Ultrasound-triggered delivery of paclitaxel encapsulated in an emulsion at low acoustic pressures

We investigated the in vitro ultrasound-triggered delivery of paclitaxel, a well known anti-cancerous drug, encapsulated in an emulsion and in the presence of CT26 tumor cells. The emulsion was made of nanodroplets, whose volume comprised 95% perfluoro-octyl bromide and 5% tributyl O-acetylcitrate, in which paclitaxel was solubilized. These nanodroplets, prepared using a high-pressure microfluidizer, were stabilized by a tailor-made and recently patented biocompatible fluorinated surfactant. The delivery investigations were performed at 37 °C using a high intensity focused ultrasound transducer at a frequency of 1.1 MHz. The ultrasonic pulse was made of 275 sinusoidal periods and the pulse repetition frequency was 200 Hz with a duty cycle of 5%. The measured viabilities of CT26 cells showed that paclitaxel delivery was achievable for peak-to-peak pressures of 0.4 and 3.5 MPa, without having to vaporize the perfluorocarbon part of the droplet or to induce inertial cavitation.

T1 mapping-derived signature of myocardial involvement in idiopathic inflammatory myopathy compared to acute viral myocarditis: a texture-based analysis

Funding Acknowledgements

Type of funding sources: None.

Background. Recent studies revealed the ability of MRI T1 mapping to characterize myocardial involvement in both idiopathic inflammatory myopathy (IIM) and acute viral myocarditis (AVM), as compared to healthy controls. However, neither myocardial T1 nor T2 maps were able to discriminate between IIM and AVM patients, when considering conventional myocardial mean values and derived indices such as lambda and extracellular volume.

Purpose. To investigate the ability of T1 mapping-derived texture analysis to differentiate IIM from AVM.

Methods. Forty patients, 20 with IIM (51 ± 17 years, 9 men) and 20 with AVM (34 ± 13 years, 16 men) underwent 1.5T MRI T1 mapping using a modified Look-Locker inversion-recovery sequence before and 15 minutes after injection of a gadolinium contrast agent. After manual delineation of endocardial and epicardial borders and co-registration of all inversion time images, native and post-contrast T1 maps were estimated. Myocardial texture analysis was performed on native T1 maps. Textural features such as: autocorrelation, contrast, dissimilarity, energy and sum entropy were used to build a least squares-based linear regression model. Finally, receiver operating characteristic (ROC) analysis was used to investigate the ability of such texture features score to classify IIM vs. AVM patients, compared to the performance of mean myocardial T1. A Wilcoxon rank-sum test was also used to test difference significance between groups.

Results. Both native and post-contrast mean myocardial T1 values were comparable between IIM (native: 1022 ± 43 ms; post-contrast: 319 ± 44 ms) and AVM (1056 ± 59 ms, p = 0.07; 318 ± 35 ms, p = 0.90, respectively) groups. Results of ROC analyses are provided in the Table, indicating that a better discrimination between IIM and AVM patients was obtained when using texture features, with higher AUC and accuracy than mean T1 values (Figure).

Conclusion. Texture analysis derived from MRI T1 maps without contrast agent injection was able to discriminate between IIM and AVM with higher accuracy, sensitivity and specificity than conventional T1 indices. Such analysis could provide a useful myocardial signature to help diagnose and manage cardiac alterations associated with IIM in patients presenting with myocarditis and primarily suspected of AVM.

Table Area under curve (AUC) Accuracy Sensitivity Specificity Native T1 0.67 0.70 0.65 0.75 Post-contrast T1 0.49 0.60 0.25 0.95 Texture features score 0.85 0.82 0.90 0.75 ROC analyses for classification between IIM and AVM patients Abstract Figure

Capturing complex right ventricular wall motion abnormalities in arrhythmogenic right ventricular cardiomyopathy by combining longitudinal and radial myocardial dynamics in feature-tracking MRI

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): INSERM Liliane Bettencourt doctoral grant

Background

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is ass­­ociated with complex spatial and temporal right ventricular (RV) wall motion abnormalities. While cardiac magnetic resonance (CMR) is the gold-standard imaging technique, its diagnosic performance remains suboptimal and additional CMR biomarkers reflecting ARVC pathophysiology are needed.

