Synthesis and evaluation of 11C-LY2795050 as a κ-opioid receptor antagonist radiotracer for PET imaging

Kappa-opioid receptors (KOR) are believed to be involved in the pathophysiology of depression, anxiety disorders, drug abuse, and alcoholism. To date, only 1 tracer, the KOR agonist (11)C-GR103545, has been reported to be able to image KOR in primates. The goal of the present study was to synthesize the selective KOR antagonist (11)C-LY2795050 and evaluate its potential as a PET tracer to image KOR in vivo.

METHODS

The in vitro binding affinity of LY2795050 was measured in radioligand competition binding assays. Ex vivo experiments were conducted using microdosing of the unlabeled ligand in Sprague-Dawley rats and in wild-type and KOR knockout mice, to assess the ligand's potential as a tracer candidate. Imaging experiments with (11)C-LY2795050 in monkeys were performed on the Focus-220 scanner with arterial blood input function measurement. Binding parameters were determined with kinetic modeling analysis.

RESULTS

LY2795050 displays full antagonist activity and high binding affinity and selectivity for KOR. Microdosing studies in rodents and ex vivo analysis of tissue concentrations with liquid chromatography-tandem mass spectrometry identified LY2795050 as an appropriate tracer candidate able to provide specific binding signals in vivo. (11)C-LY2795050 was prepared in an average yield of 12% and greater than 99% radiochemical purity. In rhesus monkeys, (11)C-LY2795050 displayed a moderate rate of peripheral metabolism, with approximately 40% of parent compound remaining at 30 min after injection. In the brain, (11)C-LY2795050 displayed fast uptake kinetics (regional activity peak times of <20 min) and an uptake pattern consistent with the distribution of KOR in primates. Pretreatment with naloxone (1 mg/kg, intravenously) resulted in a uniform distribution of radioactivity. Further, specific binding of (11)C-LY2795050 was reduced by the selective KOR antagonist LY2456302 in a dose-dependent manner.

CONCLUSION

(11)C-LY2795050 displayed favorable pharmacokinetic properties and binding profiles in vivo and therefore is a suitable ligand for imaging the KOR in primates. This newly developed KOR antagonist tracer has since been advanced to PET imaging of KOR in humans and constitutes the first successful KOR antagonist radiotracer.

Biomechanical analysis of a new minimally invasive system for osteosynthesis of pubis symphysis disruption

INTRODUCTION

We analysed the effectiveness of a new percutaneous osteosynthesis system for the treatment of pelvis fractures with rotational instability.

METHODS

A pre-clinical cross-sectional experimental study wherein Tile type B1 injuries (open-book fractures) were produced in 10 specimens of fresh human cadavers, including the L4-5 vertebrae, pelvic ring, and proximal third of the femur, keeping intact the capsular and ligamentous structures, is presented in this paper. The physiological mobility of the intact pelvis in a standing position post-injury was compared to that following the performance of a minimally invasive osteosynthesis of the symphysis with two cannulated screws. A specially designed test rig capable of applying loads simulating different weights, coupled with a photogrammetry system, was employed to determine the 3D displacements and rotations in three test cases: intact, injured and fixed.

RESULTS

After applying an axial load of 300 N, no differences were observed in the average displacement (mm) of the facet joints of the intact pubic symphysis in comparison to those treated with screws (p >0.7). A statistical difference was observed between the average displacements of the sacroiliac facet joints and pelvises with symphyseal fractures treated with screws after the application of a load (p <0.05).

CONCLUSION

The symphyseal setting with two crossed screws appears to be an effective alternative to osteosynthesis in pelvic fractures with rotational instability.

Neutrophil to lymphocyte ratio (NLR) as an indicator of poor prognosis in stage IV non-small cell lung cancer

BACKGROUND

Neutrophil to lymphocyte ratio (NLR), an index of systemic inflammation, has been associated with worse survival for many types of cancer. The aim of this study is to investigate the clinical significance of the blood NLR as a prognostic factor in non-small cell lung cancer (NSCLC) patients.

