Integrating rare genetic variants into DPYD pharmacogenetic testing may help preventing fluoropyrimidine-induced toxicity.

Variability in genes involved in drug pharmacokinetics or drug response can be responsible for suboptimal treatment efficacy or predispose to adverse drug reactions. In addition to common genetic variations, large-scale sequencing studies have uncovered multiple rare genetic variants predicted to cause functional alterations in genes encoding proteins implicated in drug metabolism, transport and response. To understand the functional importance of rare genetic variants in DPYD, a pharmacogene whose alterations can cause severe toxicity in patients exposed to fluoropyrimidine-based regimens, massively parallel sequencing of the exonic regions and flanking splice junctions of the DPYD gene was performed in a series of nearly 3000 patients categorized according to pre-emptive DPD enzyme activity using the dihydrouracil/uracil ([UH2]/[U]) plasma ratio as a surrogate marker of DPD activity. Our results underscore the importance of integrating next-generation sequencing-based pharmacogenomic interpretation into clinical decision making to minimize fluoropyrimidine-based chemotherapy toxicity without altering treatment efficacy.

Dalbavancin plasma concentrations in 133 patients: a PK/PD observational study.

OBJECTIVES: Limited pharmacokinetics data support dalbavancin long-term use in off-label indications and the optimal dosing regimen is debated. We aimed to describe dalbavancin concentrations in an observational retrospective multicentre study. METHODS: Patients from 13 French hospitals, treated with 1500 mg doses of dalbavancin and for whom therapeutic drug monitoring was performed from June 2018 to March 2021 were included. Dalbavancin plasma concentrations were described at peak and 1, 2, 3, 4, 6 and 8 weeks after the last 1500 mg dose. Concentrations in patients weighing more or less than 75 kg and with a GFR greater or less than 60 mL/min were compared. Microbiological data were collected and dalbavancin MIC was measured when possible. RESULTS: One hundred and thirty-three patients were included (69% treated for bone and joint infections, 16% for endocarditis). Thirty-five patients received a single dose of dalbavancin and 98 received several administrations. Two, 3 and 4 weeks after the last dose, median plasma concentrations were respectively 25.00, 14.80 and 9.24 mg/L for the first doses and 34.55, 22.60 and 19.20 mg/L for the second or subsequent doses. Weight and renal function had an impact on pharmacokinetics. Infection was documented in 105 patients (Staphylococcus spp. in 68% of cases). Staphylococcus aureus was isolated in 32.5% of cases (median MIC: 0.047 mg/L) and Staphylococcus epidermidis in 27% of cases (median MIC of 0.047 mg/L). CONCLUSIONS: Plasma concentrations of dalbavancin were consistent with those described in clinical trials and those sought during the industrial development of the molecule.

Metabolic ratios and SNPs implicated in tramadol-related deaths.

Tramadol (TR) metabolism is performed by polymorphic enzymes that are influenced by genetic polymorphisms. Within this scope, the study presented here aimed to describe 41 genetic variants within CYP2D6, CYP2B6, and CYP3A4 genes in 48 cases of TR-related death that may be involved in the response to TR and to assess whether there is a correlation between these genetic variants and metabolic ratios (MRs). Blood samples from 48 victims of a TR-related death were analyzed to determine the concentrations of TR and its metabolites [O-desmethyltramadol (M1) & N-desmethyltramadol (M2)] using a LC-MS/MS method. All the samples were also genotyped for 41 common CYP2D6, CYP2B6, and CYP3A4 single nucleotide polymorphisms (SNPs) using the HaloPlex Target Enrichment system. Cases with the T/- genotype (rs35742686 in CYP2D6) had significantly higher M2/M1 ratio than cases with T/T genotype and cases with the G/A genotype (rs35599367 in CYP3A4) had significantly higher MR2 (TR/M2) ratio than cases with G/G genotype. The frequency of tested SNPs which belong to CYP2D6, CYP2B6, and CYP3A4 revealed the over-presentation of 2 SNPs (rs1058172 in CYP2D6 and rs4803419 in CYP2B6) in TR overdose group, which could have toxicological implications. These results indicate these polymorphisms in CYP2D6, CYP2B6, and CYP3A4 might influence the function and could increase the risk of toxicity. However, these findings should be supported in future studies with larger groups of cases.

