Adverse drug effect in the context of drug shortage: the CIRUPT prospective study from the French pharmacovigilance network.

OBJECTIVES: Drug shortages are of increasing concern to worldwide public health. The consequences of drug shortages for patient safety have been little studied, especially from a pharmacovigilance point of view. In this context, the network of French pharmacovigilance centres conducted the CIRUPT study (Conséquences Iatrogènes des RUPTures de stock/iatrogenic consequences of drug shortages) based on a prospective campaign of adverse effects occurring in the context of drug shortage notifications. METHODS: All notifications involving a shortage drug submitted to the French pharmacovigilance centres between 1 January 2020 and 30 June 2021 were collected and registered in the French national pharmacovigilance database with the standardised high level term 'product supply and availability issues' and with predefined keywords in the narrative section. RESULTS: 224 cases were included, involving mainly adverse drug reactions (ADRs) (n=131/224, 59%) and medication errors (n=51/224, 23%); 29% of the cases were serious. The most represented classes of shortage drugs were: vaccines (n=78/224, 35%); drugs for acid-related disorders (H2-receptor antagonists) (n=27/224, 12%); antineoplastic agents (n=17/224, 8%); and antiepileptics (n=15/224, 7%). In 82% of cases, the involved shortage drug was the subject of information delivered to health professionals by the National Agency for the Safety of Medicines and Health Products. Drug shortages were associated with an ADR related to replacement drugs in 59% (n=131/224) of the cases, drug inefficacy in 18% (n=41/224), and/or an aggravation of the underlying disease in 11% (n=25/224). CONCLUSIONS: From a pharmacovigilance point of view, a large diversity of anatomical therapeutic classes is involved and the risk related to drug shortages is not limited to drugs registered on 'major therapeutic interest or essential drug' lists. Information from health agencies is not sufficient to avoid the risks, and further strategies should be developed.

Cross-reactivity among and between macrolides, lincosamides, and streptogramins: Study on the French pharmacovigilance database.

BACKGROUND: Hypersensitivity reactions (HSR) are reported for the macrolides, lincosamides, and streptogramins (MLS) antibiotic family. Data about cross-reactivity among and between MLS remain scarce or controversial. OBJECTIVES: The aim of this study was to provide an overview of hypersensitivity cross-reactions among MLSs based on data extracted from the French National Pharmacovigilance Database (FPVD). METHODS: Cases of HSR to MLSs reported between January 1985 and December 2019 were extracted from the FPVD using standardized MedDRA queries (SMQ). Cases including an allergological test involving multiple MLSs and giving at least one positive result were included. RESULTS: Of the 8394 cases reviewed, 149 were included. HSR mainly involved pristinamycin (n = 83; 53.2%) and spiramycin (n = 31; 19.9%). HSR to MLS was immediate in 54 cases and delayed in 94 cases. Skin tests represented the majority of the allergological tests performed (n = 728; 84.7%), followed by reintroduction tests (n = 79; 9.2%). Eighty-six cross-reactivities among MLS were identified in 62 cases (41.6%). All the 25 explorations performed for streptogramins showed cross-reactivities, but only 30/253 among macrolides (11.9%). Cross-reactivities between the three MLS were observed in 31/322 (9.6%) of the allergological explorations. CONCLUSION: This study highlights the possibility of cross-reactivity among and between MLSs. Dermatologists and allergologists managing patients with HSR to MLSs should be aware of a risk of cross-reactivity among the macrolides and between the different classes of MLS and to perform MLSs allergological testing before recommending an alternative antibiotic, especially in severe drug hypersensitivity from the MLS family.

Ultrabright two-photon excitable red-emissive fluorogenic probes for fast and wash-free bioorthogonal labelling in live cells.

