Pyrene derivatives as donors and acceptors

Pyrene derivatives as donors and acceptorsrnrnAlmost 200 years have passed since pyrene was first discovered, and to this day it garners unbroken interest by chemists around the world. One of the most fascinating areas of pyrene chemistry is its selective functionalization, since it is still currently a challenge to specifically functionalize different positions on the molecule.[1]rnIn this work, two new patterns of pyrene substitution have been developed. Under suitable conditions, a fourfold bromination of 4,5,9,10 tetramethoxypyrene is possible to yield eightfold functionalized pyrenes. Based on these molecules a novel series of 1,3,4,5,6,8,9,10-substituted pyrene derivatives was achieved. Synthetic approaches to a non-quinoidal, strong pyrene-4,5,9,10-tetraone based acceptor have been discussed. It emerged that the chosen synthetic approach is suitable for intermediate acceptors, yet it failed very electron deficient pyrene derivatives. Donors based on 4,5,9,10-tetramethoxypyrene (2,7- and 1,3,6,8-substitued) have been prepared and studied as CT complexes. In the SFB/TR 49 these complexes were analyzed in the solid state. For the first time charge transfer in a non-TTF CT-complex was studied by HAXPES and NEXAFS.rnBased on the works of ZÖPHEL et al.[2] it was possible to obtain an asymmetric 4,9,10 substituted pyrene derivative. This was used as a building block to prepare a non-planar acceptor molecule as well as electron-rich rylene-type molecules. rnFinally, two separate series of molecules intended as emitters for OLEDs were presented. Thermally activated delayed fluorescence (TADF) in OLEDs attracted significant academic interest as it is considered a promising approach to improve the efficiency of fluorescent OLEDs.[3] Our molecules were designed to have a deep blue emission spectrum and a minimal singlet triplet energy gap (∆ES1->T1) while retaining a high fluorescence quantum yield ϕPL. The initial OD series has a small ∆ES1->T1, yet had an insufficient ϕPL for the use in OLEDs. The Py series emitters, in contrast, combine both desired properties and were successfully implemented in efficient OLED devices.rn[1]. T. M. Figueira-Duarte and K. Müllen, Chem. Rev., 2011, 111, 7260-7314.rn[2]. L. Zöphel, V. Enkelmann and K. Müllen, Org. Lett., 2013, 15, 804-807.rn[3]. H. Uoyama, K. Goushi, K. Shizu, H. Nomura and C. Adachi, Nature, 2012, 492, 234-238.

Determination of voriconazole in human serum and plasma by micellar electrokinetic chromatography

The micellar electrokinetic capillary chromatography (MEKC) separation and analysis of voriconazole and UK 115794 (internal standard) were examined and an assay for determination of voriconazole in human plasma and serum was developed. The MEKC medium comprises a 2:15 (v/v) mixture of methanol and a pH 9.3 buffer composed of 5mM Na(2)B(4)O(7), 7 mM Na(2)HPO(4) and 54 mM SDS. Sample preparation is based upon liquid/liquid extraction with ethylacetate and dichloromethane (75%/25%) at physiological pH. Using this approach with 250 microl serum or plasma and reconstitution of the dried extract into 100 microl of a buffer composed of 0.5mM Na(2)B(4)O(7) and 0.7 mM Na(2)HPO(4) (pH 9.3), the detection and quantitation limits were determined to be 0.1 and 0.2 microg/ml, respectively, a sensitivity that is suitable for therapeutic drug monitoring of voriconazole (provisional therapeutic range: 1-6 microg/ml) in human plasma and serum samples. The method was validated and compared to an HPLC method, showing excellent agreement between the two for a set of 91 samples that stemmed from patients being treated with voriconazole. The MEKC assay is also demonstrated to be suitable to explore pharmacokinetic data of voriconazole.

Functional Imaging of Pheochromocytoma with Ga-DOTATOC and C-HED in a Genetically Defined Rat Model of Multiple Endocrine Neoplasia

Rats affected by the MENX multitumor syndrome develop pheochromocytoma (100%). Pheochromocytomas are uncommon tumors and animal models are scarce, hence the interest in MENX rats to identify and preclinically evaluate novel targeted therapies. A prerequisite for such studies is a sensitive and noninvasive detection of MENXassociated pheochromocytoma. We performed positron emission tomography (PET) to determine whether rat pheochromocytomas are detected by tracers used in clinical practice, such as 68Ga-DOTATOC (somatostatin analogue) or (11)C-Hydroxyephedrine (HED), a norepinephrine analogue. We analyzed four affected and three unaffected rats. The PET scan findings were correlated to histopathology and immunophenotype of the tumors, their proliferative index, and the expression of genes coding for somatostatin receptors or the norepinephrine transporter. We observed that mean 68Ga-DOTATOC standard uptake value (SUV) in adrenals of affected animals was 23.3 ± 3.9, significantly higher than in control rats (15.4 ± 7.9; P = .03). The increase in mean tumor-to-liver ratio of (11)C-HED in the MENX-affected animals (1.6 ± 0.5) compared to controls (0.7 ± 0.1) was even more significant (P = .0016). In a unique animal model, functional imaging depicting two pathways important in pheochromocytoma biology discriminated affected animals from controls, thus providing the basis for future preclinical work with MENX rats.

