Osteoprotegerin mediate RANK/RANKL signaling inhibition eases asthma inflammatory reaction by affecting the survival and function of dendritic cells.

INTRODUCTION: Asthma is a chronic inflammatory, heterogeneous airway disease affecting millions of people around the world. Dendritic cells (DCs) are considered the most important antigen-presenting cell in asthma airway inflammatory reaction. But whether osteoprotegerin (OPG) mediate RANK/RANKL signaling inhibition influences asthma development by affecting the survival and function of DCs remains unclear. In this study, we assessed the effects of OPG on DCs and asthma. MATERIAL AND METHODS: BALB/c mice immunized with ovalbumin (OVA) were challenged thrice with an aerosol of OVA every second day for eight days. Dexamethasone (1.0mg/kg) or OPG (50µg/kg) was administered intraperitoneally to OVA-immunized BALB/c mice on day 24 once a day for nine days. Mice were analyzed for effects of OPG on asthma, inflammatory cell infiltration and cytokine levels in lung tissue. The expression of RANK and ß-actin was detected by Western Blot. DCs were isolated from mouse bone morrow. Cell survival was assessed by cell counting. The content of IL-12 was detected by ELISA. RESULTS: Results showed that OVA increased the number of inflammatory factors in BALF, elevated lung inflammation scores in mice. OPG reversed the alterations induced by OVA in the asthmatic mice. OPG inhibited the survival and function of DC via inhibition of RANK/RANKL signaling. CONCLUSIONS: This research proved inhibition of RANK/RANKL signaling by OPG could ease the inflammatory reaction in asthma, providing new evidence for the application of OPG on asthma.

[Establishment of macrophage model of iron overload in vitro and the injury induced by oxidative stress on macrophage with iron overload].

OBJECTIVE: To establish macrophage iron overload model in vitro by co-culture macrophages with iron, and to explore the effect of iron overload on cell reactive oxygen species (ROS) and the impact of ROS on macrophages. METHOD: Iron overload group were treated with different concentrations (0, 5, 10, 20, 40, 80 µmol/L respectively) of ferric ammonium citrate (FAC). The control group was the group of macrophages without FAC treatment. We detected the number and state of cells, metabolic activity, the change of phagocytosis, the levels of ROS and reactive nitrogen, and changes of related oxidative stress signaling pathways in different groups. Changes in the above indexes were detected after application of deferasirox (DFX) to remove iron and the antioxidant N -acetylcysteine (NAC) to clear excess oxidative stress. RESULTS: (1)The levels of labile iron pool (LIP) in macrophages co-cultivated with iron was increased with the increase of iron concentration in a dose-dependent manner. The LIP levels was the highest in the macrophages treated with 80 µmol/L. (2)The increase of FAC concentration, the metabolic activity of macrophages in the 5 FAC-treated groups decreased to 51.58%, 40.98%, 16.23%, 3.46%, and 0.05% of the activity level of the control group (all P< 0.05). The group with the metabolic activity decreased to 16.23% (20 µmol/L) was selected as the iron overload group for the following experiments. (3)Compared with the control group, the number of macrophages in the iron overload group reduced to 32.80% (P<0.05), and the state of cells changed from adherence to partial suspension. The phagocytosis of macrophages in the iron overload group reduced to 20.40% of the control group (P<0.05). (4)Our further experiment showed that the levels of ROS and the activity nitrogen in the iron overload group increased by 7.71-and 1.45-fold compared with the control group (both P<0.05). The RT-PCR showed up-regulated mRNA expression of genes related with ROS production, i. e. nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX 4) gene related with ROS production and inducible nitric oxide synthase (iNOS) gene related with reactive nitrogen production, down-regulated mRNA expression of glutathione peroxidase 1 (GPX1) gene which participated in ROS clearance. Moreover, mRNA expression of phosphatidylinositol-3-kinase (PI3K) gene involved in oxidative stress signaling pathway in the iron overload group was up-regulated, while fork head protein O3 (FOXO3) which regulated oxidative stress through negative feedback showed a down-regulation level of mRNA expression compared with the control group. (5)After iron chelation and antioxidant treatment, the above-mentioned damage in the iron overload group were partially reversed. CONCLUSIONS: The damages of iron overload on macrophages may be mediated by inducing oxidative stress and activating oxidative stress signaling pathways. Our established model provides a method to explore the mechanism of iron overload on macrophage, and may shed some new light on possible therapeutic target in treating iron overload patients.