Fluorogenic bioorthogonal reactions are promising tools for tracking small molecules or biomolecules in living organisms. Two-photon excitation, by shifting absorption towards the red, significantly increases the signal-to-noise ratio and decreases photodamage, while allowing imaging about 10 times deeper than with a confocal microscope. However, efficient two-photon excitable fluorogenic probes are currently lacking. We report here the design and synthesis of fluorogenic probes based on a two-photon excitable fluorophore and a tetrazine quenching moiety. These probes react with bicyclo[6.1.0]no-4-yn-9ylmethanol (BCN) with a good to impressive kinetic rate constant (up to 1.1 × 103 M-1 s-1) and emit in the red window with moderate to high turn-on ratios. TDDFT allowed the rationalization of both the kinetic and fluorogenic performance of the different probes. The best candidate displays a 13.8-fold turn-on measured by quantifying fluorescence intensities in live cells under one-photon excitation, whereas a value of 3 is sufficient for high contrast live-cell imaging. In addition, live-cell imaging under two-photon excitation confirmed that there was no need for washing to monitor the reaction between BCN and this probe since an 8.0-fold turn-on was measured under two-photon excitation. Finally, the high two-photon brightness of the clicked adduct (>300 GM) allows the use of a weak laser power compatible with in vivo imaging.

Renal Safety Profile of BCR-ABL Tyrosine Kinase Inhibitors in a Real-Life Setting: A Study Based on Vigibase®, the WHO Pharmacovigilance Database.

BACKGROUND: Alongside their BCR-ABL specificity, TKIs used in chronic myeloid leukemia also target other tyrosine kinases expressed in the kidney such as PDGFR, c-KIT, SRC, and VEGFR, which may result in specific renal adverse drug reaction (ADR). To evaluate the renal safety profile in real-life conditions, a case/non-case study was performed on VigiBase®, the WHO global safety database. METHODS: From 7 November 2001 to 2 June 2021, all cases in which the involvement of imatinib, dasatinib, nilotinib, bosutinib, and ponatinib was suspected in the occurrence of renal ADR were extracted from VigiBase®. Disproportionality analyses were assessed using the reporting odds ratio. RESULTS: A total of 1409 cases were included. Imatinib accounts for half of the reported cases. A signal of disproportionate reporting (SDR) of renal failure and fluid retention was found for the five TKIs. Only dasatinib and nilotinib were related to an SDR for nephrotic syndrome. Nilotinib and ponatinib were related to an SDR for renal artery stenosis, while dasatinib was related to an SDR for thrombotic microangiopathy. No SDR for tubulointerstitial nephritis was observed. CONCLUSION: This study identified a new safety signal, nephrotic syndrome, for nilotinib and highlights the importance of post-marketing safety surveillance.

Adverse drug reaction related to drug shortage: A retrospective study on the French National Pharmacovigilance Database.

AIM: Drug shortages are a growing global health issue. The aim of the study was to evaluate the consequences of drug shortages on patient safety based on data recorded in the French National Pharmacovigilance Database. METHODS: All cases involving drug shortages reported from 1985 to the end of 2019 were extracted from the database. RESULTS: Following the selection process, 462 cases were included. The number of cases increased significantly from 2004 to 2019. Cases mainly involved drugs from the nervous system (22.1%, 95% confidence interval [CI] 17.5-27.0%), the cardiovascular system (16.4%, 95% CI 11.9-21.4%) and anti-infectives for systemic use (14.3%, 95% CI 9.7-19.2%) ATC classes. Most of the cases reported an adverse drug reaction (ADR) belonging to the SOC nervous system (21%, 95% CI 18-24%), skin and subcutaneous (14%, 95% CI 11-17%), general (13%, 95% CI 10-17%) and gastrointestinal (8%, 95% CI 5-11%) disorders. Disease worsening was observed in 15.9% of the cases, mostly related to a lack of efficacy of the replacement drug. Half of the cases were considered as serious. Evolution was favourable in 79.4% of the cases. Death and/or life-threatening situations were reported in 5.8% of the cases. Medication errors (MEs) were identified in 51 cases (11%), mostly occurring at the administration step and involving a human factor. CONCLUSION: This study emphasizes the clinical impact of drug shortage in terms of ADRs, ME and inefficiency. These observations underline the importance of a global health policy programme to limit the occurrence of drug shortages and to reinforce the information provided to patients and health care professionals in this context to limit risk.

