Microdialysis as a potential tool for comparative assessment of tissue pharmacokinetics of two different patches containing lidocaine: A crossover pilot study.

OBJECTIVE: Lidocaine 5% patches are approved for the treatment of post-herpetic neuralgia in adults. Little information is available on the penetration of lidocaine into skin and skin-related soft tissue, which are thought to be closer to the site where lidocaine exerts its pharmacological action on neuronal structures. This pilot study investigated subcutaneous and systemic pharmacokinetics of lidocaine during topical application of two different lidocaine 5% patches. MATERIALS AND METHODS: This randomized two-way, two-period crossover study assessed lidocaine concentrations in subcutaneous tissue (by microdialysis) and plasma of n = 5 healthy subjects during 12-hour-long applications of a recently developed lidocaine 5% patch (Laboratorios Gebro Pharma, SA, Barcelona, Spain) and a marketed reference patch (Versatis 5% lidocaine patch, Grünenthal, Brunn am Gebirge, Austria), respectively. RESULTS: Lidocaine was detectable in subcutaneous tissue within 60 minutes from start of patch application, and in plasma only after a marked delay. The test formulation led to increased exposure to lidocaine in both subcutaneous tissue and plasma. CONCLUSION: This study has underscored the potential of microdialysis to comparatively assess the pharmacokinetics of two different drug formulations and encourages its further use in this area.

Measuring sucrose in blood after oral administration to detect abomasal ulcers in calves.

Abomasal ulcers are common in cattle, especially in calves, and to date, there is no reliable antemortem method for diagnosis, to our knowledge. We assessed if measuring sucrose in blood after oral administration in calves could be used to identify animals with abomasal ulcers. Terminally ill calves (n = 12; part A) and calves designated for slaughter (n = 123; part B) were given a sucrose solution per os, and blood samples were taken 15, 30, 60, 90, and 120 min (part A) or 30 and 60 min (part B) after administration. The calves were then euthanized or slaughtered, and their abomasa were examined. Serum samples were analyzed using highperformance liquid chromatography-mass spectrometry, and data were analyzed using general linear mixed models. Calves both with and without affected abomasa had increasing sucrose values over time without significant differences. Also, there was no relationship between the size of the mucosal lesion and sucrose values.

Effect of particle deposition density of dry powders on the results produced by an in vitro test system simulating dissolution- and absorption rates in the lungs.

The surface area of the air/liquid interface in the lungs is substantial, so deposited doses of aerosol medicines per interface surface area when administered via the inhalation route is always quite low. However, in most in vitro systems used for dissolution testing of dry powder inhalables, the dose per surface area is generally much higher. The aim of this study was to investigate in one in vitro lung dissolution system, the DissolvIt, the manner in which the deposited dose per test surface area of drug particles influences the simulated dissolution- and absorption rate. Here we used the dissolution test method DissolvIt to investigate the influence on dissolution behavior by varying the deposited surface density of tested drugs. Dry powders of three different active pharmaceutical ingredients with different solubilities were used; salmeterol, budesonide and fluticasone propionate. It was found that by varying the dose density from 0.23 to 29 µg/cm2 the dissolution- and absorption rate of test particles was affected for all three substances, with decreasing relative dissolution rates above certain dose limits. The effect was much more prominent with the least soluble fluticasone propionate. In contrast, in a real lung it has been shown that a tenfold increase of the even less soluble fluticasone furoate did not affect the pulmonary dissolution- and absorption as measured in the ex vivo isolated perfused rat lung. This indicates that the deposited particle dose on the test surface used must be carefully considered in all in vitro dissolution testing apparatuses used for inhalation drugs, especially when aiming for in vitro-in vivo correlations. Conclusive data show that in the DissolvIt system consistent normalized dissolution- and absorption data can be obtained if the deposition density of test substance are kept below 1 µg/cm2 and the variability between the initial drug doses is smaller than 10-15% expressed as standard deviation.

Diversity of glycosphingolipid GM2 and cholesterol accumulation in NPC1 patient-specific iPSC-derived neurons.

