Broadband Green Luminescence and Phase Transition in Low-Dimensional Organic-Inorganic Hybrid Iodate.

Organic-inorganic hybrid iodide systems, which can form highly ordered chromophores and uniformly oriented transition dipole moments, serve as optimal host-guest systems for the fabrication of micrometer-scale optical devices. In particular, those with low-dimensional structures can exhibit strong quantum-limited and highly localized charges, enabling the generation of high exciton energies and stable excitation emission. In this study, we report a novel instance of an organic-inorganic hybrid iodate, (C13H11N2)(IO3), which was synthesized by incorporating the optically active organic compound, 9-aminoacridine. Upon crystallization in the monoclinic space group P21/c, this compound exhibits a direct optical band gap of 2.66 eV. The incorporation of discrete organic units within the low-dimensional structures induces pronounced local charges, culminating in broadband green luminescence with a peak at 540 nm under UV excitation. This corresponds to the CIE coordinates (0.37, 0.56). A potential phase transition was inferred through a comprehensive analysis of the variable temperature structure and emission spectra. Furthermore, first-principles calculations revealed the pivotal role of organic cations in facilitating broadband luminescence.

Integrating Mendelian Randomization with Single-cell Sequencing Data Reveals the Causal Effect and Related Mechanisms of Smoking on Parkinson's Disease.

INTRODUCTION: Smoking (nicotine) has been reported to possibly be neuroprotective and conducive to patients with early Parkinson's disease (PD). However, the causal effect of smoking on PD and the molecular mechanisms of smoking-related genes (SRGs) are vague. METHODS: First, genome-wide association study summary data on smoking (ukb-b-6244) and PD (ieu-b-7) were retrieved from the Integrative Epidemiology Unit OpenGWAS database for Mendelian randomization (MR) analysis. Sensitivity analyses were performed to validate the results of the MR analyses. Subsequently, a differential analysis of PD patients and controls was performed to identify differentially expressed SRGs (DE-SRGs). Finally, the expression of DE-SRGs was analyzed in annotated cell types. RESULTS: The MR analysis revealed that smoking was a protective factor causally related to PD (P=0.008, odds ratio=0.288). Furthermore, a total of five DE-SRGs enriched in Toll-like receptor signaling pathways were identified in GSE7621 dataset. Regarding single-cell analysis of GSE184950 dataset, a total of nine cell types were annotated. The expression of LRRN1 in oligodendrocyte progenitor cells and oligodendrocytes, respectively, differed significantly between PD patients and controls. CONCLUSIONS: Our study supported a causal relationship between smoking and PD and found that five SRGs (MAPK8IP1, LRRN1, LINC00324, HIST1H2BK, and YOD1) enriched in Toll-like receptor signaling pathways might be beneficial in PD. In addition, single-cell sequencing indicated that four SRGs were differentially expressed in different cell types. All four genes except MAPK8IP1 were significantly correlated with the 10 genes calculated by scPagwas. Thus, this evidence provides a theoretical basis for further research on the effect of nicotine (smoking) on PD. IMPLICATIONS: In order to explore the potential etiology and pathogenesis of Parkinson's disease, this study combined Mendelian randomization, transcriptomics and single-cell sequencing analysis to explore the association between exposure factors and Parkinson's disease, observe and confirm the relationship and mechanism between the two from the perspective of genetics, and provide more reliable evidence for causal inference.

Accelerometer-measured sedentary volume and bouts during the segmented school day among Chinese school students.

Background: This study examined sedentary volume and bouts of Chinese primary and middle school students during different segments of a school day and determined whether gender and school level are associated with their sedentary volume and bouts. Methods: A total of 472 students participated in this study. Accelerometers were used to measure the sedentary volume and sedentary bouts of different durations (i.e., 1-4 min, 5-9 min and ≥10 min) during all segments. Results: The participants spent the majority of their time in sitting (61.7%) and sitting bouts of ≥10 min (37.3%). They spent higher percentages of time in sitting during regular classes (76.7%) and out-of-school time (54.5%), and lower during physical education (PE) classes (32.2%), lunch break (35.4%) and recess (38.0%). The highest proportions of time were in sedentary bouts of ≥10 min during regular classes (50.2%), out-of-school time (28.0%) and lunch break (18.8%), while the greatest percentages occurred in sitting bouts of 1-4 min during PE class (16.4%) and recess (18.6%). Girls and middle school students had higher percentages of sedentary volume than boys and primary school students during most segments. They spent greater proportions of time in sitting bouts of ≥10 min during regular classes, lunch break, and out-of-school time, and higher proportions in sedentary bouts of 1-4 min than boys and primary students during PE classes. Conclusion: Regular class and out-of-school time were identified as key segments for reducing sedentary volume and breaking up prolonged sitting. Interventions on interrupting prolonged sitting during lunch break should also be explored. Girls and middle school students should receive more attention in future interventions.