Four-year follow-up of surface contamination by antineoplastic drugs in a compounding unit.

OBJECTIVES: This study aimed to monitor the contamination by antineoplastic drugs on work surfaces in a compounding unit 4 years after its implementation. METHODS: This descriptive study was done in a unit performing on average 45 000 preparations per year. Surface sampling points (N=23) were monitored monthly in the frame of routine activity from the opening of an anticancer drug compounding unit. Contamination with nine antineoplastic drugs (cyclophosphamide, ifosfamide, dacarbazine, 5-fluorouracil, methotrexate, gemcitabine, cytarabine, irinotecan and doxorubicin) was assessed on wipes with a local liquid chromatography coupled with a tandem mass spectrometer analysis. The contamination rate (CR, %) was prospectively monitored every month during the entire study period. The occurrence of critical incidents was also registered. The effect of each safety measure implemented during this period was also analysed. RESULTS: Based on the 1104 samples collected between March 2016 and March 2020, the CR was 18.5%. If three different critical incidents among a vial breakage that occurred were individually considered, this CR was slightly lower than that in the literature. Eight months after opening and taking different corrective actions, the overall CR dropped from 42.39% to 11.52% (p<0.001). Contamination was limited to the area that includes the compounding room and, more precisely, the welder and the QC-Prep+ sampling points. CONCLUSIONS: From the beginning of the study and from month to month, surface contamination was limited to the nearest sampling points to the compounding unit. This 4-year monitoring study allowed us to determine the intravenous conventional antineoplastic drugs and sampling points to be focused on.

Tranexamic acid dose-response relationship for antifibrinolysis in postpartum haemorrhage during Caesarean delivery: TRACES, a double-blind, placebo-controlled, multicentre, dose-ranging biomarker study.

BACKGROUND: The optimal dose of tranexamic acid to inhibit hyperfibrinolysis in postpartum haemorrhage is unclear. Tranexamic Acid to Reduce Blood Loss in Hemorrhagic Cesarean Delivery (TRACES) was a double-blind, placebo-controlled, randomised, multicentre dose-ranging study to determine the dose-effect relationship for two regimens of intravenous tranexamic acid vs placebo. METHODS: Women experiencing postpartum haemorrhage during Caesarean delivery were randomised to receive placebo (n=60), tranexamic acid 0.5 g (n=57), or tranexamic acid 1 g i.v. (n=58). Biomarkers of fibrinolytic activation were assayed at five time points, with inhibition of hyperfibrinolysis defined as reductions in the increase over baseline in D-dimer and plasmin-antiplasmin levels and in the plasmin peak time. RESULTS: In the placebo group, hyperfibrinolysis was evidenced by a mean increase over baseline [95% confidence interval] of 93% [68-118] for D-dimer level at 120 min and 56% [25-87] for the plasmin-antiplasmin level at 30 min. A dose of tranexamic acid 1 g was associated with smaller increases over baseline (D-dimers: 38% [13-63] [P=0.003 vs placebo]; plasmin-antiplasmin: -2% [-32 to 28] [P=0.009 vs placebo]). A dose of tranexamic acid 0.5 g was less potent, with non-significant reductions (D-dimers: 58% [32-84] [P=0.06 vs placebo]; plasmin-antiplasmin: 13% [18-43] [P=0.051]). Although both tranexamic acid doses reduced the plasmin peak, reduction in plasmin peak time was significant only for the 1 g dose of tranexamic acid. CONCLUSIONS: Fibrinolytic activation was significantly inhibited by a dose of intravenous tranexamic acid 1 g but not 0.5 g. Pharmacokinetic-pharmacodynamic modelling of these data might identify the best pharmacodynamic monitoring criteria and the optimal tranexamic acid dosing regimen for treatment of postpartum haemorrhage. CLINICAL TRIAL REGISTRATION: NCT02797119.

Involuntary 5F-ADB-related intoxication following e-cigarette use.