Niemann-Pick disease Type C1 (NPC1) is a rare progressive neurodegenerative disorder caused by mutations in the NPC1 gene. On the cellular level NPC1 mutations lead to an accumulation of cholesterol and gangliosides. As a thorough analysis of the severely affected neuronal cells is unfeasible in NPC1 patients, we recently described the cellular phenotype of neuronal cells derived from NPC1 patient iPSCs carrying the compound heterozygous mutation c.1836A>C/c.1628delC. Here we expanded the analysis to cell lines carrying the prevalent mutation c.3182T>C and the novel mutation c.1180T>C, as well as to the determination of GM2 and GM3 gangliosides in NPC1 patient-specific iPSC-derived neurons and glia cells. Immunocytochemical detection of GM2 revealed punctated staining pattern predominantly localized in neurons. Detection of cholesterol by filipin staining showed a comparable staining pattern, colocalized with GM2, indicating a deposit of GM2 and cholesterol in the same cellular compartments. Accumulations were not only restricted to cell bodies, but were also found in the neuronal extensions. A quantification of the GM2 amount by HPLC-MS/MS confirmed significantly higher amounts in neurons carrying a mutation. Additionally, these cells displayed a lowered activity of the catabolic enzyme Hex A, but not B4GALNT1. Molecular docking simulations indicated binding of cholesterol to Hex A, suggesting cholesterol influences the GM2 degradation pathway and, subsequently, leading to the accumulation of GM2. Taken together, this is the first study showing an accumulation of GM2 in neuronal derivatives of patient-specific iPSCs and thus proving further disease-specific hallmarks in this human in vitro model of NPC1.

A novel, highly sensitive and specific biomarker for Niemann-Pick type C1 disease.

BACKGROUND: Lysosomal storage disorders (LSDs), are a heterogeneous group of rare disorders caused by defects in genes encoding for proteins involved in the lysosomal degradation of macromolecules. They occur at a frequency of about 1 in 5,000 live births, though recent neonatal screening suggests a higher incidence. New treatment options for LSDs demand a rapid, early diagnosis of LSDs if maximal clinical benefit is to be achieved. METHODS: Here, we describe a novel, highly specific and sensitive biomarker for Niemann-Pick Type C disease type 1 (NPC1), lyso-sphingomyelin-509. We cross-validate this biomarker with cholestane-3ß,5α,6ß-triol and relative lysosomal volume. The primary cohort for establishment of the biomarker contained 135 NPC1 patients, 66 NPC1 carriers, 241 patients with other LSDs and 46 healthy controls. RESULTS: With a sensitivity of 100.0% and specificity of 91.0% a cut-off of 1.4 ng/ml was established. Comparison with cholestane-3ß,5α,6ß-triol and relative acidic compartment volume measurements were carried out with a subset of 125 subjects. Both cholestane-3ß,5α,6ß-triol and lyso-Sphingomyelin-509 were sufficient in establishing the diagnosis of NPC1 and correlated with disease severity. CONCLUSION: In summary, we have established a new biomarker for the diagnosis of NPC1, and further studies will be conducted to assess correlation to disease progress and monitoring treatment.

Bioanalysis for plasma protein binding studies in drug discovery and drug development: views and recommendations of the European Bioanalysis Forum.

Plasma protein binding (PPB) is an important parameter for a drug's efficacy and safety that needs to be investigated during each drug-development program. Even though regulatory guidance exists to study the extent of PPB before initiating clinical studies, there are no detailed instructions on how to perform and validate such studies. To explore how PPB studies involving bioanalysis are currently executed in the industry, the European Bioanalysis Forum (EBF) has conducted three surveys among their member companies: PPB studies in drug discovery (Part I); in vitro PPB studies in drug development (Part II); and in vivo PPB studies in drug development. This paper reflects the outcome of the three surveys, which, together with the team discussions, formed the basis of the EBF recommendation. The EBF recommends a tiered approach to the design of PPB studies and the bioanalysis of PPB samples: 'PPB screening' experiments in (early) drug discovery versus qualified/validated procedures in drug development.

A FIM study to assess safety and exposure of inhaled single doses of AP301-A specific ENaC channel activator for the treatment of acute lung injury.

