Magnetic Bimerons in Cylindrical Nanotubes.

This work presents the analysis of the stability of magnetic bimerons in a cylindrical nanotube. Through micromagnetic simulations, we study the influence of magnetic and geometrical parameters on the bimeron existence and size. The obtained results allow us to present diagram states showing the stability region of a bimeron as a function of the nanotube's height and radius for different anisotropy and Dzyaloshinskii-Moriya interaction strengths. We also obtain two other magnetic states in the range of parameters where the bimeron is not stable: helicoidal and saturated states.

Neuron-specific enolase levels in drug-naïve young adults with major depressive disorder.

The aim of this study is to assess neuron-specific enolase (NSE) levels and clinical features in subjects with major depressive disorder (MDD). This is a cross-sectional study with drug-naïve young adults with MDD (aged 18-29 years). Serum levels of NSE were assessed using the electrochemiluminescence method. MDD diagnosis, suicidal ideation, and time of disease were assessed using the Structured Clinical Interview for DSM-IV (SCID). The Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Rating Scale (HARS) were used to assess depressive and anxiety symptoms. No relationship was observed between NSE levels and severity of depressive and anxiety symptoms, time of disease, and suicidal ideation. These results suggest that NSE serum levels were not associated with clinical features of MDD among drug-naïve young adults.

Serum levels of nerve growth factor (NGF) in patients with major depression disorder and suicide risk.

Nerve growth factor (NGF) is an important member of the neurotrophins group and their involvement in the pathophysiology of major depression disorder (MDD) and suicide risk (SR) has been recently suggested. The aim of this study is to evaluate the changes in NGF serum levels in individuals with MDD and with or without risk of suicide, in subjects from a young population-based sample. This is a paired cross-sectional study nested in a population-based study. Individuals were rated for MDD and SR by a diagnostic interview--Mini International Neuropsychiatric Interview (M.I.N.I). The total population of the sample was comprised of 141 subjects distributed in three groups: 47 healthy controls, 47 subjects with current depressive episode without SR (MDD) and 47 subjects with current depressive episode and with SR (MDD + SR). NGF serum levels were significantly reduced in the MDD and MDD + SR groups when compared with controls (p ≤ 0.001). However, there were no differences in NGF levels between the MDD and MDD + SR groups (p = 1.000). These results suggest that reduced NGF serum levels can be a possible biomarker of MDD.

The Met allele of BDNF Val66Met polymorphism is associated with increased BDNF levels in generalized anxiety disorder.

BACKGROUND: Generalized anxiety disorder (GAD) is a common psychiatric disorder characterized by long-term worry, tension, nervousness, fidgeting, and symptoms of autonomic system hyperactivity. The neurobiology of this disorder is still unclear, although it has been shown consistently that the environment and the genetic profile could increase its risk. We examined whether a polymorphism in the brain-derived neurotrophic factor (BDNF) gene, which plays a role in neuroplasticity and memory, could increase the vulnerability to this disorder. PARTICIPANTS AND METHODS: In our study, 816 participants from a population-based study were genotyped by qPCR for the BDNF functional variant rs6265 (Val66Met) and the BDNF serum levels were measured by ELISA. RESULTS: Our results showed a significant association between the Met allele and risk for GAD (P=0.014), but no differences were observed in the serum levels of BDNF according to diagnosis (P=0.531) or genotype distribution (P=0.197). However, after stratification according to the GAD diagnosis, the Met allele was associated significantly with an increase in serum BDNF levels compared with the Val/Val genotype in GAD participants (F=3.93; P=0.048). The logistic regression analysis confirmed the independent association of Met allele as a risk factor for development of GAD after adjusting for confounder variables (ß=0.528; 95% confidence interval: 0.320-0.871; P=0.012). CONCLUSION: These results suggest that BDNF could be involved in the neurobiology of GAD and might represent a useful marker associated with the disease.

Increased serum neurotrophin levels related to alcohol use disorder in a young population sample.

BACKGROUND: The diagnosis of alcohol use disorder is based on clinical signs and on the measurement of biological markers. However, these markers are neither sufficiently sensitive, nor specific enough, for determining the effects of alcohol abuse on the central nervous system. Serum neurotrophins are important regulators of neural survival, development, function, and plasticity and have been found to be reduced in alcohol use disorder. The aim of this study was to investigate the alterations in serum neurotrophin levels (brain-derived neurotrophic factor [BDNF], glial-derived neurotrophic factor [GDNF], and nerve growth factor [NGF]) in alcohol use disorder in a young population, and thus possibly representing the early stages of the illness. METHODS: This is a cross-sectional study, nested in a population-based study of people aged 18 to 35, involving 795 participants. The participants responded to the CAGE questionnaire, and a CAGE score of ≥2 was considered to be a positive screen for the abuse/dependence or moderate to severe alcohol use disorder. Serum BDNF, GDNF, and NGF levels were measured by ELISA. RESULTS: In the CAGE ≥ 2 group, GDNF (p ≤ 0.001) and NGF (p ≤ 0.001) serum levels were significantly increased, and the BDNF elevation was near a statistical significance (p = 0.068) when compared to the CAGE < 2 group. A significantly positive correlation was observed only in the CAGE ≥ 2 group for BDNF/GDNF (r = 0.37, p < 0.001) and GDNF/NGF (r = 0.84, p < 0.001) levels. The correlation between the NGF and BDNF levels was significantly positive in both groups (r = 0.28, p < 0.001 for the CAGE < 2 group, and r = 0.30, p = 0.008 for the CAGE ≥ 2 group). CONCLUSIONS: These results suggest that elevated neurotrophins are candidate markers for the early stages of alcohol misuse.