Theoretical and experimental investigation of the molecular depolarization ratio for broadband polarization lidar techniques.

The molecular depolarization ratio (MDR) is of great significance for polarization lidar techniques in terms of validating the measurement accuracy, etc. However, previous studies mainly focused on cases with narrowband laser linewidths, and the transmittance of the Cabannes line in the receiver has been assumed constant. In this work, the narrowband theoretical model of MDR has been re-examined by taking the transmittance of the Cabannes line into account. A large relative deviation of beyond 200% has been found if the wavelength-shift reaches up to 0.5 nm for a receiving bandwidth of 0.5 nm at 532 nm, which is much larger than the case without considering the transmittance of the Cabannes line, i.e., only 15%, reported in previous studies. Besides, a broadband theoretical model has been proposed to evaluate the MDR for polarization lidar using high-power multimode laser diodes as light sources. Simulation studies have revealed that the MDR is highly related to the laser linewidth, the receiving bandwidth, as well as the wavelength-shift between the laser wavelength and the center wavelength of the receiver. The MDR at 520 nm calculated by the broadband theoretical model is about 21% larger than the value evaluated without considering the laser linewidth, when the receiving bandwidth is equivalent to the laser linewidth (e.g., 2 nm). Validation measurements, employing a 520-nm imaging-based polarization lidar with a 3.4-nm laser linewidth and a 10-nm receiving bandwidth, illustrated that the volume depolarization ratio in a clean atmospheric region (0.129±0.0025) was highly consistent with the theoretical MDR (0.132). The good agreement between theoretical and experimental results demonstrated a high measurement accuracy of the imaging-based polarization lidar and excellent feasibility of the broadband theoretical model.

A Simple Grading Scale for Predicting Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy.

INTRODUCTION: Hemorrhagic transformation, especially symptomatic intracranial hemorrhage (sICH), is a common complication after mechanical embolectomy. This study explored a grading scale based on clinical and radiological parameters to predict sICH after mechanical embolectomy. METHODS: Demographic and clinical data were retrospectively collected from patients with acute ischemic stroke treated with mechanical embolectomy at West China Hospital. Clinical and radiological factors associated with sICH were identified and used to develop the "STBA" grading scale. This score was then validated using data from an independent sample at the First Affiliated Hospital of Kunming Medical University. RESULTS: We analyzed 268 patients with acute ischemic stroke who were treated with mechanical embolectomy at West China Hospital, of whom 30 (11.2%) had sICH. Patients were rated on an "STBA" score ranging from 0 to 6 based on whether systolic blood pressure was ≥145 mm Hg at admission (yes = 2 points; no = 0 points), time from acute ischemic stroke until groin puncture was ≥300 min (yes = 1; no = 0), blood glucose was ≥8.8 mmol/L (yes = 1; no = 0), and the Alberta Stroke Program Early Computed Tomography score at admission was 0-5 (2 points), 6-7 (1 point), or 8-10 (0 points). The STBA score showed good discrimination in the derivation sample (area under the receiver operating characteristic curve = 0.858) and in the validation sample (area = 0.814). CONCLUSIONS: The STBA score may be a reliable clinical scoring system to predict sICH in acute ischemic stroke patients treated with mechanical embolectomy.

Differences in risk factors and outcome after acute stroke in patients with tandem occlusion and those with isolated intracranial occlusion after endovascular treatment.

