Effectiveness of electronic patient reporting outcomes, by a digital telemonitoring platform, for prostate cancer care: the Protecty study

Research aim and purpose

The benefits of Electronic Patient -Reported Outcomes (e-PRO) for telemonitoring are well established, allowing early detection of illnesses and continuous monitoring of patients. The primary objective of the PROTECTY study was to assess the compliance with patient use of the telemonitoring platform Cureety. An exploratory objective was to assess if the first-month health status is a prognostic factor of progression free-survival (PFS) and overall survival (OS) for prostate cancer patient.

Methods

This prospective study was conducted at the Military Hospital Bégin on prostate cancer patients. Patients were allowed to respond to a symptomatology questionnaire based on CTCAE v.5.0, personalized to their pathology and treatment. An algorithm evaluates the health status of the patient based on the reported adverse events, with a classification into 2 different states: Good Health Status (GHS) and Poor Health status (PHS).

Results

Sixty-one patients were enrolled between July 1st, 2020 and September 30th, 2021. The median age was 74.0 (range 58.0-94.0). 78% presented a metastatic stage, and the most represented cancer was mHSPC. Overall, 2,457 questionnaires were completed by the patients, 4.0% resulted in a health classification in to monitor or critical state. 87% of patients were classified in the GHS group. The compliance was 72% in the overall population during the first month, 71% in GHS group and 75% in PHS group. The median follow-up was 8 months. PFS at 6 months was 84% in GHS group vs. 57% in PHS group, p = 0.19. OS at 6 months was 98% in GHS group vs. 83% in PHS group, p = 0.31.

Conclusions

Our study showed that compliance was satisfactory. The feasibility of remote monitoring for prostate cancer patients means that they should benefit from its implementation. Our study is also the first to assess the correlation between treatment tolerance and survival. The initial results suggest that e-PRO assessment could help identify in the early stages the patients that require further health assessment and potential therapeutic changes. While further follow-up of more patients will be required, our study highlights the importance of e-PRO in cancer patient care.

Microphase separation of living cells

Self-organization of cells is central to a variety of biological systems and physical concepts of condensed matter have proven instrumental in deciphering some of their properties. Here we show that microphase separation, long studied in polymeric materials and other inert systems, has a natural counterpart in living cells. When placed below a millimetric film of liquid nutritive medium, a quasi two-dimensional, high-density population of Dictyostelium discoideum cells spontaneously assembles into compact domains. Their typical size of 100 μm is governed by a balance between competing interactions: an adhesion acting as a short-range attraction and promoting aggregation, and an effective long-range repulsion stemming from aerotaxis in near anoxic condition. Experimental data, a simple model and cell-based simulations all support this scenario. Our findings establish a generic mechanism for self-organization of living cells and highlight oxygen regulation as an emergent organizing principle for biological matter.

A new agarose-based microsystem to investigate cell response to prolonged confinement

Emerging evidence suggests the importance of mechanical stimuli in normal and pathological situations for the control of many critical cellular functions. While the effect of matrix stiffness has been and is still extensively studied, few studies have focused on the role of mechanical stresses. The main limitation of such analyses is the lack of standard in vitro assays enabling extended mechanical stimulation compatible with dynamic biological and biophysical cell characterization. We have developed an agarose-based microsystem, the soft cell confiner, which enables the precise control of confinement for single or mixed cell populations. The rigidity of the confiner matches physiological conditions and its porosity enables passive medium renewal. It is compatible with time-lapse microscopy, in situ immunostaining, and standard molecular analyses, and can be used with both adherent and non-adherent cell lines. Cell proliferation of various cell lines (hematopoietic cells, MCF10A epithelial breast cells and HS27A stromal cells) was followed for several days up to confluence using video-microscopy and further documented by Western blot and immunostaining. Interestingly, even though the nuclear projected area was much larger upon confinement, with many highly deformed nuclei (non-circular shape), cell viability, assessed by live and dead cell staining, was unaffected for up to 8 days in the confiner. However, there was a decrease in cell proliferation upon confinement for all cell lines tested. The soft cell confiner is thus a valuable tool to decipher the effects of long-term confinement and deformation on the biology of cell populations. This tool will be instrumental in deciphering the impact of nuclear and cytoskeletal mechanosensitivity in normal and pathological conditions involving highly confined situations, such as those reported upon aging with fibrosis or during cancer.

