A French single-center experience on allogeneic stem cell transplant cryopreservation during severe acute respiratory syndrome coronavirus 2 pandemic.

BACKGROUND AIMS: Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a curative treatment for chemo-resistant hematological malignancies. Because of transport restriction imposed by the coronavirus disease 2019 pandemic, regulatory bodies and societies recommended graft cryopreservation before recipient conditioning. However, the freezing and thawing processes, including washing steps, might impair CD34+ cell recovery and viability, thereby impacting the recipient engraftment. Over 1 year (between March 2020 and May 2021), we aimed to analyze the results of frozen/thawed peripheral blood stem cell allografts in terms of stem cell quality and clinical outcomes. METHODS: Transplant quality was evaluated by comparing total nucleated cells (TNCs), CD34+ cells and colony-forming unit-granulocyte/macrophage (CFU-GM)/kg numbers as well as TNC and CD34+ cell viabilities before and after thawing. Intrinsic biological parameters such as granulocyte, platelet and CD34+ cell concentrations were analyzed, as they might be responsible for a quality loss. The impact of the CD34+ cell richness of the graft on TNC and CD34 yields was evaluated by designing three groups of transplants based on their CD34 /kg value at collection: >8 × 10 6/kg, between 6 and 8 × 106/kg and <6 × 106/kg. The consequences of cryopreservation were compared in the fresh and thawed group by evaluating the main transplant outcomes. RESULTS: Over 1 year, 76 recipients were included in the study; 57 patients received a thawed and 19 patients a fresh allo-SCT. None received allo-SCT from a severe acute respiratory syndrome coronavirus 2-positive donor. The freezing of 57 transplants led to the storage of 309 bags, for a mean storage time (between freezing and thawing) of 14 days. For the fresh transplant group, only 41 bags were stored for potential future donor lymphocyte infusions. Regarding the graft characteristics at collection, median number of cryopreserved TNC and CD34+ cells/kg were greater than those for fresh infusions. After thawing, median yields were 74.0%, 69.0% and 48.0% for TNC, CD34+ cells and CFU-GM, respectively. The median TNC dose/kg obtained after thawing was 5.8 × 108, with a median viability of 76%. The median CD34+ cells/kg was 5 × 106, with a median viability of 87%. In the fresh transplant group, the median TNC/kg was 5.9 × 108/kg, and the median CD34+ cells/kg and CFU-GM/kg were 6 × 106/kg and 276.5 × 104/kg, respectively. Sixty-one percent of the thawed transplants were out of specifications regarding the CD34+ cells/ kg requested cell dose (6 × 106/kg) and 85% of them would have had this dose if their hematopoietic stem cell transplant had been infused fresh. Regarding fresh grafts, 15.8% contained less than 6 × 106 CD34+ cells /kg and came from peripheral blood stem cells that did not reach 6 × 106 CD34+ cells /kg at collection. Regarding the factor that impaired CD34 and TNC yield after thawing, no significant impact of the granulocyte count, the platelet count or the CD34+ cells concentration/µL was observed. However, grafts containing more than 8 × 10 6/kg at collection showed a significantly lower TNC and CD34 yield. CONCLUSIONS: Transplant outcomes (engraftment, graft-versus-host disease, infections, relapse or death) were not significantly different between the two groups.

Adipocyte size, adipose tissue fibrosis, macrophage infiltration and disease risk are different in younger and older individuals with childhood versus adulthood onset obesity.

