Real time 3D US-tagging combined with 3D phase-based motion estimation

International audienceBy contrast with 2D imaging, quantitative analysis of 3D motion from ultrasound images can provide improved information in several applications, such as arterial mechanical assessment, heart motion and blood flow. Unfortunately, it remains difficult to obtain a high definition of the motion estimate in the lateral and elevation directions (i.e. perpendicular to the beam axis). To increase the definition in both these directions, this paper presents a 3D extension of a the transverse oscillations method that enables one to obtain ultrasound fields featuring oscillations along the 3 spatial dimensions, using a single apodization function. The 3D motion method is estimated using the phases of the images. Simulation results show that a 3D trajectory can be followed with a relative mean error smaller than 8%

Filtrage spatiotemporel de séquences d'images ultrasonores pour l'estimation d'un champ dense de vitesses

Ce papier propose une nouvelle méthode d'estimation de champ de vitesses complémentaire à l'imagerie Doppler qui est une référence pour l'estimation de vitesse mais qui présente quelques limites. On s'appuie sur la réponse impulsionnelle 3D du système d'imagerie pour développer un banc de filtres qui estime une orientation locale de texture spatiotemporelle dans le volume 2D+t de données pour en déduire le champ de vitesse 2D. La méthode est appliquée à des séquences d'images ultrasonores de flux calibré dans un vaisseau. Ces images sont caractérisées par leur texture, appelée speckle, liée au processus de formation de l'image

Clinical risk scores for predicting stroke-associated pneumonia: A systematic review:A systematic review

Purpose Several risk stratification scores for predicting stroke-associated pneumonia have been derived. We aimed to evaluate the performance and clinical usefulness of such scores for predicting stroke-associated pneumonia. Method A systematic literature review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, with application of the Quality Assessment of Diagnostic Accuracy-2 tool. Published studies of hospitalised adults with ischaemic stroke, intracerebral haemorrhage, or both, which derived and validated an integer-based clinical risk score, or externally validated an existing score to predict occurrence of stroke-associated pneumonia, were considered and independently screened for inclusion by two reviewers. Findings We identified nine scores, from eight derivation cohorts. Age was a component of all scores, and the NIHSS score in all except one. Six scores were internally validated and five scores were externally validated. The A2DS2 score (Age, Atrial fibrillation, Dysphagia, Severity [NIHSS], Sex) was the most externally validated in 8 independent cohorts. Performance measures were reported for eight scores. Discrimination tended to be more variable in the external validation cohorts (C statistic 0.67–0.83) than the derivation cohorts (C statistic 0.74–0.85). Discussion Overall, discrimination and calibration were similar between the different scores. No study evaluated influence on clinical decision making or prognosis. Conclusion The clinical prediction scores varied in their simplicity of use and were comparable in performance. Utility of such scores for preventive intervention trials and in clinical practice remains uncertain and requires further study

Factors Associated with Negative Direct Sputum Examination in Asian and African HIV-Infected Patients with Tuberculosis (ANRS 1260)

OBJECTIVE: To identify factors associated with negative direct sputum examination among African and Cambodian patients co-infected by Mycobacterium tuberculosis and HIV. DESIGN: Prospective multicenter study (ANRS1260) conducted in Cambodia, Senegal and Central African Republic. METHODS: Univariate and multivariate analyses (logistic regression) were used to identify clinical and radiological features associated with negative direct sputum examination in HIV-infected patients with positive M. tuberculosis culture on Lowenstein-Jensen medium. RESULTS: Between September 2002 and December 2005, 175 co-infected patients were hospitalized with at least one respiratory symptom and pulmonary radiographic anomaly. Acid-fast bacillus (AFB) examination was positive in sputum samples from 110 subjects (63%) and negative in 65 patients (37%). Most patients were at an advanced stage of HIV disease (92% at stage III or IV of the WHO classification) with a median CD4 cell count of 36/mm³. In this context, we found that sputum AFB negativity was more frequent in co-infected subjects with associated respiratory tract infections (OR = 2.8 [95%CI:1.1-7.0]), dyspnea (OR = 2.5 [95%CI:1.1-5.6]), and localized interstitial opacities (OR = 3.1 [95%CI:1.3-7.6]), but was less frequent with CD4 ≤ 50/mm³ (OR = 0.4 [95%CI:0.2-0.90), adenopathies (OR = 0.4 [95%CI:0.2-0.93]) and cavitation (OR = 0.1 [95%CI:0.03-0.6]). CONCLUSIONS: One novel finding of this study is the association between concomitant respiratory tract infection and negative sputum AFB, particularly in Cambodia. This finding suggests that repeating AFB testing in AFB-negative patients should be conducted when broad spectrum antibiotic treatment does not lead to complete recovery from respiratory symptoms. In HIV-infected patients with a CD4 cell count below 50/mm3 without an identified cause of pneumonia, systematic AFB direct sputum examination is justified because of atypical clinical features (without cavitation) and high pulmonary mycobacterial burden