Risk of Parkinson's disease following anxiety disorders: a nationwide population-based cohort study.

BACKGROUND AND PURPOSE: Anxiety is potentially a pre-motor symptom of Parkinson's disease (PD). Our aim was to investigate the association between anxiety and subsequent PD risk in a population-based sample. METHODS: A total of 174 776 participants, who were free of prior PD, dementia and stroke, were enrolled from Taiwan National Health Insurance Research Database between 1 January 2005 and 31 December 2005. The association between anxiety at the beginning of the study and the incidence of PD was examined using a Cox regression model. Information regarding comorbidities, especially depression, and concomitant medication use was adjusted in the proportional hazards models. RESULTS: Over an average follow-up of 5.5 years, 2258 incident PD cases were diagnosed. After adjusting for age, sex, comorbidities and concomitant medication use, patients with anxiety were more likely to develop PD than subjects without anxiety [adjusted hazard ratio (HR) 1.38; 95% confidence interval (CI) 1.26-1.51]. Anxiety severity was dose-dependently associated with increased likelihood of PD: crude HR 1.27 (95% CI 1.11-1.44) for mild anxiety, 1.35 (95% CI 1.19-1.53) for moderate anxiety and 2.36 (95% CI 2.13-2.62) for severe anxiety (P < 0.0001). Results were similar after adjustment for age, sex, comorbid depression and other PD risk factors, and in the sensitivity analyses excluding participants with comorbid depression or with a PD diagnosis <3 years after anxiety diagnosis, and controlling for Charlson's scores. CONCLUSIONS: The likelihood of developing PD was greater amongst patients with anxiety than patients without anxiety, and the severity of anxiety correlated with risk of PD.

Restless legs syndrome is associated with cardio/cerebrovascular events and mortality in end-stage renal disease.

BACKGROUND AND PURPOSE: Earlier studies suggested an association between idiopathic restless legs syndrome (RLS) and cardiovascular diseases. However, the risk of cardiovascular events in patients with secondary RLS due to end-stage renal disease (ESRD) is unclear. Our aim was to examine whether ESRD patients with RLS had an increased risk of cardio/cerebrovascular events and mortality. METHODS: In all, 1093 ESRD patients were recruited between 2009 and 2010. The diagnosis and severity of RLS were assessed in a face-to-face interview. The occurrence of cardio/cerebrovascular events and death were confirmed by medical record review. The association between RLS and the outcomes of interest was examined using an adjusted multivariate Cox regression model. RESULTS: After a mean follow-up period of 3.7 ± 0.8 years, ESRD patients with RLS had a significantly higher risk of developing cardiovascular events and strokes [adjusted hazard ratio (aHR) 2.82, 95% confidence interval (CI) 2.02-4.11, and aHR 2.41, 95% CI 1.55-3.75, respectively] compared with patients without RLS. Increasing RLS severity was associated with an increasing likelihood of cardiovascular events [mild RLS severity, aHR 1.71 (95% CI 1.02-2.87); moderate, 2.79 (1.64-4.66); severe, 2.85 (1.99-4.46)] and strokes [mild, 1.89 (0.87-4.16); moderate, 2.42 (1.50-3.90); severe, 2.64 (1.49-4.91)] in a dose-dependent manner. RLS also increased the risk of total mortality in patients with ESRD [aHR 1.53 (95% CI 1.07-2.18), P = 0.02]; this association attenuated slightly after stratification by individual RLS severity category [mild RLS severity, aHR 1.44 (95% CI 0.78-2.67); moderate, 1.49 (0.98-2.55); severe, 2.03 (0.93-4.45)]. CONCLUSIONS: ESRD patients with RLS demonstrated an increased likelihood of cardio/cerebrovascular events and mortality.

Association of candidate genetic variants with restless legs syndrome in end stage renal disease: a multicenter case-control study in Taiwan.