Risk factors associated with immune checkpoint inhibitor-induced acute kidney injury compared with other immune-related adverse events: a case-control study.

Background: Immune checkpoint inhibitors (ICIs) foster anti-cancer immune responses. Their efficacy comes at the cost of immune-related adverse events (IRAEs). The latter affects various organs, including kidneys, mostly as acute tubulointerstitial nephritis, the pathophysiology of which remains unclear. We conducted a multicentre case-control study to compare the characteristics of patients with renal IRAEs (ICI-AKI) with those of patients diagnosed with other IRAEs. Methods: We queried the French pharmacovigilance database for all adverse events involving ICIs. Reports were classified as ICI-AKI or extrarenal IRAE. For each ICI-AKI report, four reports of extrarenal IRAEs were randomly included (control group, 4:1 ratio). Variables showing an association with a P < 0.05 were included as covariates in a multivariate analysis. Results: Therefore, 167 ICI-AKI reports were compared with 668 extrarenal IRAEs. At least one concomitant extrarenal IRAE was mentioned in 44.3% of ICI-AKI reports. Patients with ICI-AKI were significantly older than patients with extrarenal IRAEs (69.1 versus 64.6 years; P = 0.0135), and chronic kidney disease was significantly more prevalent (12.0% versus 3.3%; P = 0.0125). Patients with ICI-AKI were significantly more likely to be treated with fluindione [adjusted odds ratio (OR) 6.53, 95% confidence interval (95% CI) 2.21-19.31; P = 0.0007], a non-steroidal anti-inflammatory drug (NSAID, OR 3.18, 95% CI 1.07-9.4; P = 0.0368) or a proton-pump inhibitor (PPI, OR 2.18, 95% CI 1.42-3.34; P = 0.0004). Conclusion: This study is limited by a lack of data, preventing confirmation of numerous reports therefore not included in the analysis. We are unable to draw definite pathophysiological conclusions from our data. Nonetheless, we suggest that ICIs may be a 'second-hit' that precipitates acute kidney injury caused by another concomitant drug (fluindione, NSAID or PPI).

Modification of erythrocyte membrane phospholipid composition in preterm newborns with retinopathy of prematurity: The omegaROP study.

N-3 polyunsaturated fatty acids (PUFAs) may prevent retinal vascular abnormalities observed in oxygen-induced retinopathy, a model of retinopathy of prematurity (ROP). In the OmegaROP prospective cohort study, we showed that preterm infants who will develop ROP accumulate the n-6 PUFA arachidonic acid (ARA) at the expense of the n-3 PUFA docosahexaenoic acid (DHA) in erythrocytes with advancing gestational age (GA). As mice lacking plasmalogens -That are specific phospholipids considered as reservoirs of n-6 and n-3 PUFAs- Display a ROP-like phenotype, the aim of this study was to determine whether plasmalogens are responsible for the changes observed in subjects from the OmegaROP study. Accordingly, preterm infants aged less than 29 weeks GA were recruited at birth in the Neonatal Intensive Care Unit of University Hospital Dijon, France. Blood was sampled very early after birth to avoid any nutritional influence on its lipid composition. The lipid composition of erythrocytes and the structure of phospholipids including plasmalogens were determined by global lipidomics using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). LC-HRMS data confirmed our previous observations by showing a negative association between the erythrocyte content in phospholipid esterified to n-6 PUFAs and GA in infants without ROP (rho = -0.485, p = 0.013 and rho = -0.477, p = 0.015 for ethanolamine and choline total phospholipids, respectively). Phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) species with ARA, namely PtdCho16:0/20:4 (rho = -0.511, p < 0.01) and PtdEtn18:1/20:4 (rho = -0.479, p = 0.015), were the major contributors to the relationship observed. On the contrary, preterm infants developing ROP displayed negative association between PtdEtn species with n-3 PUFAs and GA (rho = -0.380, p = 0.034). They were also characterized by a positive association between GA and the ratio of ethanolamine plasmalogens (PlsEtn) with n-6 PUFA to PlsEtn with n-3 PUFAs (rho = 0.420, p = 0.029), as well as the ratio of PlsEtn with ARA to PlsEtn with DHA (rho = 0.843, p = 0.011). Altogether, these data confirm the potential accumulation of n-6 PUFAs with advancing GA in erythrocytes of infants developing ROP. These changes may be partly due to plasmalogens.