AP301 is an activator of ENaC-mediated Na(+) uptake for the treatment of pulmonary permeability edema in acute respiratory distress syndrome (ARDS). The purpose of this "first-in-man" study was to examine local and systemic safety and systemic exposure of ascending single doses of AP301, when inhaled by healthy male subjects. In a double-blind, placebo-controlled study, 48 healthy male subjects were randomized to 6 ascending dose groups (single doses up to 120 mg) of 8 subjects each (3:1 randomization of AP301: placebo). Serial assessments included spirometry, exhaled nitric oxide (eNO), vital signs, ECG, safety laboratory, adverse events (AE), and blood samples for the quantification of AP301 in plasma. Descriptive statistics was applied. All 48 subjects received treatment, and completed the study as per protocol. No serious, local (e.g., hoarseness, cough, bronchospasm), or dose-limiting AEs were noted. None of the assessments indicated notable dose or time-related alterations of safety outcomes. Observed AP301 systemic exposure levels were very low, with mean Cmax values of <2.5 ng/mL in the highest dose groups. Inhaled AP301 single doses up to 120 mg were safe and well tolerated by healthy male subjects. Distribution of inhaled AP301 was largely confined to the lung, as indicated by very low AP301 systemic exposure levels.

Glucosylsphingosine is a highly sensitive and specific biomarker for primary diagnostic and follow-up monitoring in Gaucher disease in a non-Jewish, Caucasian cohort of Gaucher disease patients.

BACKGROUND: Gaucher disease (GD) is the most common lysosomal storage disorder (LSD). Based on a deficient ß-glucocerebrosidase it leads to an accumulation of glucosylceramide. Standard diagnostic procedures include measurement of enzyme activity, genetic testing as well as analysis of chitotriosidase and CCL18/PARC as biomarkers. Even though chitotriosidase is the most well-established biomarker in GD, it is not specific for GD. Furthermore, it may be false negative in a significant percentage of GD patients due to mutation. Additionally, chitotriosidase reflects the changes in the course of the disease belatedly. This further enhances the need for a reliable biomarker, especially for the monitoring of the disease and the impact of potential treatments. METHODOLOGY: Here, we evaluated the sensitivity and specificity of the previously reported biomarker Glucosylsphingosine with regard to different control groups (healthy control vs. GD carriers vs. other LSDs). FINDINGS: Only GD patients displayed elevated levels of Glucosylsphingosine higher than 12 ng/ml whereas the comparison controls groups revealed concentrations below the pathological cut-off, verifying the specificity of Glucosylsphingosine as a biomarker for GD. In addition, we evaluated the biomarker before and during enzyme replacement therapy (ERT) in 19 patients, demonstrating a decrease in Glucosylsphingosine over time with the most pronounced reduction within the first 6 months of ERT. Furthermore, our data reveals a correlation between the medical consequence of specific mutations and Glucosylsphingosine. INTERPRETATION: In summary, Glucosylsphingosine is a very promising, reliable and specific biomarker for GD.

Functional characterisation of alpha-galactosidase a mutations as a basis for a new classification system in fabry disease.

Fabry disease (FD) is an X-linked hereditary defect of glycosphingolipid storage caused by mutations in the gene encoding the lysosomal hydrolase α-galactosidase A (GLA, α-gal A). To date, over 400 mutations causing amino acid substitutions have been described. Most of these mutations are related to the classical Fabry phenotype. Generally in lysosomal storage disorders a reliable genotype/phenotype correlation is difficult to achieve, especially in FD with its X-linked mode of inheritance. In order to predict the metabolic consequence of a given mutation, we combined in vitro enzyme activity with in vivo biomarker data. Furthermore, we used the pharmacological chaperone (PC) 1-deoxygalactonojirimycin (DGJ) as a tool to analyse the influence of individual mutations on subcellular organelle-trafficking and stability. We analysed a significant number of mutations and correlated the obtained properties to the clinical manifestation related to the mutation in order to improve our knowledge of the identity of functional relevant amino acids. Additionally, we illustrate the consequences of different mutations on plasma lyso-globotriaosylsphingosine (lyso-Gb3) accumulation in the patients' plasma, a biomarker proven to reflect the impaired substrate clearance caused by specific mutations. The established system enables us to provide information for the clinical relevance of PC therapy for a given mutant. Finally, in order to generate reliable predictions of mutant GLA defects we compared the different data sets to reveal the most coherent system to reflect the clinical situation.

Analysis of lyso-globotriaosylsphingosine in dried blood spots.