BACKGROUND AND PURPOSE: Recent genome-wide association studies have shown associations between multiple genetic variants and primary restless legs syndrome (RLS). Their roles in end stage renal disease (ESRD) related secondary RLS are not clear and studies in Asian populations are scarce. The association between candidate genetic variants and uremic RLS was investigated in a large cohort of Taiwanese dialysis patients. METHODS: Sixteen RLS-related genetic variants at six loci, including MEIS1, BTBD9, MAP2K5/SKOR1, PTPRD, TOX3/BC034767 and the intergenic region of chromosome 2p14, in a total of 993 ESRD patients (259 subjects with and 734 subjects without RLS) were genotyped using TaqMan genotyping assays. Multivariate logistic regression analysis was used to test for associations between the genotypes and RLS in ESRD. Power calculations were completed using the CATs Genetic Power Calculator with settings of a multiplicative genetic model. RESULTS: A modest association between the PTPRD variant rs4626664 and uremic RLS (odds ratio 1.52, 95% CI 1.03-2.23, P = 0.03) and a trend that TOX3/BC034767 variant rs3104767 may associate with the occurrence of RLS were observed in our dialysis population (odds ratio 1.74, 95% CI 0.97-3.11, P = 0.06). No associations between other genetic variants and risk and severity of RLS were observed in our ESRD cohort. CONCLUSIONS: The genetic variants of primary RLS candidate genes did not play a major role in our uremic RLS populations. The ethnic difference and heterogeneous etiologies underlying renal failure may partly explain the minor genetic contribution to uremic RLS in our populations. Further studies for other ethnicities will be of worth.

Preceding pain symptoms and Parkinson's disease: a nationwide population-based cohort study.

BACKGROUND AND PURPOSE: Painful sensations are recently reported to be a non-motor feature of Parkinson's disease (PD). The non-steroidal anti-inflammatory drug ibuprofen is a common painkiller and was reported to be associated with a decreased risk of PD. The aim of the present study was to examine the relationship amongst preceding pain symptoms, use of ibuprofen and risk of PD in a nationwide population-based cohort. METHODS: The data of participants who were free of PD at baseline were obtained from two large National Health Interview Surveys (NHIS) in Taiwan, conducted in 2001 and 2005. The information regarding pain status included severity and location of pain. Information regarding pain status, use of ibuprofen, comorbidity of depression and PD-associated risk/protective behaviors was adjusted using proportional hazards models. RESULTS: Amongst 33 388 participants, 32 cases of incident PD were identified after a mean follow-up of 3 years. After adjusting for the use of ibuprofen and other PD risk factors, subjects with preceding pain symptoms had a higher incidence of PD than those without pain at baseline, and the hazard ratio was 1.79 (95% CI: 0.71-4.51, P = 0.21) for mild pain and 2.88 (95% CI: 1.05-7.86, P = 0.04) for moderate or severe pain. The PD risk increased by 34% with each additional increment in pain score [hazard ratio = 1.34 (1.03-1.75), P = 0.03], showing a dose-response relationship. CONCLUSIONS: These findings support the hypothesis that pain is associated with PD in the pre-motor stage of the disease. Further research is needed to clarify the role of sensory system involvement in the pre-motor phase of PD.

Restless legs syndrome in end-stage renal disease: a multicenter study in Taiwan.

BACKGROUND AND PURPOSE: Restless legs syndrome (RLS) is an underestimated movement disorder in patients with end-stage renal disease (ESRD). Several clinical and laboratory factors were inconsistently reported to associate with RLS. We aim to perform a large-scale multicenter study to investigate the possible associated risk factors of RLS in patients with ESRD in Taiwan, a country with the highest incidence of uremia in the world. METHODS: From October 2009 to October 2011, we constitutively recruited 1130 patients with ESRD from 17 hemodialysis centers. Demographic, laboratory data, presence and severity of RLS were collected. Odds ratios (ORs) were estimated by logistic regression models. RESULTS: We found the prevalence of RLS to be 25.3% in patients with ESRD. Having type 2 diabetes [OR = 3.61 (2.27-5.77), P < 0.01], low serum transferrin saturation [OR = 1.42 (1.01-2.03), P < 0.05] and duration of dialysis [OR = 1.09 (1.03-1.14), P < 0.01] were associated with RLS. In contrast, high serum hemoglobin level was inversely associated with RLS [OR = 0.61 (0.40-0.89), P < 0.05]. RLS has a significant impact on sleep quality in dialysis patients. Among patients with RLS, history of type 2 diabetes [OR = 4.04 (1.65-10.79), P < 0.05], low serum hemoglobin level [OR = 5.41 (2.43-13.12), P < 0.01] and duration of dialysis [OR = 1.01 (1.01-1.02), P < 0.01] were associated with increased severity of RLS. CONCLUSIONS: Our findings demonstrated that RLS is common in Taiwanese dialysis patients. Clinicians should have a high suspicion for the presence of RLS symptoms in patients with ESRD, especially those with type 2 diabetes, anemia, low serum iron status and long duration of dialysis.