METHODS AND PATIENTS

Stage IV NSCLC patients diagnosed in our institution between April 2004 and March 2009 were retrospectively reviewed. Potential prognostic factors such as histology, gender, performance status, response to chemotherapy and NLR were analyzed. NLR was assessed baseline and during chemotherapy treatment. Overall survival (OS) and progression free survival (PFS) were calculated by the Kaplan-Meier method.

RESULTS

A total of 171 patients were included in the study and 60 patients (35.1 %) presented a NLR ≥ 5. Median survival for the entire cohort was 9.3 months. We found that patients with undifferentiated carcinoma and patients with NLR ≥ 5 had a worse survival. Median PFS of patients with NLR <5 was 5.62 months and in patients with NLR ≥ 5 was 3.25 months (p = 0.098), and OS was 11.1 versus 5.6 months for patients with NLR<5 and NLR ≥ 5, respectively (p = 0.017). During the chemotherapy treatment, patients who normalized NLR after one cycle presented better outcomes (OS 8.7 vs. 4.3 months, p = 0.001, for patients who normalized NLR and for patients who remained persistently elevated). After multivariate analysis, histology and NLR remained independent predictors of survival (p < 0.05).

CONCLUSION

In our analysis, elevated NLR is a predictor of shorter survival in patients with advanced NSCLC and the variation of NLR during the first cycle of treatment predicts survival. NLR is an easily measured, reproducible test that could be considered to be incorporated in the routine practice in NSCLC patients.

Delays in the diagnosis of pulmonary tuberculosis in Coahuila, Mexico

OBJECTIVE

To determine diagnostic delay in pulmonary tuberculosis (PTB) cases and analyse associated factors.

METHODS

New PTB cases were studied in Coahuila, Northern Mexico, between 2008 and 2009. We obtained census data and data on residential address, symptoms and diagnosis from the national patient database; sociodemographic variables were obtained during home visits. Bivariate analyses used the Kaplan-Meier method; multivariate analysis consisted of modelling survival.

RESULTS

We studied 458 subjects (median age 48 years), who were predominantly males (56.1%); the median years of schooling was 6.0 years, 83.4% were urban residents, 50.3% were unemployed, and 87.7% suffered from food poverty. The median delay between the onset of symptoms and the first medical consultation was 53.5 days. Lack of formal education (P = 0.050) and living ≥5 km from a health unit (P = 0.034) were associated with longer delays and consequently with severe symptoms (cough ≥2 weeks, P = 0.001; chest pain, P = 0.032; malnutrition, P = 0.003). Mean health system delay (between first consultation and smear test result) was 18.5 days, and was significantly longer when the first consultation was with a private physician (P < 0.001) and when patient age was ≥46 years (P = 0.001).

CONCLUSIONS

In Coahuila, lack of formal education, living ≥5 km from a health unit, first consultation with a private physician, and being aged ≥46 years contributed to delays in PTB diagnosis.

Disease severity impairs sleep quality in allergic rhinitis (The SOMNIAAR study)

BACKGROUND

Sleep is impaired in allergic rhinitis (AR) patients, with subsequent effects on daytime performance and health-related quality of life (QOL). Sleep quality in AR has rarely been considered through validated tools and consensus classifications.

OBJECTIVE

To evaluate sleep quality and daytime somnolence in AR patients, and to estimate its relationship to disease severity according to Allergic Rhinitis and Its Impact on Asthma (ARIA) conventional and modified classifications, as well as in terms of QOL and comorbidities.

METHODS

Allergic rhinitis adult patients were evaluated through a prospective, observational, multicentre survey in Spain. Symptoms were assessed using the Total Symptoms Score (TSS), specific QOL by the Rhinitis Quality of Life Questionnaire (RQLQ), sleep quality by Pittsburgh scale, and diurnal somnolence by a scale based on Epworth's, all recorded in a unique visit.

