Super-Resolution Scanning Transmission X-Ray Imaging Using Single Biconcave Parabolic Refractive Lens Array

A new super resolution imaging technique which potentially enables sub-µm spatial resolution, using a detector of pixels much larger than the spatial resolution, is proposed. The method utilizes sample scanning through a large number of identical X-ray microprobes periodically spaced (the period corresponds to a multiple of the pixel size), which reduces drastically the scanning time. The information about the sample illuminated by the microprobes is stored by large detector pixels. Using these data and sample position information, a super-resolution image reconstruction is performed. With a one-dimensional (1D) high aspect ratio nickel single lens array designed for theoretically expected sub-µm microprobes at 17 keV and fabricated by deep X-ray lithography and electroforming technique, 2 µm X-ray microprobes with a period of 10 µm were achieved. We performed a first experiment at KARA synchrotron facility, and it was demonstrated that the smallest structure of a test pattern with a size of 1.5 µm could be easily resolved by using images generated from a detector having a pixel size of 10.4 µm. This new approach has a great potential for providing a new microscopic imaging modality with a large field of view and short scan time.

P2573Modelling the duchenne muscular dystrophy-induced dilated cardiomyopathy using patient-specific induced pluripotent stem cells-derived cardiomyocytes

Introduction

Duchenne Muscular Dystrophy (DMD) is a X-linked degenerative pathology with a prevalence of 1/3500 boys due to absence of functional dystrophin in muscles. In a late stage of DMD, patients developed a dilated cardiomyopathy (DCM) which can lead to heart failure and premature death.

In the past, we showed that DMD (mdx) mice exhibit a perturbation of the intracellular calcium homeostasis correlated to a pathological remodelling of the calcium ryanodine receptor channel (RyR2) leading to DCM with aging. However, mouse model does not represent a pertinent prototype to study DMD. Human pluripotent stem-cell derived-cardiomyocytes (hiPSC-CMs) are a pertinent tool to model patient-specific inherited cardiac diseases and screen pharmacological drugs in a Petri dish.

Objective

Based on the clinical history of DMD patients in the local Hospital, our main objective is to model DMD-induced DCM using hiPSC-CMs and compare the functional and molecular features with the clinical echocardiography. To that, we hypothesize that hiPSC-CMs are a powerful technology to model in vitro DCM and to better understand the pathophysiological mechanisms underlying DCM.

Methods

3 blood samples from DMD patients with different DCM degrees of severity and 3 from healthy control (HC) were collected, reprogrammed in hiPSC and differentiated into cardiomyocytes.

Results

Our preliminary data indicate that DMD hiPSC-CMs present an abnormal intracellular calcium homeostasis characterized by the presence of leaky diastolic calcium events compared to HC hiPSC-CMs suggesting a RyR2 dysfunction. In DMD hiPSC-CMs, we also observe alterations in the contractile properties and a perturbation of the mitochondrial respiration.

Conclusion

Our results support the fact that DMD-inducing DCM can be modelled in the dish using patient-specific hiPSC-CMs. Such modelling may provide a better understanding of the pathophysiological mechanisms and the pharmacological treatment of the DMD-induced DCM.

Plasminogen Activator Inhibitor 1: Biosynthesis and mRNA Level Are Increased by Insulin in Cultured Human Hepatocytes

Clinical studies have shown that plasma insulin levels are closely related to plasma plasminogen activator inhibitor 1 (PAI-1) levels. To investigate a possible involvement of hepatocytes we have studied the effect of insulin on PAI-1 production by primary cultures of human hepatocytes. We have isolated human hepatocytes from seven left liver lobes. PAI-1 activity measured in 24 hours conditioned medium varied considerably between the various hepatocyte preparations (from 2.9 to 8.5 units per 5 cm2of cells) possibly as a result of interindividual variability in basal PAI-1 production by hepatocytes from different donors. In all cases, however, the relative extent, time profile and dose-dependency of the insulin-induced increase in PAI-1 synthesis were consistent. Up to about 7 nM, insulin dose-dependently increased both PAI-1 activity and PAI-1 antigen production. The increase in PAI-1 synthesis became measurable between 4 and 8 hours after addition of the hormone, and maximally reached twofold control values. The increase in PAI-1 synthesis could be fully explained by a concomitant increase in PAI-1 mRNA levels. The effect of insulin seems fairly specific for the synthesis of PAI-1: overall protein synthesis and mRNA levels of some control proteins (albumin and fibrinogen) did not markedly change after insulin addition. These results, obtained with primary cultures of human hepatocytes, are fully comparable with those obtained with the hepatocellular carcinoma cell line Hep G2. They strengthen the suggestion that the elevated level of PAI-1 in high insulin plasma might be the result of increased hepatic synthesis of PAI-1.

Somatostatin Receptor Scintigraphy of a Patient with a Giant Invasive Prolactinoma

A 41-year-old with a giant prolactinoma underwent ln-111 pentetreotide (Octreotide) imaging showing very intense tracer uptake in the region of the anterior skull base. In contrast, there was no significant response to Octreotide therapy. Prediction of clinical responsiveness to Octreotide therapy in patients with pituitary adenomas may depend on the presence of somatostatin receptor subtype 5. Pentetreotide does not avidly bind to this receptor subtype and therefore, cannot be used clinically to predict therapeutic Octreotide responsiveness in patients with large prolactinomas.

