A new in vitro method to predict in vivo photoprotection of skin hyperpigmentation induced by visible light.

BACKGROUND: Ultraviolet radiation is the main cause of skin pigmentation, but more recently visible light has been shown to be an important contributor especially in melano-competent subjects. Photoprotection from visible light can improve several hyperpigmentation disorders. Recently, a visible light photoprotection assessment method has been proposed based on in vivo pigmentation; the visible light photoprotection factor (VL-PF) is determined by assessment of the change in colorimetry parameter ITA over several days measured using a chromameter. Although in vivo methods remain the most representative of real life, in vitro methods are more suited to screening sunscreen formulations. OBJECTIVE: The aim of this study was to evaluate the correlation between in vivo and in vitro methods in assessing protection against visible light induced pigmentation. METHODS: We first analysed the in vitro protective properties of the 10 commercially available sunscreens using transmission measurements in the visible spectrum. Then, we performed a monocentric, double-blind, randomized controlled study with intra-individual comparisons in 20 healthy subjects and measure the VL-PF in vivo of those sunscreens. The correlation between the VL-PF and the percentage of blocked light was evaluated using the coefficient of determination R2 . RESULTS: A strong significant correlation was demonstrated between in vivo visible light protection factor and in vitro transmittance measurements, with the highest correlation factor at 420 nm and in the spectrum covering from 400 to 469 nm. CONCLUSION: Transmittance measurements were found to be a good predictive tool to evaluate sunscreen visible light photoprotection efficacy and could be used to select formulations for final in vivo testing.

Pharmacist intervention to detect drug adverse events on admission to the emergency department: Two case reports of neuroleptic malignant syndrome.

WHAT IS KNOWN AND OBJECTIVE: Neuroleptic malignant syndrome (NMS) is a rare but severe adverse effect of antipsychotic drugs. CASE DESCRIPTION: We report two cases of NMS highlighted by clinical pharmacists in an emergency unit during summer. One of them was fatal. Medication reconciliation processes performed at admission identified treatment with loxapine for one of them and with loxapine and clozapine for the other. Interview of the patients highlighted clinical symptoms suggesting NMS, allowing the pharmacists to alert the medical team. WHAT IS NEW AND CONCLUSION: Adverse drug events may be severe and clinical pharmacists in emergency departments can help to detect them.

Application to a cartilage targeting strategy: synthesis and in vivo biodistribution of (14)C-labeled quaternary ammonium-glucosamine conjugates.

As part of a cartilage targeting program based on the affinity of the quaternary ammonium (QA) moiety for cartilage, QA derivatives of D-glucosamine (DG), an antirheumatic drug exhibiting a natural tropism for cartilaginous tissues, were designed and evaluated by pharmacokinetic studies. Two QA-DG conjugates were synthesized and labeled with (14)C by cross-linking the QA entity (trimethylammonium or pyridinium) to [(14)C]DG via an amide bond in a two-step procedure. After intravenous injection to male Sprague-Dawley rats, the two (14)C-labeled conjugates exhibited similar pharmacokinetic profiles, but their behavior clearly differed from that of unconjugated DG in several ways. (i) The tissue distribution for the conjugates was more restricted, with a decreased radioactivity level for whole tissues except for kidney, cartilage, and skin. (ii) The radioactivity concentrated more rapidly and strongly in cartilage for the conjugates than for DG for the short times after injection; on the other hand, 1 h after administration, the radioactivity level in cartilage was higher for DG, this result being consistent with the tropism already observed for this compound. (iii) Both conjugates were eliminated predominantly by the urinary route (85%); the radioactivity level in urine for DG was lower (45% of the injected dose), and significant (14)CO(2) was found in expired air, indicating metabolization and utilization of DG for energy-consuming processes. (iv) Blood and plasma kinetics studies displayed an enterohepatic cycle for DG, whereas for the QA conjugates, a rapid disappearance was observed. (v) HPLC analyses of plasma and urine indicated a low degree of metabolization for the conjugates, most of the radioactivity recovered in urine and plasma corresponding to the unchanged molecule. This study demonstrates that the introduction of the QA moiety on DG modifies its biodistribution and lends it a greater specificity for cartilage, at least for short times after injection. These findings justify further work on QA derivatives of other antirheumatic agents.

New quaternary ammonium oxicam derivatives targeted toward cartilage: synthesis, pharmacokinetic studies, and antiinflammatory potency.

Analogues of nonsteroidal antiinflammatory drugs (NSAIDs) oxicams, in which the active group was linked to a quaternary ammonium function [(4-hydroxy-2-methyl-2H-1,2-benzothiazine-1, 1-dioxide-3-carboxamido)2-methylpyridinium iodide or piroxicam-N(+) and [3-(4-hydroxy-2-methyl-2H-1,2-benzothiazine-1, 1-dioxide-3-carboxamido)propyl]trimethylammonium iodide or propoxicam-N(+)] were synthesized. Compounds were labeled with tritium for piroxicam-N(+) and carbon-14 for propoxicam-N(+). Pharmacokinetic studies conducted on rats showed that these molecules were able to highly concentrate in joint cartilages but their bioavailability by the oral way was low. Only propoxicam-N(+) exhibited a sufficient water solubility to be administered intravenously. This molecule was able to restore proteoglycans biosynthesis in cultured articular chondrocytes treated with Interleukin-1beta with an efficiency identical to that of indomethacin. These results suggest that the functionalization of oxicam derivatives by a quaternary ammonium group greatly increases their affinity toward articular cartilage without eliminating their pharmacological activity. New drugs synthesized according to this scheme could be useful to obtain a significant decrease of the efficient administered dose and consequently an attenuation of adverse effects such as digestive toxicity.

[Odontogenic tumors. The importance of a correct histopathological diagnosis]. / Tumori odontogenetici. Importanza di una corretta diagnosi istopatologica.

The troubles in the exact diagnosis of odontogenic tumors spring from the poor knowledge of the histological type of the lesion, from mutations in the ectodermal cells of the tumors and from the uncommonness of the pathology. Wrong diagnosis in this field of stomatology often lead to unnecessary surgical resection and could be avoid with better cooperation between surgeon and pathologist.