RESULTS

A total of 2275 patients were included. According to ARIA criteria, 50.2% had persistent and 49.8% intermittent rhinitis, whereas 87.6% were classified as moderate-severe and 12.4% as mild; 52.8% had poor sleep quality, with a global median score for Pittsburgh scale of 6 (normal < 5) and 21.1% suffered from excessive diurnal somnolence. Correlation between Pittsburgh scale and RQLQ was moderate (r = 0.54). Among symptoms, nasal obstruction and concomitant asthma mainly, contributed to bad sleep quality. In a logistic regression model, moderate-severe rhinitis and nasal obstruction were all associated with a worse sleep quality.

CONCLUSIONS AND CLINICAL RELEVANCE

Sleep quality is altered in AR patients. Sleep quality was worse in moderate-severe, and particularly in severe AR. Nasal obstruction and RQLQ deterioration are associated with a poorer sleep quality. Sleep impairment is common in allergic rhinitis, particularly in more severe forms. Nasal obstruction and concomitant asthma should be considered as contributing factors.

CAPSULE SUMMARY

This is a large epidemiological survey of patients with allergic rhinitis showing a strong relationship between disease severity, as assessed by a consensus classification, and sleep impairment, as measured by a validated sleep quality tool.

Chitinase 3-like 1 plasma levels are increased in patients with progressive forms of multiple sclerosis

Background:

Chitinase 3-like 1 (CHI3L1) is upregulated in a wide variety of inflammatory conditions. Recent studies have pointed to a role of CHI3L1 in multiple sclerosis (MS) pathogenesis.

Objective:

The objective of this study was to investigate the role of plasma CHI3L1 in MS clinical course and disease activity and to evaluate the effect of interferon-beta (IFNβ) treatment on protein levels.

Methods:

Plasma CHI3L1 levels were determined by ELISA in 57 healthy controls (HC), 220 untreated MS patients [66 primary progressive MS patients (PPMS), 30 secondary progressive MS patients (SPMS), and 124 relapsing–remitting MS patients (RRMS), 94 during clinical remission and 30 during relapse], and 32 MS patients receiving IFNβ treatment. A polymorphism of the CHI3L1 gene, rs4950928, was genotyped in 3274 MS patients and 3483 HC.

Results:

Plasma CHI3L1 levels were significantly increased in patients with progressive forms of MS compared with RRMS patients and HC. CHI3L1 levels were similar between RRMS patients in relapse and remission. A trend towards decreased CHI3L1 levels was observed in IFNβ-treated patients. Allele C of rs4950928 was significantly associated with PPMS patients and with higher plasma CHI3L1 levels.

Conclusions:

These findings point to a role of CHI3L1 in patients with progressive forms of MS, particularly in those with PPMS.

IL28B polymorphisms are not associated with the response to interferon-β in multiple sclerosis

Recent studies have revealed an association between interleukin 28B (IL28B) and response to IFN-alpha treatment in hepatitis C patients. Here we investigated the influence of IL28B polymorphisms in the response to interferon-beta (IFNβ) in multiple sclerosis (MS) patients. We genotyped two SNPs of the IL28B gene (rs8099917 and rs12979860) in 588 MS patients classified into responders (n=281) and non-responders (n=307) to IFNβ. Combined analysis of the study cohorts showed no significant associations between SNPs rs8099917 and rs12979860 and the response to treatment. These findings do not support a role of IL28B polymorphisms in the response to IFNβ in MS patients.

Pollen competition as a reproductive isolation barrier represses transgene flow between compatible and co-flowering citrus genotypes

BACKGROUND/OBJECTIVE

Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved.

METHODOLOGY/PRINCIPAL FINDINGS

Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations.

CONCLUSIONS/SIGNIFICANCE

Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species.