OBJECTIVE: This study aimed to compare the clinical features, treatment, and clinical outcome of patients with tandem occlusion and isolated intracranial occlusion through endovascular treatment (EVT). METHODS: Patients with acute cerebral infarction who received EVT in two stroke centers were retrospectively included. According to MRI or CTA results, the patients were divided into tandem occlusion group or isolated intracranial occlusion group. The baseline data, etiological classification, treatment, post-stroke complications, image features, and clinical outcome were compared. Multivariate logistic regression analysis was used to evaluate the related factors affecting the prognosis of patients with EVT. RESULTS: Among 161 patients with acute cerebral infarction, there were 33 cases (20.5%) in the tandem occlusion group and 128 cases (79.5%) in the isolated intracranial occlusion group. Compared with isolated intracranial occlusion, the patients with tandem occlusion had higher rates of large artery atherosclerosis (P = 0.028), symptomatic intracerebral hemorrhage (sICH) (P = 0.023), bilateral infarction (P = 0.042), and longer time for endovascular procedure (P = 0.026). There was no significant statistical difference in 90-day mRS score between the two groups (P = 0.060). Multivariate logistic regression identified the following independent predictors of poor functional outcome: older age, high fasting blood glucose, infarction area > 1/3, and hemorrhagic transformation. CONCLUSIONS: Compared with isolated intracranial occlusion, there was not a worse prognosis among patients with tandem occlusion who received EVT.

Characterization of microbiome and metabolite analyses in patients with metabolic associated fatty liver disease and type II diabetes mellitus.

BACKGROUND: State-of-the-art renewal has indicated the improvement of diagnostics of patients with metabolic associated fatty liver disease (MAFLD) and/or type II diabetes mellitus (T2DM) by dissecting the clinical characteristics as well as genomic analysis. However, the deficiency of the characterization of microbial and metabolite signatures largely impedes the symptomatic treatment. METHODS: For the purpose, we retrospectively analyzed the clinical data of 20 patients with MAFLD (short for "M"), 20 cases with MAFLD and T2DM (short for "MD"), together with 19 healthy donors (short for "Ctr"). Microbial and metabolite analyses were further conducted to explore the similarities and differences among the aforementioned populations based on feces and blood samples, respectively. RESULTS: Compared with those in the Ctr group, patients with M or MD revealed multifaceted similarities (e.g., Age, ALP, LDL, BUN) and distinctions in clinical indicators of liver (e.g., BMI, ALT, PCHE, CAP). With the aid of microbial and metabolite analyses as well as bioinformatic analyses, we found that the characteristics of gut microbiota (e.g., abundance, hierarchical clustering, cladogram, species) and lipid metabolism (e.g., metabolite, correlation coefficient and scatter plot) were distinct among the indicated groups. CONCLUSIONS: The patients with MD revealed multifaceted similarities and distinctions in characteristics of microbiome and metabolites with those in the M and HD groups, and in particular, the significantly expressed microbes (e.g., Elusimicrobiota, Berkelbacteria, Cyanobacteria, Peregrinibacteria) and lipid metabolites (e.g., Lipid-Q-P-0765, Lipid-Q-P-0216, Lipid-Q-P-0034, Lipid-Q-P-0800), which would collectively benefit the clinical diagnosis of MAFLD and T2DM.

Development and validation of a nomogram for freezing of gait in patients with Parkinson's Disease.

OBJECTIVES: Freezing of gait (FOG) is a common and complex disabling episodic gait disturbance in patients with Parkinson's disease (PD). Currently, the treatment of FOG remains a challenge for clinicians. The aim of our study was to develop a nomogram for FOG risk based on data collected from Chinese patients with PD. MATERIALS & METHODS: A total of 379 PD patients (197 with FOG) from Kunming Medical University were recruited as a training cohort. Additionally, 339 PD patients (166 with FOG) were recruited from West China Hospital of Sichuan University, to serve as the validation cohort. The least absolute shrinkage and selection operator regression model was used to select clinical and demographic characteristics as well as blood markers, which were incorporated into a predictive model using multivariate logistic regression to predict the risk of developing FOG. The model was validated using the validation dataset, and model performance was evaluated using the C-index, calibration plot, and decision curve analyses. RESULTS: The final predictive model included the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) score, Parkinson's Disease Questionnaire (PDQ39), H-Y stage, and visuospatial function. The model showed good calibration and good discrimination, with a C-index value of 0.772 against the training cohort and 0.766 against the validation cohort. Decision curve analysis demonstrated the clinical utility of the nomogram. CONCLUSION: A nomogram incorporating RBDSQ, PDQ39, H-Y stage, and visuospatial function may reliably predict the risk of FOG in PD patients.

