Kynurenine pathway in post-mortem prefrontal cortex and cerebellum in schizophrenia : relationship with monoamines and symptomatology

The cortico-cerebellar-thalamic-cortical circuit has been implicated in the emergence of psychotic symptoms in schizophrenia (SZ). The kynurenine pathway (KP) has been linked to alterations in glutamatergic and monoaminergic neurotransmission and to SZ symptomatology through the production of the metabolites quinolinic acid (QA) and kynurenic acid (KYNA). This work describes alterations in KP in the post-mortem prefrontal cortex (PFC) and cerebellum (CB) of 15 chronic SZ patients and 14 control subjects in PFC and 13 control subjects in CB using immunoblot for protein levels and ELISA for interleukins and QA and KYNA determinations. Monoamine metabolites were analysed by high-performance liquid chromatography and SZ symptomatology was assessed by Positive and Negative Syndrome Scale (PANSS). The association of KP with inflammatory mediators, monoamine metabolism and SZ symptomatology was explored. In the PFC, the presence of the anti-inflammatory cytokine IL-10 together with IDO2 and KATII enzymes decreased in SZ, while TDO and KMO enzyme expression increased. A network interaction analysis showed that in the PFC IL-10 was coupled to the QA branch of the kynurenine pathway (TDO-KMO-QA), whereas IL-10 associated with KMO in CB. KYNA in the CB inversely correlated with negative and general PANSS psychopathology. Although there were no changes in monoamine metabolite content in the PFC in SZ, a network interaction analysis showed associations between dopamine and methoxyhydroxyphenylglycol degradation metabolite. Direct correlations were found between general PANSS psychopathology and the serotonin degradation metabolite, 5-hydroxyindoleacetic acid. Interestingly, KYNA in the CB inversely correlated with 5-hydroxyindoleacetic acid in the PFC. Thus, this work found alterations in KP in two brain areas belonging to the cortico-cerebellar-thalamic-cortical circuit associated with SZ symptomatology, with a possible impact across areas in 5-HT degradation. The online version contains supplementary material available at 10.1186/s12974-021-02260-6

Influence of Surface Mechanical Attrition Treatment on the oxidation behaviour of 316L stainless steel

International audienceThe present article investigates the effect of Surface Mechanical Attrition Treatment (SMAT) on the high temperature oxidation of AISI 316L, during isothermal oxidation between 650 and 750 °C in air. The observations show a beneficial effect of the SMAT process on the oxidation resistance of 316L steel, for high temperatures. Indeed, the oxidation kinetics of the treated samples is shown to be related to a preferential growth of chromia starting at 700 °C up to 750 °C. This leads us to conclude that the SMAT used on the 316L reverses the main oxide phase, inhibiting the growth of the hematite and promoting the chromia. © 2018 Elsevier Lt

Kynurenine pathway in post-mortem prefrontal cortex and cerebellum in schizophrenia: relationship with monoamines and symptomatology

Background: The cortico-cerebellar-thalamic-cortical circuit has been implicated in the emergence of psychotic symptoms in schizophrenia (SZ). The kynurenine pathway (KP) has been linked to alterations in glutamatergic and monoaminergic neurotransmission and to SZ symptomatology through the production of the metabolites quinolinic acid (QA) and kynurenic acid (KYNA). Methods: This work describes alterations in KP in the post-mortem prefrontal cortex (PFC) and cerebellum (CB) of 15 chronic SZ patients and 14 control subjects in PFC and 13 control subjects in CB using immunoblot for protein levels and ELISA for interleukins and QA and KYNA determinations. Monoamine metabolites were analysed by high-performance liquid chromatography and SZ symptomatology was assessed by Positive and Negative Syndrome Scale (PANSS). The association of KP with inflammatory mediators, monoamine metabolism and SZ symptomatology was explored. Results: In the PFC, the presence of the anti-inflammatory cytokine IL-10 together with IDO2 and KATII enzymes decreased in SZ, while TDO and KMO enzyme expression increased. A network interaction analysis showed that in the PFC IL-10 was coupled to the QA branch of the kynurenine pathway (TDO-KMO-QA), whereas IL-10 associated with KMO in CB. KYNA in the CB inversely correlated with negative and general PANSS psychopathology. Although there were no changes in monoamine metabolite content in the PFC in SZ, a network interaction analysis showed associations between dopamine and methoxyhydroxyphenylglycol degradation metabolite. Direct correlations were found between general PANSS psychopathology and the serotonin degradation metabolite, 5-hydroxyindoleacetic acid. Interestingly, KYNA in the CB inversely correlated with 5-hydroxyindoleacetic acid in the PFC. Conclusions: Thus, this work found alterations in KP in two brain areas belonging to the cortico-cerebellar-thalamic-cortical circuit associated with SZ symptomatology, with a possible impact across areas in 5-HT degradation

Optoelectronic properties of zinc blende ZnSSe and ZnBeTe alloys

The compositional dependence of the electronic band structure has been computed for zinc blende ZnSxSe1-x and Zn1-xBexTe alloys with composition x ranging from 0 to 1. The empirical pseudo potential method with the virtual crystal approximation have been used. A particlar attention has been paid to the effect of alloy disorder on the electronic properties of the II-VI studied compounds. For this purpose, the compositional disorder is added to the virtual crystal approximation as an effective potential. Such correction approximates significantly our calculated values of the band gap bowing parameters to experimental ones. The ZnSxSe1-x gap energy shows a nonlinear behavior with strong bowing for low compositions of sulfur. The Zn1-xBexTe compound, as it is known, can be direct or indirect semiconductor depending on its beryllium composition x. The electron effective mass and the refractive index have been investigated as well. Polynomial approximations are obtained for both the energy gap and the effective mass as functions of alloy composition at Γ and X valleys. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005

First record of Wolbachia in South American terrestrial isopods: prevalence and diversity in two species of Balloniscus (Crustacea, Oniscidea)

Wolbachia are endosymbiotic bacteria that commonly infect arthropods, inducing certain phenotypes in their hosts. So far, no endemic South American species of terrestrial isopods have been investigated for Wolbachia infection. In this work, populations from two species of Balloniscus (B. sellowii and B. glaber) were studied through a diagnostic PCR assay. Fifteen new Wolbachia 16S rDNA sequences were detected. Wolbachia found in both species were generally specific to one population, and five populations hosted two different Wolbachia 16S rDNA sequences. Prevalence was higher in B. glaber than in B. sellowii, but uninfected populations could be found in both species. Wolbachia strains from B. sellowii had a higher genetic variation than those isolated from B. glaber. AMOVA analyses showed that most of the genetic variance was distributed among populations of each species rather than between species, and the phylogenetic analysis suggested that Wolbachia strains from Balloniscus cluster within Supergroup B, but do not form a single monophyletic clade, suggesting multiple infections for this group. Our results highlight the importance of studying Wolbachia prevalence and genetic diversity in Neotropical species and suggest that South American arthropods may harbor a great number of diverse strains, providing an interesting model to investigate the evolution of Wolbachia and its hosts