Novel micelle carriers for cyclosporin A topical ocular delivery: in vivo cornea penetration, ocular distribution and efficacy studies.

Cornea transplantation is one of the most performed graft procedures worldwide with an impressive success rate of 90%. However, for "high-risk" patients with particular ocular diseases in addition to the required surgery, the success rate is drastically reduced to 50%. In these cases, cyclosporin A (CsA) is frequently used to prevent the cornea rejection by a systemic treatment with possible systemic side effects for the patients. To overcome these problems, it is a challenge to prepare well-tolerated topical CsA formulations. Normally high amounts of oils or surfactants are needed for the solubilization of the very hydrophobic CsA. Furthermore, it is in general difficult to obtain ocular therapeutic drug levels with topical instillations due to the corneal barriers that efficiently protect the intraocular structures from foreign substances thus also from drugs. The aim of this study was to investigate in vivo the effects of a novel CsA topical aqueous formulation. This formulation was based on nanosized polymeric micelles as drug carriers. An established rat model for the prevention of cornea graft rejection after a keratoplasty procedure was used. After instillation of the novel formulation with fluorescent labeled micelles, confocal analysis of flat-mounted corneas clearly showed that the nanosized carriers were able to penetrate into all corneal layers. The efficacy of a 0.5% CsA micelle formulation was tested and compared to a physiological saline solution and to a systemic administration of CsA. In our studies, the topical CsA treatment was carried out for 14 days, and the three parameters (a) cornea transparency, (b) edema, and (c) neovascularization were evaluated by clinical observation and scoring. Compared to the control group, the treated group showed a significant higher cornea transparency and significant lower edema after 7 and 13 days of the surgery. At the end point of the study, the neovascularization was reduced by 50% in the CsA-micelle treated animals. The success rate of cornea graft transplantation was 73% in treated animals against 25% for the control group. This result was as good as observed for a systemic CsA treatment in the same animal model. This new formulation has the same efficacy like a systemic treatment but without the serious CsA systemic side effects. Ocular drug levels of transplanted and healthy rat eyes were dosed by UPLC/MS and showed a high CsA value in the cornea (11710 ± 7530 ng(CsA)/g(tissue) and 6470 ± 1730 ng(CsA)/g(tissue), respectively). In conclusion, the applied formulation has the capacity to overcome the ocular surface barriers, the micelles formed a drug reservoir in the cornea from, where a sustained release of CsA can take place. This novel formulation for topical application of CsA is clearly an effective and well-tolerated alternative to the systemic treatment for the prevention of corneal graft rejection.

Detection, Determination of Chemical Composition and Chemical Profiling of Counterfeit Medicines by Raman Spectroscopy.

Raman spectroscopy has become a widespread technique for the analysis ofpharmaceutical solid forms. The application proposed here is the investigationof counterfeit medicines. This serious global issue requires quick and accurateidentification methods to fight against this phenomenon. Thanks to its chemicalselectivity, rapidity of analysis and potential of generating repeatable spectralprofiles, Raman spectroscopy presents distinct advantages for the analysis ofcounterfeits. Combined with chemometric tools, the technique enablesthe detection, the determination of chemical composition and the profiling ofmedicine counterfeits.

Detection of possible variant forms of hemoglobin in HbA1c measurements by chromatography liquid ion exchange high resolution (HPLC)

Background: The glycosylated hemoglobin (HbA1c) is used to help monitor the degree of a diabetic’s hyperglycemia. Security and accuracy of the methods used in its detection are affected by variants forms of Hb or elevations in levels of Fetal Hb (HbF). These interference are the result of a change in the haemoglobin total net charge of the variant due of a substitution of one amino acid in the remaining amino terminal of the beta chain. International Standardization for HbA1c values (NGSP) not include interference assessment as part of the certification program. Therefore, the effect of each variant or the lifting of the HbF on HbA1c result should be examined in each sample depending on the detected variant and the method used for the detection of the same. The objectives were: to describe the possible variants of Hb and their interference in HbA1c measurement by our method, after the implementation of a computer program for their detection. To identify some variants detected by chromatography liquid ion exchange high resolution (HPLC) with DNA molecular sequencing.

Ganciclovir exposure under a 450mg daily dosage of valganciclovir for cytomegalovirus prevention in kidney transplantation: a prospective study.