BACKGROUND: The timing of obesity onset and age have been shown to affect the risk of obesity-related comorbidities, although the impact of each of these factors on markers of adipose tissue function remains unclear. OBJECTIVE: The aim of this study was to determine whether differences in regional adipose tissue characteristics vary with age and age of obesity onset, and whether these differences are associated with the markers of cardiometabolic health. METHODS: Adipose tissue samples were obtained from 80 female bariatric surgery candidates who were classified by age of obesity onset and age into 4 groups: (1) younger adults (<40 y) with childhood-onset obesity (<18 y) (Child-Young); (2) younger adults with adulthood-onset obesity (>18 y) (Adult-Young); (3) older adults (>55 y) with childhood-onset obesity (Child-Old); and (4) older adults with adulthood-onset obesity (Adult-Old). Adipocyte diameter, adipose tissue fibrosis, and macrophage infiltration were determined in subcutaneous (SAT) and visceral adipose tissue (VAT). Clinical parameters were obtained from participants' medical records. RESULTS: Visceral adipocyte size in the Child-Young group was the smallest of all the groups. Age affected visceral infiltration of M1-like cells with greater percent of M1-like cells in the Adult-Old and Child-Old groups. Though not significant, a stepwise increase in M2-like macrophages in VAT was observed with Adult-Young having the smallest followed by Adult-Old, Child-Young, and Child-Old having the greatest percent of M2-like macrophages. Pericellular fibrosis accumulation in SAT and VAT varied with both age and onset, particularly in the Child-Old group, which had the lowest fibrosis levels. Markers of cardiometabolic health (fasting glucose, glycated hemoglobin, total, HDL- and LDL-cholesterol and triglyceride concentrations) were positively and well-associated with adipose tissue characteristics of the Child-Old group but not of the Adult-Young group. CONCLUSION: Older adults with childhood-onset obesity, who had the greatest duration of obesity exposure, were particularly vulnerable to the cardiometabolic effects associated with perturbations in adipose tissue characteristics. These results suggest that age and age of obesity onset may have independent and cumulative effects on obesity pathology.

[Chronic lymphocytic leukemia]. / La leucémie lymphoïde chronique.

Chronic lymphocytic leukemia (CLL) is a low-grade B cell lymphoma with circulating cells, often revealed by hyperlymphocytosis. Its diagnosis and therapeutic indications (not systematic) have been defined in 2018. In fact, CLL can be separated in two entities differentiating themselves by their IGHV mutational status, but the search of other prognostic parameters like TP53 disruption is mandatory before treatment. Numerous genetic alterations and mutations exist in CLL. CLL cells are highly dependent from their b-cell receptor stimulation and from their microenvironment, which takes a central place in disease progression. Infections, dysimmune manifestations, cancers and Richter transformation are classic complications, and patients have poor vaccine response even without a treatment. Chemoimmunotherapy is being challenged by the new highly active drugs such as Bruton tyrosine-kinase inhibitors (ibrutinib, acalabrutinib) and by the association of venetoclax and anti-CD20. Future treatment strategies might integrate both new drugs and classical chemoimmunotherapy.

Muscle regeneration after high-dose radiation exposure: therapeutic potential of Hedgehog pathway modulation?

Purpose: Intentional or accidental exposure of relatively large as well as localized areas of the skin to ionizing radiation can lead to severe damage of many of its cellular components and cutaneous radiation syndrome. Patients can be treated with an invasive surgical procedure coupled with autologous cell therapy. However, this approach remains perfectible, especially for muscle repair. Indeed, a severe underlying muscle defect persists, in particular because of the damage to the satellite cells which ensure muscle regeneration. To overcome these shortcomings, a solution could be to develop new therapeutic strategies based on pharmacological treatments to improve post-irradiation muscle regeneration. In this study, we focus on the Hedgehog signaling pathway as a target, due to its involvement in myogenesis.Materials and methods: To evaluate the benefit of the pro-myogenic Hedgehog signaling pathway modulation, recombinant Sonic Hedgehog (rShh; agonist) or Cyclopamine (antagonist) were used in a stable cell line of mouse C2C12 myoblasts exposed to radiation (X-rays; 5 Gy). Our in vitro studies were carried out under either proliferation or differentiation conditions. Proliferation, migration, survival (apoptosis) and expression of myogenic genes/proteins were evaluated.Results: A high dose of radiation was shown to exert a serious negative impact in our in vitro model of mouse muscle progenitors after irradiation in proliferation or differentiation conditions. Interestingly, Hh pathway stimulation by rShh promotes the proliferation of myoblasts and their survival while its blockade by Cyclopamine significantly increases cell differentiation toward mature myotubes.Conclusion: These data suggest that, after irradiation, the sequence of activation and inhibition of the Hh pathway could allow rescue and proliferation of satellite cells, followed by their differentiation to regenerate new fibers. On the basis of these encouraging in vitro results, the second phase of our study will involve the in vivo validation of this treatment in a new murine model of ultra-localized muscle irradiation.

