BACKGROUND:Mycophenolate mofetil is widely used in liver transplantation but poses dosing challenges owing to the narrow therapeutic window and high pharmacokinetic variability of its active moiety, mycophenolic acid (MPA). Overexposure increases the risk of adverse effects, whereas underexposure increases the risk of rejection and graft loss. The ImmunoSuppressant Bayesian Dose Adjustment (ISBA) platform estimates the MPA area under the curve (AUC) 0-12h using 3 post-dose samples (20 minutes, 1 hour, 3 hours) and provides dose recommendations to target an AUC 0-12h of 30-60 mg·h/L. The aim of this study was to describe the MPA AUC 0-12h and assess the impact of ISBA-guided dose adjustments. METHODS:MPA concentrations were measured at each visit, and AUCs were estimated in real time during routine clinical follow-up. All data collected from liver-transplant recipients aged ≥18 years from October 2005 to May 2020 were retrospectively analyzed. Dosing recommendations were adjusted proportionally to reach the AUC target of 45 mg.h/L. RESULTS:A total of 3632 requests involving 1872 patients were analyzed, making this the largest real-world cohort of this population reported to date. Among them, 658 patients benefited from at least 2 successive dose adjustments, allowing for a comparison between the results obtained without any prior use of the online platform and those obtained after the first visit (AUC of the second visit). At the first visit (before any dose recommendation) during the first year after transplantation, the median AUC 0-12h (interquartile range) was 27 (16-39) mg·h/L (n = 422). After dose adjustment recommendation, the median AUC 0-12h increased significantly to 38 (30-49) mg·h/L (n = 205, P < 0.001). The proportion of patients within the therapeutic target range (30-60 mg.h/L) increased from 40% to 61% (+21%, P < 0.001). CONCLUSIONS:Many patients were underexposed to MPA before dose adjustment. The ISBA recommendations significantly improved target attainment rates.

LCP-tacrolimus displays enhanced oral bioavailability compared to immediate-release (IR-) tacrolimus. The ENVARSWITCH study aimed to compare tacrolimus AUC(0-24 h) in stable kidney (KTR) and liver transplant recipients (LTR) on IR-tacrolimus converted to LCP-tacrolimus, in order to re-evaluate the 1:0.7 dose ratio recommended in the context of a switch and the efficiency of the subsequent dose adjustment. Tacrolimus AUC(0-24 h) was obtained by Bayesian estimation based on three concentrations measured in dried blood spots before (V2), after the switch (V3), and after LCP-tacrolimus dose adjustment intended to reach the pre-switch AUC(0-24 h) (V4). AUC(0-24 h) estimates and distributions were compared using the bioequivalence rule for narrow therapeutic range drugs (Westlake 90% CI within 0.90-1.11). Fifty-three KTR and 48 LTR completed the study with no major deviation. AUC(0-24 h) bioequivalence was met in the entire population and in KTR between V2 and V4 and between V2 and V3. In LTR, the Westlake 90% CI was close to the acceptance limits between V2 and V4 (90% CI = [0.96-1.14]) and between V2 and V3 (90% CI = [0.96-1.15]). The 1:0.7 dose ratio is convenient for KTR but may be adjusted individually for LTR. The combination of DBS and Bayesian estimation for tacrolimus dose adjustment may help with reaching appropriate exposure to tacrolimus rapidly after a switch.