The detection of synthetic cannabinoid (SC) intoxication cases is challenging, even more when the involved SC identification is requested in a forensic context. This situation can be complicated by new modes of SC consumption, non-specific symptomatology, and analytical pitfalls. To illustrate these issues, we report the case of a 16-year-old man who presented symptoms evocating of a seizure disorder in the minutes following the use of a friend's e-cigarette. At admission in the emergency department, his electroencephalogram was interpreted as coherent with a recent seizure episode. 5F-ADB, a third generation SC, was detected in the e-liquid and in an early collected (H2 after the e-cigarette use) serum sample (0.50 µg/L), but not in urine samples (H18 and H38). One 5F-ADB metabolite, O-desmethyl-5F-ADB (M5), was detectable in urine up to at least 38 h after intoxication. Neither 5F-ADB nor its metabolites could be detected in victim's hair sampled 3 months after the intoxication. Although leading to a non-specific symptomatology, acute SC intoxication should be considered when the case history is related to e-cigarette or e-liquid use. Early biological samples are recommended, even if analytical screening can be positive for SC metabolites in urine sampled until 2 days after exposure. Accordingly, data from the literature and the present case underscore the relevance of adding both main 5F-ADB metabolites (M5 and 5-OH-pentyl-ADB) to mass spectrum databases used for toxicological screening in order to reduce the risk of false-negative results in intoxication cases involving 5F-ADB.

Putatively lethal ingestion of isopropyl alcohol-related case: interpretation of post mortem isopropyl alcohol and acetone concentrations remains challenging.

Isopropyl alcohol, or propan-2-ol (IPA), is found in numerous chemicals including alcohol-based hand rubs whose use has been recently widely extended to the general population since the onset of the COVID-19 pandemic. This widespread of IPA use could potentially, but not necessarily, be responsible for an increase in IPA poisoning cases (e.g., in alcoholics and/or for suicide attempt, even more in a lockdown situation). Forensic identification of IPA-related fatalities remains challenging as IPA post mortem detection can also result from antemortem or post mortem production, or post mortem contamination. In order to illustrate this issue, we report the case of a 33-year-old man found dead with a bottle of pure IPA liquid close to him. Toxicological positive results only consisted in IPA (464, 260, 465 and 991 mg/L) and acetone (1560, 2340, 3040 and 1360 mg/L) in blood, vitreous humour, urine and bile, respectively (determinations using headspace gas chromatography with flame ionization detection). These IPA absolute concentrations and IPA-to-acetone ratios appear inferior to those usually reported in the literature (higher than 1000 mg/L and 1.1, respectively) in IPA poisoning cases. In conclusion, this death can be cautiously regarded as an IPA ingestion-related fatality in the hypothesis of a survival time which have promoted IPA metabolism to acetone: this hypothesis is supported by the putative limited IPA-ingested dose. This report emphasizes the fact that post mortem IPA and acetone concentration interpretation involves to take account of (i) results in multiple biological specimens, (ii) complete case history, and (iii) a search of possible IPA presence at the scene of death.

Long-Term Analgesia following a Single Application of Fentanyl Transdermal Solution in Pigs.

INTRODUCTION: In animal research, obtaining efficient and constant pain control is regulatory but challenging. The gold standard pain management consists of opioid analgesic administration, such as buprenorphine or fentanyl extended-release patches. However, as in all drugs with a short half-life time, repeated buprenorphine administrations are needed, leading to multiple injections that affect the research protocol. On the other hand, fentanyl patch efficacy is discussed in some species. These elements highlight the need of an optimal formulation of analgesic drugs for laboratory animals. In this study, we investigated how Recuvyra®, a fentanyl transdermal solution (FTS), validated in dog perioperative pain management, could provide sustained analgesia after a single topical administration in pigs in a surgical context. METHODS: A total of 11 minipigs were used in this study. As a preliminary experiment, two different doses were tested as a single application on five pigs: two pigs at full dose (2.6 mg/kg) and three pigs at half dose (1.3 mg/kg). Plasma fentanyl dosages were performed during 4 consecutive days, using liquid chromatography with tandem mass spectrometry detection. The efficacy of FTS was then evaluated in a perioperative period. Six minipigs benefited from a surgical intervention comprising a laparotomy. The FTS was blotted on the skin in a single application 20 min before the surgical incision and plasma fentanyl dosages, clinical examination (body weight, food intake, heart rate, and body temperature) and pain assessment were performed for 7 consecutive days. RESULTS: During the preliminary experiment, all fentanyl concentrations reached the minimum effective concentration (MEC) extrapolated in pigs (fentanylemia ≥0.2 ng/mL) throughout the 4 days. The half dose was chosen for the next step of the study. After the surgical intervention, all plasma fentanyl concentrations remained above the MEC up to 7 days post administration. Pig clinical examinations and pain evaluations showed efficient and constant pain control at the half dose, and few adverse events were observed. DISCUSSION AND CONCLUSION: This study confirms the pharmacological and clinical efficacy of FTS at 1.3 mg/kg in pigs throughout at least 7 postoperative days following laparotomy. The clinical analgesic effect of FTS appears more efficient and well-tolerated than the one observed with repeated injections of buprenorphine. This analgesic drug formulation could be universally used in animal research to provide optimal perioperative pain management and long-term analgesia.