Recently, lyso-globotriaosylsphingosine (lyso-Gb3) was found to be elevated in plasma of treatment naive male patients and some female patients with Fabry Disease (FD). This study tested whether lyso-Gb3 could be analyzed in dried blood spots (DBS) from filter cards and whether concentrations are elevated in newborn infants with FD. Lyso-Gb3 concentrations were analyzed in DBS following extraction using a novel HPLC-mass spectrometry (MS)/MS method. Lyso-Gb3 levels in DBS were above the lower limit of quantitation (0.28 ng/mL) in 5/17 newborn FD infants (16 males; range: 1.02-8.81 ng/mL), but in none of the newborn controls, in all 13 patients (4 males) with classic FD (range: 2.06-54.1 ng/mL), in 125/159 Taiwanese individuals with symptomatic or asymptomatic FD who carry the late onset α-galactosidase A (GLA) mutation c.936+919G>A (IVS4+919G>A) (3.75±0.69 ng/mL; range: 0.418-3.97 ng/mL) and in 20/29 healthy controls (0.77±0.24 ng/mL; range: 0.507-1.4 ng/mL). The HPLC-MS/MS method for analysis of lyso-Gb3 is robust and yields reproducible results in DBS in patients with FD. However, concentrations of lyso-Gb3 were below the limit of quantitation in most newborn infants with FD rendering this approach not suitable for newborn screening. In addition, most females with the late onset mutation have undetectable lyso-Gb3 concentrations.

Lyso-Gb3 Indicates that the Alpha-Galactosidase A Mutation D313Y is not Clinically Relevant for Fabry Disease.

The X-chromosomal-linked lysosomal storage disorder Fabry disease can lead to life-threatening manifestations. The pathological significance of the Fabry mutation D313Y is doubted, because, in general, D313Y patients do not present clinical manifestations conformable with Fabry disease. This is in contrast to the analysis of the alpha-galactosidase A activity, which is reduced in D313Y patients. We report a comprehensive clinical, biochemical and molecular genetic analysis of two patients with a D313Y mutation. The alpha-galactosidase A activity was reduced in both patients. No Fabry symptoms or Fabry organ involvement was detected in these patients. The new biomarker lyso-Gb3, severely increased in classical Fabry patients, was determined and in both patients lyso-Gb3 was below the average of a normal population.Our data for the first time not only clinically but also biochemically supports the hypothesis that the D313Y mutation is not a classical one, but a rare variant mutation.

Acute cerebrovascular disease in the young: the Stroke in Young Fabry Patients study.

BACKGROUND AND PURPOSE: Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients. METHODS: Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol. RESULTS: Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%-0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18-24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%). CONCLUSIONS: Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov.Unique identifier: NCT00414583.

Lyso-globotriaosylsphingosine (lyso-Gb3) levels in neonates and adults with the Fabry disease later-onset GLA IVS4+919G>A mutation.

Lyso-globotriaosylsphingosine (lyso-Gb3) is a useful biomarker in the diagnosis and monitoring of treatment for Fabry disease. However, it is unclear whether lyso-Gb3 is elevated in patients with later-onset Fabry disease. Thus, we measured lyso-Gb3 levels from dried blood spots (DBS) from male newborns with the Fabry disease later-onset phenotype, IVS4+919G>A mutation, and their family members. The lyso-Gb3 levels were below the detection limit in normal control newborns and were slightly higher in adults. In males of all ages with the IVS4+919G>A mutation, lyso-Gb3 levels were elevated and were higher than in age-matched controls. The elevation of lyso-Gb3 levels in males with the IVS4+919G>A mutation was only slightly elevated compared with patients with the classical Fabry phenotype. The measurement of lyso-Gb3 levels is useful in the diagnosis of Fabry disease, including the later-onset phenotype. The DBS lyso-Gb3 level was not elevated in IVS4+919G>A heterozygotes, and is not useful for their diagnosis. Since lyso-Gb3 levels are elevated from birth in Fabry disease males, "an elevated lyso-Gb3 level" may be of little values for deciding when to begin enzyme replacement therapy.

Sensitive determination of the peptide AP301--a motif of TNF-α--from human plasma using HPLC-MS/MS.

