Major impact of body position on arterial stiffness indices derived from radial applanation tonometry in pregnant and non pregnant woman

Pendant la grossesse, la pression artérielle reste stable malgré une nette augmentation du volume d'éjection systolique et du débit cardiaque. Cette stabilité vient d'un côté d'une vasodilatation périphérique entraînant une diminution des résistances périphériques et d'un autre côté d'une moindre rigidité des principales artères notamment l'aorte. En conséquence, l'amplitude des ondes de pouls est atténuée, de même que leur vitesse de propagation dans le sens tant antérogade que rétrograde (ondes réfléchies). Les ondes réfléchies tendent ainsi à atteindre l'aorte ascendante plus tard durant la systole, voire durant la diastole, ce qui peut contribuer à diminuer la pression puisée. La prééclampsie perturbe massivement ce processus d'adaptation. Il s'agit d'une maladie hypertensive de la grossesse engendrant une importante morbidité et mortalité néonatale et maternelle. Il est à remarquer que la diminution de la rigidité artérielle n'est pas observée chez les patientes atteintes avec pour conséquence une forte augmentation de la pression systolique centrale (aortique) par les ondes réfléchies. Ce fait a été établi grâce à l'existence de la tonométrie d'aplanation, une méthode permettant l'évaluation non invasive de l'onde de pouls centrale. Dans cette méthode, un senseur de pression piézo-électrique permet de capter l'onde de pouls périphérique, le plus souvent sur l'artère radiale. Par la suite, un algorithme validé permet d'en déduire la forme de l'onde de pouls centrale et de visualiser à quel moment du cycle cardiaque s'y ajoutent les ondes réfléchies. Plusieurs études font état d'une forte augmentation de la pression systolique centrale par les ondes réfléchies chez les patientes atteintes de prééclampsie, suggérant l'utilisation de cette méthode pour le diagnostic et le monitoring voire pour le dépistage de ces patientes. Pour atteindre ce but, il est nécessaire d'établir des normes en rapport notamment avec l'âge gestationnel. Dans la littérature, les données pertinentes actuellement disponibles sont variables, voire contradictoires. Par exemple, les ondes réfléchies proéminentes dans la partie diastolique de l'onde de pouls centrale disparaissaient chez des patientes enceintes au 3eme trimestre comparées à des contrôles non enceintes dans une étude lausannoise, alors que deux autres études présentent l'observation contraire. Autre exemple, certains auteurs décrivent une diminution progressive de l'augmentation systolique jusqu'à l'accouchement alors que d'autres rapportent un nadir aux environs du 6ème mois, suivi d'un retour à des valeurs plus élevées en fin de grossesse. Les mesures effectuées dans toutes ces études différaient dans leur exécution, les patientes étant notamment dans des postions corporelles différentes (couchées, semi-couchées, assises, en décubitus latéral). Or nous savons que le status hémodynamique est très sensible aux changements de position, particulièrement durant la grossesse où l'utérus gravide est susceptible d'avoir des interactions mécaniques avec les veines et possiblement les artères abdominales. Ces différences méthodologiques pourraient donc expliquer, au moins en partie, l'hétérogénéité des résultats concernant l'onde de pouls chez la femme enceinte, ce qui à notre connaissance n'a jamais été exploré. Nous avons mesuré l'onde de pouls dans les positions assise et couchée chez des femmes enceintes, au 3eme trimestre d'une grossesse non compliquée, et nous avons effectué une comparaison avec des données similaire obtenues chez des femmes non enceintes en bonne santé habituelle. Les résultats montrent que la position du corps a un impact majeur sur la forme de l'onde de pouls centrale. Comparée à la position assise, la position couchée se caractérise par une moindre augmentation systolique et, par contraste, une augmentation diastolique plus marquée. De manière inattendue, cet effet s'observe aussi bien en présence qu'en l'absence de grossesse, suggérant que la cause première n'en réside pas dans les interactions mécaniques de l'utérus gravide avec les vaisseaux sanguins abdominaux. Nos observations pourraient par contre être expliquées par l'influence de la position du corps, via un phénomène hydrostatique simple, sur la pression transmurale des artères éloignées du coeur, tout particulièrement celles des membres inférieurs et de l'étage abdominal. En position verticale, ces vaisseaux augmenteraient leur rigidité pour résister à la distension de leur paroi, ce qui y accroîtrait la vitesse de propagation des ondes de pression. En l'état, cette explication reste hypothétique. Mais quoi qu'il en soit, nos résultats expliquent certaines discordances entre les études conduites à ce jour pour caractériser l'influence de la grossesse physiologique sur la forme de l'onde de pouls central. De plus, ils indiquent que la position du corps doit être prise en compte lors de toute investigation utilisant la tonométrie d'applanation pour déterminer la rigidité des artères chez les jeunes femmes enceintes ou non. Il sera aussi nécessaire d'en tenir compte pour établir des normes en vue d'une utilisation de la tonométrie d'aplanation pour dépister ou suivre les patientes atteintes de prééclampsie. Il serait enfin intéressant d'évaluer si l'effet de la position sur la forme de l'onde de pouls central existe également dans l'autre sexe et chez des personnes plus âgées.