Constraints on Lorentz Invariance Violation from HAWC Observations of Gamma Rays above 100 TeV

Because of the high energies and long distances to the sources, astrophysical observations provide a unique opportunity to test possible signatures of Lorentz invariance violation (LIV). Superluminal LIV enables the decay of photons at high energy. The high altitude water Cherenkov (HAWC) observatory is among the most sensitive gamma-ray instruments currently operating above 10 TeV. HAWC finds evidence of 100 TeV photon emission from at least four astrophysical sources. These observations exclude, for the strongest of the limits set, the LIV energy scale to 2.2×10^{31}  eV, over 1800 times the Planck energy and an improvement of 1 to 2 orders of magnitude over previous limits.

Multiple Galactic Sources with Emission Above 56 TeV Detected by HAWC

We present the first catalog of gamma-ray sources emitting above 56 and 100 TeV with data from the High Altitude Water Cherenkov Observatory, a wide field-of-view observatory capable of detecting gamma rays up to a few hundred TeV. Nine sources are observed above 56 TeV, all of which are likely galactic in origin. Three sources continue emitting past 100 TeV, making this the highest-energy gamma-ray source catalog to date. We report the integral flux of each of these objects. We also report spectra for three highest-energy sources and discuss the possibility that they are PeVatrons.

Publisher Correction: Very-high-energy particle acceleration powered by the jets of the microquasar SS 433

In this Letter, owing to a production error, the penultimate version of the PDF was published. The HTML version was always correct. The PDF has been corrected online.

Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth

The unexpectedly high flux of cosmic-ray positrons detected at Earth may originate from nearby astrophysical sources, dark matter, or unknown processes of cosmic-ray secondary production. We report the detection, using the High-Altitude Water Cherenkov Observatory (HAWC), of extended tera-electron volt gamma-ray emission coincident with the locations of two nearby middle-aged pulsars (Geminga and PSR B0656+14). The HAWC observations demonstrate that these pulsars are indeed local sources of accelerated leptons, but the measured tera-electron volt emission profile constrains the diffusion of particles away from these sources to be much slower than previously assumed. We demonstrate that the leptons emitted by these objects are therefore unlikely to be the origin of the excess positrons, which may have a more exotic origin.

Differences in trochlear parameters between native and prosthetic kinematically or mechanically aligned knees

INTRODUCTION

Kinematic (KA) and mechanical (MA) alignment techniques are two different philosophies of implant positioning that use the same TKA implants. This might generate differences in the resulting prosthetic trochleae parameters between the two techniques of alignment. Our study aim was to test the following hypotheses : (1) mechanically or kinematically aligned femoral implant understuffs the native trochlear articular surface and poorly restores the native groove orientation, and (2) the orientation of the prosthetic trochlear groove and trochlear fill are different between MA and KA.

METHODS

Three-dimensional models of the femur were made from segmentation of preoperative Magnetic Resonance Imaging scans (MRIs) of ten subjects with isolated medial tibiofemoral osteoarthritis. In-house planning and analysis software kinematically and mechanically aligned a modern cruciate retaining femoral component and determined differences in parameters of the trochlear fit between native and prosthetic trochleae, and between KA and MA prosthetic trochleae.

RESULTS

The MA prosthetic trochleae did not fill (understuffed) the entire length of the native medial facet and the proximal 70% of the native groove and lateral facet, and oriented the trochleae groove 8° more valgus than native. The KA prosthetic trochleae understuffed the proximal 70% of the native trochleae, and had a groove 6° more valgus than native. The KA trochleae understuffed the medial facet distally and oriented the groove 2° less valgus and 3° more internally rotated than the MA trochleae.

CONCLUSION

MA and KA prosthetic trochleae substantially understuff and create a prosthetic groove more valgus compared to native trochlear anatomy, and they also differed between each other regarding trochleae stuffing and groove alignment. Although randomized trials have not shown differences in patellofemoral complications between KA and MA, a femoral component designed specifically for KA that more closely restores the native trochlear anatomy might improve patient reported satisfaction and function.

LEVEL OF EVIDENCE

Level 2 controlled laboratory study.