On the Road Toward More Efficient Biocompatible Two-Photon Excitable Fluorophores.

Red-to-NIR absorption and emission wavelengths are key requirements for intravital bioimaging. One of the way to reach such excitation wavelengths is to use two-photon excitation. Unfortunately, there is still a lack of two-photon excitable fluorophores that are both efficient and biocompatible. Thus, we design a series of biocompatible quadrupolar dyes in order to study their ability to be used for live-cell imaging, and in particular for two-photon microscopy. Hence, we report the synthesis of 5 probes based on different donor cores (phenoxazine, acridane, phenazasiline and phenothiazine) and the study of their linear and non-linear photophysical properties. TD-DFT calculations were performed and were able to highlight the structure-property relationship of this series. All these studies highlight the great potential of three of these biocompatible dyes for two-photon microscopy, as they both exhibit high two-photon cross-sections (up to 3650 GM) and emit orange to red light. This potential was confirmed through live-cell two-photon microscopy experiments, leading to images with very high brightness and contrast.

Cellular Detection of a Mitochondria Targeted Brominated Vinyl Triphenylamine Optical Probe (TP-Br) by X-Ray Fluorescence Microscopy.

Triphenylamine (TP) derivatives such as two-branch cationic vinylbenzimidazolium triphenylamine TP-2Bzim are promising turn-on fluorescent probes suitable for two-photon imaging, labelling mitochondria in live cells. Here, we designed two TP-2Bzim derivatives as bimodal probes suitable for X-ray fluorescence imaging. The conjugation of the TP core with a rhenium tricarbonyl moiety in the TP-RePyta probe altered the localisation in live cells from mitochondria to lysosomes. The introduction of bromine on the TP core generated the TP-Br probe retaining good photophysical properties and mitochondria labelling in live cells. The influence of calcium channels in the uptake of TP-Br was studied. Synchrotron Radiation X-ray Fluorescence (SXRF) imaging of bromine enabled the detection of TP-Br and suggested a negligible presence of the probe in an unbound state in the incubated cells, a crucial point in the development of these probes. This study paves the way towards the development of TP probes as specific organelle stainers suitable for SXRF imaging.

Renal Safety Profile of EGFR Targeted Therapies: A Study from VigiBase® the WHO Global Database of Individual Case Safety Reports.

Kidney EGFR expression together with reported cases of glomerular diseases in the context of anti-EGFR drug administration raise concerns about the renal safety profile of these drugs. This issue is addressed in a case/non-case study carried out on VigiBase®, the WHO global database of individual case safety reports (ICRS). Disproportionality analysis of renal adverse effects related to the selected anti-EGFR drugs, erlotinib, gefitinib, afatinib, osimertinib, cetuximab and panitumumab, was assessed using the reporting odds ratio (ROR). Nine hundred and eighty-nine ICRSs were included. A signal of disproportionate reporting (SDR) was found for afatinib (ROR = 2.70; 95% CI [2.22-3.29]) and erlotinib (ROR = 1.73; 95% CI [1.46-2.04]) with acute kidney injury, and for afatinib (ROR = 2.41; 95% CI [1.78-3.27]), cetuximab (ROR = 1.42; 95% CI [1.14-1.78]) and erlotinib (ROR = 2.23; 95% CI [1.80-2.77]) with renal failure. The preferred term "diarrhoea" was frequently reported in the included cases. An SDR was found for erlotinib with haemolytic and uremic syndrome (ROR = 4.01; 95% CI [1.80-8.94]) and thrombotic microangiopathy (ROR = 4.94; 95% CI [2.80-8.72]). No SDR was seen for glomerular or tubule-interstitial diseases. This study showed that the anti-EGFR drug renal toxicity is mainly related to renal failure in the context of digestive toxicity.