Manuel O, Pascual M, Perrottet N, Lamoth F, Venetz J-P, Decosterd LA, Buclin T, Meylan PR. Ganciclovir exposure under a 450 mg daily dosage of valganciclovir for cytomegalovirus prevention in kidney transplantation: a prospective study. 
Clin Transplant 2010: 24: 794-800. Abstract:  This prospective study aimed at determining the ganciclovir exposure observed under a daily dosage of 450 mg valganciclovir routinely applied to kidney transplant recipients with a GFR above 25 mL/min at risk for cytomegalovirus (CMV) disease. Ganciclovir levels at trough (C(trough) ) and at peak (C(3 h) ) were measured monthly. Ganciclovir exposure (area under the curve [AUC(0-24) ]) was estimated using Bayesian non-linear mixed-effect modeling (NONMEM). Thirty-six patients received 450 mg of valganciclovir daily for three months. Median ganciclovir C(3 h) was 3.9 mg/L (range: 1.3-7.1), and C(trough) was 0.4 mg/L (range 0.1-2.7). Median AUC(0-24) of ganciclovir was 59.3 mg h/L (39.0-85.3) in patients with GFR(MDRD) 26-39 mL/min, 35.8 mg h/L (24.9-55.8) in patients with GFR(MDRD) 40-59 mL/min, and 29.6 mg h/L (22.0-43.2) in patients with GFR(MDRD)  ≥ 60 mL/min. No major differences in adverse events according to ganciclovir exposure were observed. CMV viremia was not detected during prophylaxis. After discontinuing prophylaxis, CMV viremia was seen in 8/36 patients (22%), and 4/36 patients (11%) developed CMV disease. Ganciclovir exposure after administration of valganciclovir 450 mg daily in recipients with GFR ≥60 mL/min was comparable to those previously reported with oral ganciclovir. A routine daily dose of 450 mg valganciclovir appears to be acceptable for CMV prophylaxis in most kidney transplant recipients.

Normal forms, stability and splitting of invariant manifolds I. Gevrey Hamiltonians

In this paper, we give a new construction of resonant normal forms with a small remainder for near-integrable Hamiltonians at a quasi-periodic frequency. The construction is based on the special case of a periodic frequency, a Diophantine result concerning the approximation of a vector by independent periodic vectors and a technique of composition of periodic averaging. It enables us to deal with non-analytic Hamiltonians, and in this first part we will focus on Gevrey Hamiltonians and derive normal forms with an exponentially small remainder. This extends a result which was known for analytic Hamiltonians, and only in the periodic case for Gevrey Hamiltonians. As applications, we obtain an exponentially large upper bound on the stability time for the evolution of the action variables and an exponentially small upper bound on the splitting of invariant manifolds for hyperbolic tori, generalizing corresponding results for analytic Hamiltonians.

Normal forms, stability and splitting of invariant manifolds II. Finitely differentiable Hamiltonians

This paper is a sequel to ``Normal forms, stability and splitting of invariant manifolds I. Gevrey Hamiltonians", in which we gave a new construction of resonant normal forms with an exponentially small remainder for near-integrable Gevrey Hamiltonians at a quasi-periodic frequency, using a method of periodic approximations. In this second part we focus on finitely differentiable Hamiltonians, and we derive normal forms with a polynomially small remainder. As applications, we obtain a polynomially large upper bound on the stability time for the evolution of the action variables and a polynomially small upper bound on the splitting of invariant manifolds for hyperbolic tori.

Measurement of glomerular filtration rate in obese patients: pitfalls and potential consequences on drug therapy.

Epidemiological studies have shown that obesity is associated with chronic kidney disease and end stage renal disease. These studies have used creatinine derived equations to estimate glomerular filtration rate (GFR) and have indexed GFR to body surface area (BSA). However, the use of equations using creatinine as a surrogate marker of glomerular filtration and the indexation of GFR for BSA can be questioned in the obese population. First, these equations lack precision when they are compared to gold standard GFR measurements such as inulin clearances; secondly, the indexation of GFR for 1.73 m(2) of BSA leads to a systematic underestimation of GFR compared to absolute GFR in obese patients who have BSA that usually exceed 1.73 m(2). Obesity is also associated with pathophysiological changes that can affect the pharmacokinetics of drugs. The effect of obesity on both renal function and drug pharmacokinetics raises the issue of correct drug dosage in obese individuals. This may be particularly relevant for drugs known to have a narrow therapeutic range or excreted by the kidney.

Morphologic and electroretinographic phenotype of SR-BI knockout mice after a long-term atherogenic diet.