Alignment options for total knee arthroplasty: A systematic review

In spite of improvements in implant designs and surgical precision, functional outcomes of mechanically aligned total knee arthroplasty (MA TKA) have plateaued. This suggests probable technical intrinsic limitations that few alternate more anatomical recently promoted surgical techniques are trying to solve. This review aims at (1) classifying the different options to frontally align TKA implants, (2) at comparing their safety and efficacy with the one from MA TKAs, therefore answering the following questions: does alternative techniques to position TKA improve functional outcomes of TKA (question 1)? Is there any pathoanatomy not suitable for kinematic implantation of a TKA (question 2)? A systematic review of the existing literature utilizing PubMed and Google Scholar search engines was performed in February 2017. Only studies published in peer-reviewed journals over the last ten years in either English or French were reviewed. We identified 569 reports, of which 13 met our eligibility criteria. Four alternative techniques to position a TKA are challenging the traditional MA technique: anatomic (AA), adjusted mechanical (aMA), kinematic (KA), and restricted kinematic (rKA) alignment techniques. Regarding osteoarthritic patients with slight to mid constitutional knee frontal deformity, the KA technique enables a faster recovery and generally generates higher functional TKA outcomes than the MA technique. Kinematic alignment for TKA is a new attractive technique for TKA at early to mid-term, but need longer follow-up in order to assess its true value. It is probable that some forms of pathoanatomy might affect longer-term clinical outcomes of KA TKA and make the rKA technique or additional surgical corrections (realignment osteotomy, retinacular ligament reconstruction etc.) relevant for this sub-group of patients. Longer follow-up is needed to define the best indication of each alternative surgical technique for TKA. Level I for question 1 (systematic review of Level I studies), level 4 for question 2.

The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis

INTRODUCTION

Kinematic alignment (KA) technique is an alternative technique for positioning a TKA, which aims a patient-specific implant positioning in order to reproduce the pre-arthritic knee anatomy. Because reliability in implant positioning is of interest to obtain reproducible good functional results, our study tests the hypothesis that the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically aligned femoral component are similar.

METHODS

Preoperative knee magnetic resonance imaging (MRI) and postoperative knee computed tomography (CT) of 13 patients implanted with a KA Persona^® TKA (Zimmer, Warsaw, USA) using manual instrumentation (kinematically-aligned TKA procedure pack^®, Zimmer Biomet, Warsaw, USA) were segmented to create 3D femoral models. The kinematic alignment position of the femoral component was planned on the 3D model created from the preoperative MRI. Differences in the positions of the planned and surgically implanted kinematically-aligned femoral component were determined with in-house analysis software.

RESULTS

The average differences between the medial and lateral distal and posterior positions of the planned and surgically implanted kinematically-aligned femoral component were inferior to 1mm and no statistically significant. In terms of variability, 62% (8/13) of performed implants matched all four positions within 1.5mm, and the maximum difference was 3mm.

CONCLUSION

In this small series, intraoperative kinematic positioning of the femoral component with the specific manual instrumentation closely matched the planned position, which suggests that this technique reliably aligned the flexion-extension axis of the femoral component to the cylindrical axis.

LEVEL OF EVIDENCE

Level 3.

Mechanical alignment technique for TKA: Are there intrinsic technical limitations?

BACKGROUND

Mechanically aligned (MA) total knee arthroplasty (TKA) is affected by disappointing functional outcomes in spite of the recent improvements in surgical precision and implant designs. This might suggest the existence of intrinsic technical limitations. Our study aims to compare the prosthetic and native trochlear articular surfaces and to estimate the extent of collateral ligament imbalance, which is technically uncorrectable by collateral ligament release when TKA implants are mechanically aligned.

STUDY HYPOTHESIS

Conventional MA technique generates a high rate of prosthetic overstuffing of the distal groove, distal lateral trochlear facet and distal lateral femoral condyle (Hypothesis 1), and technically uncorrectable collateral ligament imbalance (hypothesis 2)? Disregarding the distal femoral joint line obliquity (DFJLO) when performing femoral cuts explains distal lateral femoral prosthetic stuffing and uncorrectable imbalance (hypothesis 3)?

METHODS

Twenty patients underwent a conventional MA TKA. Pre-operative MRI-based 3D knee models were generated and MA TKA was simulated. Native and prosthetic trochlear articular surfaces were compared using in-house analysis software. Following the automatic determination by the planning software of the size of the extension and flexion gaps, an algorithm was applied to balance the gaps and the frequency and amplitude of technically uncorrectable knee imbalance were estimated.

RESULTS

The conventional MA technique generates a significant slight distal lateral femoral prosthetic overstuffing (mean 0.6mm, 0.8mm, 1.25mm for the most distal lateral facet point, groove, and at the most distal point of lateral femoral condyle, respectively) and a high rate of type 1 and 2 uncorrectable knee imbalance (30% and 40%, respectively). The incidence of distal lateral prosthetic overstuffing (trochlea and condyle) and uncorrectable knee imbalance were strongly to very strongly correlated with the DFJLO (r=0.53 to 0.89).

CONCLUSION

Conventional MA technique for TKA generates frequent lateral distal femoral prosthetic overstuffing and technically uncorrectable knee imbalance secondary to disregarding the DFJLO when adjusting the femoral component frontal and axial rotations, respectively.

LEVEL OF EVIDENCE

level 4.

