Inter-rater reliability of the Greek version of CAARMS among two groups of mental health professionals.

There is increasing interest within the Greek psychiatric community in the early detection and prevention of psychotic disorders. To support this, there is a need for a valid and reliable tool to identify young people that may be at risk of developing a psychotic disorder. Our team has previously translated the Comprehensive Assessment of At-Risk Mental States (CAARMS). The validity of the CAARMS was ensured by the procedure of translation and the aim of the current study was to estimate the interrater reliability of the CAARMS Greek translation among residents in psychiatry and specialized mental health professionals. 43 mental health workers (27 residents in psychiatry and 16 specialized mental health professionals (i.e. 11 psychiatrists and 5 psychologist) participated in two seminars that covered theoretical information about the ultra high risk concept and training in the CAARMS. During the seminars, 10 vignettes with psychiatric history cases were presented, including healthy, ultra high risk and first episode psychosis. The mean correlated percentage of agreement with the correct answers regarding diagnosis of the presented history cases among all our subjects was 81.42, among specialized mental health professionals 77.88, and among residents 84.46. Intraclass correlation co-efficients were 0.994 for specialized mental health professionals and 0.997 for residents. The translated Greek version of CAARMS presents a satisfying interrater reliability when used by both residents and specialized mental health professionals. Residents declare even higher intraclass correlation co-efficients and mean correlated percentage of agreement than specialized mental health professionals, which indicate that residents are capable of using the CAARMS in early intervention units.

Experience of trauma and conversion to psychosis in an ultra-high-risk (prodromal) group.

OBJECTIVE: We aimed to replicate a recent finding of high prevalence of trauma history in patients at 'ultra-high risk' (UHR) of psychotic disorder and to investigate whether trauma predicts conversion to psychosis in this population. METHOD: A consecutive sample of UHR patients was assessed. History of trauma was accessed with the General Trauma Questionnaire. Cox regression models were used to explore relationship between conversion to psychosis and trauma. RESULTS: Of 92 UHR patients nearly 70% had experienced a traumatic event and 21.7% developed psychosis during follow-up (mean 615 days). Patients who had experienced a sexual trauma (36%) were significantly more likely to convert to first-episode psychosis (OR 2.96) after controlling for meeting multiple UHR intake groups. CONCLUSION: UHR patients have a high prevalence of history of trauma. Previous sexual trauma may be a predictor of onset of psychotic disorder in this population.

Characterization of an on-line commercial fluorescence probe: modeling of the probe signal.

A biosensor model was developed for a commercial NADH fluorescence probe to describe the single-frequency excitation and emission fluorescence behavior of an aqueous mixture of fluorophores. This model is essential in correlating the measured signals to the concentrations of fluorescent compounds in a bioreactor. In addition to the concentrations of fluorescent components, the relevant parameters of the model are the absorbance at both the excitation and the emission frequencies by the solvent and other absorbing species, the background signals, the light path length of the bioreactor vessel, the fluorescence yield, and the lampdetector configuration. Due to inner-filter effects and other interferences, the probe signal is intrinsically nonlinear in both the fluorophore concentration and the path length. An important parameter in the model is the geometric constant, S, which accounts for variations in the monitoring efficiency throughout the sample because fluorescent light is emitted in all directions. Previous models, derived from an unrealistic assumption that fluorescent light is emitted only in one direction parallel to the probe axis, are shown to be seriously deficient. The validity of the model was verified experimentally for a single-component solution in which both the fluorophore concentration and path length were varied.

Fluorescence modeling in a multicomponent system.

An extensive fluorescence database for binary tyrosinetryptophan mixtures utilizing 280 nm excitation was collected. The database spanned three orders of magnitude (10(-6)M-10(-3)M) and covered all compositions within this range. A generalized model for describing the multicomponent fluorescence signals as a function of emission wavelength, excitation wavelength, and sample composition was derived. A geometric integral that contained all the geometric factors affecting fluorescence was introduced; thus the model was applicable to various configurations, including the three used in this study: an NADH probe, a backscatter laser-induced fluorescence setup, and a commercial spectroflurometer. A correction factor was proposed that allowed linearization of the fluorescence signals with respect to fluorophore concentrations. The effect of the water Raman on fluorescence spectra was also modeled. The model contains only two wavelength-dependent parameters for each of the components present in a sample, one specifying absorption of the excitation energy and the other specifying the species' fluorescence tendency. These wavelength-dependent parameters were correlated with polynomials. The average prediction error at each wavelength was 10-20%, a major portion of which was attributed to experimental uncertainties.