Electrophoresis of a soft toroid of nonuniform structure.

The electrophoresis of a nonuniformly structured soft particle is modeled theoretically by considering an isolated soft toroid comprising a rigid core and a polyelectrolyte layer with exponential segment distribution. The influences of the thickness of double layer, and the fixed charge density, the friction coefficient, the uniformity, and the thickness of the polyelectrolyte layer on the electrophoresis behavior of the toroid are examined. We show that for a specified fixed charge density, the electrophoresis mobility of the toroid increases with increasing double layer thickness, and the higher that density the larger the mobility. The thicker the polyelectrolyte layer and/or more uniform the segment distribution of that layer the higher the fixed charge density, yielding a larger mobility. The thicker the double layer the more significant is the influence of the polyelectrolyte layer structure of a toroid on its mobility.

Importance of the porous structure of a soft particle on its electrophoretic behavior.

The importance of the porous structure of a soft particle comprising a rigid core and a porous layer on its electrophoretic behavior is investigated. The porous layer is simulated by an aggregate of primary units, rendering it to have a radially varying fixed charge and hydrodynamic resistance. Key factors, including the thickness of double layer, the linear size of a primary unit, the aggregate dimension, and the thickness and the fixed charge density of the porous layer, are examined for their influence on the mobility of a particle. We show that if the fixed charge density is fixed, then the mobility increases with increasing double layer thickness, and the mobility increases with increasing fixed charge density. Increasing the linear size of a primary unit raises appreciably the mobility. In addition, the mobility increases with increasing thickness or aggregate dimension of the porous layer. The structure of the porous layer of a particle affects most significantly its mobility when the double layer is thick.

Death-associated protein kinase 1 variation and Parkinson's disease.

BACKGROUND AND PURPOSE: Mutations of the LRRK2 gene are now recognized as major risk factors for Parkinson's disease. The Lrrk2 protein is a member of the ROCO family, which also includes Lrrk1 and Dapk1. Functional genetic variants of the DAPK1 gene (rs4877365 and rs4878104) have been previously associated with Alzheimer's disease. METHODS: Herein, we assessed the role of DAPK1 variants (rs4877365 and rs4878104) in risk of Parkinson's disease with Sequenom iPLEX genotyping, employing one Taiwanese series (391 patients with Parkinson's disease, 344 controls) and five separate Caucasian series' (combined sample size 1962 Parkinson's disease patients, 1900 controls). RESULTS: We observed no evidence of association for rs4877365 and rs4878104 and risk of Parkinson's disease in any of the individual series or in the combined Caucasian series under either an additive or recessive model. CONCLUSION: These specific DAPK1 intronic variants do not increase the risk of Parkinson's disease. However, further functional studies are required to elucidate the potential therapeutic implications with the dimerization of the Dapk1 and Lrrk2 proteins.

Electrophoresis of an arbitrarily oriented toroid in an unbounded electrolyte solution.

The electrophoresis of a non-conducting rigid toroid in an unbounded Newtonian electrolyte solution having an arbitrary orientation is modeled theoretically under the condition of low surface potential. In particular, the influence of the orientation angle, defined as the angle between the applied electric field and the center line of the toroid, on its electrophoretic behavior as the thickness of double layer varies is investigated. The results of numerical simulation reveal that both the thickness of double layer and the orientation angle can influence appreciably the mobility of the toroid. In general, for a fixed orientation, the mobility of the toroid increases with decreasing double layer thickness, and for a fixed double layer thickness, the scaled electrophoresis mobility increases with increasing orientation angle. If the double layer is infinitely thin, then the present result reduces to that predicted by Smoluchowski, that is, the scaled electrophoretic mobility of the toroid is unity, and is not influenced by its shape. On the other hand, if it is infinitely thick, then the present result follows the same trend as that predicted by Henry, that is, the electrophoretic mobility of the toroid depends highly on its form effect, and the thicker the double layer the smaller that mobility. If the thickness of double layer is comparable to the radius of a toroid, the variation in the orientation angle can lead to as much as 40% difference in the mobility.