A microrobotic platform actuated by thermocapillary flows for manipulation at the air-water interface.

Future developments in micromanufacturing will require advances in micromanipulation tools. Several robotic micromanipulation methods have been developed to position micro-objects mostly in air and in liquids. The air-water interface is a third medium where objects can be manipulated, offering a good compromise between the two previously mentioned ones. Objects at the interface are not subjected to stick-slip due to dry friction in air and profit from a reduced drag compared with those in water. Here, we present the ThermoBot, a microrobotic platform dedicated to the manipulation of objects placed at the air-water interface. For actuation, ThermoBot uses a laser-induced thermocapillary flow, which arises from the surface stress caused by the temperature gradient at the fluid interface. The actuated objects can reach velocities up to 10 times their body length per second without any on-board actuator. Moreover, the localized nature of the thermocapillary flow enables the simultaneous and independent control of multiple objects, thus paving the way for microassembly operations at the air-water interface. We demonstrate that our setup can be used to direct capillary-based self-assemblies at this interface. We illustrate the ThermoBot's capabilities through three examples: simultaneous control of up to four spheres, control of complex objects in both position and orientation, and directed self-assembly of multiple pieces.

Impact of UV Radiation on the Raman Signal of Cystine: Implications for the Detection of S-rich Organics on Mars.

Traces of life may have been preserved in ancient martian rocks in the form of molecular fossils. Yet the surface of Mars is continuously exposed to intense UV radiation detrimental to the preservation of organics. Because the payload of the next rovers going to Mars to seek traces of life will comprise Raman spectroscopy tools, laboratory simulations that document the effect of UV radiation on the Raman signal of organics appear critically needed. The experiments conducted here evidence that UV radiation is directly responsible for the increase of disorder and for the creation of electronic defects and radicals within the molecular structure of S-rich organics such as cystine, enhancing the contribution of light diffusion processes to the Raman signal. The present results suggest that long exposure to UV radiation would ultimately be responsible for the total degradation of the Raman signal of cystine. Yet because the degradation induced by UV is not instantaneous, it should be possible to detect freshly excavated S-rich organics with the Raman instruments on board the rovers. Alternatively, given the very short lifetime of organic fluorescence (nanoseconds) compared to most mineral luminescence (micro- to milliseconds), exploiting fluorescence signals might allow the detection of S-rich organics on Mars. In any case, as illustrated here, we should not expect to detect pristine S-rich organic compounds on Mars, but rather by-products of their degradation.

Ultrafast multi-cycle terahertz measurements of the electrical conductivity in strongly excited solids.

Key insights in materials at extreme temperatures and pressures can be gained by accurate measurements that determine the electrical conductivity. Free-electron laser pulses can ionize and excite matter out of equilibrium on femtosecond time scales, modifying the electronic and ionic structures and enhancing electronic scattering properties. The transient evolution of the conductivity manifests the energy coupling from high temperature electrons to low temperature ions. Here we combine accelerator-based, high-brightness multi-cycle terahertz radiation with a single-shot electro-optic sampling technique to probe the evolution of DC electrical conductivity using terahertz transmission measurements on sub-picosecond time scales with a multi-undulator free electron laser. Our results allow the direct determination of the electron-electron and electron-ion scattering frequencies that are the major contributors of the electrical resistivity.

2D monochromatic x-ray imaging for beam monitoring of an x-ray free electron laser and a high-power femtosecond laser.