Low Immune Response to Hepatitis B Vaccine among Children in Dakar, Senegal

HBV vaccine was introduced into the Expanded Programme on Immunization (EPI) in Senegal and Cameroon in 2005. We conducted a cross-sectional study in both countries to assess the HBV immune protection among children. All consecutive children under 4 years old, hospitalized for any reason between May 2009 and May 2010, with an immunisation card and a complete HBV vaccination, were tested for anti-HBs and anti-HBc. A total of 242 anti-HBc-negative children (128 in Cameroon and 114 in Senegal) were considered in the analysis. The prevalence of children with anti-HBs ≥10 IU/L was higher in Cameroon with 92% (95% CI: 87%–97%) compared to Senegal with 58% (95% CI: 49%–67%), (p<0.001). The response to vaccination in Senegal was lower in 2006–2007 (43%) than in 2008–2009 (65%), (p = 0.028). Our results, although not based on a representative sample of Senegalese or Cameroonian child populations, reveal a significant problem in vaccine response in Senegal. This response problem extends well beyond hepatitis B: the same children who have not developed an immune response to the HBV vaccine are also at risk for diphtheria, tetanus, pertussis (DTwP) and Haemophilus influenzae type b (Hib). Field biological monitoring should be carried out regularly in resource-poor countries to check quality of the vaccine administered

Liver Stiffness Measurement and Biochemical Markers in Senegalese Chronic Hepatitis B Patients with Normal ALT and High Viral Load

Despite the high prevalence of chronic hepatitis B (CHB) in Africa, few studies have been performed among African patients. We sought to evaluate liver stiffness measurement by FibroScan® (LSM) and two biochemical scores (FibroTest®, Fibrometer®) to diagnose liver fibrosis in Senegalese CHB patients with HBV plasma DNA load ≥3.2 log(10) IU/mL and normal alanine aminotransferase (ALT) values.LSM and liver fibrosis biochemical markers were performed on 225 consecutive HBV infected Senegalese patients with high viral load. Patients with an LSM range between 7 and 13 kPa underwent liver biopsy (LB). Two experienced liver pathologists performed histological grading using Metavir and Ishak scoring.225 patients were evaluated (84% male) and LB was performed in 69 patients, showing F2 and F3 fibrosis in 17% and 10% respectively. In these patients with a 7-13 kPa range of LSM, accuracy for diagnosis of significant fibrosis according to LB was unsatisfactory for all non-invasive markers with AUROCs below 0.70. For patients with LSM values below 7 kPa, FibroTest® (FT), and Fibrometer® (FM) using the cut-offs recommended by the test promoters suggested a fibrosis in 18% of cases for FT (8% severe fibrosis) and 8% for FM. For patients with LSM values greater than 13 kPa, FT, FM suggested a possible fibrosis in 73% and 70%, respectively.In highly replicative HBV-infected African patients with normal ALT and LSM value below 13 kPa, FibroScan®, FibroTest® or Fibrometer® were unsuitable to predict the histological liver status of fibrosis

Cell Cycle- and Cancer-Associated Gene Networks Activated by Dsg2: Evidence of Cystatin A Deregulation and a Potential Role in Cell-Cell Adhesion

This work was supported by grants from the National Institutes of Health (Mahoney, R01AR056067; Riobo, RO1 GM088256). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Characterization of Leishmania spp. causing cutaneous leishmaniasis in Manaus, Amazonas, Brazil

In the State of Amazonas, American tegumentary leishmaniasis is endemic and presents a wide spectrum of clinical variability due to the large diversity of circulating species in the region. Isolates from patients in Manaus and its metropolitan region were characterized using monoclonal antibodies and isoenzymes belonging to four species of the parasite: Leishmania (Viannia) guyanensis, 73% (153/209); Leishmania (Viannia) braziliensis, 14% (30/209); Leishmania (Leishmania) amazonensis, 8% (17/209); and Leishmania (Viannia) naiffii, 4% (9/209). The most prevalent species was L. (V.) guyanensis. The principal finding of this study was the important quantity of infections involving more than one parasite species, representing 14% (29/209) of the total. The findings obtained in this work regarding the parasite are further highlighted by the fact that these isolates were obtained from clinical samples collected from single lesions