Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and control

Rapport de synthèse : L'ostéoporose est reconnue comme un problème majeur de santé publique. Comme il existe actuellement des traitements préventifs efficaces pour minimiser le risque de fracture, il est essentiel de développer des nouvelles stratégies de détection des femmes à risque de fracture. Les marqueurs spécifiques du remodelage osseux dosés dans les urines ainsi que les ultrasons quantitatifs du talon ont été étudiés comme outils cliniques pour prédire le risque fracturaire chez les femmes âgées. Il n'existe cependant que très peu de donnée sur la combinaison de ces deux outils pour améliorer la prédiction du risque de fracture. Cette étude cas-contrôle, réalisée chez 368 femmes âgées de 76 ans en moyenne d'une cohorte suisse de femmes ambulatoires, évalue la capacité discriminative entre 195 femmes avec fracture non-vertébrale à bas traumatisme et 173 femmes sans fractures - de deux marqueurs urinaires de la résorption osseuse, les pyridinolines et les deoxypyridinolines, ainsi que deux ultrasons quantitatifs du talon, le Achilles+ (GE-Lunar, Madison, USA) et le Sahara (Hologic, Waltham, USA). Les 195 patientes avec une fracture ont été choisies identiques aux 173 contrôles concernant Page, l'indice de masse corporel, le centre médical et la durée de suivi jusqu'à la fracture. Cette étude montre que les marqueurs urinaires de la résorption osseuse ont une capacité environ identique aux ultrasons quantitatifs du talon pour discriminer entre les patientes avec fracture non-vertébrale à bas traumatisme et les contrôles. La combinaison des deux tests n'est cependant pas plus performante qu'un seul test. Les résultats de cette étude peuvent aider à concevoir les futures stratégies de détection du risque fracturaire chez les femmes âgées, qui intègrent notamment des facteurs de risque cliniques, radiologiques et biochimiques. Abstract : Summary : This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information. Introduction : Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture. Methods In a nested case-control analysis, we studied 368 women (mean age 76.213.2 years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS. Results : Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.560.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.600.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD. Conclusions : Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alone.

Aging effects on selective attention-related electroencephalographic patterns during face encoding.

Previous electrophysiological studies revealed that human faces elicit an early visual event-related potential (ERP) within the occipito-temporal cortex, the N170 component. Although face perception has been proposed to rely on automatic processing, the impact of selective attention on N170 remains controversial both in young and elderly individuals. Using early visual ERP and alpha power analysis, we assessed the influence of aging on selective attention to faces during delayed-recognition tasks for face and letter stimuli, examining 36 elderly and 20 young adults with preserved cognition. Face recognition performance worsened with age. Aging induced a latency delay of the N1 component for faces and letters, as well as of the face N170 component. Contrasting with letters, ignored faces elicited larger N1 and N170 components than attended faces in both age groups. This counterintuitive attention effect on face processing persisted when scenes replaced letters. In contrast with young, elderly subjects failed to suppress irrelevant letters when attending faces. Whereas attended stimuli induced a parietal alpha band desynchronization within 300-1000 ms post-stimulus with bilateral-to-right distribution for faces and left lateralization for letters, ignored and passively viewed stimuli elicited a central alpha synchronization larger on the right hemisphere. Aging delayed the latency of this alpha synchronization for both face and letter stimuli, and reduced its amplitude for ignored letters. These results suggest that due to their social relevance, human faces may cause paradoxical attention effects on early visual ERP components, but they still undergo classical top-down control as a function of endogenous selective attention. Aging does not affect the face bottom-up alerting mechanism but reduces the top-down suppression of distracting letters, possibly impinging upon face recognition, and more generally delays the top-down suppression of task-irrelevant information.