Immune checkpoint inhibitors-induced nephropathy: a French national survey.

Immune checkpoint inhibitors (ICIs), aiming to foster cancer-targeted immune response, proved to be effective in several advanced malignancies at the price of immune-related adverse events affecting various organs, notably the kidneys. Herein, a retrospective descriptive analysis was performed on all biopsy-confirmed cases of ICI-induced nephropathy notified to the French Pharmacovigilance database to date. Data were gathered about patients' characteristics, acute kidney injuries and histopathological features. A total of 63 biopsy-proven cases were included for analysis. Immune-related nephropathy occurred after a mean of 105.5 ± 98.6 (standard deviation) days after the introduction of the ICI. Kidney Disease: Improving Global Outcomes acute kidney injury stage 3 occurred in 36.5% of patients, and the mean peak serum creatinine was 288 µmol/L. Histopathology suggested acute tubule-interstitial nephritis in 52 patients (83%), while signs of acute tubular necrosis were found in 18 (29%) and glomerular involvement in 5 of them (8%). Another immune-related adverse event was documented in 25 patients (39.7%). Patients were treated with corticosteroids in 88.9% of cases. All in all, 27.0% fully recovered, 54.0% partially recovered, 12.7% did not recover. Rechallenge was attempted in 19 patients and one patient relapsed. Three-quarters of patients received a medication known to cause acute tubule-interstitial nephritis. The major limits of this study are those inherent to pharmacovigilance studies, such as its retrospective nature and incomplete data. Although it cannot pretend drawing any pathophysiological conclusion, this study depicts the clinical and histopathological pictures of ICI-induced nephropathies in a large cohort of biopsied patients with all grades of severity.

Modulation of Cellular Fate of Vinyl Triarylamines through Structural Fine Tuning: To Stay or Not To Stay in the Mitochondria?

Mitochondria are involved in many cellular pathways and dysfunctional mitochondria are linked to various diseases. Hence efforts have been made to design mitochondria-targeted fluorophores for monitoring the mitochondrial status. However, the factors that govern the mitochondria-targeted potential of dyes are not well-understood. In this context, we synthesized analogues of the TP-2Bzim probe belonging to the vinyltriphenylamine (TPA) class and already described for its capacity to bind nuclear DNA in fixed cells and mitochondria in live cells. These analogues (TP-1Bzim, TPn -2Bzim, TP1+ -2Bzim, TN-2Bzim) differ in the cationic charge, the number of vinylbenzimidazolium branches and the nature of the triaryl core. Using microscopy, we demonstrated that the cationic derivatives accumulate in mitochondria but do not reach mtDNA. Under depolarisation of the mitochondrial membrane, TP-2Bzim and TP1+ -2Bzim translocate to the nucleus in direct correlation with their strong DNA affinity. This reversible phenomenon emphasizes that these probes can be used to monitor ΔΨm variations.

Delayed thrombocytopenia following administration of abciximab: Pharmacovigilance survey and literature review.

BACKGROUND: Abciximab (ABX) is used for acute coronary syndrome and unstable angina. Thrombocytopenia is a frequent adverse effect described as occurring in the first 24hours. The aim of this study was to evaluate, in a context of pharmacovigilance survey, the occurrence of delayed thrombocytopenia following ABX infusion in pharmacovigilance database reports and in the literature. METHODS: Individual case safety reports (ICSRs) of delayed thrombocytopenia-between 3 and 30 days - with ABX presented as a single suspect were selected in VigiBase®, the WHO global database of ICSRs. The French cases were then extracted from the French national pharmacovigilance database. In addition, a literature review of published cases was performed using PubMed. RESULTS: Among the 84 ICSRs selected from VigiBase®, 43 were also reported in the FPVD. Mean age was 60.1±12.3 years with a majority of male patients (77.4%). The average time to onset (TTO) was 8.9±5.2 days. Thrombocytopenia regressed in 5.1±2.7 days. Haemorrhagic complications were reported in 15% of ICSRs. In the French cases, the median nadir of platelet count was 28×109/L (range 1-110) with a majority of grade 4 thrombocytopenia (39.5%). The literature review identified 42 cases and provided additional information on administered therapies, which include platelet units, corticosteroids, and IV immunoglobulins. GPIIb/IIIa-ABX complex antibodies were described in 26 published cases. CONCLUSION: Delayed thrombocytopenia, probably due to immune reaction, is a possible life-threatening adverse effect of ABX with a mean TTO of 9 days, supporting the recommendation of a platelet count monitoring during at least two weeks. This recommendation was added to the abcximab SmPC in 2019.