In pump-probe experiments with an X-ray Free Electron Laser (XFEL) and a high-power optical laser, spatial overlap of the two beams must be ensured to probe a pumped area with the x-ray beam. A beam monitoring diagnostic is particularly important in short-pulse laser experiments where a tightly focused beam is required to achieve a relativistic laser intensity for generation of energetic particles. Here, we report the demonstration of on-shot beam pointing measurements of an XFEL and a terawatt class femtosecond laser using 2D monochromatic Kα imaging at the Matter in Extreme Conditions end-station of the Linac Coherent Light Source. A thin solid titanium foil was irradiated by a 25-TW laser for fast electron isochoric heating, while a 7.0 keV XFEL beam was used to probe the laser-heated region. Using a spherical crystal imager (SCI), the beam overlap was examined by measuring 4.51 keV Kα x rays produced by laser-accelerated fast electrons and the x-ray beam. Measurements were made for XFEL-only at various focus lens positions, laser-only, and two-beam shots. Successful beam overlapping was observed on ∼58% of all two-beam shots for 10 µm thick samples. It is found that large spatial offsets of laser-induced Kα spots are attributed to imprecise target positioning rather than shot-to-shot laser pointing variations. By applying the Kα measurements to x-ray Thomson scattering measurements, we found an optimum x-ray beam spot size that maximizes scattering signals. Monochromatic x-ray imaging with the SCI could be used as an on-shot beam pointing monitor for XFEL-laser or multiple short-pulse laser experiments.

Treating brain diseases using systemic parenterally-administered protein therapeutics: Dysfunction of the brain barriers and potential strategies.

The parenteral administration of protein therapeutics is increasingly gaining importance for the treatment of human diseases. However, the presence of practically impermeable blood-brain barriers greatly restricts access of such pharmaceutics to the brain. Treating brain disorders with proteins thus remains a great challenge, and the slow clinical translation of these therapeutics may be largely ascribed to the lack of appropriate brain delivery system. Exploring new approaches to deliver proteins to the brain by circumventing physiological barriers is thus of great interest. Moreover, parallel advances in the molecular neurosciences are important for better characterizing blood-brain interfaces, particularly under different pathological conditions (e.g., stroke, multiple sclerosis, Parkinson's disease, and Alzheimer's disease). This review presents the current state of knowledge of the structure and the function of the main physiological barriers of the brain, the mechanisms of transport across these interfaces, as well as alterations to these concomitant with brain disorders. Further, the different strategies to promote protein delivery into the brain are presented, including the use of molecular Trojan horses, the formulation of nanosystems conjugated/loaded with proteins, protein-engineering technologies, the conjugation of proteins to polymers, and the modulation of intercellular junctions. Additionally, therapeutic approaches for brain diseases that do not involve targeting to the brain are presented (i.e., sink and scavenging mechanisms).

Optimization of radiochromic film stacks to diagnose high-flux laser-accelerated proton beams.

Here, we extend flatbed scanner calibrations of GafChromic EBT3, MD-V3, and HD-V2 radiochromic films using high-precision x-ray irradiation and monoenergetic proton bombardment. By computing a visibility parameter based on fractional errors, optimal dose ranges and transitions between film types are identified. The visibility analysis is used to design an ideal radiochromic film stack for the proton energy spectrum expected from the interaction of a petawatt laser with a cryogenic hydrogen jet target.

Impact of the Mechanical Properties of a Functionalized Cross-Linked Binder on the Longevity of Li-S Batteries.

One of the very challenging aspects of Li-S battery development is the fabrication of a sulfur electrode with high areal loading using conventional Li-ion binders. Herein, we report a new multifunctional polymeric binder, synthesized by the free-radical cross-linking polymerization of [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETMAC) and ethylene glycol diacrylate (EGDA) to form poly(AETMAC- co-EGDA), that not only helps to confine the soluble polysulfide species but also has the desired mechanical properties to allow stable cycling of high-sulfur loading cathodes. Through a combination of spectroscopic and electrochemical studies, we elucidate the chemical interactions that inhibit polysulfide shuttling. We also show that extensive cross-linkage enables this polymeric binder to exhibit a low degree of swelling as well as high tensile modulus and toughness. These attributes are essential to maintain the architectural integrity of the sulfur cathode during extended cycling. Using this material, Li-S cells with a high-sulfur loading (6.0 mg cm-2) and a low-intermediate electrolyte/sulfur ratio (7 µL:1 mg) achieve an areal capacity of 5.4 mA h cm-2 and can be (dis)charged for 300 cycles with stable reversible redox behavior after the initial cycles.

Setup for meV-resolution inelastic X-ray scattering measurements and X-ray diffraction at the Matter in Extreme Conditions endstation at the Linac Coherent Light Source.