Background: The Immunosuppressant Bayesian Dose Adjustment web site aids clinicians and pharmacologists involved in the care of transplant recipients; it proposes dose adjustments based on the estimated area under the concentration–time curve (AUCs). Three concentrations (T 20 min , T 1 h , and T 3 h ) are sufficient to estimate mycophenolic acid (MPA) AUC 0–12 h in pediatric kidney transplant recipients. This study investigates mycophenolate mofetil (MMF) doses and MPA AUC values in pediatric kidney transplant recipients, and target exposure attainment when the proposed doses were followed, through a large-scale analysis of the data set collated since the inception of the Immunosuppressant Bayesian Dose Adjustment web site. Methods: In this study, 4051 MMF dose adjustment requests, corresponding to 1051 patients aged 0–18 years, were retrospectively analyzed. AUC calculations were performed in the back office of the Immunosuppressant Bayesian Dose Adjustment using published Bayesian and population pharmacokinetic models. Results: The first AUC request was posted >12 months posttransplantation for 41% of patients. Overall, only 50% had the first MPA AUC 0–12 h within the recommended 30–60 mg.h/L range. When the proposed dose was not followed, the proportion of patients with an AUC in the therapeutic range for MMF with cyclosporine or tacrolimus at the subsequent request was lower (40% and 45%, respectively) than when it was followed (58% and 60%, respectively): P = 0.08 and 0.006, respectively. Furthermore, 3 months posttransplantation, the dispersion of AUC values was often lower at the second visit when the proposed doses were followed, namely, P = 0.03, 0.003, and 0.07 in the 4 months–1 year, and beyond 1 year with <6-month or >6-month periods between both visits, respectively. Conclusions: Owing to extreme interindividual variability in MPA exposure, MMF dose adjustment is necessary; it is efficient at reducing such variability when based on MPA AUC.

While the needs of dependent seniors needs are important in Nursing Home (NH), the medical resources are low in residences located in a medical desert. Access to care in these NH is very unequal and can result in a loss of chance for residents who are immediately transferred to emergency with a risk of iatrogeny or inappropriate hospitalization. Objective: We aim to find new models of care organization to optimize management of elderly in NH thanks to new technologies Artificial Intelligence (AI) associated to telemedicine. Method: Intel@Care is a 3 steps program planned over 5 years : 1- faisability study : Intel@Med-Faisa (2019-2020); 2- proof of concept : Intel@Med-POC with socio-environmental study (2020-2022); 3- efficiency study with medico-economic assessment Intel@Med-Efficiency (2022-2024). Results: Intel@Med-Faisa : 18 residents were included in 2 NHs; 20 additional diagnoses were created to adapt the Artificial Intelligence algorithm to the clinical characteristics of the elderly. Intel@Med-POC: (study in progress): 306 residents to be included to validate development of evidence-based decision tool to help physician to make decisions to manage healthcare interventions, verify the acceptability of the new care organization. A medico-economic study is also conducted. Perspectives : This program aims to secure the use of this tool by professionals and to identify the obstacles and levers about use, perception and find an economic model for the deployment on the territory. In parallel, a clinical research will be conducted in order to adapt this organization to elderly people living at home in medical desert areas.

Background: Immunosuppressant Bayesian Dose Adjustment (ISBA) is an online expert system that estimates the area under the curve (AUC) of immunosuppressive drugs through pharmacokinetic modelling and Bayesian estimation to propose dose adjustments to reach predefined exposure targets. The ISBA database was retrospectively analyzed to describe tacrolimus pharmacokinetics and exposure, evaluate the efficiency of ISBA dose recommendations, and propose tacrolimus AUC(0-12h) target ranges for pediatric renal allograft recipients treated with immediate release tacrolimus. Methods: The database included 1935 tacrolimus dose adjustment requests from 419 patients <19 years old who were treated with immediate-release tacrolimus and followed in 21 French hospitals. The tacrolimus exposure evolution with patient age and posttransplantation time, the correlation between trough tacrolimus concentration (C-0) and AUC(0-12h) at different periods posttransplantation, and the efficiency of dose recommendations to avoid underexposure and overexposure and to decrease between-patient AUC variability were investigated. Results: Tacrolimus AUC showed large between-patient variability (CV% = 40%) but moderate within-patient variability (median = 24.3% over a 3-month period). Dose-standardized exposure but not the AUC/C-0 ratio significantly decreased with time posttransplantation and patient age. We derived AUC(0-12h) ranges from the consensual C-0 ranges using linear regression equations. When the ISBA recommended dose was applied, the AUC distribution was narrower and a significantly higher proportion was within the targets (P < 0.0001). Conclusions: ISBA efficiently reduced tacrolimus underexposure and overexposure. The AUC(0-12h) target ranges for pediatric patients derived from the database were similar to those previously reported for adults. Estimating the AUC/C-0 ratio could help determine personalized C-0 targets.