Étude exploratoire de la stabilité à long terme des indices standard du WISC-IV

Par le biais d'une procédure Test-Retest, la stabilité à long terme des indices standard du WISC-IV français a été évaluée. L'intervalle moyen entre les deux passations est de 2,33 ans. L'échantillon comprend 96 enfants « tout venant » âgés de huit à 12 ans. Les comparaisons entre les moyennes des deux passations ne montrent pas de différence significative pour indice de compréhension verbale (ICV), indice de raisonnement perceptif (IRP), indice de mémoire de travail (IMT), indice d'aptitude générale (IAG) et QIT. Au niveau interindividuel, les coefficients de corrélations témoignent d'une bonne stabilité à long terme pour ICV, IAG et QIT (allant de 0,81 à 0,82). Une analyse des différences de performances entre les deux passations indique une stabilité intra-individuelle satisfaisante pour IMT et IAG. Seul IAG présente donc une stabilité à long terme satisfaisante au niveau inter- et intra-individuel. By a Test-Retest procedure, this study explores the long-term stability of the French WISC-IV index scores. The average Test-Retest interval was 2.33 years. The sample consisted of 96 non-clinical children aged between 8 and 12 years. Mean difference between the two testings was not statistically significant for VCI, PRI, WMI, GAI and FSIQ. Test-Retest reliability correlations between the two assessments are high for VCI, GAI and FSIQ (ranging from .81 to .82). An analysis of the performance differences between two assessments indicates intra-individual stability for WMI and GAI. In sum, only GAI demonstrates reliable long-term stability at an inter-and intra-individual level.

PET-measured responses of MBF to cold pressor testing correlate with indices of coronary vasomotion on quantitative coronary angiography.

The aims of this study were to determine whether responses in myocardial blood flow (MBF) to the cold pressor testing (CPT) method noninvasively with PET correlate with an established and validated index of flow-dependent coronary vasomotion on quantitative angiography. METHODS: Fifty-six patients (57 +/- 6 y; 16 with hypertension, 10 with hypercholesterolemia, 8 smokers, and 22 without coronary risk factors) with normal coronary angiograms were studied. Biplanar end-diastolic images of a selected proximal segment of the left anterior descending artery (LAD) (n = 27) or left circumflex artery (LCx) (n = 29) were evaluated with quantitative coronary angiography in order to determine the CPT-induced changes of epicardial luminal area (LA, mm(2)). Within 20 d of coronary angiography, MBF in the LAD, LCx, and right coronary artery territory was measured with (13)N-ammonia and PET at baseline and during CPT. RESULTS: CPT induced on both study days comparable percent changes in the rate x pressure product (%DeltaRPP, 37% +/- 13% and 40% +/- 17%; P = not significant [NS]). For the entire study group, the epicardial LA decreased from 5.07 +/- 1.02 to 4.88 +/- 1.04 mm(2) (DeltaLA, -0.20 +/- 0.89 mm(2)) or by -2.19% +/- 17%, while MBF in the corresponding epicardial vessel segment increased from 0.76 +/- 0.16 to 1.03 +/- 0.33 mL x min(-1) x g(-1) (DeltaMBF, 0.27 +/- 0.25 mL x min(-1) x g(-1)) or 36% +/- 31% (P <or= 0.0001). However, in normal controls without coronary risk factors (n = 22), the epicardial LA increased from 5.01 +/- 1.07 to 5.88 +/- 0.89 mm(2) (19.06% +/- 8.9%) and MBF increased from 0.77 +/- 0.16 to 1.34 +/- 0.34 mL x min(-1) x g(-1) (74.08% +/- 23.5%) during CPT, whereas patients with coronary risk factors (n = 34) revealed a decrease of epicardial LA from 5.13 +/- 1.48 to 4.24 +/- 1.12 mm(2) (-15.94% +/- 12.2%) and a diminished MBF increase (from 0.76 +/- 0.20 to 0.83 +/- 0.25 mL x min(-1) x g(-1) or 10.91% +/- 19.8%) as compared with controls (P < 0.0001, respectively), despite comparable changes in the RPP (P = NS). In addition, there was a significant correlation (r = 0.87; P <or= 0.0001) between CPT-related percent changes in LA on quantitative angiography and in MBF as measured with PET. CONCLUSION: The observed close correlation between an angiographically established parameter of flow-dependent and, most likely, endothelium-mediated coronary vasomotion and PET-measured MBF further supports the validity and value of MBF responses to CPT as a noninvasively available index of coronary circulatory function.