The influence of spine-hip relations on total hip replacement: A systematic review

Sagittal pelvic kinematics along with spino-pelvic angular parameters have recently been studied by numerous investigators for their effect on total hip replacement (THR) clinical outcomes, but many issue of spine-hip relations (SHR) are currently unexplored. Therefore, our review aims at clarifying the following questions: is there any evidence of a relationship between articular impingement/dislocation risk in primary THR and (1) certain sagittal pelvic kinematics patterns, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilising PubMed and Google search engines was performed in January 2017. Only clinical or computational studies published in peer-reviewed journals over the last five years in either English or French were reviewed. We identified 769 reports, of which 12 met our eligibility criteria. A review of literature shows that sagittal pelvic kinematics, but not the pelvic incidence, influences the risk of prosthetic impingement/dislocation. We found no study having assessed the relationship between this risk and the types of SHRs. Sagittal pelvic kinematics is highly variable among individuals and certain kinematic patterns substantially influences the risk of prosthetic impingement/dislocation. Recommendations for cup positioning are therefore switching from a systematic to a patient-specific approach, with the standing cup orientation Lewinneck safe zone progressively giving way to a new parameter of interest: the functional orientation of the cup. Based on a recently published classification for SHRs, We propose a new concept of "kinematically aligned THR" for the purposes of THR planning. Further studies are needed to investigate the relevance of such a classification towards the assumptions and hypothesis we have made. Level of evidence,- Level IV, systematic review of level III and IV studies.

Spine-hip relations add understandings to the pathophysiology of femoro-acetabular impingement: A systematic review

Relationship between hip pathoanatomy and symptomatic FAI has been reported to be weak. This is explained by the reciprocal interaction between proximal femur and acetabular anatomies, but potentially also by the individual spine-hip relations (SHR). The key-answer for a complete understanding of the pathophysiology of FAI might lie in the comprehension of the SHRs, which have not yet been fully addressed. Therefore we conducted a systematic review to answer the subsequent questions: Is there any evidence of a relationship between FAI and (1) sagittal pelvic kinematics, (2) pelvic incidence, and (3) types of SHRs? A systematic review of the existing literature utilizing PubMed and Google search engines was performed in December 2016. Only studies published in peer-reviewed journals over the last ten years in either English or French were reviewed. We identified 90 reports, of which 9 met our eligibility criteria. Review of literature shows Caucasian FAI patients have a pelvis with higher anterior tilt, lesser sagittal mobility, and lower pelvic incidence compared to healthy patients. We found no study having assessed the relationship between SHR and FAI. In order to help further investigations at answering questions 3 and 4, we have developed a classification for SHRs. The classification according spino-pelvic parameters allows identifying patient at risk regarding FAI occurrence. Higher anterior pelvic tilt in standing, sitting and squatting positions and lower pelvic incidence have been found to correlate with symptomatic FAI. Because defining the individual SHR might increase the understanding of the pathophysiology of hip impingement, we have developed a classification for SHRs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Metal-on-metal hip resurfacing compared with 28-mm diameter metal-on-metal total hip replacement: a randomised study with six to nine years' follow-up

A total of 219 hips in 192 patients aged between 18 and 65 years were randomised to 28-mm metal-on-metal uncemented total hip replacements (THRs, 107 hips) or hybrid hip resurfacing (HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3) there was no significant difference between the THR and HR groups regarding rate of revision (4.0% (4 of 99) vs 5.8% (6 of 104), p = 0.569) or re-operation rates without revision (5.1% (5 of 99) vs 2.9% (3 of 104), p = 0.428). In the THR group one recurrent dislocation, two late deep infections and one peri-prosthetic fracture required revision, whereas in the HR group five patients underwent revision for femoral head loosening and one for adverse reaction to metal debris. The mean University of California, Los Angeles activity scores were significantly higher in HR (7.5 (sd 1.7) vs 6.9 (sd 1.7), p = 0.035), but similar mean Western Ontario and McMaster Universities Osteoarthritis Index scores were obtained (5.8 (sd 9.5) in HR vs 5.1 (sd 8.9) in THR, p = 0.615) at the last follow-up. Osteolysis was found in 30 of 81 THR patients (37.4%), mostly in the proximal femur, compared with two of 83 HR patients (2.4%) (p < 0.001). At five years the mean metal ion levels were < 2.5 μg/l for cobalt and chromium in both groups; only titanium was significantly higher in the HR group (p = 0.001). Although revision rates and functional scores were similar in both groups at mid-term, long-term survival analysis is necessary to determine whether one procedure is more advantageous than the other.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Multi-luminescent hybrid gadolinium oxide nanoparticles as potential cell labeling