Plasma neurofilament light chain levels are associated with depressive and anxiety symptoms in Parkinson's disease.

The present study aimed to explore the association of plasma neurofilament light chain (NfL) levels with depression and anxiety in Parkinson's disease (PD). This prospective study enrolled 116 patients with PD and 38 healthy controls, and found plasma NfL levels were higher in patients with depression or anxiety than in those without these symptoms. Binary logistic regression identified NfL concentration as an independent predictor of depression and anxiety in PD. In conclusion, elevated plasma NfL may be associated with severity of depression and anxiety in PD patients and may serve as a diagnostic biomarker of PD with moderate to severe depression or anxiety.

Association between levels of high-sensitivity C-reactive protein in plasma and freezing of gait in Parkinson's disease.

This study explored the potential relationship between levels of high-sensitivity C-reactive protein (hs-CRP) in plasma and freezing of gait (FOG) in Parkinson's disease (PD) in China. A total of 72 healthy subjects, 62 PD patients with FOG, and 83 PD patients without FOG from our center were enrolled in this prospective study. Patients with FOG showed significantly higher hs-CRP levels than controls, but patients without FOG did not. Binary logistic regression analysis identified levels of hs-CRP in plasma to be an independent risk factor for FOG among the patients in our cohort (OR 6.371, 95% CI 2.589-15.678, p < 0.001). In fact, a cut-off level of 0.935 mg/L distinguished patients with or without FOG [area under the ROC curve (AUC) = 0.908, sensitivity 87.1%, specificity 89.2%]. Our study suggests that high levels of hs-CRP in plasma are associated with the occurrence of FOG in PD. The pooled data combined with a previous study carried out in Spain also indicate a positive association between plasma hs-CRP levels and FOG in PD. However, more research is still needed to verify the plasma hs-CRP as a potential biomarker of FOG.

REM sleep behavioral disorder may be an independent risk factor for orthostatic hypotension in Parkinson's disease.

PURPOSE: The purpose of this study was to evaluate the association between clinically possible rapid eye movement (REM) sleep behavioral disorder (pRBD) and orthostatic hypotension (OH) in PD patients, as well as to explore the mechanisms underlying the association. METHODS: PD patients (n = 116) were assigned to a group with OH (PD-OH) or without OH (PD-NOH). General demographic and clinical data were collected. A series of scales were used to assess the clinical symptoms in the two groups. RESULTS: A total of 27 patients (23.3%) had OH. The PD-OH group showed significantly higher H-Y staging score and significantly higher frequencies of pRBD, anxiety, depression, and cognitive impairment than the PD-NOH group. Binary logistic regression analysis identified the following factors as independently associated with PD-OH: H-Y staging [odds ratio (OR) 2.565, 95% confidence interval (CI) 1.160-5.673; P = 0.020], RBD (OR 7.680, 95% CI 1.944-30.346; P = 0.004), UPDRS II (OR 1.021, 95% CI 0.980-1.063; P = 0.020), depression (OR 7.601, 95% CI 1.492-38.718; P = 0.015), and cognitive impairment (OR 0.824, 95% CI 0.696-0.976; P = 0.025). CONCLUSIONS: Our results suggest that pRBD is an independent risk factor for OH in patients with PD. We speculate that there may be a close relationship between RBD and OH, which requires attention. Early diagnosis of RBD may help predict the appearance of OH in PD patients.

Suicide and suicide attempts after subthalamic nucleus stimulation in Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Deep-brain stimulation is a well-established, effective treatment for patients with advanced Parkinson's disease. Recent studies examining rates of suicide attempts and suicides after deep-brain stimulation in the bilateral subthalamic nucleus have reported varying results. Using this systematic review and meta-analysis, we aim to obtain a comprehensive understanding of suicidality in Parkinson's patients after subthalamic nucleus deep brain stimulation. METHODS: We systematically examined Medline, PubMed, Web of Science, and Embase databases to identify studies published before November 2019 that measured rates of suicidality in Parkinson's patients who underwent subthalamic nucleus stimulation. A meta-analysis of the data from the included studies was conducted using Stata 12.0. RESULTS: A total of 18 studies met the eligibility criteria of this study. We found that the pooled rate of suicidal ideation was 4% (95% CI 0.00-7.2%, range 2-17%). The pooled rate of suicide attempts was 1% (95% CI 1.0-2.0%), while the pooled rate of suicide was 1% (95% CI 0.0-1.0%). CONCLUSIONS: Our findings indicate a relatively high rate of suicidality among Parkinson's patients after subthalamic nucleus deep-brain stimulation. It is important for clinicians to carefully monitor psychiatric disorders, especially suicidal ideation and suicide attempts, in Parkinson's patients before and after subthalamic nucleus deep-brain stimulation.