A new anti-cancer drug delivery system, based on gold nanoparticles, has been designed for hydrophobic active compounds. The system is a conjugate of gold/polyethyleneimine (AuNPs/PEI) nanoparticles and sulphated β-cyclodextrin (CD). Anionic cyclodextrin was attached to the positively charged AuNPs/PEI nanoparticles by ionic bonds. Tanshinone IIA and α-mangostin were extracted, purified and encapsulated into the AuNPs/PEI/CD nanoparticles. In vitro preliminary cell viability assays against prostate cancer cell lines PC-3 and DU145 showed that encapsulation resulted in increased cytotoxicity.

Myofibroblasts differentiate, invade and repair injured tissues by secreting and organizing the extracellular matrix and by developing contractile forces. When tissues are damaged, tissue homeostasis must be re-established, and repair mechanisms have to rapidly provide harmonious mechanical tissue organization, a process essentially supported by (myo)fibroblasts. Under physiological conditions, the secretory and contractile activities of myofibroblasts are terminated when the repair is complete (scar formation) but the functionality of the tissue is only rarely perfectly restored. At the end of the normal repair process, myofibroblasts disappear by apoptosis but in pathological situations, myofibroblasts likely remain leading to excessive scarring. Myofibroblasts originate from different precursor cells, the major contribution being from local recruitment of connective tissue fibroblasts. However, local mesenchymal stem cells, bone marrow-derived mesenchymal stem cells and cells derived from an epithelial-mesenchymal transition process, may represent alternative sources of myofibroblasts when local fibroblasts are not able to satisfy the requirement for these cells during repair. These diverse cell types probably contribute to the appearance of myofibroblast subpopulations which show specific biological properties and which are important to understand in order to develop new therapeutic strategies for treatment of fibrotic and scarring diseases.

Myofibroblasts play a key role in the wound-healing process, promoting wound closure and matrix deposition. These cells normally disappear from granulation tissue by apoptosis after wound closure, but under some circumstances, they persist and may contribute to pathological scar formation. Myofibroblast differentiation and apoptosis are both modulated by cytokines, mechanical stress, and, more generally, cell-cell and cell-matrix interactions. Tissue repair allows tissues and organs to recover, at least partially, functional properties that have been lost through trauma or disease. Embryonic skin wounds are repaired without scarring or fibrosis, whereas skin wound repair in adults always leads to scar formation, which may have functional or esthetic consequences, as in the case of hypertrophic scars, for example. Skin wound repair involves a precise remodeling process, particularly in the dermal compartment, during which fibroblasts/myofibroblasts play a central role. This article reviews the origins of myofibroblasts and their role in normal and pathological skin wound healing. This article focuses on traumatic skin wound healing, but largely, the same mechanisms apply in other physiological and pathological settings. Tissue healing in other organs is examined by comparison, as well as the stromal reaction associated with cancer. New approaches to wound/scar therapy are discussed.

Melanoma is one of the most aggressive forms of cancer with a continuously growing incidence worldwide and is usually resistant to chemotherapy agents, which is due in part to a strong resistance to apoptosis. The resistance mechanisms are complex and melanoma cells may have diverse possibilities for regulating apoptosis to generate apoptotic deficiencies. In this study, we investigated the relationship between melanogenesis and resistance to apoptosis induced by ursolic acid, a natural chemopreventive agent, in B16-F0 melanoma cells. We demonstrated that cells undergoing apoptosis are able to delay their own death. It appeared that tyrosinase and TRP-1 up-regulation in apoptotic cells and the subsequent production of melanin were clearly implicated in an apoptosis resistance mechanism; while TRP-2, a well known mediator of melanoma resistance to cell death, was repressed. Our results confirm the difficulty of treating melanomas, since, even undergoing apoptosis, cells are nevertheless able to trigger a resistance mechanism to delay death.