Purpose

To evaluate the performance of a CMR feature-tracking (FT)-derived parameter combining both longitudinal and radial RV deformation and motion for the characterization of RV wall motion abnormalities in ARVC.

Methods

Thirty-nine patients with definite or borderline ARVC (median age 45 years, interquartile range 31–51, 56% males) were compared to 20 healthy controls with comparable age, sex and weight distributions. All subjects had 1.5T CMR including short axis and 4-chamber views steady-state free precession acquisitions. A custom FT software adapted to RV wall segmentation and tracking was used to assess RV wall deformation and motion in the 3 space directions resulting in: 1) global longitudinal strain (GLS) estimated on the 4 chamber view from the RV free wall, 2) basal circumferential strain (BCS) and radial motion fraction (BRMF) estimated as an average of short-axis slices comprised in the RV third basal portion. To capture the complex RV motion in ARCV, a longitudinal to radial strain loop (LRSL) was displayed and its area was calculated.

Results

The ARVC group comprised 28 (72%) patients with definite and 11 (28%) with borderline diagnosis . As compared to controls, LVEF and RVEF were significantly lower in ARVC patients (61(interquartile range (IQR) 52-71) vs. 71%(IQR 55-88) , p = 0.03 and 47%(IQR 16-63) vs. 57%(IQR 49-63) , p = 0.02, respectively), LVEF remaining within normal range limits. While there was no significant difference in RV GLS between ARVC patients and controls (median -17.7%(IQR -24–15) vs. -17.5%(IQR -20.1–15.2), p = 0.67) , BCS and BRMF were significantly lower in ARVC patients vs. controls [-7.5%(IQR -12.3–8.4.) vs. -9.8%(IQR -13.8–8.6.), p = 0.004 and -12.2(IQR -14.4–8.7.) vs. -14.9%(IQR -16.6–13.2) p = 0.0007, respectively] . The LRSL area was significantly and markedly lower in ARVC patients vs. controls [70.6 (IQR 16.3-63.1) vs. 144.1 (IQR 110.4-251.3), p = 0.0002] . LRSL area outperformed RVEF, BCS and BRS in separating ARVC from controls (area under receiving operator characteristics curve 0.82 vs. 0.78, 0.73 and 0.78, respectively).

Conclusion

In ARVC, a FT-derived parameter combining longitudinal and radial RV wall deformation and motion provided better discrimination of ARVC patients from controls than conventional FT measurements. Its implementation in clinical practice may bolster CMR performance to characterize ARVC wall motion abnormalities.

Abstract Figure

Wave decomposition applied to LA phasic longitudinal strain evaluated from MRI feature tracking to estimate a true LA booster strain index

Funding Acknowledgements

Type of funding sources: None.

Background. Feature tracking (FT) is an emerging approach for the evaluation of both left atrium (LA) and left ventricular (LV) myocardial strain from the same cine MRI dataset. We hypothesized that the LA active contraction longitudinal strain, is a merge of an intrinsic LA booster contraction with the early diastolic LA emptying, especially when this latter is extended because of a poor LV relaxation (Figure 1, bottom). Such index can be estimated through LA phasic strain wave-decomposition as conventionally done for pressure curves to estimate forward and reflected components.

Purpose. To compare the newly proposed LA intrinsic or "true" booster index (Sla_fit) against the conventional index (Sla) in terms of associations with LV remodeling (LV mass/ LV volume), LV systolic longitudinal strain (LV_GLS), and transmitral LV filling indices in healthy controls and aortic valve stenosis (AVS) patients with preserved LV ejection fraction.

Methods. We studied 55 patients (34 AVS:71 ± 11years, 21 controls:66 ± 9years) who had an MRI exam with cine SSFP and phase contrast (PC) images. FT was applied to cine images to extract LV and LA phasic longitudinal strain and strain rates. Transmitral flow early (E, cm/s) and late (A, cm/s) filling peak velocities were calculated from PC data. To estimate intrinsic LA booster index, the LA longitudinal strain curve corresponding to the reservoir and conduit phases was fitted using two half cosine waves, to account for an eventual LA filling to LA early emptying asymmetry, while fitting the LA contraction with a full cosine wave (Figure 1). The peak of this latter wave was defined as the intrinsic LA booster strain index (Sla_fit), while the second peak of the measured LA strain was defined as the conventional LA booster strain (Sla).