The AP301 peptide mimics the lectin-like domain of TNF-α. The synthetic peptide AP301 (molecular weight 1923.1amu) is composed of 17 amino acids and contains an intramolecular disulfide bond between the N-terminal and the C-terminal cysteine. AP301 interacts with the endothelial sodium channel (ENaC) and activates pulmonary liquid clearance both in vitro and in animal studies. Currently, AP301 is subject to clinical investigations for the treatment of pulmonary oedema. With HPLC-MS/MS on reversed phase chromatography a determination limit of 1ng AP301/mL human plasma can be achieved. The MS-ionisation was done with ESI positive. 50µL of human plasma was mixed with the internal standard (a stable isotope labelled AP301, with a total of 6 carbon 13) in acetonitrile for protein precipitation. After centrifugation a part of the clear supernatant was injected into HPLC-MS/MS. Validation was performed according to FDA-guideline in three batches [U.S. Department of Health and Human Services, Food and Drug Administration (FDA): Guidance for Industry, Bioanalytical Method Validation, May 2001]. By using a 6xC13 isotopically labelled internal standard good precision, accuracy and linearity can be gained. The inter-batch precision (CV) of the quality control samples in human plasma (conc. 2.50/20/240ng/mL) ranged from 5.54 to 10.15%. The inter-batch accuracy (with reference to the mean value) of the quality control samples in plasma ranged from 96.1% to 99.9%. The analyte was stable in human plasma over three freeze/thaw cycles, or for 4h at room temperature, or for at least 20weeks when stored at below -20°C. This method was used for quantifying AP301 after inhalative application in a phase I-study.

Bioavailability and disposition of azelastine and fluticasone propionate when delivered by MP29-02, a novel aqueous nasal spray.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: • The topical second generation anti-histamine azelastine hydrochloride (AZE) and the potent corticosteroid fluticasone propionate (FP) are well established first-line treatments in allergic rhinitis (AR). • MP29-02, a novel intranasal AZE and FP formulation, has been shown to control AR symptoms faster and better than standard intranasal AZE or FP. • The systemic bioavailabilities of marketed AZE and FP nasal spray products have been established at about 40% and 1% only, respectively. • For new combination medicinal products such as MP29-02, the determination of possible pharmacokinetic (PK) drug-drug interactions between both active components and formulation-based bioavailability alterations is essential. WHAT THIS STUDY ADDS: • This paper provides for the first time information on potential drug-drug interactions, AZE and FP bioavailability and disposition characteristics of each component administered by the novel nasal spray formulation MP29-02. • The studies employed highly sensitive FP and AZE LC-MS/MS assays and could therefore be conducted with recommended therapeutic doses, thereby circumventing previously recognized draw-backs that required nasal bioavailability studies to be conducted using supra-therapeutic doses. • No significant PK drug-drug interaction between the active components AZE and FP was noted for MP29-02. • AZE bioavailabilty was equivalent when MP29-02 data were compared with MP29-02-AZE-mono and Astelin®. • Increased FP exposure was observed with MP29-02-based products compared with FP-BI. FP serum concentrations were generally very low with all investigational products suggesting no clinically meaningful pharmacodynamic differences in terms of systemic safety. AIM(S): To determine azelastine hydrochloride (AZE) and fluticasone propionate (FP) bioavailabilities of the novel nasal spray combination product MP 29-02, compared with MP29-02-based products containing only AZE (MP29-02-AZE-mono), FP (MP29-02-FP-mono), marketed AZE and FP single entity products (Astelin® and FP Boehringer-Ingelheim; FP-BI). METHODS: Two randomized, three period, six sequence, three treatment crossover studies were conducted in healthy subjects. Study 1 administered 200 µg FP as MP29-02, MP29-02-FP-mono or FP-BI. Study 2 administered 548 µg AZE as MP29-02, MP29-02-AZE-mono or Astelin®. Each dose consisted of two sprays/nostril. Serum FP and plasma AZE were followed over 24 (FP) and 120 h (AZE) and quantified by LC-MS/MS. Peak (C(max) ) and total exposures AUC(0,t(last) ) were compared between the treatments by anova. RESULTS: Study 1: Average FP C(max) was very low with all products (≤ 10 pg ml(-1) ). FP AUC(0,t(last) ) point estimates (90% CIs) for MP29-02 : MP29-02-FP-mono and MP29-02 : FP-BI ratios (%) were 93.6 (83.6, 104.7) and 161.1 (137.1, 189.3). Corresponding ratios for C(max) were 91.0 (82.5, 100.4) and 157.4 (132.5, 187.1). Study 2: AZE AUC(0,t(last) ) point estimates (90% CIs) for MP29-02 : MP29-02-AZE-mono and MP29-02 : Astelin® ratios (%) were 98.8 (91.0, 107.4) and 105.5 (95.6, 116.4). Corresponding outcomes for C(max) were 102.7 (92.1, 114.4) and 107.3 (92.6, 124.3). CONCLUSIONS: No interactions of AZE and FP were found with the MP29-02 formulation. Azelastine bioavailability was similar for MP29-02 and Astelin®. Maximum and total FP exposure was higher for MP29-02-based products compared with FP-BI. FP concentrations were generally very low with all investigational products and did not suggest clinically meaningful differences concerning systemic safety.