Clinical value of C-reactive protein/albumin ratio in Guillain-Barré syndrome.

BACKGROUND: Respiratory failure in patients with Guillain-Barré syndrome (GBS) can lead to serious complications and dysfunctions, emphasizing the importance of early detection. The C-reactive protein-to-albumin ratio (CAR) is emerging as a novel inflammatory marker for predicting neurological outcome. We aimed to identify the association of CAR with respiratory failure and short-term outcome in GBS patients. METHODS: A total of 200 patients diagnosed with GBS were retrospectively analyzed. Data were collected from an electronic database. The associations of C-reactive protein (CRP), albumin, and CAR at admission with outcomes were evaluated by logistic regression analysis. Using receiver operating characteristic curves, we calculated the cutoff value for the CAR and compared its discriminatory power with that of C-reactive protein alone. RESULTS: Fifty-two (26%) patients showed poor short-term outcome, and 50 (25%) developed respiratory failure. CAR > 0.21 was an independent predictor of respiratory failure, and CAR > 0.19 was an independent predictor of poor short-term outcome. CAR showed a better predictive value than CRP alone. In addition, the c-index of the predictive nomogram for respiratory failure was higher when it included CAR (0.962) than when it did not (0.958). A similar result was observed for the predictive nomogram for poor short-term outcome (0.953 vs 0.947). CONCLUSION: CAR > 0.21, a novel inflammatory biomarker, is independently associated with the occurrence of respiratory failure in GBS patients, while CAR > 0.19 is independently associated with poor short-term outcome. CAR may help identify GBS patients at high risk of poor prognosis.

Spectroscopic Investigation and Nanoscale Characterization of Epinephrine Autooxidation under Alkaline Conditions.

Melanins are intriguing biomaterials with unique physical and chemical properties. Due to the insoluble nature of the synthetic melanins prepared from different precursors, such as 3,4-dihydroxy-phenylalanine (DOPA) and dopamine (DA), it is still challenging to reveal the structure-property relationships. In this work, the autoxidation of epinephrine (EP) under basic conditions was investigated from the perspective of supramolecular chemistry, and the formed soluble epinephrine-melanin (EPM) was characterized on the nanoscale. The supramolecular aggregate nature of oxidation products has been identified on the basis of spectroscopic investigations. A two-dimensional sheet-like morphology with highly ordered in-plane stacking structures was observed for the first time, and the thickness of the nanosheet increased with increasing EPM concentration. More importantly, in contrast to the well-known monotonic absorption profiles of synthetic melanins, EPM shows featured and unusual pH-responsible absorption profiles in the near-ultraviolet region (UVA). The decrease in pH can induce the disappearance of the absorption in the lower-energy band and the reduction of aggregate size. The oxidative and aggregation kinetic processes of EP were investigated in three different alkaline systems by the combination of absorption and fluorescence spectroscopies. The oxidation process of EP shows concentration- and buffer-dependent behaviors. The unusual absorption properties of EPM were exploited for the fabrication of transparent UV-shielding chitosan biofilms and gelatin hydrogels. Extensive research on the molecular structures, supramolecular exciton coupling, and material-oriented property exploitation of EPM is highly anticipated.

Clinical characteristics of patients with essential tremor or essential tremor plus.