Results. While conventional Sla was significantly higher than intrinsic LA booster Sla_fit in AVS patients (13.55 ± 4.26 vs. 8.09 ± 6.07, p = 0.0002), it was nearly equivalent in controls (14.34 ± 4.30 vs.13.43 ± 4.23, p =.49). But the newly proposed LA booster strain index was significantly related to LV_GLS (r=-48,p=.0004); to LV remodeling (r=-.44,p = 0.0012) as well as to transmitral flow A wave ( r=-.49, p=.0005) none of these associations were significant when considering conventional LA booster strain. Interestingly our intrinsic LA booster index Sla_fit was significantly associated with LV longitudinal strain in both controls (r=-.55,p = 0.009) and asymptomatic AVS (N = 10) (r=-.77,p = 0.0081) but not in symptomatic AVS (N = 24) (p>.70). This may reveal a maintained LA-LV coupling in the asymptomatic phase and an uncoupling in the symptomatic phase, caused by elevated LV filling pressures.

Conclusions. A promising index for the quantitative evaluation of intrinsic LA booster function was proposed and its consistency was demonstrated through its significant associations with LV remodeling, LV longitudinal strain and transmitral late filling peak.

Abstract Figure.

In vitro evaluation of polymeric nanoparticles with a fluorine core for drug delivery triggered by focused ultrasound

Polymeric nanoparticles are being intensively investigated as drug carriers. Their efficiency could be enhanced if the drug release can be triggered using an external stimulus such as ultrasound. This approach is possible using current commercial apparatus that combine focused ultrasound with MRI to perform ultrasonic surgery. In this approach, nanoparticles made of a perfluoro-octyl bromide core and a thick polymeric (PLGA-PEG) shell may represent suitable drug carriers. Indeed, their perfluorocarbon core are detectable by ¹⁹F MRI, while their polymeric shell can encapsulate drugs. However, their applicability in ultrasound-triggered drug delivery remains to be proven. To do so, we used Nile red as a model drug and we measured its release from the polymeric shell by spectrofluorometry. In the absence of ultrasound, only a small amount of Nile red release was measured (<5%). Insonations were performed in a controlled environment using a 1.1 MHz transducer emitting tone bursts for a few minutes, whereas a focused broadband hydrophone was used to detect the occurrence of cavitation. In the absence of detectable inertial cavitation, less than 5% of Nile red was released. In the presence of detectable inertial cavitation, Nile red release was ranging from 10% to 100%, depending of the duty cycle, acoustic pressure, and tank temperature (25 or 37 °C). Highest releases were obtained only for duty cycles of 25% at 37 °C and 50% at 25 °C and for a peak-to-peak acoustic pressure above 12.7 MPa. Electron microscopy and light scattering measurements showed a slight modification in the nanoparticle morphology only at high release contents. The occurrence of strong inertial cavitation is thus a prerequisite to induce drug release for these nanoparticles. Since strong inertial cavitation can lead to many unwanted biological effects, these nanoparticles may not be suitable for a therapeutic application using ultrasound-triggered drug delivery.

Are Gadolinium-Enhanced MR Sequences Needed in Simultaneous 18F-FDG-PET/MRI for Tumor Delineation in Head and Neck Cancer?

BACKGROUND AND PURPOSE

PET/MRI with ¹⁸F-FDG has demonstrated the advantages of simultaneous PET and MR imaging in head and neck cancer imaging, MRI allowing excellent soft-tissue contrast, while PET provides metabolic information. The aim of this study was to evaluate the added value of gadolinium contrast-enhanced sequences in the tumor delineation of head and neck cancers on ¹⁸F-FDG-PET/MR imaging.

MATERIALS AND METHODS

Consecutive patients who underwent simultaneous head and neck ¹⁸F-FDG-PET/MR imaging staging or restaging followed by surgery were retrospectively included. Local tumor invasion and lymph node extension were assessed in 45 head and neck anatomic regions using ¹⁸F-FDG-PET/MR imaging by 2 rater groups (each one including a radiologist and a nuclear medicine physician). Two reading sessions were performed, one without contrast-enhanced sequences (using only T1WI, T2WI, and PET images) and a second with additional T1WI postcontrast sequences. The results were compared with the detailed histopathologic analysis, used as reference standard. The κ concordance coefficient between the reading sessions and sensitivity and specificity for each region were calculated.