Broad spectrum of Fabry disease manifestation in an extended Spanish family with a new deletion in the GLA gene.

BACKGROUND: Fabry disease (FD) is an X-linked inherited disease based on the absence or reduction of lysosomal-galactosidase (Gla) activity. The enzymatic defect results in progressive impairment of cerebrovascular, renal and cardiac function. Normally, female heterozygote mutation carriers are less strongly affected than male hemizygotes aggravating disease diagnosis. METHOD: Close examination of the patients by renal biopsy, echo- and electrocardiography and MRI. Blood work and subsequent DNA analysis were carried out utilizing approved protocols for PCR and Sequencing. MLPA analysis was done to unveil deletions within the GLA gene locus. Quantitative detection of Glycolipids in patient plasma and urine were carried out using HPLC/MS-MS and ESI-MS. RESULTS: In the presented case, a female index patient led to the examination of three generations of a Spanish family. She presented with severe oto-cochlear symptoms and covert renal and cardiac involvement. While conventional sequencing failed to detect a causative mutation, MLPA analysis revealed a deletion within the GLA gene locus, which we were able to map to a region spanning exon 2 and adjacent intronic parts. The analysis of different biomarkers revealed elevated lyso-Gb3 levels in all affected family members. CONCLUSION: Our findings highlight the broad intrafamilial spectrum of symptoms of FD and emphasise the need to use MLPA screening in symptomatic females without conclusive sequencing result. Finally, plasma lyso-Gb3 proved to be a reliable biomarker for the diagnosis of FD.

Morphological alterations of the cornea in the mouse model of niemann-pick disease type c1.

PURPOSE: Niemann-Pick disease type C1 (NPC1) is a genetic neurovisceral disorder characterized by abnormalities in intracellular sterol trafficking. A knockout mouse model (NPC1) is an important tool for the study of pathogenesis and treatment strategies. In the present study, NPC1 mice were examined for pathological changes in the cornea. METHODS: Fifteen inbred homozygous NPC1 knockout mice (NPC1, 5-10 weeks old), 5 age-matched heterozygous mice (NPC1), and 14 wild-type control mice (NPC1) were examined. In vivo confocal laser scanning microscopy (CLSM) was performed on both eyes of each animal; afterward, the eyes were processed for histology, electron microscopy, and lipid analysis. RESULTS: In vivo CLSM disclosed hyperreflective intracellular deposits in the intermediate and basal cell layers of corneal epithelium in all NPC1 mice. At the electron microscopy level, however, vacuolated cytoplasmic structures, 200-500 nm in diameter, with electron-dense material appeared in all structures investigated, including all epithelial layers and stromal keratocytes. These deposits were negative for filipin, a marker for unesterified cholesterol. Lipid analysis showed a marked increase in disialotetrahexosylganglioside 2 (GM2) level in NPC1 mice corneas, whereas no changes were detected in free cholesterol and disialotetrahexosylganglioside 3 (GM3) levels when compared with controls. CONCLUSIONS: Morphological changes characteristic for the NPC1 mouse cornea were visualized in all epithelial layers and keratocytes. In vivo CLSM findings were confirmed by other techniques. In vivo detection of ocular manifestations and analysis of ocular tissue have the potential to aid the diagnosis of NPC1 disease and to monitor the efficacy of treatment.

Exposure patterns of UV filters, fragrances, parabens, phthalates, organochlor pesticides, PBDEs, and PCBs in human milk: correlation of UV filters with use of cosmetics.