A study compared nine patient-specific indices for musculoskeletal disorders.

BACKGROUND AND OBJECTIVE: Patient-specific quality of life indices show great potential, but certain conceptual and methodological concerns have yet to be fully addressed. The present study reviewed nine patient-specific instruments used in musculoskeletal disorders: the Canadian Occupational Performance Measure (COPM), Juvenile Arthritis Quality of life Questionnaire (JAQQ), McMaster-Toronto Arthritis questionnaire (MACTAR), Measure Yourself Medical Outcome Profile (MYMOP), Patient-Specific Index (PASI) for total hip arthroplasty, Problem Elicitation Technique (PET), Patient Generated Index (PGI) of quality of life, Patient-Specific Functional Scale (PSFS), and Schedule for the Evaluation of Individual Quality of Life (SEIQoL). STUDY DESIGN AND SETTING: Each tool was evaluated for purpose, content validity, face validity, feasibility, psychometric properties, and responsiveness. RESULTS: This critical appraisal revealed important differences in terms of the concept underlying these indices, the domains covered, the item-generation techniques and the scoring (response scale, methods) in each scale. The nine indices would generate different responses and likely scores for the same patient, despite the fact that they all include patient-generated items. CONCLUSION: Although the value of these indices in treatment planning and monitoring at an individual level is strong, more studies are needed to improve our understanding of how to interpret the numeric scores of patient-specific indices at both an individual and a group level.

Clinical growth rate of acoustic schwannomas: correlation with the growth fraction as defined by the monoclonal antibody ki-67.

The growth rate of acoustic tumors, although slow, varies widely. There may be a continuous spectrum or distinct groups of tumor growth rates. Clinical, audiologic, and conventional histologic tests have failed to shed any light on this problem. Modern immunohistochemical methods may stand a better chance. The Ki-67 monoclonal antibody stains proliferating cells and is used in this study to investigate the growth fraction of 13 skull base schwannomas. The acoustic tumors can be divided into two different growth groups, one with a rate five times the other. The literature is reviewed to see if this differentiation is borne out by the radiologic studies. Distinct growth rates have been reported: one very slow, taking 50 years to reach 1 cm in diameter, a second rate with a diameter increase of 0.2 cm/year, and a third rate five times the second, with a 1.0 cm increase in diameter per year. A fourth group growing at 2.5 cm/year is postulated, but these tumors cannot be followed for long radiologically, since symptoms demand surgical intervention. The clinical implications of these separate growth rates are discussed.

Auditory-somatosensory multisensory interactions are spatially modulated by stimulated body surface and acoustic spectra

Previous research has provided inconsistent results regarding the spatial modulation of auditory-somatosensory interactions. The present study reports three experiments designed to investigate the nature of these interactions in the space close to the head. Human participants made speeded detection responses to unimodal auditory, somatosensory, or simultaneous auditory-somatosensory stimuli. In Experiment 1, electrocutaneous stimuli were presented to either earlobe, while auditory stimuli were presented from the same versus opposite sides, and from one of two distances (20 vs. 70cm) from the participant's head. The results demonstrated a spatial modulation of auditory-somatosensory interactions when auditory stimuli were presented from close to the head. In Experiment 2, electrocutaneous stimuli were delivered to the hands, which were placed either close to or far from the head, while the auditory stimuli were again presented at one of two distances. The results revealed that the spatial modulation observed in Experiment 1 was specific to the particular body part stimulated (head) rather than to the region of space (i.e. around the head) where the stimuli were presented. The results of Experiment 3 demonstrate that sounds that contain high-frequency components are particularly effective in eliciting this auditory-somatosensory spatial effect. Taken together, these findings help to resolve inconsistencies in the previous literature and suggest that auditory-somatosensory multisensory integration is modulated by the stimulated body surface and acoustic spectra of the stimuli presented.