RESULTS

Thirty patients were included. There was excellent agreement between the contrast-free and postgadolinium reading sessions in delineating precise tumor extension in the 45 anatomic regions studied (Cohen κ = 0.96, 95% CI = [0.94-0.97], P < .001). The diagnostic accuracy did not differ between contrast-free and postgadolinium reading sessions, being 0.97 for both groups and both reading sessions. For the 2 rater groups, there was good sensitivity for both contrast-free (0.83 and 0.85) and postgadolinium reading sessions (0.88 and 0.90, respectively). Moreover, there was excellent specificity (0.98) for both groups and reading sessions.

CONCLUSIONS

Gadolinium chelate contrast administration showed no added value for accurate characterization of head and neck primary tumor extension and could possibly be avoided in the PET/MR imaging head and neck workflow.

Contribution of endobronchial ultrasound elastography to the characterization of mediastinal lymphadenopathy: A single-center, prospective, observational study

BACKGROUND

Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a reliable technique providing high diagnostic yield in mediastinal lymphadenopathy. However, mediastinoscopy is sometimes necessary to eliminate false-negative results. Elastography is a recent technique that can be combined with EBUS to evaluate the elasticity and consequently the nature of a tissue. The primary objective was to evaluate the diagnostic performance of EBUS-TBNA combined with elastography for the assessment of mediastinal lymph nodes.

METHODS

Single-center, prospective study in patients with mediastinal lymphadenopathy. EBUS-TBNA combined with elastography was performed in each patient. Several elastographic parameters were studied: colorimetric score, average elasticity, elasticity ratio, percentage of hard areas. The final diagnosis was that obtained by TBNA cytology, histology of a surgical biopsy, when performed, or follow-up CT and PET-CT at 6 months.

RESULTS

Overall, 110 lymph nodes were examined in 87 patients: 44 were malignant according to TBNA. These nodes had significantly higher elasticity ratio, percentage of hard areas and colorimetric score and significantly lower average elasticity compared to benign nodes (P<0.001). With a negative predictive value of 100%, the cut-offs defined by receiver operating characteristic curves were 1.4 for elasticity ratio, 84.8 for average elasticity, 32.6 for percentage of hard areas and 3 for colorimetric score. No adverse events were observed.

CONCLUSION

Endobronchial ultrasound elastography is a non-invasive technique that can contribute to prediction of the nature of lymph nodes by distinguishing malignant from benign nodes. Although EBUS cannot replace histological examination, elastography can provide reliable complementary information when combined with EBUS.

Patient emergency assessment following deliberate self-poisoning with benzodiazepines: Can cognitive markers predict recall of the psychiatric interview? A pilot study

STUDY HYPOTHESIS

In cases of deliberate self-poisoning (DSP), patients often ingest benzodiazepines (BZDs), known to alter memory. Experts recommend recovery of the patient's cognitive capacity before psychiatric assessment. Unfortunately, there is no validated tool in common practice to assess whether sufficient cognitive recovery has occurred after DSP with BZDs to ensure patient memory of the assessment.

OBJECTIVE

The aim of the study was to identify cognitive functions and markers which predict preserved memory of the mental health care plan proposed at the emergency department after DSP.

METHODS

We recruited patients admitted for DSP with BZDs and control patients. At the time of the psychiatric assessment, we performed cognitive tests and we studied the relationship between these tests and the scores of a memory test performed 24 h after.

RESULTS

In comparison with the control group, we found memory impairment in the BZD group. We found significant impairment on the Trail Making Test A (TMT A) in the BZD group in comparison with the control group, while TMT A and Wechsler Adult Intelligence Scale (WAIS) Coding test scores were significantly correlated with memory scores.

CONCLUSIONS

Attentional functions tested by WAIS Coding test and TMT A were correlated with memory score. It could be profitable to assess it in clinical practice prior to a psychiatric interview.