Detecting anomalies in a deliberately biased tomotherapy plan: Comparison of two patient-specific quality assurance processes involving ArcCHECK® and Gafchromic® EBT3 films

PURPOSE

This work proposes a comparative evaluation of two of our patient-specific quality assurance processes involving ArcCHECK^® (Sun Nuclear) and Gafchromic^® EBT3 films (Ashland) in order to determine which detector is able to most effectively detect an anomaly in a deliberately biased tomotherapy plan.

MATERIAL AND METHODS

A complex clinical head and neck tomotherapy plan was deliberately biased by introducing six errors: multileaf collimator leaf positional errors by leaving one and two central leafs closed during the whole treatment, initial radiation angle errors (+0.5° and +1.0°) and multileaf collimator leafs opening time errors (+0.5% and +1.0%). For each error-induced plan, comparison of ArcCHECK^® with Gafchromic^® EBT3 films (20.3×25.4cm²) was performed through two methods: a dose matrices subtraction study and a gamma index analysis.

RESULTS

The dose matrices subtraction study shows that our ArcCHECK^® processing is able to detect all the six induced errors contrary to the one using films, which are only able to detect the two biases involving multileaf collimator leaf positional errors. The gamma index analysis confirms the previous method, since it shows all six errors induced in the reference plan seem to be widely detected with ArcCHECK^® with the more restrictive 1%/1mm gamma criterion, whereas films may only be able to detect biases in relation to multileaf collimator leaf positional errors. It also shows the common 3%/3mm gamma criterion does not allow deciding between both detectors in the detection of the six induced biases.

CONCLUSION

Both comparative methods showed ArcCHECK^® processing is more suitable to detect the six errors introduced in the reference treatment plan.

[Algorithms and urinary incontinence in the elderly. Assessment, treatment, recommendations and levels of evidence. Review]

OBJECTIVES

Search processing algorithms in a primary care setting, analyzing the specifics of care management for seniors suffering from urinary incontinence (UI), described the recommendations and levels of evidence of treatment.

METHODS

A literature review carried out via PubMed^® and websites of scientific societies with search keywords classified according to an algorithm.

RESULTS

One hundred algorithms have been discovered in the field of evaluation and treatment of UI. Screening for UI risk factors began early on in the treatment of reversible or chronic comorbidities, avoiding iatrogenic. Specific clinical features (red flags) required specialized advice. Non-pharmacological conservative treatment should be offered first in line for seniors: behavioral therapy, changes in lifestyle, walk, treatment of constipation. For women, pelvic floor muscle training combined biofeedback and functional electrical stimulation. After failure and persistence of UI with urgency, the information of the risk of a possible urinary retention or cognitive impairments preceded the prescription of an anticholinergic and the measurement of post-voiding residue done by ultrasounds. Older age is not a cons-indication for surgery UI least invasive. The cough test and Bonney maneuver can confirm a masked stress urinary incontinence and/or an associated prolapse. Cases of failure of UI, doubtful diagnosis or programmed surgery required urodynamic assessment.

CONCLUSION

Algorithms and recommendations of UI should remain a valuable aid to the clinical assessment, diagnosis and treatment of UI in the elderly.

Benzylpenicillin plus an aminoglycoside versus meropenem in neutropenic lymphoma and leukaemia patients with a suspected bacterial infection: a randomized, controlled trial

OBJECTIVES

In Norway, initial treatment of febrile neutropenia (FN) has traditionally been benzylpenicillin plus an aminoglycoside. Internationally, FN is often treated with a broad-spectrum β-lactam antibiotic. We aimed to compare these two regimens in a prospective, randomized, trial in patients with lymphoma or leukaemia with an expected period of neutropenia ≥7 days, and a suspected bacterial infection.

METHODS

Adult neutropenic patients with lymphoma or leukaemia, and a suspected bacterial infection, were randomized for treatment with benzylpenicillin plus an aminoglycoside or meropenem. The primary endpoint was clinical success, defined as no modification of antibiotics and clinical stability 72 h after randomization.

RESULTS

Among 322 randomized patients, 297 proved evaluable for analyses. Fifty-nine per cent (95% CI 51%-66%), (87/148) of the patients given benzylpenicillin plus an aminoglycoside were clinically stable, and had no antibiotic modifications 72 h after randomization, compared with 82% (95% CI 75%-87%), (122/149) of the patients given meropenem (p <0.001). When the antibiotic therapy was stopped, 24% (95% CI 18%-32%), (36/148) of the patients given benzylpenicillin plus an aminoglycoside, compared with 52% (95% CI 44%-60%), (78/149) of the patients given meropenem, had no modifications of their regimens (p <0.001). In the benzylpenicillin plus an aminoglycoside arm, the all-cause fatality within 30 days of randomization was 3.4% (95% CI 1.2%-7.9%), (5/148) of the patients, compared with 0% (95% CI 0.0%-3.0%), (0/149) of the patients in the meropenem arm (p 0.03).

CONCLUSION

Clinical success was more common in FN patients randomized to meropenem compared with the patients randomized to benzylpenicillin plus an aminoglycoside. The all-cause fatality was higher among the patients given benzylpenicillin plus an aminoglycoside.