We describe a setup for performing inelastic X-ray scattering and X-ray diffraction measurements at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Light Source. This technique is capable of performing high-, meV-resolution measurements of dynamic ion features in both crystalline and non-crystalline materials. A four-bounce silicon (533) monochromator was used in conjunction with three silicon (533) diced crystal analyzers to provide an energy resolution of ∼50 meV over a range of ∼500 meV in single shot measurements. In addition to the instrument resolution function, we demonstrate the measurement of longitudinal acoustic phonon modes in polycrystalline diamond. Furthermore, this setup may be combined with the high intensity laser drivers available at MEC to create warm dense matter and subsequently measure ion acoustic modes.

Experimental evidence for the enhanced and reduced stopping regimes for protons propagating through hot plasmas.

Our understanding of the dynamics of ion collisional energy loss in a plasma is still not complete, in part due to the difficulty and lack of high-quality experimental measurements. These measurements are crucial to benchmark existing models. Here, we show that such a measurement is possible using high-flux proton beams accelerated by high intensity short pulse lasers, where there is a high number of particles in a picosecond pulse, which is ideal for measurements in quickly expanding plasmas. By reducing the energy bandwidth of the protons using a passive selector, we have made proton stopping measurements in partially ionized Argon and fully ionized Hydrogen plasmas with electron temperatures of hundreds of eV and densities in the range 1020-1021 cm-3. In the first case, we have observed, consistently with previous reports, enhanced stopping of protons when compared to stopping power in non-ionized gas. In the second case, we have observed for the first time the regime of reduced stopping, which is theoretically predicted in such hot and fully ionized plasma. The versatility of these tunable short-pulse laser based ion sources, where the ion type and energy can be changed at will, could open up the possibility for a variety of ion stopping power measurements in plasmas so long as they are well characterized in terms of temperature and density. In turn, these measurements will allow tests of the validity of existing theoretical models.

Crystal-to-Crystal Transition of Ultrasoft Colloids under Shear.

Ultrasoft colloids typically do not spontaneously crystallize, but rather vitrify, at high concentrations. Combining in situ rheo-small-angle-neutron-scattering experiments and numerical simulations we show that shear facilitates crystallization of colloidal star polymers in the vicinity of their glass transition. With increasing shear rate well beyond rheological yielding, a transition is found from an initial bcc-dominated structure to an fcc-dominated one. This crystal-to-crystal transition is not accompanied by intermediate melting but occurs via a sudden reorganization of the crystal structure. Our results provide a new avenue to tailor colloidal crystallization and the crystal-to-crystal transition at the molecular level by coupling softness and shear.

Impedance-based real-time position sensor for lab-on-a-chip devices.

This paper presents the theoretical and experimental development of an integrated position sensor for lab-on-a-chip devices. The interest for single cell analysis is growing. However, this requires monitoring and controlling cell displacements in real time during their journey in the chip. Due to the high number of cells that must be monitored at the same time, classical vision-based sensors are not suitable. This paper aims to present an alternative based on impedance measurement. The position of the cells is obtained from the variation of impedance measured between two electrodes. This technique presents several advantages: the sensor is integrated into the chip, the measurement electrodes are compatible with the fabrication process of actuation electrodes for dielectrophoresis, the sampling time of the sensor is high and the position of the cells can be obtained in real time. This article highlights the concept of position-sensitive impedance sensing. The design of the chip, and in particular of the electrodes, is discussed to improve the sensitivity and repeatability of the measurement. The issue of real-time detection in a noisy environment is solved by using an extended Kalman filter. As a first proof of concept, this article presents experimental validation on a 1D case to determine the longitudinal position of 8.7 µm diameter beads in a channel.

Relativistic Electron Streaming Instabilities Modulate Proton Beams Accelerated in Laser-Plasma Interactions.