Assessment of drug-drug interaction in an elderly human immunodeficiency virus population: Comparison of 3 expert databases.

AIMS: Polypharmacy increase the risk of drug-drug interactions (DDIs) in the elderly population living with human immunodeficiency virus (HIV). Several expert databases can be used to evaluate DDIs. The aim of the study was to describe actual DDIs between antiretroviral drugs and comedications in an elderly population and to compare grading of the DDIs in 3 databases. METHODS: All treatments of HIV-infected subjects aged 65 years and older were collected in 6 French HIV centres. Summary of Product Characteristic (SPC), French DDI Thesaurus (THES), and Liverpool HIV DDI website (LIV) were used to define each DDI and specific grade. DDIs were classified in yellow flag interaction (undefined grade in SPC and THES or potential weak interaction in LIV), amber flag interaction (to be considered/precaution of use in SPC and THES and potential interaction in LIV) and red flag interaction (not recommended/contraindication in SPC and THES and do not administer/contraindication in LIV). RESULTS: Among 239 subjects included, 60 (25.1%) had at least 1 DDI for a total of 126 DDIs: 23/126 red flag DDIs were identified in 17 patients. All these 23 DDIs were identified in LIV. THES and SPC missed 6 and 1 red flag DDIs, respectively. Seven of 23 red flag DDIs were identified in the 3 databases concomitantly. CONCLUSION: Polypharmacy is frequent in this elderly HIV population leading to DDI in a quarter of the subjects. The discrepancies between databases can be explained by differences in analysis methods. A consensus between databases would be helpful for clinicians.

Interplay between Cellular Uptake, Intracellular Localization and the Cell Death Mechanism in Triphenylamine-Mediated Photoinduced Cell Death.

Triphenylamines (TPAs) were previously shown to trigger cell death under prolonged one- or two-photon illumination. Their initial subcellular localization, before prolonged illumination, is exclusively cytoplasmic and they translocate to the nucleus upon photoactivation. However, depending on their structure, they display significant differences in terms of precise initial localization and subsequent photoinduced cell death mechanism. Here, we investigated the structural features of TPAs that influence cell death by studying a series of molecules differing by the number and chemical nature of vinyl branches. All compounds triggered cell death upon one-photon excitation, however to different extents, the nature of the electron acceptor group being determinant for the overall cell death efficiency. Photobleaching susceptibility was also an important parameter for discriminating efficient/inefficient compounds in two-photon experiments. Furthermore, the number of branches, but not their chemical nature, was crucial for determining the cellular uptake mechanism of TPAs and their intracellular fate. The uptake of all TPAs is an active endocytic process but two- and three-branch compounds are taken up via distinct endocytosis pathways, clathrin-dependent or -independent (predominantly caveolae-dependent), respectively. Two-branch TPAs preferentially target mitochondria and photoinduce both apoptosis and a proper necrotic process, whereas three-branch TPAs preferentially target late endosomes and photoinduce apoptosis only.

Drug-induced vitiligo: a case/non-case study in Vigibase® , the WHO pharmacovigilance database.