This manuscript analyses the use of newly developed hybrid gadolinium oxide nanoparticles as cell-labeling tracers. The nanoparticles are core-shell particles composed of a core of gadolinium oxide of [2-4] nm and a protecting shell of polysiloxane [1-3 nm] where different organic dyes (fluoresceine isothiocyanate (FITC) or rhodamine B isothiocyanate (RBITC)) are embedded. They are functionalized with poly(ethylene glycol)bis(carboxymethyl) to ensure their colloidal stability in biological buffers. These particles are potential multi-labeling tracers (magnetic and optical). In this paper, we show by optical imaging that they can be efficiently internalized in cells without cell alteration. The in-vitro uptake of the nanoparticles was followed in two cell lines (human fibroblasts and a human adenocarnima cell lines MCF7 cells). Nanoparticles distribution within cells was analysed by confocal analysis, and gadolinium concentration within cells was quantified by mass spectrometry (ICP-MS analysis). Nanoparticles uptake is found to be fast and efficient for both cell lines, with fluorescent labeling visible after 10 min of incubation whatever the nature of the fluorophore. The fluorescent intensity is mainly found as concentrated dots in the perinuclear region of the cells and decreases with the number of days in culture, but is still easily detectable after 3 days in culture. No significant effect on cell growth was detected. Finally, we show in this study the protective effect of the polysiloxane layer: encapsulation of RBITC within the polysiloxane shell, leads to a better photostability of this low cost dye than Cy3 and even reach a level comparable to Alexa 595. With their high photostability and long-lasting contrast properties, these hybrid luminescent nanoparticles appears thus as a versatile solution to assess multiple cell fate both in in-vitro cell model as well as in-vivo.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Changes in the magnitude and distribution of forces at different Dictyostelium developmental stages

The distribution of forces exerted by migrating Dictyostelium amebae at different developmental stages was measured using traction force microscopy. By using very soft polyacrylamide substrates with a high fluorescent bead density, we could measure stresses as small as 30 Pa. Remarkable differences exist both in term of the magnitude and distribution of forces in the course of development. In the vegetative state, cells present cyclic changes in term of speed and shape between an elongated form and a more rounded one. The forces are larger in this first state, especially when they are symmetrically distributed at the front and rear edge of the cell. Elongated vegetative cells can also present a front-rear asymmetric force distribution with the largest forces in the crescent-shaped rear of the cell (uropod). Pre-aggregating cells, once polarized, only present this last kind of asymmetric distribution with the largest forces in the uropod. Except for speed, no cycle is observed. Neither the force distribution of pre-aggregating cells nor their overall magnitude are modified during chemotaxis, the later being similar to the one of vegetative cells (F(0) approximately 6 nN). On the contrary, both the force distribution and overall magnitude is modified for the fast moving aggregating cells. In particular, these highly elongated cells exert lower forces (F(0) approximately 3 nN). The location of the largest forces in the various stages of the development is consistent with the myosin II localization described in the literature for Dictyostelium (Yumura et al.,1984. J Cell Biol 99:894-899) and is confirmed by preliminary experiments using a GFP-myosin Dictyostelium strain.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Magnetic control of Dictyostelium aggregation

We report the control of cell migration by external magnetic forces during the early stage of Dictysostelium discoideum morphogenesis. Magnetically labeled aggregating cells respond to the presence of a magnetic field created by a thin magnetic tip: forces as low as 30 pN are sufficient to elicit the aggregation of the cells at the extremity of the tip. This induced magnetotaxis is competitive to classical chemotaxis. We therefore underline the interplay between external mechanical forces and morphogenesis. This magnetic assay will open new possibilities in the study of morphogenesis in Dictyostelium.

Internal structure of magnetic endosomes

The internal structure of biological vesicles filled with magnetic nanoparticles is investigated using the following complementary analyses: electronic transmission microscopy, dynamic probing by magneto-optical birefringence and structural probing by Small Angle Neutron Scattering (SANS). These magnetic vesicles are magnetic endosomes obtained via a non-specific interaction between cells and anionic magnetic iron oxide nanoparticles. Thanks to a magnetic purification process, they are probed at two different stages of their formation within HeLa cells: (i) adsorption of nanoparticles onto the cellular membrane and (ii) their subsequent internalisation within endosomes. Differences in the microenvironment of the magnetic nanoparticles at those two different stages are highlighted here. The dynamics of magnetic nanoparticles adsorbed onto cellular membranes and confined within endosomes is respectively 3 and 5 orders of magnitude slower than for isolated magnetic nanoparticles in aqueous media. Interestingly, SANS experiments show that magnetic endosomes have an internal structure close to decorated vesicles, with magnetic nanoparticles locally decorating the endosome membrane, inside their inner-sphere. These results, important for future biomedical applications, suggest that multiple fusions of decorated vesicles are the biological processes underlying the endocytosis of that kind of nanometric materials.