We report experimental evidence that multi-MeV protons accelerated in relativistic laser-plasma interactions are modulated by strong filamentary electromagnetic fields. Modulations are observed when a preplasma is developed on the rear side of a µm-scale solid-density hydrogen target. Under such conditions, electromagnetic fields are amplified by the relativistic electron Weibel instability and are maximized at the critical density region of the target. The analysis of the spatial profile of the protons indicates the generation of B>10 MG and E>0.1 MV/µm fields with a µm-scale wavelength. These results are in good agreement with three-dimensional particle-in-cell simulations and analytical estimates, which further confirm that this process is dominant for different target materials provided that a preplasma is formed on the rear side with scale length ≳0.13λ_{0}sqrt[a_{0}]. These findings impose important constraints on the preplasma levels required for high-quality proton acceleration for multipurpose applications.

Clinical presentation, treatment and outcome in 31 dogs with presumed primary colorectal lymphoma (2001-2013).

The objective of this multicentre retrospective study was to describe clinical presentation, treatment and outcome and to determine prognostic factors for dogs with presumed primary colorectal lymphoma (PCRL). A total of 31 dogs were included. The predominant features of PCRL were high grade (n = 18) and immunophenotype B (n = 24). Most dogs were substage b (n = 25) with higher prevalence of haematochezia (n = 20). One dog had surgery only. Thirty dogs received chemotherapy; amongst them 13 had surgery or radiotherapy. Progression free survival (PFS) was 1318 days and disease-related median survival time (MST) was 1845 days. Fourteen dogs were alive at the end of the study with a median follow-up time of 684 days (3-4678 days). Younger dogs had longer PFS (P = 0.031) and disease-related MST (P = 0.01). Presence of haematochezia corresponded with longer PFS (P = 0.02). Addition of local treatment to chemotherapy did not significantly improve the outcome (P = 0.584). Canine PCRL has considerably longer PFS and MST than other forms of non-Hodgkin's lymphoma.

Releasable and traceless PEGylation of arginine-rich antimicrobial peptides.

Arginine-rich antimicrobial peptides (AMPs) are emerging therapeutics of interest. However, their applicability is limited by their short circulation half-life, caused in part by their small size and digestion by blood proteases. This study reports a strategy to temporarily mask arginine residues within AMPs with methoxy poly(ethylene glycol). Based on the reagent used, release of AMPs occurred in hours to days in a completely traceless fashion. In vitro, conjugates were insensitive to serum proteases, and released native AMP with full in vitro bioactivity. This strategy is thus highly relevant and should be adaptable to the entire family of arginine-rich AMPs. It may potentially be used to improve AMP-therapies by providing a more steady concentration of AMP in the blood after a single injection, avoiding toxic effects at high AMP doses, and reducing the number of doses required over the treatment duration.

Evolution of subcutaneous adipose tissue fibrosis after bariatric surgery.

AIM: Obesity is associated with the development of metabolic complications such as insulin resistance (IR). The mechanisms leading to IR remain unclear. This study aimed to investigate the relationship between adipose tissue fibrosis and IR in obese patients before and after bariatric surgery. METHODS: Thirty-five obese patients awaiting bariatric surgery (12 with type 2 diabetes) were included in the study. Non-diabetic patients were classified as either insulin-sensitive (n=11) or insulin-resistant (n=12), based on the Matsuda insulin sensitivity index (ISIMatsuda). Homoeostasis model assessment (HOMA-IR) was used for longitudinal evaluation of insulin resistance. Fibrosis was quantified by Masson's trichrome staining on microscopy, and mRNA levels of fibrosis-related genes were examined in subcutaneous (SAT) and visceral adipose tissue (VAT) biopsies collected during and 6 months after bariatric surgery (SAT only). RESULTS: Despite their similar age, body mass index and fat mass, SAT fibrosis was significantly higher in diabetic vs insulin-sensitive patients (P<0.05), and associated with IR as assessed by both ISIMatsuda (r=-0.417, P=0.038) and HOMA-IR (r=0.464, P=0.007) at baseline, whereas VAT fibrosis was not. Six months after surgery and significant weight loss, fibrosis levels remained unchanged in SAT, although IR was significantly reduced in all groups (P<0.0001). No correlation was found between SAT fibrosis and IR after surgery. CONCLUSION: Overall, these results show a significant but, most likely, transient association between SAT fibrosis and IR in obese humans.