Deep brain stimulation therapy for Parkinson's disease using frameless stereotaxy: comparison with frame-based surgery.

BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) surgery has been performed using frame-based stereotaxy traditionally; however, in recent years, it has also been performed using frameless stereotaxy. The purpose of this study was to compare the experience at our centre in performing DBS surgery using frameless surgery for patients with Parkinson's disease with that of using frame-based surgery. METHODS: Twenty-four patients with advanced Parkinson's disease underwent DBS surgery, 12 with frameless and 12 with frame-based stereotaxy. After identifying the subthalamus by microelectrode recording (MER), the DBS electrodes were implanted and connected to an implanted programmable generator in all patients. Programming was started 1 month after the operation and the outcome of the patients was followed up regularly for at least 12 months. RESULTS: After 1 year of follow-up, the patients who received frameless surgery showed no difference in the degree of improvement in clinical motor function compared with the patients who received frame-based surgery (P = 0.819); the average improvement was 60.9% and 56.9%, respectively, in the stimulation alone/medication-off state, as evaluated by the Unified Parkinson's Disease Rating Scale-III motor subscore. However, the frameless group had significantly shorter total MER time (P = 0.0127) and a smaller number of trajectories (P = 0.0096) than the frame-based group. CONCLUSIONS: Our data indicate that frameless DBS surgery has a similar outcome when compared with frame-based surgery; however, frameless surgery can decrease the operation time, MER time, and MER trajectory number.

Analysis of the UCHL1 genetic variant in Parkinson's disease among Chinese.

The inverse association of the functional ubiquitin carboxy-terminal hydrolase L1 (UCHL1) S18Y variant with Parkinson's disease (PD) among Caucasian populations has been debated. We conducted a large-scale analysis to investigate the age-of-onset effect of the UCHL1 variant in PD among ethnic Chinese. Individual data sets from 5 centers comprising a total of 4088 study subjects were analyzed. In the univariate analysis, only data from 1 center showed a trend towards a protective effect among young subjects. However, in the combined analysis, no significant association between the UCHL1 variant and PD was detected (A allele frequency 0.531 vs. 0.528, p=0.87, OR 1.01, 95% CI 0.92-1.1). Among subjects less than 60 years old, the OR is 0.99 (95% CI 0.84-1.16, p=0.88). A multivariate logistic regression analysis showed that family history, UCHL1 variant and the interaction of UCHL1 variant and age at onset (p=0.816) were not significantly associated with PD.

3D simulations of hydrodynamic drag on a nonhomogeneously structured permeable sphere and advective flow thereof.

The influence of the structure of a permeable sphere on the flow field and the hydrodynamic drag acting on it are investigated theoretically under the conditions of low to medium large Reynolds number. The anisotropic nature of the permeability of the sphere is taken into account by considering a three-dimensional permeability model. We show that although the permeability in the main flow direction dominates, the permeability in the other directions cannot be neglected. If Reynolds number is small, the larger the permeability in the main flow direction the more significant the influence of the permeability in the other directions. If Reynolds number takes a medium large value, the influence of the permeability in the other directions may decrease if the permeability in the main flow direction is sufficiently large. Depending on the levels of Reynolds number and the permeability, the extent of that influence can be on the order of 10%.

Plasma calcitonin gene-related peptide in diagnosing and predicting paediatric migraine.

To investigate the role of plasma calcitonin gene-related peptide (CGRP) in paediatric migraine, we prospectively collected 134 blood samples during or between attacks from 66 migraine, 33 non-migraine headache (non-migraine) and 22 non-headache patients, aged 4-18 years. Plasma CGRP concentrations were measured by enzyme-linked immunosorbent assay and disability by Pediatric MIgraine Disability ASsessment (PedMIDAS) questionnaire. Migraineurs had higher plasma CGRP levels than non-migraine patients (P = 0.007). The attack level was higher than the non-attack level in migraine (P = 0.036), but not in non-migraine, patients. This was also revealed in paired comparison (n = 9, P = 0.015 vs. n = 4, P = 0.47). Using a threshold of 55.1 pg/ml, the sensitivity of the attack level in predicting migraine was 0.81, and specificity 0.75. The PedMIDAS score tended to be higher in the high CGRP (> 200 pg/ml, n = 7) group than in the low (< 200 pg/ml, n = 33) group (26.07 vs. 19.32, P = 0.16) using Mann-Whitney test. Plasma CGRP is useful for diagnosis in paediatric migraine.