Perception of pharmacy students toward opioid-related disorders and roles of community pharmacists: A French nationwide cross-sectional study.

Background: Community pharmacists are among the frontline health professionals who manage patients with an opioid-related disorder (ORD). Pharmacists frequently have a negative attitude toward these patients, which could have a negative impact on their management. However, education on ORD may improve the attitude of future healthcare professionals. This cross-sectional study aimed to assess French pharmacy students' perceptions of ORD. Methods: This online survey was performed by emails sent to French pharmacy schools (between January 14, 2019 and May 31, 2019). The primary outcome was the perception (visual analogic scale) of ORD as a disease, the roles of community pharmacies (delivery of opioid agonist therapy-OAT and harm reduction kits), and the efficacy of OAT. The secondary outcomes assessed professional experience, university experience of and education on ORD, and the individual characteristics of students. Results: Among the 1,994 students included, 76.3% perceived ORD as a disease and felt that it was normal for pharmacists to deliver OAT (78.9%) and harm reduction kits (74.6%). However, only 46.9% perceived OAT as being effective. Multivariable analyses showed that females had a more positive perception in recognizing ORD as a disease. The progression through university years increased the positive perception of ORD as a disease and the delivery of OAT and harm reduction kits by pharmacists. Education on substance-related disorders had no impact on any scores. Students who had already delivered OAT had a negative perception of their efficacy. The students who had already performed pharmacy jobs or traineeships had a negative perception of harm reduction kit delivery. Conclusion: Education on substance-related disorders had no impact on students' perceptions. It seemed that the maturity acquired through university years had a stronger impact on the students' perceptions of ORD. Efforts must be made to improve our teaching methods and reinforce the confidence of students in the roles of community pharmacists.

Pitfalls of toxicological investigations in hair, bones, and nails in extensively decomposed bodies: illustration with two cases.

It is difficult to carry out toxicological investigations in biological samples collected from extensively decomposed bodies and to interpret obtained results as several pitfalls should be considered: redistribution phenomena, degradation of xenobiotics during the postmortem period, contamination by putrefaction fluids, and external contamination. This work aims to present two cases in order to illustrate and discuss these difficulties in this tricky situation. Case#1: the body of a 30-year-old woman was found in a wooded area (1 month after she has been reported missing by her family): hair and a femur section were sampled. Case#2: the decomposed corpse of a 52-year-old man was found in a ditch: hair and nails were sampled. After decontamination steps, toxicological investigations were performed using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, the same drugs or metabolites (benzodiazepines, propranolol, tramadol, acetaminophen, paroxetine, and oxetorone) were detected in hair and in bone specimens. This result combination strongly suggests intakes close to the time of death for three of them (oxazepam, lormetazepam, and propranolol). In case#2, results of toxicological investigations in hair and nails [(hair/nail concentration in ng/mg) nordiazepam (1.12/1.06), oxazepam (0.113/0.042), zolpidem (0.211/< 0.01), hydroxyzine (0.362/< 0.01), and cetirizine (0.872/1.110)] were both consistent with several drug intakes but were not contributory to cause of death determination. In case of positive toxicological results in biological samples collected from extensively decomposed bodies (such as hair, bones, or nails), it is challenging to determine the time, and even more, the level of the dose of exposure(s).

Exposure to metal fumes and circulating miRNAs in Algerian welders.