Regulation of α₂-adrenoceptor gene expression by chronic lithium treatment in rat brain

One of the approaches for the treatment of bipolar disorder involves the coadministration of lithium, a mood stabilizer, with α₂-adrenoceptor antagonists possessing an antidepressant effect. Since lithium accelerates the recovery of α₂(D)-adrenoceptors following their irreversible inactivation with N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), our aim was to examine if it could be to some changes in Adra2A gene expression which codifies these adrenoceptors. Animals were treated with lithium chloride (120 mg/kg i.p.) or saline once a day for 10 days. A group of lithium- or saline-treated rats was killed 48 h after the last injection. The remaining animals were treated with EEDQ and were killed at 0.25, 4 and 14 days following this administration. Total RNA was extracted from cerebral cortex and Adra2A gene expression was measured by RT-QPCR. The results show that chronic lithium raised the Adra2A gene expression (P < 0.05), and after EEDQ administration this expression decreased to the basal level. No change in Adra2A gene expression was detected in the saline-treated group. However, EEDQ administration produced an insignificant increase in α₂-adrenoceptors mRNA levels followed by a progressive decrease until basal levels. Lithium produced an overexpression of the Adra2A gene after chronic treatment that made the neuron ready to produce α₂-adrenoceptors to deal with their inactivation.

Mild Pd-catalyzed N-arylation of methanesulfonamide and related nucleophiles: avoiding potentially genotoxic reagents and byproducts

A convenient, general, and high yielding Pd-catalyzed cross-coupling of methanesulfonamide with aryl bromides and chlorides is reported. The use of this method eliminates concern over genotoxic impurities that can arise when an aniline is reacted with methanesulfonyl chloride. The application of this method to the synthesis of dofetilide is also reported.

Oxidative stress-induced glucocorticoid resistance is prevented by dual PDE3/PDE4 inhibition in human alveolar macrophages

BACKGROUND

Oxidative stress is present in airway diseases such as severe asthma or Chronic Obstructive Pulmonary Disease and contributes to the low response to glucocorticoids through the down-regulation of histone deacetylase (HDAC) activity.

OBJECTIVE

To study the effects of the phosphodiesterase (PDE)-3 and 4 inhibitors and their combination vs. glucocorticoids in a model of lipopolysaccharide (LPS)-induced cytokine release in alveolar macrophages under oxidative stress conditions.

METHODS

Differentiated U937 or human alveolar macrophages were stimulated with H(2) O(2) (10-1000 μM) or cigarette smoke extract (CSE, 0-15%) for 4 h before LPS (0.5 μg/mL, 24 h) addition. In other experiments, cells were pre-treated with dexamethasone or budesonide (10(-9) -10(-6) M), with the PDE4 inhibitor rolipram (10(-9) -10(-5) M), PDE3 inhibitor motapizone (10 μM), 3',5'-cyclic monophosphate enhancer PGE(2) (10 nM), or with the combination of rolipram (10(-6) M)+PGE(2) (10 nM)+motapizone (10 μM) 15 min before oxidants. IL-8 and TNF-α were measured by ELISA and HDAC activity by a colorimetric assay.

RESULTS

Budesonide and dexamethasone produced a concentration-dependent inhibition of the LPS-induced IL-8 and TNF-α secretion with an E(max) about 90% of inhibition, which was reduced by approximately 30% in the presence of H(2)O(2) or CSE. Pre-treatment with rolipram, motapizone or PGE2 only reached about 20% of inhibition but was not affected by oxidative stress. In contrast, PDE4/PDE3 combination in presence of PGE2 effectively inhibited the LPS-induced cytokine secretion by about 90% and was not affected by oxidative stress. Combined PDE4 and PDE3 inhibition reversed glucocorticoid resistance under oxidative stress conditions. HDAC activity was reduced in the presence of oxidative stress, and in contrast to glucocorticoids, pre-treatment with PDE4/PDE3 combination was able to prevent HDAC inactivity.

CONCLUSIONS & CLINICAL RELEVANCE

This study shows that the combination of the PDE3/PDE4 inhibitors prevents alveolar macrophage activation in those situations of glucocorticoid resistance, which may be of potential interest to develop new effective anti-inflammatory drugs in airway diseases.