BACKGROUND: The International Parkinson and Movement Disorder Society introduced the category of essential tremor (ET)-plus in its new ET classification scheme, but how the clinical correlates of ET-plus differ from those of "pure" ET is unclear. By comparing the clinical characteristics of ET and ET-plus patients, we expect to better understand the impact and invoked questions of the new classification on clinical practice. METHODS: We reviewed the medical records of 280 ET syndrome patients in an ongoing cross-sectional study in a Chinese population and reclassified them according to the new criteria. Clinico-demographic characteristics were compared between ET and ET-plus patients. Risk factors of diagnosis of ET-plus were explored using logistic regression. RESULTS: A total of 121 patients (50.8%) were reclassified as having ET and 117 as having ET-plus. ET-plus group was significantly older at tremor onset, less educated, and more likely to have cranial tremor, depression symptom, anxiety symptom, and probable REM sleep behavior disorder. ET-plus group also showed more severe upper limb tremor and cognition impairment. Regression analysis identified four independent risk factors associated with ET-plus: late tremor onset (OR 3.04, 95%CI 1.60-5.79), less educated (OR 0.91, 95%CI 0.85-0.97), severe upper limb tremor (OR 2.46, 95%CI 1.30-4.62), and presence of cranial tremor (OR 2.30, 95%CI 1.20-4.41). CONCLUSIONS: The new classification scheme emphasized that ET syndrome is heterogeneous. ET-plus cannot be seen as a subtype or a diagnosis of ET syndrome, but rather as a placeholder, representing an area of current scientific uncertainty.

A nomogram to predict mechanical ventilation in Guillain-Barré syndrome patients.

INTRODUCTION: Guillain-Barré syndrome (GBS) is one of the most common causes of acute flaccid paralysis, with up to 20%-30% of patients requiring mechanical ventilation. The aim of our study was to develop and validate a mechanical ventilation risk nomogram in a Chinese population of patients with GBS. METHODS: A total of 312 GBS patients were recruited from January 1, 2015, to June 31, 2018, of whom 17% received mechanical ventilation. The least absolute shrinkage and selection operator (LASSO) regression model was used to select clinicodemographic characteristics and blood markers that were then incorporated, using multivariate logistic regression, into a risk model to predict the need for mechanical ventilation. The model was characterized and assessed using the C-index, calibration plot, and decision curve analysis. The model was validated using bootstrap resampling in a prospective study of 114 patients recruited from July 1, 2018, to July 10, 2019. RESULTS: The predictive model included hospital stay, glossopharyngeal and vagal nerve deficits, Hughes functional grading scale scores at admission, and neutrophil/lymphocyte ratio (NLR). The model showed good discrimination with a C-index value of 0.938 and good calibration. A high C-index value of 0.856 was reached in the validation group. Decision curve analysis demonstrated the clinical utility of the mechanical ventilation nomogram. CONCLUSIONS: A nomogram incorporating hospital stay, glossopharyngeal and vagal nerve deficits, Hughes functional grading scale scores at admission, and NLR may reliably predict the probability of requiring mechanical ventilation in GBS patients.

Non-motor symptoms are associated with midline tremor in essential tremor.

OBJECTIVES: Essential tremor (ET) patients presenting tremor in the midline structures may be a distinct subtype of the syndrome. Therefore, we sought to explore the clinical manifestations, especially non-motor symptoms (NMS) of Chinese ET patients with midline tremor (MT). METHODS: In the cross-sectional study, we grouped 290 definite or probable ET patients based on their MT conditions. The NMS in ET patients were evaluated using the NMS scale (NMSS). NMS and other clinical correlates were then compared among subgroups with, and without MT. RESULTS: We revealed that 39.0%, 27.6%, and 6.9% of the patients respectively had neck, voice, and facial tremors. With the accumulation of tremor in midline structures, NMS became more severe and prevalent. Logistic regression analyses revealed that factors such as: female gender (OR = 2.164, 95% CI: 1.307-3.583), having least or highest action arm tremor (OR = 2.512, 95% CI: 1.520-4.151), having higher score of sleep/fatigue domain (OR = 1.692, 95% CI: 1.004-2.850) and mood/apathy (OR = 1.926, 95% CI: 1.143-3.246) domain, to be independently associated with MT manifestation. CONCLUSIONS: Our study demonstrates the heterogeneity of symptoms in ET patients with MT, especially in prominent NMS. In addition, the discrepancy of NMS between patients with, and without MT provides novel insight into the underlying pathophysiology and therapeutic of ET.