PURPOSE: A cross-sectional study was conducted in a group of Algerian welders to study the relationship between the exposure to metal particles from welding fumes and the concentration of three circulating miRNAs, miR-21, miR-146a and miR-155, as markers of renal function injury. METHODS: Characteristics of the subjects and the curriculum laboris were determined by questionnaires. We measured the concentrations of metals in blood and urine samples using ICP-MS. The three circulating miRNAs studied were measured by quantitative PCR. Associations between miRNAs and internal exposure markers were assessed by simple and multiple regression analyses. RESULTS: miR-21 was significantly lower among welders (p = 0.017), compared with controls, adjusted for age, body mass index, smoking status and seniority. Significant adjusted associations were observed between miR-21 or miR-155 and urinary chromium (p = 0.005 or p = 0.041, respectively), miR-146a and urinary nickel (p = 0.019). The results of the multivariate analysis showed that duration of employment was the main factor responsible for the variation of miRNAs among welders. CONCLUSION: In conclusion, a recent exposure to certain metals, mainly chromium and nickel, appears to be associated to a decrease in plasma expression of miR-21, miR-146a and miR-155. Further larger studies would help to determine the mechanisms of action of metal particles on miRNA expression.

Fastidious chemical decontamination after cyclophosphamide vial breakage in a compounding unit.

An important amount of cytotoxic drug may accumulate in the workplace following the breakage of a vial containing an anticancer drug. Thanks to the monthly monitoring of the surface contamination in our compounding unit, a strong increase of cyclophosphamide contamination was highlighted in the storage area following the breakage of the vial, despite application of the emergency procedure. This study presents an analysis of chemical decontamination in the context of massive contamination. Samples were taken on the floor and on the caster of a storage shelf where the vial broke. The residual contamination was measured with a liquid chromatography-mass spectrometry/mass spectrometry method. An admixture of 10-2 M sodium dodecyl sulfate and 70% isopropanol (SDS/IPA 8:2) was selected as the decontamination solution. High amounts of cyclophosphamide were retrieved. The initial contamination on the floor was over 20 ng/cm2. Three decontaminations with SDS/IPA were carried out at Day 61, Day 68, and Day 71. The amount of cyclophosphamide decreased to 0.45 ng/cm2 at D134. However, high values were still measured on the caster despite successive decontaminations, with a maximal value of 19.78 ng/cm2 observed at Day 106. Continuous monitoring in our unit led us to highlight the inefficiency of our emergency procedure to eliminate high cyclophosphamide contamination. The procedure involving the SDS/IPA admixture was more efficient on the floor compared to the caster, which is a different surface type and porosity. This work highlights the importance of improving the procedures of incident management using contamination monitoring and repeated decontamination procedures adapted to different contaminants and surfaces.

Case report: relevance of metabolite identification to detect new synthetic opioid intoxications illustrated by U-47700.

Today, new psychoactive substances (NPS) producers increasingly appear to be targeting new synthetic opioids (NSOs), and the recent emergence of NSOs is causing considerable concern in North America and in Europe. For toxicologists, NSO detection in a forensic context presents three additional difficulties to the general NPS analytical detection challenge: (i) high frequency of new products, (ii) low concentrations (in µg/L range and under) in biological samples related to their high opioid potency, and (iii) extensive metabolism. In this context, the present work aims to highlight the relevance of NSO metabolite detection in potential intoxication cases. Illustration is given with U-47700, an emerging NSO, (i) that was identified in a powder recently collected in France and in a fatality case, (ii) whose metabolites were in vitro produced using human liver microsomes and their mass spectra (MS) added in our MS/MS and HRMS libraries, and (iii) for which metabolism data were compared to those of the literature: U-47700 was identified in the powder and at 3040 µg/L in peripheral blood in the fatality case. In addition, high amounts of several U-47700 metabolites, especially N-desmethyl-U-47700, were observed in urine. Even if metabolite formation may largely depend on the enzymatic activity as well as on the length of the survival time, confrontation of these results to data found in the literature strongly suggests that this metabolite is regularly a better blood and (mainly) urine biomarker of U-47700 intake than U-47700 itself. Indeed, in this fatality and in other previous reports, N-desmethyl-U-47700 produced the main observed chromatographic signal (i) systematically in vitro and (ii) commonly in vivo, especially in urines. N,N-Didesmethyl-U-47700 is also sometimes a better biomarker of U-47700 intake than U-47700 itself. Accordingly, we suggest adding N-desmethyl-U-47700 (and N,N-didesmethyl-U-47700) in mass spectrum databases used for toxicological screening in order to reduce the risk of false-negative results in intoxication cases involving U-47700.

The association between blood cadmium and glycated haemoglobin among never-, former, and current smokers: A cross-sectional study in France.