Signaling through the phosphatidylinositol 3-kinase regulates mechanotaxis induced by local low magnetic forces in Entamoeba histolytica

In micro-organisms, as well as in metazoan cells, cellular polarization and directed migration are finely regulated by external stimuli, including mechanical stresses. The mechanisms sustaining the transduction of such external stresses into intracellular biochemical signals remain mainly unknown. Using an external magnetic tip, we generated a magnetic field gradient that allows migration analysis of cells submitted to local low-intensity magnetic forces (50 pN). We applied our system to the amoeba Entamoeba histolytica. Indeed, motility and chemotaxis are key activities that allow this parasite to invade and destroy the human tissues during amoebiasis. The magnetic force was applied either inside the cytoplasm or externally at the rear pole of the amoeba. We observed that the application of an intracellular force did not affect cell polarization and migration, whereas the application of the force at the rear pole of the cell induced a persistent polarization and strongly directional motion, almost directly opposed to the magnetic force. This phenomenon was completely abolished when phosphatidylinositol 3-kinase activity was inhibited by wortmanin. This result demonstrated that the applied mechanical stimulus was transduced and amplified into an intracellular biochemical signal, a process that allows such low-intensity force to strongly modify the migration behavior of the cell.

Long-term expression and repeated administration of AAV type 1, 2 and 5 vectors in skeletal muscle of immunocompetent adult mice

Adeno-associated viral (AAV) vectors promote long-term gene transfer into muscle in many animal species. Increased expression levels may be obtained by using alternative serotypes in combination with repeated administrations. Here we compared AAV vectors based on serotypes 1, 2 and 5 in immunocompetent mice and assessed the feasibility of multiple administrations of either identical (readministration) or different (cross-administration) serotype-based vectors. A 1-year-long dose-response study confirmed the superiority of recombinant (r)AAV1, achieving transduction levels 5 to 10-fold higher than rAAV2 and rAAV5 in mouse skeletal muscle, respectively. Repeated administration demonstrated that increased gene transfer level was achieved with a second injection of rAAV1 following the first administration of rAAV2 or rAAV5. A readministration study with a vector encoding a different gene allowed the evaluation of gene expression from the second vector only. All three rAAVs were inhibited when the animals were previously exposed to the same serotype. In contrast, no significant change in gene expression from the second vector was observed in cross-administration. A humoral immune response was elicited against the viral capsid for all three serotypes following the initial exposure. Neutralizing antibody (NAB) levels correlated with the vector dose injected. No significant cross-reactivity of NAB from a given serotype toward another was observed in vitro. These data provide the first direct comparative evaluation of re- and cross-administration of rAAV1, rAAV2 and rAAV5 in muscle, and further indicate that rAAV1 is capable of transducing muscle tissue when cross-administered.

Response to Antiretroviral Therapy among Patients Exposed to Three Classes of Antiretrovirals: Results from the Eurosida Study

There is an increasing proportion of HIV-positive patients exposed to all licensed classes of antiretrovirals, and the response to salvage regimens may be poor. Among over 8500 patients in EuroSIDA, the proportion of treated patients exposed to nucleosides, protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitor (NNRTI) increased from 0% in 1996 to 47% in 2001. Four-hundred-and-thirteen patients, who had failed virologically two highly active antiretroviral therapy (HAART) regimens and experienced all three main drug classes, started a salvage regimen of at least three drugs, in which at least one new PI or NNRTI was included. Median viral load was 4.7 log copies/ml [Interquartile range (IQR) 4.2–5.2], CD4 lymphocyte count 150/mm3 (IQR 60–274/mm3) and follow-up 14 months. Of these patients, 283 (69%) subsequently experienced at least a 1 log decline in viral load and 202 (49%) achieved a viral load <500 copies/ml. Conversely, the CD4 count halved from the baseline value in 88 (21%), and 45 (11%) experienced a new AIDS-defining disease. In multivariable analyses, a 1 log viral load reduction was related to baseline viral load [relative hazard (RH) 1.27 per 1 log higher; P=0.008], a previous viral load of less than 500 copies/ml (RH 1.69; P=0.002), more recent initiation of the regimen (RH 1.36 per year more recent; P=0.02), number of new drugs in the regimen (RH 1.20 per drug; P=0.02), time since start of antiretroviral therapy (RH 0.94 per extra year; P=0.035) and time spent on HAART with viral load >1000 copies/ml (RH 0.96 per extra month; P=0.0001). Analysis of factors associated with CD4 count decline and new AIDS disease also indicated improved outcomes in more recent times and a tendency for a better response in those starting more new drugs, but no relationship with the total number of drugs. Outcomes in people starting salvage regimens appear to depend on the number of new drugs started but not on the total number of drugs being used.

