being “struck by” the opponent in more than 2/3 of the incidents. Nearly 2/3 (66.7%) of all injured fighters reported that the injury did not interfere with the completion of the fight and was not a factor in the bout outcome (i.e., win, loss, draw). Nearly 25% reported they missed no training time as a result of the injury incurred during the fight. Subsequent regression models yielded several individual level variables of interest relative to the injury outcome. These included fighter status, weight, age, equipment and previous injury. The majority of the injuries incurred by fighters were mild in severity to the extremities, as a result of being struck by or striking the opponent. Lighter, younger, and more experienced fighters were at increased odds for injury within this sample

Allosterische Metallkomplex-Katalysatoren : Synthesen, Strukturen und reaktionskinetische Untersuchungen

Die allosterische Regulation der katalytischen Aktivität ist ein in der Enzymkatalyse weit verbreitetes Phänomen, wurde aber bei synthetischen Katalysatoren bisher nicht untersucht. Im Rahmen der Arbeitmehrkernige Metallkomplexe als Modellsysteme für allosterische Metalloenzyme untersucht. Die Katalysatoren sind durch eine dinukleare, katalytische Untereinheit und eine allosterische Untereinheit mit strukturellem Metallion (MS=M(II)) charakterisiert. Von den isolierten Komplexen, darunter 4 mononukleare ((L2-2H)Ms, Ms=Cu(1), Ni (3) und Pd (4)) und (L3-2H)Cu (2), wurden 3 (1,5,6) kristallographisch charakterisiert, wodurch Einblicke in die strukturelle Rolle von MS erhalten wurden. 5 (dachförmig) und 6 (helical), welche die trinuklearen Einheiten mit verbrückenden Anionen (Oxalat, Glycinhydroxamat) enthalten, konnten ein Gefühl für den zugänglichen Konformationsraum der (L2-2H)Cu3-Untereinheiten vermitteln. Reaktionskinetische Untersuchungen zur katalytischen Spaltung RNA-Analogons 2-Hydroxypropyl-p-nitrophenylphosphat (HPNP) zeigten, daß das allosterische Metallion in den Komplexen (L2-2H)MSCu2 starken Einfluß auf die Aktivität hat. Mit MS=Cu ist die Aktivität doppelt so hoch wie mit MS=Pd. Auch die Struktur und Flexibilität des Liganden bestimmt die Aktivität: Der etwas flexiblere Komplex (L2-2H)Cu3 katalysiert die Spaltung des koordinierten HPNP 2.3 mal schneller als (L3-2H)Cu3, während dieser das Substrat besser bindet. Die kompetitive Hemmung dieser Reaktion durch verbrückend koordinierende Anionen ist besonders effizient bei Oxoanionen mit einem O...O-Abstand ("Bißweite") von 2.5 - 2.8 A, der etwa dem des Oxalats in 5 entspricht. (L2-2H)Cu3 wird durch größere Anionen wie ReO4-, (L3-2H)Cu3 dagegen durch kleinere stärker gehemmt. Hieraus wird die Hypothese abgeleitet, daß (L2-2H)Cu3 den sterisch anspruchsvollen Übergangszustand der Spaltreaktion besser stabilisiert, weil Konformationen mit größerem Abstand der funktionellen Cu2+-Ionen, bedingt durch die Rückgrat-Flexibilität von L2, besser zugänglich und damit energiegünstiger sind als in (L3-2H)Cu3

Subclinical Thyroid Dysfunction and Fracture Risk: A Meta-analysis

IMPORTANCE Associations between subclinical thyroid dysfunction and fractures are unclear and clinical trials are lacking. OBJECTIVE To assess the association of subclinical thyroid dysfunction with hip, nonspine, spine, or any fractures. DATA SOURCES AND STUDY SELECTION The databases of MEDLINE and EMBASE (inception to March 26, 2015) were searched without language restrictions for prospective cohort studies with thyroid function data and subsequent fractures. DATA EXTRACTION Individual participant data were obtained from 13 prospective cohorts in the United States, Europe, Australia, and Japan. Levels of thyroid function were defined as euthyroidism (thyroid-stimulating hormone [TSH], 0.45-4.49 mIU/L), subclinical hyperthyroidism (TSH <0.45 mIU/L), and subclinical hypothyroidism (TSH ≥4.50-19.99 mIU/L) with normal thyroxine concentrations. MAIN OUTCOME AND MEASURES The primary outcome was hip fracture. Any fractures, nonspine fractures, and clinical spine fractures were secondary outcomes. RESULTS Among 70,298 participants, 4092 (5.8%) had subclinical hypothyroidism and 2219 (3.2%) had subclinical hyperthyroidism. During 762,401 person-years of follow-up, hip fracture occurred in 2975 participants (4.6%; 12 studies), any fracture in 2528 participants (9.0%; 8 studies), nonspine fracture in 2018 participants (8.4%; 8 studies), and spine fracture in 296 participants (1.3%; 6 studies). In age- and sex-adjusted analyses, the hazard ratio (HR) for subclinical hyperthyroidism vs euthyroidism was 1.36 for hip fracture (95% CI, 1.13-1.64; 146 events in 2082 participants vs 2534 in 56,471); for any fracture, HR was 1.28 (95% CI, 1.06-1.53; 121 events in 888 participants vs 2203 in 25,901); for nonspine fracture, HR was 1.16 (95% CI, 0.95-1.41; 107 events in 946 participants vs 1745 in 21,722); and for spine fracture, HR was 1.51 (95% CI, 0.93-2.45; 17 events in 732 participants vs 255 in 20,328). Lower TSH was associated with higher fracture rates: for TSH of less than 0.10 mIU/L, HR was 1.61 for hip fracture (95% CI, 1.21-2.15; 47 events in 510 participants); for any fracture, HR was 1.98 (95% CI, 1.41-2.78; 44 events in 212 participants); for nonspine fracture, HR was 1.61 (95% CI, 0.96-2.71; 32 events in 185 participants); and for spine fracture, HR was 3.57 (95% CI, 1.88-6.78; 8 events in 162 participants). Risks were similar after adjustment for other fracture risk factors. Endogenous subclinical hyperthyroidism (excluding thyroid medication users) was associated with HRs of 1.52 (95% CI, 1.19-1.93) for hip fracture, 1.42 (95% CI, 1.16-1.74) for any fracture, and 1.74 (95% CI, 1.01-2.99) for spine fracture. No association was found between subclinical hypothyroidism and fracture risk. CONCLUSIONS AND RELEVANCE Subclinical hyperthyroidism was associated with an increased risk of hip and other fractures, particularly among those with TSH levels of less than 0.10 mIU/L and those with endogenous subclinical hyperthyroidism. Further study is needed to determine whether treating subclinical hyperthyroidism can prevent fractures