INTRODUCTION: The association between cadmium levels in the body and diabetes has been extensively studied, with sometimes contrasting results. Smoking is the primary non-occupational source of cadmium, and constitutes a risk factor for diabetes. One can therefore hypothesize that the putative association with cadmium is actually explained by tobacco. To fully control for this confounding factor, we studied the relationship between blood cadmium and glycated haemoglobin (HbA1c) levels separately in never-, former and current smokers. METHODS: We studied a sample of 2749 middle-aged adults from the cross-sectional ELISABET survey in and around the cities of Lille and Dunkirk; none had chronic kidney disease or a history of haematological disorders, and none were taking antidiabetic medication. The blood cadmium level-HbA1c associations in never-, former and current smokers were studied in separate multivariate models. The covariables included age, sex, city, educational level, tobacco consumption (or passive smoking, for the never-smokers), body mass index, estimated glomerular filtration rate, and (to take account of the within-batch effect) the cadmium batch number. RESULTS: In the multivariate analysis, a significant association between cadmium and HbA1c levels was found in all three smoking status subgroups. A 0.1 µg/L increment in blood cadmium was associated with an HbA1c increase [95% confidence interval] of 0.016% [0.003; 0.029] among never-smokers, 0.024% [0.010; 0.037] among former smokers, and 0.020% [0.012; 0.029] among current smokers. CONCLUSIONS: The observation of a significant association between the blood cadmium concentration and HbA1c levels in a group of never-smokers strengthens the hypothesis whereby diabetes is associated with cadmium per se and not solely with tobacco use. The small effect size observed in our population of never smokers with low levels of exposure to cadmium suggested that the risk attributable to this metal is not high. However, the impact of exposure to high cadmium levels (such as occupational exposure) on the risk of diabetes might be of concern.

Risk factors associated to tobacco and alcohol use in a large French cohort of pregnant women.

Tobacco and/or alcohol use during pregnancy is a major public health concern. The aim of our study was to identify risk factors associated to maternal alcohol and tobacco use assessed by maternal self-reports combined with biological measurements in meconium samples of cotinine and ethylglucuronide which reflect fetal exposure to tobacco and alcohol, respectively, during the 3rd trimester of pregnancy. We conducted a prospective study in three maternity hospitals in a large urban area during consecutive weeks (2010 and 2011). Maternal sociodemographic and clinical characteristics were assessed after delivery, using the French version of the Addiction Severity Index. Cotinine and ethylglucuronide were measured in meconium samples. Seven hundred and twenty-four women were included, and 645 meconium samples collected. Using multivariate analyses, we found that not being married or having a smoking partner predicts maternal tobacco use. In contrast, a decreased risk was associated with higher education level and wanted pregnancy. The risk for alcohol use increased when the mother had been in conflict with any relative or her partner for a long time throughout her life, as well as in case of previous treatment for any mental or emotional disorder. Using multivariate analyses and cotinine presence in meconium samples, the risks were similar except for marital status, which was not associated to cotinine presence. Community education and prevention programs should urgently be improved for all women of childbearing age with a special focus on those with past histories of mental or emotional disorders and addictive disorders. Smoking cessation should be recommended to both parents.

Anti-ictogenic and antiepileptogenic properties of perampanel in mature and immature rats.

OBJECTIVE: Perampanel (PER) is a selective noncompetitive antagonist at α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, the first of its class approved for the adjunctive treatment of partial onset seizures and generalized seizures. This study explored anti-ictogenic and antiepileptogenic effects of PER in rats at different stages of development. METHODS: Using a rapid kindling model in postnatal day 14 (P14), P21, P28, and P60 rats, we studied two doses of PER: 1 and 2 mg/kg injected intraperitoneally 30 min before afterdischarge assessment. We also assessed blood and brain concentrations of PER 30 min after the injection. RESULTS: PER 2 mg/kg significantly increased the afterdischarge threshold (ADT) at all ages, whereas PER at 1 mg/kg increased ADT only in P21 rats. PER 2 mg/kg also shortened the afterdischarge duration in P14 and P28 rats. PER increased the number of stimulations required to achieve a stage 4-5 seizure in a dose-dependent manner in P14 and P21 rats, with almost complete elimination of stage 4-5 seizures. At P28, only PER 2 mg/kg increased the number of stimulations required to develop a stage 4-5 seizure. In contrast, PER had no effect on the number of stage 4-5 seizures at P60. We did not observed any age-dependent significant difference in the serum and brain levels of PER 30 min after the injection. SIGNIFICANCE: PER exerted anti-ictogenic effects from P14 to P60 independent of brain maturation. PER also exhibited antiepileptogenic effects with a stronger effect in the younger animals.