Validity of the acoustic approximation in full-waveform seismic crosshole tomography

Acoustic waveform inversions are an increasingly popular tool for extracting subsurface information from seismic data. They are computationally much more efficient than elastic inversions. Naturally, an inherent disadvantage is that any elastic effects present in the recorded data are ignored in acoustic inversions. We investigate the extent to which elastic effects influence seismic crosshole data. Our numerical modeling studies reveal that in the presence of high contrast interfaces, at which P-to-S conversions occur, elastic effects can dominate the seismic sections, even for experiments involving pressure sources and pressure receivers. Comparisons of waveform inversion results using a purely acoustic algorithm on synthetic data that is either acoustic or elastic, show that subsurface models comprising small low-to-medium contrast (?30%) structures can be successfully resolved in the acoustic approximation. However, in the presence of extended high-contrast anomalous bodies, P-to-S-conversions may substantially degrade the quality of the tomographic images. In particular, extended low-velocity zones are difficult to image. Likewise, relatively small low-velocity features are unresolved, even when advanced a priori information is included. One option for mitigating elastic effects is data windowing, which suppresses later arriving seismic arrivals, such as shear waves. Our tests of this approach found it to be inappropriate because elastic effects are also included in earlier arriving wavetrains. Furthermore, data windowing removes later arriving P-wave phases that may provide critical constraints on the tomograms. Finally, we investigated the extent to which acoustic inversions of elastic data are useful for time-lapse analyses of high contrast engineered structures, for which accurate reconstruction of the subsurface structure is not as critical as imaging differential changes between sequential experiments. Based on a realistic scenario for monitoring a radioactive waste repository, we demonstrated that acoustic inversions of elastic data yield substantial distortions of the tomograms and also unreliable information on trends in the velocity changes.

How do Swiss Gastroenterologists assess Activity of Inflammatory Bowel Disease in Daily Practice: by Clinical Indices, Endoscopic Activity, or Biomarkers?

Background a nd A ims: There is a n ongoing d ebate which i sthe most appropriate w ay t o measure inflammatory boweldisease (IBD) activity (be it b y clinical i ndices, e ndoscopy, orbiomarkers). Accumulating evidence associates m ucosalhealing with a reduction in I BD-related s urgery andhospitalizations. We a imed to i nvestigate which outcomeparameters are used in daily practice for IBD monitoring.Methods: A q uestionnaire was sent in J uly 2010 t o all boardcertified gastroenterologists in S witzerland to evaluate t heassessment strategy of IBD activity, t he items on whichtherapeutic decisions w ere based upon, and the kind ofbiomarkers used for monitoring IBD activity.Results: Response rate was 57% (153/270). Mean physician'sage was 5 0±9years, mean duration o f gastroenterologicpractice 1 4±8years, 52% of them were working in p rivatepractice a nd 48% in h ospitals. S eventy-eight percent usedclinical activity i ndices as g old standard for IBD activityassessment, followed by 15% choosing endoscopic activity, and7% favouring biomarkers. Gastroenterologists based theirtherapeutic decisions in 70% on clinical activity indices, 24% onendoscopic activity, a nd 6% o n biomarkers. Most frequentlyused biomarkers were C-reactive protein (94%), complete bloodcount (78%) and fecal calprotectin (74%).Conclusions: I n daily p ractice, most IBD patients a remonitored based u pon t heir clinical a ctivity. B iomarkers a reperceived as l ess important compared to clinical andendoscopic activity. S imilar to activity a ssessment, alsotherapeutic decisions a re mostly made on the basis of clinicalactivity indices. The upcoming scientific evidence on the impactof mucosal h ealing does n ot yet seem to influence the dailypractice of gastroenterologists.

Association of biomarkers of lipid modification with functional and morphological indices of coronary stenosis severity in stable coronary artery disease.

Biomarkers of blood lipid modification and oxidative stress have been associated with increased cardiovascular morbidity. We sought to determine whether these biomarkers were related to functional indices of stenosis severity among patients with stable coronary artery disease. We studied 197 consecutive patients with stable coronary artery disease due to single vessel disease. Fractional flow reserve (FFR) ≤ 0.80 was assessed as index of a functionally significant lesion. Serum levels of secretory phospholipase A2 (sPLA2) activity, secretory phospholipase A2 type IIA (sPLA2-IIA), myeloperoxydase (MPO), lipoprotein-associated phospholipase A2 (Lp-PLA2), and oxidized low-density lipoprotein (OxLDL) were assessed using commercially available assays. Patients with FFR > 0.8 had higher sPLA2 activity, sPLA2 IIA, and OxLDL levels than patients with FFR ≤ 0.8 (21.25 [16.03-27.28] vs 25.85 [20.58-34.63] U/mL, p < 0.001, 2.0 [1.5-3.4] vs 2.6 [2.0-3.4] ng/mL, p < 0.01; and 53.0 [36.0-71.0] vs 64.5 [50-89.25], p < 0.001 respectively). Patients with FFR > 0.80 had similar Lp-PLA2 and MPO levels versus those with FFR ≤ 0.8. sPLA2 activity, sPLA2 IIA significantly increased area under the curve over baseline characteristics to predict FFR ≤ 0.8 (0.67 to 0.77 (95 % confidence interval [CI]: 0.69-0.85) p < 0.01 and 0.67 to 0.77 (95 % CI: 0.69-0.84) p < 0.01, respectively). Serum sPLA2 activity as well as sPLA2-IIA level is related to functional characteristics of coronary stenoses in patients with stable coronary artery disease.