Assessment of routine malaria diagnosis in the Venezuelan Amazon

The quality of routine malaria diagnosis is a crucial topic of malaria control. The aim of this assessment was to monitor and evaluate the quality of routine malaria diagnosis in Amazonas (Venezuela) and to improve the quality control system. The traditional non-blinded quality control system was found to be overburdened with diagnostic samples. A modified sampling system with fewer samples to be tested was proposed. Expert microscopists blindly double-checked 1000 slides and 550 rapid diagnostic tests (RDT) (OptiMAL-IT) from health posts (HP). For Plasmodium vivax, HP microscopy and OptiMAL-IT showed sensitivies of 86% and 63%, respectively. For P. falciparum, HP microscopy and OptiMAL-IT showed sensitivities of 68% and 89%, respectively. Both methods lost accuracy when fewer parasites occurred in the sample. HP microscopists from different municipalities displayed significant differences in diagnostic quality. Overall, quality of routine malaria diagnosis in the Venezuelan Amazon is good but not optimal. The change from the traditional non-blinded quality control system to blinded cross-checking of a minimal selection of samples is - comparatively - a low cost intervention with possibly high impact on the quality of routine malaria diagnosis. The introduction of RDTs should be discussed carefully in order not to displace an existing network of HP microscopists.

Influence of facial skin attributes on the perceived age of Caucasian women

BACKGROUND AND OBJECTIVE

The facial appearance of a person does not always reflect the chronological age; some people look younger or older than they really are. Many studies have described the changes in skin properties (colour, wrinkles, sagging, micro relief, etc.) with age, but few of them have analysed their influence on the perceived age. The primary objective of this study was to assess the contribution of individual skin attributes of the face on the perceived age of Caucasian women. Secondary objectives were to assess the influence of age and gender of graders with regard to the age perception.

SUBJECTS AND METHOD

A random sample of 173 subjects of 20 to 74 years of age was taken from a database of more than 5000 healthy Caucasian women. A trained grader performed visual assessment of facial skin attributes (using a visual analogue scale), and a front face photograph was taken from each subject. Photographs were shown to 48 graders (20 men and 28 women, aged 22-64 years) who were asked to estimate the age of the subjects. Graders were classified as young (less than 35 years), middle age (35-50 years) and seniors (older than 50 years). Partial Least Square regression models were built to predict the chronological and the perceived age from the measured facial individual attributes. The contribution of each attribute within the regression model enabled to measure the relevance of this attribute with regards to age prediction.

RESULTS

The eye area and the skin colour uniformity were the main attributes related to perceived age. For age prediction, older graders' estimations were more driven by lips border definition shape and eyes opening, whereas younger graders' (older than 50 years) estimations were more driven by dark circles, nasolabial fold and brown spots. There were statistically significant differences in graders' age perception between gender and among age ranges. Our findings suggest that female graders are more accurate than male, and younger graders (under 35 years) are more accurate than older (over 50 years) to predict Caucasian women age from facial photographs.

CONCLUSIONS

Different skin attributes influence the estimation of age. These attributes have a different weight in the evaluation of the perceived age, depending on the age and of the observer. The most important attributes to estimate age are eyes, lips and skin colour uniformity.

Genomic signature: characterization and classification of species assessed by chaos game representation of sequences

We explored DNA structures of genomes by means of a new tool derived from the "chaotic dynamical systems" theory (the so-called chaos game representation [CGR]), which allows the depiction of frequencies of oligonucleotides in the form of images. Using CGR, we observe that subsequences of a genome exhibit the main characteristics of the whole genome, attesting to the validity of the genomic signature concept. Base concentrations, stretches (runs of complementary bases or purines/pyrimidines), and patches (over- or underexpressed words of various lengths) are the main factors explaining the variability observed among sequences. The distance between images may be considered a measure of phylogenetic proximity. Eukaryotes and prokaryotes can be identified merely on the basis of their DNA structures.

Panic-phobic patients and developmental trauma

BACKGROUND

Several studies suggest high rates of developmental trauma among adult anxiety disorder patients. We attempted to replicate these findings in patients with panic disorder, agoraphobia, and/or social phobia in comparison with a nonclinical population and to evaluate possible relationship of traumas and phobic subtypes.

