Relationships between early age at onset of psychotic symptoms and treatment resistant schizophrenia

Aim: Early age at schizophrenia onset (EOS) has been associated with a worse clinical course, although previous studies reported substantial heterogeneity. Despite the relevance of the subject, the relationship between the age of onset and treatment resistant schizophrenia (TRS) is less clear. Methods: We screened 197 non-affective psychotic patients. Of these, 99 suffered from schizophrenia and were putative TRS and were included in a prospective 4-to-8-week trial to assess their response to antipsychotics. According to status (TRS/nonTRS) and age-at-onset (early: ≤18 years, EOS; adult: >18 years, adult onset schizophrenia [AOS]) patients were subdivided in EOS-TRS, EOS-nonTRS, AOS-TRS, AOS-nonTRS. Multiple clinical variables were measured and compared by analysis of covariance (ANCOVA), using age as a covariate. Two-way analysis of variance (ANOVA) was used to assess whether significant differences were attributable to TRS status or age-at-onset. Results: The rate of TRS patients was significantly higher in EOS compared to AOS. At the ANCOVA, EOS-TRS had significantly worse clinical, cognitive, and psychosocial outcomes compared to the other groups. Overall, EOS-TRS were more impaired than EOS-nonTRS, while significant differences with AOS-TRS were less consistent, albeit appreciable. Two-way ANOVA demonstrated that, in the majority of the investigated variables, the significant differences among groups were attributable to the TRS status effect rather than to age-at-onset or combined effects. Conclusions: These results suggest that refractoriness to antipsychotics may be strongly linked to the early onset of psychotic symptoms, possibly as a result of common neurobiology

Complex Formation via Hydrogen bonding between Rhodamine B and Montmorillonite in Aqueous Solution

Abstract This study investigates the adsorption mechanism differences among four nitrogenous dyes, sulforhodamine G (SRG), uncharged/deprotonated rhodamine B (RhB), orange II (Or II) and methyl blue (MB) by montmorillonite (MMT). MMT adsorption capacity for cationic MB was three times that of uncharged RhB and anionic SRG, while anionic Or II was not absorbed. Colloidal MMT particles have two types of surfaces, basal and edge, that interact with nitrogenous dyes very differently. The surface acidity of MMT was characterized with the pyridine adsorption method using in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS). Adsorption of cationic MB was compared with the adsorption of RhB. In-situ attenuated total reflectance Fourier transform infrared (in-situ ATR-FTIR) spectroscopy indicated that a nitrogen atom on RhB complexes with a metal hydroxyl on an MMT edge through a water bridge. The highly polar edge hydroxyl is important to hydrogen bond formation. Cation ion exchange and washing experiments, as well as studies on the effect of temperature, pH and ionic strength on adsorption further clarified the adsorption mechanism. Our results provide insights into the effects of molecular structure on the adsorption of nitrogenous dyes by clay and the role of edge surfaces in the adsorption process

Synthesis of heterocyclic compounds via gold-catalysed enyne rearrangements

Syntheses of heterocycles using different gold-catalysed rearrangements of enynes are discussed in this chapter. The term skeletal rearrangement has been used in a broad sense to include reactions involving cyclopropyl gold carbene intermediates formed by initial enyne cyclisation, which can undergo many different transformations to give a wide range of heterocyclic structures. Other transformations involving rearrangement of propargylic esters and [3,3]-rearrangement (concerted or stepwise comprising metallic intermediates), as well as special cases, have also been covered. References to earlier work in this area and to recent reviews have been included, but the focus of the chapter is to present recent developments, interesting cases and an overview on how subtle differences in the enyne starting materials, the catalyst used or the reaction conditions can alter the reaction pathway increasing the structural diversity towards complex heterocyclic structures of high value