A peptide inhibitor of c-Jun N-terminal kinase protects against both aminoglycoside and acoustic trauma-induced auditory hair cell death and hearing loss.

Hearing loss can be caused by a variety of insults, including acoustic trauma and exposure to ototoxins, that principally effect the viability of sensory hair cells via the MAP kinase (MAPK) cell death signaling pathway that incorporates c-Jun N-terminal kinase (JNK). We evaluated the otoprotective efficacy of D-JNKI-1, a cell permeable peptide that blocks the MAPK-JNK signal pathway. The experimental studies included organ cultures of neonatal mouse cochlea exposed to an ototoxic drug and cochleae of adult guinea pigs that were exposed to either an ototoxic drug or acoustic trauma. Results obtained from the organ of Corti explants demonstrated that the MAPK-JNK signal pathway is associated with injury and that blocking of this signal pathway prevented apoptosis in areas of aminoglycoside damage. Treatment of the neomycin-exposed organ of Corti explants with D-JNKI-1 completely prevented hair cell death initiated by this ototoxin. Results from in vivo studies showed that direct application of D-JNKI-1 into the scala tympani of the guinea pig cochlea prevented nearly all hair cell death and permanent hearing loss induced by neomycin ototoxicity. Local delivery of D-JNKI-1 also prevented acoustic trauma-induced permanent hearing loss in a dose-dependent manner. These results indicate that the MAPK-JNK signal pathway is involved in both ototoxicity and acoustic trauma-induced hair cell loss and permanent hearing loss. Blocking this signal pathway with D-JNKI-1 is of potential therapeutic value for long-term protection of both the morphological integrity and physiological function of the organ of Corti during times of oxidative stress.

Comorbidity and nutritional indices as predictors of morbidity after transurethral procedures: A prospective cohort study.

INTRODUCTION: Preoperative scores are widely used predictors of complications after major surgery. These scores, however, are not widely used in transurethral procedures. The aim of this study was to assess the value of the Charlson Comorbidity Index (CCI), the age-adjusted CCI, the American Society of Anesthesiologist score (ASA) and the Nutritional Risk Score (NRS) in predicting early morbidity after transurethral urological procedures. METHODS: Consecutive patients undergoing transurethral resection of the bladder or the prostate were prospectively enrolled. The scores were calculated preoperatively; 30-day complications were prospectively recorded according to the Dindo-Clavien classification. Univariate logistic regression was performed to investigate the value of each score and of other factors (i.e., age, sex, body mass index, anemia, smoking habit, type of operation and anaesthesia) as predictors of complications. A multivariate model was then calculated using these predictors. RESULTS: Overall, 197 patients were included. The mean age was 72 (standard deviation ± 10). In total, 26.9% patients had at least 1 complication. Using univariate analysis, we found that each score significantly predicted complications. In multivariate analysis, only the ASA (odds ration [OR] 2.11; 95% confidence interval [CI] 1.01-4.43) and the NRS (OR 2.42; 95% CI 1.56-3.74) remained independent predictors. The best model incorporated ASA, NRS and gender, and predicted morbidity with an area under the curve of 76%. Our study's main limitations are population heterogeneity and limited sample size. CONCLUSION: The ASA and the NRS are important and independent determinants of early morbidity after transurethral procedures. The use of these indices may assist clinicians in the decision-making process to balance the possible benefits of transurethral procedures with the potential risks.

Tolerance and Relative Utility: Two Proposed Indices for Comparing Change in Clinical Measurement Noise Between Different Populations (Repeatability) or Measurement Methods (Agreement).

Reaching a consensus in terms of interchangeability and utility (i.e., disease detection/monitoring) of a medical device is the eventual aim of repeatability and agreement studies. The aim of the tolerance and relative utility indices described in this report is to provide a methodology to compare change in clinical measurement noise between different populations (repeatability) or measurement methods (agreement), so as to highlight problematic areas. No longitudinal data are required to calculate these indices. Both indices establish a metric of least to most effected across all parameters to facilitate comparison. If validated, these indices may prove useful tools when combining reports and forming the consensus required in the validation process for software updates and new medical devices.