In order to assess potential risks of exposure to environmental chemicals, more information on concomitant exposure to different chemicals is needed. We present data on chemicals in human milk of a cohort study (2004, 2005, 2006) of 54 mother/child pairs, where for the first time, cosmetic UV filters, synthetic musks, parabens and phthalate metabolites were analyzed in the same sample along with persistent organochlor pollutants (POPs), i.e., organochlor pesticides and metabolites, polybrominated diphenylethers and polychlorinated biphenyls (PCBs). The two groups of chemicals exhibited different exposure patterns. Six out of seven PCB congeners and a majority of pesticides were present in all milk samples, with significant correlations between certain PCB congener and pesticide levels, whereas the cosmetic-derived compounds, UV filters, parabens and synthetic musks, exhibited a more variable exposure pattern with inter-individual differences. UV filters were present in 85.2% of milk samples, in the range of PCB levels. Comparison with a questionnaire revealed a significant correlation between use of products containing UV filters and their presence in milk for two frequently used and detected UV filters, 4-methylbenzylidene camphor and octocrylene, and for the whole group of UV filters. Concentrations of PCBs and organochlor pesticides were within ranges seen in Western and Southern European countries. For several POPs, mean and/or maximum daily intake calculated from individual concentrations was above recent US EPA reference dose values. Our data emphasize the need for analyses of complex mixtures to obtain more information on inter-individual and temporal variability of human exposure to different types of chemicals.

Sensitive simultaneous determination of ciclesonide, ciclesonide-M1-metabolite and fluticasone propionate in human serum by HPLC-MS/MS with APPI.

A new and very sensitive analytical method has been developed and validated to jointly determine the anti-inflammatory drug ciclesonide (CIC), its active principle metabolite M1 (CIC-M1) and fluticasone propionate (FP) in human serum, in the low concentration range from 10 to 1000 pg/mL. This was accomplished by high-performance liquid chromatography and tandem mass spectrometry using atmospheric pressure photo ionisation (HPLC-MS/MS with APPI) using 0.5 mL of serum. Serum was mixed with the internal standards (IS) D11-CIC and D11-CIC-M1 and extracted with diisopropylether. A gradient with acetonitrile (containing 10 mM of acetic acid and 10% of acetone) was used. HPLC-MS/MS of the acetic acid adducts of the analytes was performed in negative mode. The novel aspect of this method is that instead of the dopant being introduced directly into the source by means of an external HPLC pump, it was added to the mobile phase. This provided significantly better sensitivity than the usual method of in-source addition of the dopant, and with no loss in HPLC performance. Sensitivity for the analytes was about four times greater than with either APCI or ESI. Validation was performed in three batches. The inter-batch precision (CV) of the quality control samples in human serum ranged from 4.08% to 6.78% for CIC, from 2.57% to 7.74% for CIC-M1, and from 2.38% to 9.61% for FP. The inter-batch accuracy (with reference to the mean value) of the quality control samples in human serum ranged from 99.3% to 110.0% for CIC, from 101.8% to 104.7% for CIC-M1, and from 100.4% to 101.8% for FP. Calibration data and LLOQ data are also presented in this paper. The analytes were stable in human serum over three freeze/thaw cycles, or for 4h at room temperature, or for at least 18 months when stored at below -20 degrees C. This method was used for quantifying the analytes after inhalation of low-mug amounts of the drugs by patients.

Long-term stability of amino acids and acylcarnitines in dried blood spots.

BACKGROUND: Dried blood filter cards, collected for newborn screening, are often stored for long periods of time. They may be suitable for the retrospective diagnosis of inborn errors of metabolism, but no data are currently available on the long-term stability of amino acids and acylcarnitine species. METHODS: We analyzed amino acids and acylcarnitines by tandem mass spectrometry in 660 anonymous, randomly selected filter cards from 1989 through 2004. We assessed long-term stability of metabolites by linear regression and estimated annual decrease of concentration for each metabolite. RESULTS: Concentrations of free carnitine increased by 7.6% per year during the first 5 years of storage and decreased by 1.4% per year thereafter. Alanine, arginine, leucine, methionine, and phenylalanine decreased by 6.5%, 3.3%, 3.1%, 7.3%, and 5.7% per year, respectively. Acetylcarnitine, propionylcarnitine, citrulline, glycine, and ornithine decreased by 18.5%, 27.4%, 8.1%, 14.7%, and 16.3% per year during the first 5 years, respectively; thereafter the decline was more gradual. Tyrosine decreased by 1.7% per year during the first 5 years and 7.9% per year thereafter. We could not analyze medium- and long-chain acylcarnitine species because of low physiological concentrations. CONCLUSIONS: Estimation of the annual decrease of metabolites may allow for the retrospective diagnosis of inborn errors of metabolism in filter cards that have been stored for long periods of time.