Outer skull landmark-based coordinates for measurement of cerebral blood flow and intracranial pressure in rabbits

Despite the increased use of intracranial neuromonitoring during experimental subarachnoid hemorrhage (SAH), coordinates for probe placement in rabbits are lacking. This study evaluates the safety and reliability of using outer skull landmarks to identify locations for placement of cerebral blood flow (CBF) and intraparenchymal intracranial pressure (ICP) probes. Experimental SAH was performed in 17 rabbits using an extracranial-intracranial shunt model. ICP probes were placed in the frontal lobe and compared to measurements recorded from the olfactory bulb. CBF probes were placed in various locations in the frontal cortex anterior to the coronary suture. Insertion depth, relation to the ventricular system, and ideal placement location were determined by post-mortem examination. ICP recordings at the time of SAH from the frontal lobe did not differ significantly from those obtained from the right olfactory bulb. Ideal coordinates for intraparenchymal CBF probes in the left and right frontal lobe were found to be located 4.6±0.9 and 4.5±1.2 anterior to the bregma, 4.7±0.7mm and 4.7±0.5mm parasagittal, and at depths of 4±0.5mm and 3.9±0.5mm, respectively. The results demonstrate that the presented coordinates based on skull landmarks allow reliable placement of intraparenchymal ICP and CBF probes in rabbit brains without the use of a stereotactic frame.

Management of primary ciliary dyskinesia in European children: recommendations and clinical practice

The European Respiratory Society Task Force on primary ciliary dyskinesia (PCD) in children recently published recommendations for diagnosis and management. This paper compares these recommendations with current clinical practice in Europe. Questionnaires were returned by 194 paediatric respiratory centres caring for PCD patients in 26 countries. In most countries, PCD care was not centralised, with a median (interquartile range) of 4 (2-9) patients treated per centre. Overall, 90% of centres had access to nasal or bronchial mucosal biopsy. Samples were analysed by electron microscopy (77%) and ciliary function tests (57%). Nasal nitric oxide was used for screening in 46% of centres and saccharine tests in 36%. Treatment approaches varied widely, both within and between countries. European region, size of centre and the country's general government expenditure on health partly defined availability of advanced diagnostic tests and choice of treatments. In conclusion, we found substantial heterogeneity in management of PCD within and between countries, and poor concordance with current recommendations. This demonstrates how essential it is to standardise management and decrease inequality between countries. Our results also demonstrate the urgent need for research: to simplify PCD diagnosis, to understand the natural history and to test the effectiveness of interventions.

Equine piroplasmoses at the reintroduction site of the Przewalski's horse (Equus ferus przewalskii) in Mongolia

Piroplasmosis has been identified as a possible cause of mortality in reintroduced Przewalski's horses (Equus ferus przewalskii) in the Dsungarian Gobi (Mongolia). A cross-sectional and a longitudinal study were conducted in a representative sample (n = 141) of the resident domestic horse population and in 23 Przewalski's horses to assess the prevalence of Theileria equi and Babesia caballi. Piroplasms were detected in blood by light microscopy in 6.7% (95% confidence interval [CI]: 3.6-12.2%) of the domestic horse samples. Antibody prevalence was 88.6% (95% CI: 82.4-92.9%) for T. equi and 75.2% (95% CI: 67.4-81.6%) for B. caballi. Antibody prevalence did not change over time, but antibody prevalence for both piroplasms were significantly lower in animals less than 1 yr of age. For both piroplasms, the prevalence of presumably maternal antibodies (falling titers) in foals was 100%. Only one of 16 foals seroconverted against T. equi during the study period, despite that piroplasms were found in two other individuals. The incidence density (ID) of T. equi in foals was therefore 0.0012 seroconversions per horse day (95% CI: 0.00029-0.0057). In contrast, yearlings had an ID of 0.0080 (95% CI: 0.0049-0.010) for T. equi and 0.0064 (95% CI: 0.0036-0.0093) for B. caballi, and in seven individuals piroplasms were detected. The seroprevalence of both piroplasms rose from 20% in spring to 100% in autumn. Comparison of domestic and Przewalski's horses resulted in a standardized prevalence ratio (SPR) of 0.98 (95% CI: 0.80-1.24, not significant) for B. caballi; in contrast, the prevalence of T. equi in Przewalski's horses was significantly lower than expected (SPR = 0.51, 95% CI: 0.50-0.64).