Vitiligo is a common depigmenting disorder ensuing the loss of epidermal melanocytes. It is a multifactorial disease with immunological, genetic and environmental factors including drug exposure. The purpose of the study was to investigate the drugs and therapeutic subclasses associated with vitiligo occurrence reported in VigiBase® , the WHO pharmacovigilance database. A case/non-case study was carried out by defining cases as vitiligo reports and non-cases as all other reports. The reporting odds ratio (ROR) was calculated for the 'suspected' drugs and drug classes according to ATC level 4. During the study period, 741 cases of vitiligo were registered. Mean age was 49 ± 20 years. The disproportionality analysis showed an association between vitiligo and pembrolizumab (ROR 116.9, 95% Confidence Interval (CI) 94.8, 144.3), nivolumab (ROR 22.6, 95% CI 15.8, 32.4), ipilimumab (ROR 41.7, 95% CI 25.0, 69.7), imiquimod (ROR 152.8, 95% CI 103.0, 226.7), adalimumab (ROR 3.8, 95% CI 2.5,5.8), infliximab (ROR 2.6, 95% CI 1.65, 4.01), alemtuzumab (ROR 27.8, 95% CI 17.6, 43.9), and ustekinumab (ROR 9.3, 95% CI 5.6, 15.6). Concerning the pharmacological classes ATC level 4, a significant association was found with monoclonal antibodies, interferons, selective immunosuppressants, TNF-alpha inhibitors, interleukin inhibitors, and topical antivirals. This study confirmed the expected associations between vitiligo and immune checkpoint inhibitors and strengthened the emerging signal about the association between vitiligo and imiquimod, TNF-alpha inhibitors and interferons. New signals were shown with selective immunosuppressants including alemtuzumab and interleukin inhibitors.

Alteration of erythrocyte membrane polyunsaturated fatty acids in preterm newborns with retinopathy of prematurity.

Extremely preterm infants are at high risk for retinopathy of prematurity (ROP), a potentially blinding disease characterized by abnormalities in retinal vascularization. Whereas animal studies revealed that n-3 polyunsaturated fatty acids (PUFAs) may be of benefit in preventing ROP, human studies conducted on preterm infants during the 1st weeks of life showed no association between blood n-3 PUFA bioavailability and ROP incidence and/or severity, probably because of the influence of nutrition on the lipid status of infants. In the OmegaROP prospective cohort study, we characterized the erythrocyte concentrations of PUFAs in preterm infants aged less than 29 weeks gestational age (GA) without any nutritional influence. We show that GA is positively associated with the erythrocyte n-6 to n-3 PUFA ratio, and particularly with the ratio of arachidonic acid (AA) to docosahexaenoic acid (DHA), in infants with ROP. A time-dependent accumulation of AA at the expense of DHA seems to occur in utero in erythrocytes of preterm infants who will develop ROP, thus reinforcing previous data on the beneficial properties of DHA on this disease. In addition, preliminary data on maternal erythrocyte membrane lipid concentrations suggest modifications in placental transfer of fatty acids. Documenting the erythrocyte AA to DHA ratio at birth in larger cohorts might be useful to set up new prognostic factors for ROP.

Selectivity of Terpyridine Platinum Anticancer Drugs for G-quadruplex DNA.

Guanine-rich DNA can form four-stranded structures called G-quadruplexes (G4s) that can regulate many biological processes. Metal complexes have shown high affinity and selectivity toward the quadruplex structure. Here, we report the comparison of a panel of platinum (II) complexes for quadruplex DNA selective recognition by exploring the aromatic core around terpyridine derivatives. Their affinity and selectivity towards G4 structures of various topologies have been evaluated by FRET-melting (Fluorescence Resonance Energy Transfert-melting) and Fluorescent Intercalator Displacement (FID) assays, the latter performed by using three different fluorescent probes (Thiazole Orange (TO), TO-PRO-3, and PhenDV). Their ability to bind covalently to the c-myc G4 structure in vitro and their cytotoxicity potential in two ovarian cancerous cell lines were established. Our results show that the aromatic surface of the metallic ligands governs, in vitro, their affinity, their selectivity for the G4 over the duplex structures, and platination efficiency. However, the structural modifications do not allow significant discrimination among the different G4 topologies. Moreover, all compounds were tested on ovarian cancer cell lines and normal cell lines and were all able to overcome cisplatin resistance highlighting their interest as new anticancer drugs.