A Single High Dose of Oral Vitamin D3 Is Not Enough to Correct Insufficiency and Deficiency in a Rheumatologic Population

Introduction: Vitamin D plays a major role in bone metabolism and neuromuscular function. Supplementation with vitamin D is effective to reduce the risk of fall and of fracture. However adherence to oral daily vitamin D supplementation is low. Screening and correcting vitamin D insufficiency in a general rheumatologic population could improve both morbidity and quality of life in these patients with chronic painful disorders and at high risk of osteoporosis. After determining the prevalence of vitamin D deficiency in this population, we evaluated if supplementation with a single high dose of oral 25-OH vitamin D3 was sufficient to correct this abnormality. Methods: During one month (November 2009), levels of 25-OH vitamin D were systematically determined in our rheumatology outpatient clinic and classified into three groups: vitamin D deficiency (<10 μg/l), vitamin D insufficiency (10 to 30 μg/l) or normal vitamin D (>30 μg/l). Patients with insufficiency or deficiency received respectively a single high dose of 300000 IU or 600000 IU oral vitamin D3. In addition, all patients with osteoporosis were prescribed daily supplement of calcium (1 g) and vitamin D (800 IU). 25-OH vitamin D levels were reevaluated after 3 months. Results: Vitamin D levels were initially determined in 292 patients (mean age 53, 211 women, 87% Caucasian). 77% had inflammatory rheumatologic disease (IRD), 20% osteoporosis (OP) and 12% degenerative disease (DD). Vitamin D deficiency was present in 20 (6.8%), while 225 (77.1%) had insufficiency. Of the 245 patients with levels <30 μg/l, a new determination of vitamin D level was available in 173 (71%) at 3 months. Conclusion: Vitamin D insufficiency is highly prevalent in our rheumatologic population (84%), and is not adequately corrected by a single high dose of oral vitamin D3 in more than half of the patients with IRD and DD. In patients with OP, despite association of a single high dose with daily oral vitamin D supplementation, 40% of patients are still deficient when reevaluated at 3 months.

An anti-CD19 antibody coupled to a tetanus toxin peptide induces efficient Fas ligand (FasL)-mediated cytotoxicity of a transformed human B cell line by specific CD4+ T cells.

Treatment of B cell lymphoma patients with MoAbs specific for the common B cell marker (CD20) has shown a good overall response rate, but the number of complete remissions is still very low. The use of MoAbs coupled to radioisotopes can improve the results, but induces undesirable myelodepression. As an alternative, we proposed to combine the specificity of MoAbs with the immunogenicity of T cell epitopes. We have previously shown that an anti-Ig lambda MoAb coupled to an MHC class II-restricted universal T cell epitope peptide P2 derived from tetanus toxin induces efficient lysis of a human B cell lymphoma by a specific CD4+ T cell line. Here we demonstrate that the antigen presentation properties of the MoAb peptide conjugate are maintained using a MoAb directed against a common B cell marker, CD19, which is known to be co-internalized with the B cell immunoglobulin receptor. In addition, we provide evidence that B cell lysis is mediated by the Fas apoptosis pathway, since Fas (CD95), but not tumour necrosis factor receptor (TNFr) or TNF-related receptors, is expressed by the target B cells, and FasL, but not perforin, is expressed by the effector T cells. These results show that B cell lymphomas can be 'foreignized' by MoAb-peptide P2 conjugates directed against the common B cell marker CD19 and eliminated by peptide P2-specific CD4+ T cells, via the ubiquitous Fas receptor. This approach, which bridges the specificity of passive antibody therapy with an active T cell immune response, may be complementary to and more efficient than the present therapy results with unconjugated chimeric anti-CD20 MoAbs.

Pääjohtaja Erkki Raatikainen 26/2 1973

Kirje 26.2.1973

The Genesis and Effect of French Anti-Doping Policies in Cycling

This paper focuses on the transformation of French public policy on doping and its effects on the life of cycling professionals. We first focus on the emergence and the evolution of French public policies against doping in cycling. Then the article attempts to qualitatively observe the effects of policies on cyclists. The objective is to understand how the cycling culture is evolving. This article is based on 39 interviews with new and seasoned professionals, as well as ethnographic observations over a dozen years .

Frequent users of emergency departments present very high prevalence of mental health and substance use disorders, which are largery underdiagnosed by clinicians.

