Tracking salience in young people: A psychometric field test of the Aberrant Salience Inventory (ASI).

AIM: To explore the prevalence of Aberrant Salience (AS, an alleged experiential feature of psychosis-proneness) in Italian young people and corroborate the transcultural validity of the Aberrant Salience Inventory (ASI). METHODS: Young adults attending an Italian university (n = 649) underwent serial evaluations with the ASI together with psychometric proxies for help seeking General Health Questionnaire and attenuated positive and negative symptoms Schizotypal Personality Questionnaire (SPQ). The distribution of ASI scores was explored with latent class analysis (LCA). RESULTS: Reliability of the Italian version of the ASI (I-ASI) was acceptable for all subscales (ordinal alpha >.70). Concurrent validity was in the expected direction, with higher correlations with measures of attenuated positive symptoms vs negative symptoms of psychosis (Steigers' z test, P < .005 in all comparisons). LCA identified three classes, with 217 (33.4%) participants in the "high aberrant salience" class. Gender and age were not related to class membership. Compared to the baseline class, SPQ scores in the schizotypy range were more likely in the "high aberrant salience" class (OR = 39.1; 95%confidence interval: 5.30-288.1). CONCLUSION: AS is a relatively common experience among Italian young people. The study also confirmed the validity of field-testing ASI as a tool for the real-world characterization of people with vulnerability to psychosis, such as symptomatic help seekers with clinical high-risk states.

The independence of schizotypy from affective temperaments--a combined confirmatory factor analysis of SPQ and the short TEMPS-A.

Sparse evidence of a co-aggregation of the risk of schizophrenia and bipolar disorder provides support for a shared but nonspecific genetic etiology of bipolar disorder and schizophrenia. Temperaments are conceptualized as trait sub-syndromic conditions of major pathologies. This study set out to test the hypothesis of a continuum between schizotypy and affective temperaments versus the alternative hypothesis of their independence based on a cross-sectional, survey design involving 649 (males: 47%) college students. The short 39-item TEMPS-A and the SPQ were used as measures of the affective temperaments and of schizotypy, respectively. Confirmatory factor analyses were applied to a unidimensional model, to a standard correlate traits model, to second-order representations of a common latent structure, and to a bifactor model. Confirmatory bifactor modeling provided evidence against a complete independence of the dimensions subsumed by the affective and the schizotypal traits. The best solution distinguished between two sub-domains grouping positive symptoms and negative symptoms as measured by the SPQ subscales, and a sub-domain related to the affective temperaments as measured by the TEMPS-A. Limitations due to the use of subscales from two different tools should be taken into account.

Confirmatory factor analysis and measurement invariance by gender, age and levels of psychological distress of the short TEMPS-A.

BACKGROUND: The Temperament Evaluation of Memphis, Pisa, Paris and San Diego - Autoquestionnaire (TEMPS-A) is a widely used self-reported tool aimed at measuring the affective temperaments that define the bipolar spectrum, with cyclothymic, depressive, irritable, hyperthymic, and anxious subscales. Confirmatory factor analysis (CFA) was rarely used to confirm the expected five-factor model. Measurement invariance was never tested. METHODS: Cross-sectional, survey design involving 649 Italian college students (males: 47%). The short 39-item TEMPS-A and the 12-item General Health Questionnaire (GHQ-12) were used as measures of the affective temperaments and of psychological distress, respectively. CFA was applied to the TEMPS-A. Measurement invariance by gender, age and levels of psychological distress on the GHQ-12 was calculated with the establishment of subsequent equivalence constraints in the model parameters across groups. RESULTS: The expected five-factor model had the best fit for all CFA indexes. Configural, metric and scalar invariance of the five-factor model of the TEMPS-A was proved across gender, age and levels of psychological distress of the participants. The hyperthymic temperament subscale has low or no links with the other affective temperament subscales, which were interrelated with medium to large effect sizes. LIMITATIONS: College students might be not representative of the general population. No information on the clinical status of the students was available beyond self-report data. CONCLUSION: The study proved the measurement invariance of the (short) TEMPS-A, which is a pre-requisite to compare groups or individuals in cross-sectional and longitudinal surveys. Generalizability cannot be assumed without replication of the findings in clinical samples.

Efficient biocatalyst for large-scale synthesis of cephalosporins, obtained by combining immobilization and site-directed mutagenesis of penicillin acylase.

We describe the rational design of a new efficient biocatalyst and the development of a sustainable green process for the synthesis of cephalosporins bearing a NH2 group on the acyl side chain. The new biocatalyst was developed starting from the WT penicillin acylase (PA) from Escherichia coli by combining enzyme mutagenesis, in position α146 and ß24 (ßF24A/αF146Y), and immobilization on an appropriate modified industrial support, glyoxyl Eupergit C250L. The obtained derivative was used in the kinetically controlled synthesis of cephalexin, cefprozil and cefaclor and compared to the WT-PA and an already described mutant, PA-ßF24A, with improved properties. The new biocatalyst posses a very high ratio between the rates of the synthesis and two undesired hydrolyses (acylating ester and the amidic product). In particular, a very low amidase activity was observed with PA-ßF24A/αF146Y and, consequently, the hydrolysis of the produced antibiotic was avoided during the process. Taking advantage of this property, higher conversions in the synthesis of cephalexin (99% versus 76%), cefaclor (99% versus 65%) and cefprozil (99% versus 60%) were obtained compared to the WT enzyme. Furthermore, the new mutant also show a higher synthetic activity compared to PA-ßF24A immobilized on the same support, allowing the maximum yields to be achieved in very short reaction times. The production of cephalexin with the immobilized ßF24A/αF146Y acylase has been developed on a pre-industrial scale (30 l). After 20 cycles, the average yield was 93%. The biocatalyst showed good stability properties and no significant decrease in performance.