Association between serum vitamin D levels and benign paroxysmal positional vertigo: a systematic review and meta-analysis of observational studies.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) was the most common neuro-otological disorder manifests as recurrent positional vertigo, but its risk factors are elusive. Recent studies suggest that decreased Vitamin D level may be a risk factor, but the literature is inconsistent. METHODS: The databases PubMed, Web of Science, Chinese National Knowledge Infrastructure, Wanfang, SinoMed, and Embase were systematically searched for studies on the association between BPPV and  serum Vitamin D levels published up to June 2019. Data from eligible studies were meta-analyzed using Stata 12.0. RESULTS: A total of 18 studies were included in the analysis. Serum Vitamin D levels were significantly lower in individuals with BPPV than in controls (WMD - 2.46, 95% CI - 3.79 to - 1.12, p < 0.001). Subgroup analysis by geographical area showed that vitamin D level was significantly lower in BPPV than in controls in China (WMD - 3.27, 95% CI - 4.12 to - 2.43, p < 0.001), but not outside China (WMD - 0.90, 95% CI - 4.36 to 2.56, p = 0.611). Vitamin D levels were significantly lower in recurrent than non-recurrent BPPV across all countries in the sample (WMD 2.59, 95% CI 0.35-4.82, p = 0.023). Vitamin D deficiency emerged as an independent risk factor of BPPV (OR 1.998, 95% CI 1.400-2.851, p < 0.001). CONCLUSION: The available evidence suggests that BPPV is associated with decreased levels of serum Vitamin D, and vitamin D deficiency was an independent risk factor for BPPV.

UNC13A variant rs12608932 is associated with increased risk of amyotrophic lateral sclerosis and reduced patient survival: a meta-analysis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease associated with both genetic and environmental risk factors. Previous studies trying to find an association between ALS and unc-13 homolog A (UNC13A) gene variants have shown inconsistent results. This study aimed to conduct a meta-analysis of the association between the C allele of rs12608932, a single-nucleotide polymorphism located in an intron of UNC13A, and risk of ALS and patient survival. METHODS: PubMed, Web of Science, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed databases were systematically searched for genome-wide association studies or case-control studies published up to January 2019 on the association between this variant in UNC13A and risk and/or prognosis of ALS. Data from eligible studies were extracted and analyzed. RESULTS: The pooled data (28,072 patients with sporadic ALS and 56,545 controls) showed that rs12608932(C) was associated with an increased risk of ALS (OR = 1.13, 95%CI 1.07-1.20). Subgroup analysis revealed that rs12608932(C) increased the risk of sporadic ALS in non-Asian individuals, including those from the USA and Europe (OR 1.17, 95%CI 1.10-1.25, P < 0.000), but not in Japanese or Chinese subjects (OR 1.01, 95%CI 0.92-1.10, P = 0.85). The available data demonstrated that the CC genotype decreased the survival time of patients with ALS (OR 1.33, 95%CI 1.19-1.49, P < 0.001). CONCLUSION: The present meta-analysis suggests that rs12608932(C) is associated with increased ALS susceptibility, especially in Caucasian and European subjects, and that the CC genotype of rs12608932 is associated with reduced ALS patient survival.

Decreased serum ferritin may be associated with increased restless legs syndrome in Parkinson's disease (PD): a meta-analysis for the diagnosis of RLS in PD patients.

Objective: Restless legs syndrome (RLS) is one of the most common non-motor symptoms of Parkinson's disease (PD), but its pathogenesis in a PD background is unclear. Abnormal iron metabolism may be involved, in which case it may be a marker of RLS risk. Here, the literature was systematically searched and meta-analyzed to compare iron metabolism markers between PD patients with or without RLS. Method: The databases PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang, Web of Science, and SinoMed were searched for case-control and observational studies examining RLS-related changes in iron metabolism in PD, in terms of serum iron, serum ferritin and hemoglobin. Eligible studies were meta-analyzed using Stata 12.0. Results: Meta-analysis of 11 case-control studies showed that serum ferritin concentration was lower in PD patients with RLS than in those without RLS. (95%CI -0.32 to -0.03, p = 0.018). In contrast, levels of serum iron or hemoglobin did not differ significantly between PD patients with or without RLS. Conclusion: This meta-analysis may provide the first reliable pooled estimate of the correlation between abnormal iron metabolism and RLS in PD. The available evidence indicates that levels of ferritin, but not of serum iron or hemoglobin, correlate significantly with RLS in PD, with lower ferritin levels correlating to greater prevalence of RLS.