Complexation studies of iodides of trivalent uranium and lanthanides (Ce and Nd) with 2,2'-bipyridine in anhydrous pyridine solutions

In anhydrous pyridine solution at 294 K, U(III) and Ce(III) triiodides were found to form both 1:1 (ML) and 1:2 (ML(2)) complexes with bipyridine (bipy = L) while Nd(III) triodide formed only a 1:2 complex. The 1:3 (ML(3)) complexes were identified at low temperature with a large excess of L. Conductometry measurements showed for U(III) a large increase in the conductivity when increasing the molar ratio L:U. The complex UL(2) was found to be a 1:1 electrolyte and the species UI(2)(+) was more reactive toward L in comparison with UI(3). For Ce(III) and Nd(III), MI(2)(+) and MI(3) present about the same affinity for L. The stability of the complexes is limited, and U(III) possesses a slightly higher affinity for bipy than the trivalent lanthanides. Interestingly, a preference for the formation of ML(2) complex was shown for all the studied M(III) ions. The driving force for complex formation was always the enthalpy, and, surprisingly for a bidendate ligand (bipy), no favorable entropy contribution to complex formation was observed. The X-ray crystal structures of [CeI(3)(bipy)(2)(py)](4).5py.bipy and UI(3)(bipy)(2)(py).2py were determined. The structures of the molecules MI(3)(bipy)(2)(py) are almost identical for U and Ce. The mean M(III)-N(bipy) bond distances are equal to 2.67(3) A for Ce(III) and 2.65(4) A for U(III). The slightly smaller M(III)-N(bipy) distances observed for U(III) would reflect a slightly more important covalent character of the U(III)-N(bipy) bonds, in agreement with the slightly better affinity of U(III) than Ce(III) or Nd(III) toward bipy observed in solution and with the fact that the enthalpy is the driving force for complex formation.

Hepatitis B or hepatitis C virus infection is a risk factor for severe hepatic cytolysis after initiation of a protease inhibitor-containing antiretroviral regimen in human immunodeficiency virus-infected patients. The APROCO Study Group

In a cohort of 1,047 human immunodeficiency virus type 1-infected patients started on protease inhibitors (PIs), the incidence of severe hepatic cytolysis (alanine aminotransferase concentration five times or more above the upper limit of the normal level >/= 5N) was 5% patient-years after a mean follow-up of 5 months. Only positivity for hepatitis C virus antibodies (hazard ratio [HR], 7. 95; P < 10(-3)) or hepatitis B virus surface antigen (HR, 6.67; P < 10(-3)) was associated with severe cytolysis. Before starting patients on PIs, assessment of liver enzyme levels and viral coinfections is necessary.

[White finger and hypertrophy of the lumbrical muscles]

Within the digital vascularization diseases, we found a compression of the radial and ulnar collateral arteries of a finger by hypertrophy of the lumbrical muscles which was presented clinically in the form of a chronic sub-ischemia. A surgical release made it possible to recover a vascularized and sensitive finger.

The thrombocytopenia of Wiskott Aldrich syndrome is not related to a defect in proplatelet formation

The Wiskott-Aldrich syndrome (WAS) is an X-linked hereditary disease characterized by thrombocytopenia with small platelet size, eczema, and increased susceptibility to infections. The gene responsible for WAS was recently cloned. Although the precise function of WAS protein (WASP) is unknown, it appears to play a critical role in the regulation of cytoskeletal organization. The platelet defect, resulting in thombocytopenia and small platelet size, is a consistent finding in patients with mutations in the WASP gene. However, its exact mechanism is unknown. Regarding WASP function in cytoskeletal organization, we investigated whether these platelet abnormalities could be due to a defect in proplatelet formation or in megakaryocyte (MK) migration. CD34(+) cells were isolated from blood and/or marrow of 14 WAS patients and five patients with hereditary X-linked thrombocytopenia (XLT) and cultured in serum-free liquid medium containing recombinant human Mpl-L (PEG-rHuMGDF) and stem-cell factor (SCF) to study in vitro megakaryocytopoiesis. In all cases, under an inverted microscope, normal MK differentiation and proplatelet formation were observed. At the ultrastructural level, there was also no abnormality in MK maturation, and normal filamentous MK were present. Moreover, the in vitro produced platelets had a normal size, while peripheral blood platelets of the same patients exhibited an abnormally small size. However, despite this normal platelet production, we observed that F-actin distribution was abnormal in MKs from WAS patients. Indeed, F-actin was regularly and linearly distributed under the cytoplasmic membrane in normal MKs, but it was found concentrated in the center of the WAS MKs. After adhesion, normal MKs extended very long filopodia in which WASP could be detected. In contrast, MKs from WAS patients showed shorter and less numerous filopodia. However, despite this abnormal filopodia formation, MKs from WAS patients normally migrated in response to stroma-derived factor-1alpha (SDF-1alpha), and actin normally polymerized after SDF-1alpha or thrombin stimulation. These results suggest that the platelet defect in WAS patients is not due to abnormal platelet production, but instead to cytoskeletal changes occuring in platelets during circulation.