Pharmacokinetics and clinical efficacy of cyclosporine treatment of dogs with steroid-refractory inflammatory bowel disease

The usual treatment of dogs with inflammatory bowel disease (IBD) consists of administration of immunosuppressive doses of steroids. However, some dogs are refractory to steroid treatment and pose a significant challenge to the veterinarian. Because cyclosporine A (cyA) has been shown to be effective in steroid-resistant IBD in humans, the purpose of this study was to investigate the pharmacokinetics and clinical efficacy of PO cyA treatment in dogs with steroid-refractory IBD (n = 14). All dogs were treated with cyA 5 mg/kg PO q24h for a period of 10 weeks. A clinical activity score was assigned to assess severity of clinical signs before and after treatment. The total number of infiltrating lymphocytes and T cells in duodenal biopsies were assessed before and after treatment in 9 dogs. In addition, serum concentration of cyA was measured in 8 dogs over a 24-hour period. Pharmacokinetic profiles in dogs with IBD were similar to those of healthy dogs. Improvement of clinical signs was observed in 12 of 14 dogs with IBD. Median clinical activity score after treatment with cyA was significantly reduced from a median score of 9 to a median score of 5 (P = 0.001). T cell numbers in duodenal biopsies were significantly decreased after treatment from a median +/- 95% range in the villous region of 28 (19-30) cells/10,000 microm2 before versus 7 (0-10)/10,000 microm2 after treatment, P = 0.01; and from a median +/- 95% range number in the crypt region of 15 (6-23) cells/10,000 microm2 before versus 4 (0-9)/10,000 microm2 after treatment, P = 0.02, implying T cell lysis as a possible mechanism of action. In conclusion, based on this small study, cyA appears to be an effective alternative drug in dogs with IBD that are refractory to immunosuppressive doses of steroids.

Sleep and wakefulness disturbances in Swiss pharmacy customers

BACKGROUND AND OBJECTIVE: Sleep disturbances are prevalent but often overlooked or underestimated. We suspected that sleep disorders might be particularly common among pharmacy customers, and that they could benefit from counselling. Therefore, we described the prevalence and severity of symptoms associated with sleep and wakefulness disorders among Swiss pharmacy customers, and estimated the need for counselling and treatment. METHODS: In 804 Swiss pharmacies (49% of all community pharmacies) clients were invited to complete the Stanford Sleep Disorders Questionnaire (SDQ), and the Epworth Sleepiness Scale (EPW). The SDQ was designed to classify symptoms of sleep and wakefulness into the four most prevalent disorders: sleep apnoea syndrome (SAS), insomnia in psychiatric disorders (PSY), periodic leg movement disorders/restless legs (RLS) and narcolepsy (NAR). Data were entered into an internet-linked database for analysis by an expert system as a basis for immediate counselling by the pharmacist. RESULTS: Of 4901 participants, 3238 (66.1%) were female, and 1663 (33.9%) were male. The mean age (SD) of females and males was 52.4 (18.05), and 55.1 (17.10) years, respectively. The percentages of female and male individuals above cut-off of SDQ subscales were 11.4% and 19.8% for sleep apnoea, 40.9% and 38.7% for psychiatric sleep disorders, 59.3% and 46.8% for restless legs, and 10.4% and 9.4% for narcolepsy respectively. The prevalence of an Epworth Sleepiness Scale score >11 was 16.5% in females, and 23.9% in males. Reliability assessed by Cronbach's alpha was 0.65 to 0.78 for SDQ subscales, and for the Epworth score. CONCLUSIONS: Symptoms of sleep and wakefulness disorders among Swiss pharmacy customers were highly prevalent. The SDQ and the Epworth Sleepiness Scale score had a satisfactory reliability to be useful for identification of pharmacy customers who might benefit from information and counselling while visiting pharmacies. The internet-based system proved to be a helpful tool for the pharmacist when counselling his customers in terms of diagnostic classification and severity of symptoms associated with the sleeping and waking state.