Background: The objective of this study was to determine if mental health and substance use diagnoses were equally detected in frequent users (FUs) compared to infrequent users (IUs) of emergency departments (EDs). Methods: In a sample of 399 adult patients (>= 18 years old) admitted to a teaching hospital ED, we compared the mental health and substance use disorders diagnoses established clinically and consigned in the medical files by the ED physicians to data obtained in face-to-face research interviews using the Primary Care Evaluation of Mental Disorders (PRIME-MD) and the Alcohol, Smoking and Involvement Screening Test (ASSIST). Between November 2009 and June 2010, 226 FUs (>4 visits within a year) who attended the ED were included, and 173 IUs (<= 4 visits within a year) were randomly selected from a pool of identified patients to comprise the comparison group. Results: For mental health disorders identified by the PRIME-MD, FUs were more likely than IUs to have an anxiety (34 vs. 16%, Chi2(1) = 16.74, p <0.001), depressive (47 vs. 25%, Chi2(1) = 19.11, p <0.001) or posttraumatic stress (PTSD) disorder (11 vs. 5%, Chi2(1) = 4.87, p = 0.027). Only 3/76 FUs (4%) with an anxiety disorder, 16/104 FUs (15%) with a depressive disorder and none of the 24 FUs with PTSD were detected by the ED medical staff. None of the 27 IUs with an anxiety disorder, 6/43 IUs (14%) with a depressive disorder and none of the 8 IUs with PTSD were detected. For substance use disorders identified by the ASSIST, FUs were more at risk than IUs for alcohol (24 vs. 7%, Chi2(1) = 21.12, p <0.001) and drug abuse/dependence (36 vs. 25%, Chi2(1) = 5.52, p = 0.019). Of the FUs, 14/54 (26%) using alcohol and 8/81 (10%) using drugs were detected by the ED physicians. Of the IUs, 5/12 (41%) using alcohol and none of the 43 using drugs were detected. Overall, there was no significant difference in the rate of detection of mental health and substance use disorders between FUs and IUs (Fisher's Exact Test: anxiety, p = 0.567; depression, p = 1.000; PTSD, p = 1.000; alcohol, p = 0.517; and drugs, p = 0.053). Conclusions: While the prevalence of mental health and substance use disorders was higher among FUs, the rates of detection were not significantly different for FUs vs. IUs. However, it may be that drug disorders among FUs were more likely to be detected.

Capital, wages and growth: Theory and evidence

Returns to scale to capital and the strength of capital externalities play a key role for the empirical predictions and policy implications of different growth theories. We show that both can be identified with individual wage data and implement our approach at the city-level using US Census data on individuals in 173 cities for 1970, 1980, and 1990. Estimation takes into account fixed effects, endogeneity of capital accumulation, and measurement error. We find no evidence for human or physical capital externalities and decreasing aggregate returns to capital. Returns to scale to physical and human capital are around 80 percent. We also find strong complementarities between human capital and labor and substantial total employment externalities.

Zoledronate inhibits endothelial cell adhesion, migration and survival through the suppression of multiple, prenylation-dependent signaling pathways.

BACKGROUND: Recent evidence indicates that zoledronate, a nitrogen-containing bisphosphonate used to treat conditions of increased bone resorption, may have anti-angiogenic activity. The endothelial cells signaling events modulated by zoledronate remain largely elusive. OBJECTIVES: The aim of this work was to identify signaling events suppressed by zoledronate in endothelial cells and responsible for some of its biological effects. METHODS: Human umbilical vein endothelial cells (HUVEC) were exposed to zoledronate, isoprenoid analogs (i.e. farnesol and geranylgeraniol) and various inhibitors of signaling, and the effect on adhesion, survival, migration, actin cytoskeleton and signaling events characterized. RESULTS: Zoledronate reduced Ras prenylation, Ras and RhoA translocation to the membrane, and sustained ERK1/2 phosphorylation and tumor necrosis factor (TNF) induced JNK phosphorylation. Isoprenoid analogs attenuated zoledronate effects on HUVEC adhesion, actin stress fibers and focal adhesions, migration and survival. Isoprenoid analogs also restored Ras prenylation, RhoA translocation to the membrane, sustained FAK and ERK1/2 phosphorylation and prevented suppression of protein kinase B (PKB) and JNK phosphorylation in HUVEC exposed to TNF in the presence of zoledronate. Pharmacological inhibition of Rock, a RhoA target mediating actin fiber formation, phosphatidylinositol 3-kinase, an activator of PKB, MEK1/2, an activator of ERK1/2, and JNK, recapitulated individual zoledronate effects, consistent with the involvement of these molecules and pathways and their inhibition in the zoledronate effects. CONCLUSIONS: This work has demonstrated that zoledronate inhibits HUVEC adhesion, survival, migration and actin stress fiber formation by interfering with protein prenylation and has identified ERK1/2, JNK, Rock, FAK and PKB as kinases affected by zoledronate in a prenylation-dependent manner.