Bone Mass and Strength in Older Men With Type 2 Diabetes: The Osteoporotic Fractures in Men Study

The effects of type 2 diabetes mellitus (T2DM) on bone volumetric density, bone geometry, and estimates of bone strength are not well established. We used peripheral quantitative computed tomography (pQCT) to compare tibial and radial bone volumetric density (vBMD, mg/cm3), total (ToA, mm2) and cortical (CoA, mm2) bone area and estimates of bone compressive and bending strength in a subset (n = 1171) of men (≥65 years of age) who participated in the multisite Osteoporotic Fractures in Men (MrOS) study. Analysis of covariance–adjusted bone data for clinic site, age, and limb length (model 1) and further adjusted for body weight (model 2) were used to compare data between participants with (n = 190) and without (n = 981) T2DM. At both the distal tibia and radius, patients with T2DM had greater bone vBMD (+2% to +4%, model 1, p < .05) and a smaller bone area (ToA −1% to −4%, model 2, p < .05). The higher vBMD compensated for lower bone area, resulting in no differences in estimated compressive bone strength at the distal trabecular bone regions. At the mostly cortical bone midshaft sites of the radius and tibia, men with T2DM had lower ToA (−1% to −3%, p < .05), resulting in lower bone bending strength at both sites after adjusting for body weight (−2% to −5%, p < .05) despite the lack of difference in cortical vBMD at these sites. These data demonstrate that older men with T2DM have bone strength that is low relative to body weight at the cortical-rich midshaft of the radius despite no difference in cortical vBMD. © 2010 American Society for Bone and Mineral Researc

Development and validation of a test instrument for the assessment of perceived basic motor competencies in first and second graders: the SEMOK-1-2 instrument

Both actual motor competencies (AMC) and perceived motor competencies (PMC) play an important role in motor development research and children's physical and psychological development. PMC refer to children's perceptions of their motor competencies. To assess the PMC of first and second grade children (aged 6–9 years), the SEMOK-1-2 instrument was developed. The instrument is aligned to the validated MOBAK-1-2 instrument which assesses AMC in the competence areas “object movement” and “self-movement” Accounting for possible reading difficulties in younger children, the motor tasks and answer options were illustrated and explained verbally. The purpose of this study was to test and validate the SEMOK-1-2 instrument and investigate the associations between the constructs AMC, PMC and physical activity (PA), whereby PA was measured by the participation in team and individual sports. Data from N = 404 pupils in the German-speaking part of Switzerland from first and second grades (M = 7.8 years, SD = 0.69, 49% boys) were analyzed. Confirmatory factor analyses were conducted to test the factorial validity of the SEMOK-1-2 instrument. Structural equation models were used to investigate the association between the constructs. The analyses confirmed a two-factor structure with the factors PMC “object movement” and PMC “self-movement”, corresponding to the factors existing in the MOBAK-1-2 instrument. Latent correlations between AMC factors and the corresponding PMC factors were r = 0.79 for “object movement” and r = 0.76 for “self-movement”. Associations with external criteria and covariates, such as sex, were associated with both AMC and PMC. Analyses also revealed that children who participated more often in individual and team sports showed higher levels in both AMC and PMC. The confirmation of the two-factorial structure of the SEMOK-1-2 instrument and the associations between AMC and PMC as well as external criteria indicate construct and criterion validity. The SEMOK-1-2 instrument can be economically utilized for assessing PMC and is also suitable for the monitoring of PMC in the context of Physical Education

μ-Oxalato-bis­[(2,2′-bipyridyl)­copper(II)] bis(perchlorate) dimethyl­formamide disolvate monohydrate

The title compound, [Cu2(C2O4)(C10H8N2)4](ClO4)2·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II) complex cations, perchlorate anions, and DMF and water solvate mol­ecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetra­gonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water mol­ecules are linked into recta­ngles by O—H⋯O bonds in which the perchlorate O atoms act as acceptors and the water mol­ecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7):0.547 (7), and the water molecule is half-occupied