PURPOSE: To evaluate functional and ultrastructural changes in the retina of scavenger receptor B1 (SR-BI) knockout (KO) mice consuming a high fat cholate (HFC) diet. METHODS: Three-month-old male KO and wild-type (WT) mice were fed an HFC diet for 30 weeks. After diet supplementation, plasma cholesterol levels and electroretinograms were analyzed. Neutral lipids were detected with oil red O, and immunohistochemistry was performed on cryostat ocular tissue sections. The retina, Bruch's membrane (BM), retinal pigment epithelium (RPE), and choriocapillaris (CC) were analyzed by transmission electron microscopy. RESULTS: Using the WT for reference, ultrastructural changes were recorded in HFC-fed SR-BI KO mice, including lipid inclusions, a patchy disorganization of the photoreceptor outer segment (POS) and the outer nuclear layer (ONL), and BM thickening with sparse sub-RPE deposits. Within the CC, there was abnormal disorganization of collagen fibers localized in ectopic sites with sparse and large vacuolization associated with infiltration of macrophages in the subretinal space, reflecting local inflammation. These lesions were associated with electroretinographic abnormalities, particularly increasing implicit time in a- and b-wave scotopic responses. Abnormal vascular endothelial growth factor (VEGF) staining was detected in the outer nuclear layer. CONCLUSIONS: HFC-fed SR-BI KO mice thus presented sub-RPE lipid-rich deposits and functional and morphologic alterations similar to some features observed in dry AMD. The findings lend further support to the hypothesis that atherosclerosis causes retinal and subretinal damage that increases susceptibility to some forms of AMD.

Suivi thérapeutique des médicaments (I). Les principes [Principles of therapeutic drug monitoring]

Requesting a blood level measurement of a drug is part of the global approach known as "Therapeutic Drug Monitoring". Diverse situations require this monitoring approach, such as inadequate response to treatment or organ failure. Every drug however does not possess all the characteristics for a TDM program. The therapeutic range of a TDM drug has indeed to be narrow and its interindividual pharmacokinetic variability to be wide. As the development of new drugs is currently slowing down, the precise management of existing treatments certainly deserves progress, but needs however to be applied rationally, starting from a valid indication to blood sampling, and ending with a sound dosage adaptation decision.

Monoclonal antibody against carcinoembryonic antigen (CEA) identifies two new forms of crossreacting antigens of molecular weight 90,000 and 160,000 in normal granulocytes.

Two new forms of non-specific crossreacting antigens (NCAs) were identified in the Nonidet P40 (NP-40) extracts of normal granulocytes by precipitation with the monoclonal antibody (MAb) 192 directed against carcinoembryonic antigen (CEA) and already known to crossreact with the perchloric acid soluble NCA-55. The NP-40 soluble NCAs recognized by MAb 192 have apparent mol. wts of 90,000 and 160,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Both NCAs appear to consist of a single monomeric polypeptide chain, since they have the same electrophoretic mobility in SDS-PAGE under reduced and non-reduced conditions. When granulocytes were extracted with perchloric acid instead of NP-40, only the 55,000 mol. wt antigen, corresponding to the previously described NCA-55, was precipitated by MAb 192. Furthermore, it was shown that NCA-55 is not a degradation product of NCA-90 or NCA-160 due to the perchloric acid treatment because exposure to perchloric acid of NCA preparations purified from NP-40 extracts did not change their apparent mol. wts in SDS-PAGE. It was also shown that NCA-160 is not a granulocytic form of CEA because it was not precipitated by the MAb 35 reacting exclusively with CEA. Immunocytochemical studies of granulocytes and macrophages showed that MAb 192 stained both types of cells whereas MAb 47 stained only the granulocytes and MAb 35 none of these cells. In granulocytes both MAbs reacted with antigens associated with granules and also present at the periphery of the nucleus as well as in the Golgi apparatus. The NCA-90 identified by MAb 192 was found by sequential immunodepletion to be antigenically distinct from the NCA-95 precipitated by MAb 47. The epitope recognized by MAb 192 on CEA and NCA molecules appears to be on the peptidic moiety because the antigens deglycosylated by the enzyme Endo F were still precipitated by this MAb. Taken together, the results indicate that MAb 192 identifies two novel forms of NCA (NCA-90 and NCA-160) in NP-40 extracts of granulocytes, which are distinct from CEA and the previously described NCA-55 and NCA-95 identified by MAbs 192 and 47, respectively, in perchloric acid extracts of granulocytes.

CNVs and genetic medicine (excitement and consequences of a rediscovery).

The extensive variability of individual human genomes contributes to phenotypic variability. Structural genomic variants, and copy number variants (CNVs) in particular, have recently been rediscovered as contributors to the genomic plasticity and evolution and as pathoetiologic elements for both monogenic and complex traits. Herein we review some of the consequences of CNVs in the context of human inherited diseases.

Dosage plasmatique des medicaments antidépresseurs [Recommendations for therapeutic monitoring of antidepressants].

Therapeutic drug monitoring (TDM), combined in certain situations with pharmacogenetic tests of metabolism, has proven a valuable tool for psychopharmacotherapy. Uncertain drug adherence, suboptimal tolerability, nonresponse at therapeutic doses, or pharmacokinetic drug-drug interactions are typical situations when measurement of medication concentrations is helpful. This article is an adaptation of guidelines recently issued by the AGNP-TDM group (Hiemke et al., www. agnp.de), but its content focuses mainly on the TDM of antidepressants. Finally, the potential benefits of TDM for optimization of pharmacotherapy can only be obtained if the method is adequately integrated into the clinical treatment process.