Phenotypic and functional evidence for the expression of CXCR4 receptor during megakaryocytopoiesis

The identification of stromal cell-derived factor (SDF)-1alpha as a chemoattractant for human progenitor cells suggests that this chemokine and its receptor might represent critical determinants for the homing, retention, and exit of precursor cells from hematopoietic organs. In this study, we investigated the expression profile of CXCR4 receptor and the biological activity of SDF-1alpha during megakaryocytopoiesis. CD34(+) cells from bone marrow and cord blood were purified and induced to differentiate toward the megakaryocyte lineage by a combination of stem-cell factor (SCF) and recombinant human pegylated megakaryocyte growth and development factor (PEG-rhuMGDF). After 6 days of culture, a time where mature and immature megakaryocytes were present, CD41(+) cells were immunopurified and CXCR4mRNA expression was studied. High transcript levels were detected by a RNase protection assay in cultured megakaryocytes derived from cord blood CD34(+) cells as well as in peripheral blood platelets. The transcript levels were about equivalent to that found in activated T cells. By flow cytometry, a large fraction (ranging from 30% to 100%) of CD41(+) cells showed high levels of CXCR4 antigen on their surface, its expression increasing in parallel with the CD41 antigen during megakaryocytic differentiation. CXCR4 protein was also detected on peripheral blood platelets. SDF-1alpha acts on megakaryocytes by inducing intracellular calcium mobilization and actin polymerization. In addition, in in vitro transmigration experiments, a significant proportion of megakaryocytes was observed to respond to this chemokine. This cell migration was inhibited by pertussis toxin, indicating coupling of this signal to heterotrimeric guanine nucleotide binding proteins. Although a close correlation between CD41a and CXCR4 expession was observed, cell surface markers as well as morphological criteria indicate a preferential attraction of immature megakaryocytes (low level of CD41a and CD42a), suggesting that SDF-1alpha is a potent attractant for immature megakaryocytic cells but is less active on fully mature megakaryocytes. This hypothesis was further supported by the observation that SDF-1alpha induced the migration of colony forming unit-megakaryocyte progenitors (CFU-MK) and the expression of activation-dependent P-selectin (CD62P) surface antigen on early megakaryocytes, although no effect was observed on mature megakaryocytes and platelets. These results indicate that CXCR4 is expressed by human megakaryocytes and platelets. Furthermore, based on the lower responses of mature megakaryocytes and platelets to SDF-1alpha as compared with early precursors, these data suggest a role for this chemokine in the maintenance and homing during early stages of megakaryocyte development. Moreover, because megakaryocytes are also reported to express CD4, it becomes important to reevaluate the role of direct infection of these cells by the human immunodeficiency virus (HIV)-1 in HIV-1-related thrombocytopenia.

Quantitative porosity profiles and wettability contrast visualisation in sandstone by CPMG imaging

CPMG imaging is applied to the visualisation of porosity and wetting heterogeneities in water saturated sandstone samples at 0.1 T. Porosity profiles from NMR imaging are in agreement within 1% with the standard core analysis. T2 calculated profiles show a factor greater than two between water-wet and oil-wet samples; thus, wettability contrast can be easily visualised.

Competitive inhibition of lipolytic enzymes. V. A monolayer study using enantiomeric acylamino analogues of phospholipids as potent competitive inhibitors of porcine pancreatic phospholipase A2

For the first time, we have shown that a stereospecific interaction occurs between porcine pancreatic phospholipase A2 and a monomolecular film of amidophospholipid used as inhibitor. Direct binding experiments, using radiolabelled phospholipase A2, showed that 13 times more enzyme was bound to phospholipid films of the L series by comparison with films of the D series. These results were confirmed by indirect binding studies using re-spreading experiments. Kinetic studies of the porcine pancreatic PLA2, using enantiomeric acyl-amino phospholipid analogues, have shown that: (1) inhibitors of the L series are more potent than inhibitors of the D series, (2) inhibitors having a negative charge are more potent than zwitterionic inhibitors, (3) inhibitory power values are greater when evaluated in micellar system than in a the monolayer system, (4) the inhibitory power increases continuously with surface pressure.