Lowered microvascular vessel wall oxygen consumption augments tissue pO2 during PgE1-induced vasodilation

Continuous infusion of intravenous prostaglandin E1 (PgE1, 2.5 mug/kg/min) was used to determine how vasodilation affects oxygen consumption of the microvascular wall and tissue pO(2) in the hamster window chamber model. While systemic measurements (mean arterial pressure and heart rate) and central blood gas measurements were not affected, PgE1 treatment caused arteriolar (64.6 +/- 25.1 microm) and venular diameter (71.9 +/- 29.5 microm) to rise to 1.15 +/- 0.21 and 1.06 +/- 0.19, respectively, relative to baseline. Arteriolar (3.2 x 10(-2) +/- 4.3 x 10(-2) nl/s) and venular flow (7.8 x 10(-3) +/- 1.1 x 10(-2)/s) increased to 1.65 +/- 0.93 and 1.32 +/- 0.72 relative to baseline. Interstitial tissue pO(2) was increased significantly from baseline (21 +/- 8 to 28 +/- 7 mmHg; P < 0.001). The arteriolar vessel wall gradient, a measure of oxygen consumption by the microvascular wall decreased from 20 +/- 6 to 16 +/- 3 mmHg (P < 0.001). The arteriolar vessel wall gradient, a measure of oxygen consumption by the vascular wall, decreased from 20 +/- 6 to 16 +/- 3 mmHg (P < 0.001). This reduction reflects a 20% decrease in oxygen consumption by the vessel wall and up to 50% when cylindrical geometry is considered. The venular vessel wall gradient decreased from 12 +/- 4 to 9 +/- 4 mmHg (P < 0.001). Thus PgE1-mediated vasodilation has a positive microvascular effect: enhancement of tissue perfusion by increasing flow and then augmentation of tissue oxygenation by reducing oxygen consumption by the microvascular wall.

Correlation between the area of increased autofluorescence surrounding geographic atrophy and disease progression in patients with AMD

PURPOSE: To test the hypothesis that the extension of areas with increased fundus autofluorescence (FAF) outside atrophic patches correlates with the rate of spread of geographic atrophy (GA) over time in eyes with age-related macular degeneration (AMD). METHODS: The database of the multicenter longitudinal natural history Fundus Autofluorescence in AMD (FAM) Study was reviewed for patients with GA recruited through the end of August 2003, with follow-up examinations within at least 1 year. Only eyes with sufficient image quality and with diffuse patterns of increased FAF surrounding atrophy were chosen. In standardized digital FAF images (excitation, 488 nm; emission, >500 nm), total size and spread of GA was measured. The convex hull (CH) of increased FAF as the minimum polygon encompassing the entire area of increased FAF surrounding the central atrophic patches was quantified at baseline. Statistical analysis was performed with the Spearman's rank correlation coefficient (rho). RESULTS: Thirty-nine eyes of 32 patients were included (median age, 75.0 years; interquartile range [IQR], 67.8-78.9); median follow-up, 1.87 years; IQR, 1.43-3.37). At baseline, the median total size of atrophy was 7.04 mm2 (IQR, 4.20-9.88). The median size of the CH was 21.47 mm2 (IQR, 15.19-28.26). The median rate of GA progression was 1.72 mm2 per year (IQR, 1.10-2.83). The area of increased FAF around the atrophy (difference between the CH and the total GA size at baseline) showed a positive correlation with GA enlargement over time (rho=0.60; P=0.0002). CONCLUSIONS: FAF characteristics that are not identified by fundus photography or fluorescein angiography may serve as a prognostic determinant in advanced atrophic AMD. As the FAF signal originates from lipofuscin (LF) in postmitotic RPE cells and since increased FAF indicates excessive LF accumulation, these findings would underscore the pathophysiological role of RPE-LF in AMD pathogenesis.

Coronary plaque composition of culprit/target lesions according to the clinical presentation: a virtual histology intravascular ultrasound analysis

AIMS: To evaluate the plaque composition obtained by virtual histology (VH) IVUS according to the clinical presentation and to compare those data to previously published histopathology data. METHODS AND RESULTS: VH was performed on 95 de novo significant lesions (>75% stenosis) in 85 patients [28 acute coronary syndrome (ACS) patients, 30 lesions; 57 stable angina pectoris (SAP) patients, 65 lesions]. There were a higher prevalence of positive remodelling (47 vs. 22%, P=0.013), thrombus (20 vs. 1.5%, P=0.0037), and echo-lucent area (23.3 vs. 7.7%, P=0.047) in ACS patients. At the minimal lumen site, fibrous plaque area was significantly larger in ACS lesions than in SAP lesions (66.0+/-10.7 vs. 61.4+/-8.9%, P=0.034), whereas necrotic core and dense calcium plaque area were smaller in ACS lesions (Necrotic core: 6.8+/-6.0 vs. 11.0+/-8.3%, P=0.02; Dense calcium: 2.6+/-3.0 vs. 4.9+/-5.8%, P=0.03). No differences in rate of thin cap fibroatheroma, thick fibrotheroma, or for the presence of multiple necrotic core layers were observed between both groups. CONCLUSION: Plaque composition obtained by VH-IVUS shows less necrotic core and more fibrous tissue in ACS compared to SAP lesions, which is in contradiction with previously published histopathologic data.