Mutations in IMPG1 cause vitelliform macular dystrophies.

Vitelliform macular dystrophies (VMD) are inherited retinal dystrophies characterized by yellow, round deposits visible upon fundus examination and encountered in individuals with juvenile Best macular dystrophy (BMD) or adult-onset vitelliform macular dystrophy (AVMD). Although many BMD and some AVMD cases harbor mutations in BEST1 or PRPH2, the underlying genetic cause remains unknown for many affected individuals. In a large family with autosomal-dominant VMD, gene mapping and whole-exome sequencing led to the identification of a c.713T>G (p.Leu238Arg) IMPG1 mutation, which was subsequently found in two other families with autosomal-dominant VMD and the same phenotype. IMPG1 encodes the SPACR protein, a component of the rod and cone photoreceptor extracellular matrix domains. Structural modeling indicates that the p.Leu238Arg substitution destabilizes the conserved SEA1 domain of SPACR. Screening of 144 probands who had various forms of macular dystrophy revealed three other IMPG1 mutations. Two individuals from one family affected by autosomal-recessive VMD were homozygous for the splice-site mutation c.807+1G>T, and two from another family were compound heterozygous for the mutations c.461T>C (p.Leu154Pro) and c.1519C>T (p.Arg507(∗)). Most cases had a normal or moderately decreased electrooculogram Arden ratio. We conclude that IMPG1 mutations cause both autosomal-dominant and -recessive forms of VMD, thus indicating that impairment of the interphotoreceptor matrix might be a general cause of VMD.

Tryptophan catabolism in Pseudomonas aeruginosa and potential for inter-kingdom relationship.

BACKGROUND: Pseudomonas aeruginosa (Pa) is a Gram-negative bacteria frequently involved in healthcare-associated pneumonia with poor clinical outcome. To face the announced post-antibiotic era due to increasing resistance and lack of new antibiotics, new treatment strategies have to be developed. Immunomodulation of the host response involved in outcome could be an alternative therapeutic target in Pa-induced lung infection. Kynurenines are metabolites resulting from tryptophan catabolism and are known for their immunomodulatory properties. Pa catabolizes tryptophan through the kynurenine pathway. Interestingly, many host cells also possess the kynurenine pathway, whose metabolites are known to control immune system homeostasis. Thus, bacterial metabolites may interfere with the host's immune response. However, the kynurenine pathway in Pa, including functional enzymes, types and amounts of secreted metabolites remains poorly known. Using liquid chromatography coupled to mass spectrometry and different strains of Pa, we determined types and levels of metabolites produced by Pa ex vivo in growth medium, and the relevance of this production in vivo in a murine model of acute lung injury. RESULTS: Ex vivo, Pa secretes clinically relevant kynurenine levels (µM to mM). Pa also secretes kynurenic acid and 3-OH-kynurenine, suggesting that the bacteria possess both a functional kynurenine aminotransferase and kynurenine monooxygenase. The bacterial kynurenine pathway is the major pathway leading to anthranilate production both ex vivo and in vivo. In the absence of the anthranilate pathway, the kynurenine pathway leads to kynurenic acid production. CONCLUSION: Pa produces and secretes several metabolites of the kynurenine pathway. Here, we demonstrate the existence of new metabolic pathways leading to synthesis of bioactive molecules, kynurenic acid and 3-OH-kynurenine in Pa. The kynurenine pathway in Pa is critical to produce anthranilate, a crucial precursor of some Pa virulence factors. Metabolites (anthranilate, kynurenine, kynurenic acid) are produced at sustained levels both ex vivo and in vivo leading to a possible immunomodulatory interplay between bacteria and host. These data may imply that pulmonary infection with bacteria highly expressing the kynurenine pathway enzymes could influence the equilibrium of the host's tryptophan metabolic pathway, known to be involved in the immune response to infection. Further studies are needed to explore the effects of these metabolic changes on the pathophysiology of Pa infection.