METHOD

Fifty-one patients with panic disorder with agoraphobia and/or social phobia were assessed for lifetime diagnoses using interviews and rating scales and for developmental trauma by the Life Experience Questionnaire (LEQ). Fifty-one demographically similar nonclinical subjects completed a questionnaire that included the LEQ and screening questions for lifetime psychopathology.

RESULTS

Childhood trauma was reported by 63% (N = 32) of the patients (vs. 35% or 18 of comparison subjects and 24% or 9 of subjects negative for lifetime psychopathology; chi 2 = 7.7, df = 1, p < .01). Sexual and/or physical abuse histories (and not separation and/or loss) were significantly increased in the patient group and were most specifically associated with social phobia.

CONCLUSION

We find a similar, increased rate of childhood trauma as has been reported in previous studies of anxiety disorder patients. In our findings, this most specifically represents an association of social phobia and sexual/physical abuse histories.

Conversion of COPD patients from multiple to single dose theophylline. Serum levels and symptom comparison

The objective of the present study was to determine if patients with COPD who were taking Theo-Dur bid or tid (total dose 400 to 900 mg per day) could be safely switched to Uni-Dur, 800 mg given qd at bedtime. Twenty-eight patients were enrolled in the study, and 23 completed the study. The mean daily dose of theophylline prior to the study was 828 mg, while the mean dose after three weeks of Uni-Dur therapy was 783 mg. The mean serum theophylline level 10.5 +/- 3.6h after the last Theo-Dur dose was 10.5 mg/L. After three weeks of Uni-Dur therapy, the mean theophylline level at 8:00 AM was 14.6 mg/L, while the mean theophylline level at 8:00 PM was 9.9 mg/L. This latter level did not differ significantly from that obtained at the start of the study 10.5 +/- 3.6 h after the last dose of Theo-Dur. After three weeks of Uni-Dur therapy, the peak expiratory flow rate, the FEV1, and the FVC were not significantly changed from those at the initial evaluation. Twenty-one of the 23 patients ended up receiving 800 mg Uni-Dur qd. From this study, we conclude that once daily theophylline dosing with Uni-Dur compared with bid or tid dosing with Theo-Dur produces similar theophylline levels and pulmonary function, and most COPD patients who are taking 400 to 900 mg Theo-Dur daily can be managed with 800 mg Uni-Dur once daily at bedtime.

Nonmetastatic thoracic neuroblastomas: a review of 40 cases

From 1982 to 1987, 40 children with non-metastatic thoracic neuroblastoma were treated with the same therapeutic regimen. According to TNM staging, there were 11 CS I, 19 CS II, and 10 CS III. All patients underwent surgery; 30 had primary surgical excision; in 10 whose tumors were deemed unresectable, surgery was delayed until after a trial of chemotherapy. Operation was completed by several courses of chemotherapy in case of microscopic residual disease or regional lymph node involvement; radiotherapy was delivered in case of gross residual disease. Using this therapeutic approach, EFS is 92% with a median follow-up of 40 months. Severe complications were rare and sequellae appear to be related to the disease, i.e., neurologic consequences of cord compression.

Treatment of stage IV-S neuroblastoma: a study of 34 cases treated between 1982 and 1987

Between January 1982 and December 1987, of 283 children with neuroblastoma treated in the Pediatric Department of Institut Gustave Roussy, 34 were stage IV-S. Two groups were distinguished according to the initial clinical presentation: 16/34 patients had life-threatening symptoms and needed immediate treatment, and 18/34 had no life-threatening symptoms. Hepatic irradiation was used in 12/16 patients of the first group with respiratory distress. Chemotherapy was used in three patients. Of these 16 patients, three patients died of progressive disease (one patient died of a reason not related to the tumor). Twelve are alive in first complete remission and one in second complete remission. Of the 18 patients of the second group, eight had spontaneous complete remission, and one of them relapsed thereafter and died despite treatment. Ten patients needed treatment, radiotherapy, and/or chemotherapy depending on the site of disease progression. Two of them died of the disease. The overall disease-free survival for these 34 patients is 75% at 90 months postdiagnosis. Using this therapeutic strategy, it was possible to avoid any treatment of metastases in 25% of the patients.