Differentiation therapy could be one strategy for stopping cancer cell proliferation. A plant steroid, diosgenin, is known to induce megakaryocytic differentiation in human erythroleukemia (HEL) cells. In recent studies, the use of sedimentation field-flow fractionation (SdFFF) allowed the preparation of subpopulations that may differ in regard to sensitivity to differentiation induction. The specific goal of this study was to determine the relationship between cell cycle stage and sensitivity to megakaryocytic differentiation induction of HEL cells. After first confirming the capacity of diosgenin to specifically select targets, hyperlayer SdFFF cell sorting was used to prepare fractions according to cell cycle position from crude HEL cells. The sensitivities of these fractions to diosgenin-induced differentiation were then tested. The coupling of SdFFF cell separation to imaging flow cytometry showed that G1-phase cells were more sensitive to differentiation induction than S/G2M-phase cells, confirming the relationship between cell status at the start of induction, the extent of the biological event, and the potential of SdFFF in cancer research.

The spontaneously immortalized human keratinocyte cell line HaCaT is widely used as a human keratinocyte model. In a previous comparative study between normal human keratinocytes (NHKs) and HaCaT, we reported that Ca2+ concentrations greater than 1mM induced differentiation in vitro in both cell types, notably characterized by increased expression of differentiation markers keratins 1 (K1), 10 (K10) and involucrin. Surprisingly, cells had a higher proliferative activity than those cultured with low Ca2+ levels. These results raised many questions; in particular concerning the emergence of HaCaT cells subpopulation which would have different differentiation states and/or proliferation rates throughout Ca2+-induced differentiation. To isolate these subpopulations, we used sedimentation field-flow fractionation (SdFFF). Results demonstrated that the most differentiated cells (HC-F1), characterized by the highest expression of keratinocyte differentiation markers, had the lowest proliferative activity. In contrast, less differentiated cells (HC-F2) maintained a higher proliferative activity. SdFFF is a tool to sort differentiated and/or proliferating cells from a total pool previously treated with a Ca2+ concentration inducing differentiation, and can be use to prepare biological models necessary for studying HaCaT cell proliferation after Ca2+-induced differentiation treatment.

The keratinocyte growth and differentiation switch, tightly regulated by several mechanisms, is generally associated with decreased proliferation, cell cycle arrest in G0/G1 phase and expression of epidermal differentiation markers, such as keratin 1 (K1), keratin 10 (K10) and involucrin. In vitro, the spontaneously immortalized human keratinocyte cell line HaCaT is often used as a model to study keratinocyte functions. Comparative differentiation studies between HaCaT cells and normal human keratinocytes (NHK) over an extended time-period have rarely been reported. Therefore, we studied their switch from a proliferating to a differentiated state over 13 days. As culture conditions involved changes in cellular responses, cells were cultured in a specific medium for keratinocyte growth and differentiation was induced by increasing extracellular calcium concentration from 0.09 to 1.2 mm. In NHK, addition of calcium-induced morphological changes and concomitant decreased proliferation. For HaCaT cells, calcium addition resulted in morphological changes, but in an unexpected manner, cells were more proliferative than when cultured at low calcium levels. HaCaT cell hyperproliferation correlated with cell cycle analysis, showing an accumulation in S/G2-M phases. Furthermore, RT-PCR and western blot analysis revealed a delay in the expression of the differentiation markers K1, K10 and involucrin in HaCaT cells compared with NHK. In conclusion, even though calcium-induced differentiation was not associated with a decreased cell proliferation, HaCaT cells conserved properties characteristic of differentiation.