Novel ATP13A2 variant associated with Parkinson disease in Taiwan and Singapore.

OBJECTIVES: To assess the association of ATP13A2 gene mutation among patients with early onset Parkinson disease (EOPD, onset < 50 years) in ethnic Chinese population. METHODS: Among 771 subjects, we studied 182 patients with EOPD and familial PD and 589 matched controls from two cohorts of Han Chinese in Taiwan and Singapore. The entire ATP13A2 coding region and intron-exon boundaries were sequenced in 71 probands and 70 controls in Taiwanese/ethnic Chinese. An additional 111 index patients with PD in Singapore and 589 controls were later screened to validate possible mutations that were found in the first set of study subjects. RESULTS: We identified one novel missense variant, AL746Thr, in a single heterozygous state in three patients (two were from Taiwan and one was from Singapore) (1.7% in EOPD). The variant was not observed in 589 ethnicity matched controls. The frequency of this variant was significantly higher in PD cases than controls (p = 0.01, relative risk 4.3, 95% CI 1.9-4.3). The clinical phenotype and (18)F-dopa PET image of ATP13A2 Ala78Thr carriers are similar to that seen in idiopathic PD. The variant is located between the highly conserved phosphorylation region and the fifth transmembrane domain of the ATP13A2 protein. CONCLUSIONS: A rare variant of the ATP13A2 was associated with an increased risk of Parkinson disease among ethnic Chinese in Asia. Further studies are needed to clarify the functional role of this genetic risk factor.

Acute disseminated encephalomyelitis: a follow-up study in Taiwan.

BACKGROUND: Acute-disseminated encephalomyelitis (ADEM) is a demyelinating disorder of the central nervous system, whose epidemiology, clinical presentations and functional outcome are incompletely understood in Asian populations. OBJECTIVE: To assess the clinical presentations, predisposing factors and functional outcome of ADEM in Taiwan. METHODS: 50 patients initially diagnosed with ADEM (male, 19; female, 31) were enrolled from 1991 to 2005. Diagnosis of ADEM or multiple sclerosis was established during a follow-up period of 2-120 months. 8 adult patients were noted to have taken the immunomodulatory drug, levamisole, within 3 months before onset of symptoms. The remaining 42 patients (male, 17; female, 25) were categorised by age as children (<16 years, n = 12), young adults (16-49 years, n = 21) and elderly adults (> or =50 years, n = 9). The clinical manifestations, predisposing factors and radiological findings were compared between different age groups and adult patients with or without levamisole use. Functional outcome was compared by a log-rank test. RESULTS: Preceding upper respiratory tract infection was evident in 21 (50%) patients and only one young-adult patient had received Rubella vaccine immunisation. The frequency of fever was higher in children (p = 0.04) and psychiatric symptoms were more prevalent in elderly patients (p = 0.03). Functional recovery was faster in children than in adults (p = 0.002). Initial Expanded Disability Status Scale score (odds ratio (OR) 1.9, p = 0.03) and no fever (OR 0.04, p = 0.06) were associated with poor outcome (modified Rankin scale > or =2). After a mean (SD) follow-up of 31.8 (9.9) months, 4 (9.5%) patients developed multiple sclerosis (3 (25%) children, 1 (4.7%) young adult, p = 0.03). The neurological disability, radiological and cerebrospinal fluid findings did not differ between patients with and without levamisole use. One elderly adult patient previously receiving levamisole developed multiple sclerosis of relapse-remitting type after a mean follow-up period of 36.9 months. CONCLUSION: The clinical presentations, functional outcome and risk of developing multiple sclerosis differed between different age groups. Functional recovery was faster in children than in adults. Poor functional outcome was related to initial high Expanded Disability Status Scale score and absence of fever.