Establishment of Repeated In Vitro Exposure System for Evaluating Pulmonary Toxicity of Representative Criteria Air Pollutants Using Advanced Bronchial Mucosa Models.

There is mounting evidence that shows the association between chronic exposure to air pollutants (particulate matter and gaseous) and onset of various respiratory impairments. However, the corresponding toxicological mechanisms of mixed exposure are poorly understood. Therefore, in this study, we aimed to establish a repeated exposure setting for evaluating the pulmonary toxicological effects of diesel exhaust particles (DEP), nitrogen dioxide (NO2), and sulfur dioxide (SO2) as representative criterial air pollutants. Single, combined (DEP with NO2 and SO2), and repeated exposures were performed using physiologically relevant human bronchial mucosa models developed at the air−liquid interface (bro-ALI). The bro-ALI models were generated using human primary bronchial epithelial cells (3−4 donors; 2 replicates per donor). The exposure regime included the following: 1. DEP (12.5 µg/cm2; 3 min/day, 3 days); 2. low gaseous (NO2: 0.1 ppm + SO2: 0.2 ppm); (30 min/day, 3 days); 3. high gaseous (NO2: 0.2 ppm + SO2: 0.4 ppm) (30 min/day, 3 days); and 4. single combined (DEP + low gaseous for 1 day). The markers for pro-inflammatory (IL8, IL6, NFKB, TNF), oxidative stress (HMOX1, GSTA1, SOD3,) and tissue injury/repair (MMP9, TIMP1) responses were assessed at transcriptional and/ or secreted protein levels following exposure. The corresponding sham-exposed samples under identical conditions served as the control. A non-parametric statistical analysis was performed and p < 0.05 was considered as significant. Repeated exposure to DEP and single combined (DEP + low gaseous) exposure showed significant alteration in the pro-inflammatory, oxidative stress and tissue injury responses compared to repeated exposures to gaseous air pollutants. The study demonstrates that it is feasible to predict the long-term effects of air pollutants using the above explained exposure system.

A single-blind, randomized comparison of olanzapine at a starting dose of 5 mg versus 20 mg in acute schizophrenia.

Acute psychotic episodes represent critical situations during the course of schizophrenia. Olanzapine (OLZ), a second-generation antipsychotic, is efficacious in acute settings at dosages of 5 to 20 mg/d, and it can be considered a first-line treatment for patients with an acute episode of schizophrenia. The aim of this study was to evaluate the efficacy and tolerability of OLZ at a starting dose of 5 mg versus 20 mg in acute schizophrenic patients and to compare titration versus nontitration.Fifty-one schizophrenic inpatients were randomly assigned to receive OLZ at 5 mg/d (26 patients, group 1) or 20 mg/d (25 patients, group 2) as a starting dosage during an exacerbation phase. In group 1, the OLZ dosage was increased to a mean dosage of 10.55 (+/- 4.00) mg/d. Group 2 received OLZ at a fixed dose of 20 mg throughout the hospitalization period. Olanzapine was significantly and clinically effective on Brief Psychiatric Rating Scale (BPRS), Positive and Negative Syndrome Scale, PANSS positive symptoms, and Hamilton Rating Scale for Depression in both groups. There were no significant differences between groups 1 and 2 in the percent improvement in BPRS, Positive and Negative Syndrome Scale, PANSS positive symptoms, PANSS negative symptoms, or Hamilton Rating Scale for Depression; but group 2 was significantly superior in the mean percent improvement in the BPRS items of anxiety (P < 0.001) and suspiciousness (P < 0.05). In conclusion, the higher doses evidence more efficacy on anxiety and suspiciousness, so it seems to be useful to begin therapy with a full dose of the drug to obtain the maximum effect without any significant side effects.

Predictors of clinical outcome in schizophrenic patients responding to clozapine.

Many of the patients who respond better to clozapine (CLZ) than to typical antipsychotics still have residual psychopathology, but CLZ drug resistance data are lacking. The aim of this study was to evaluate the possible predictive factors of a clinical response to CLZ in a group of 20 schizophrenic patients (DSM-IV: 13 males and 7 females with a mean age of 35.5 years +/- 7.1 SD) resistant to typical antipsychotics but CLZ responders as assessed by the Brief Psychiatric Rating Scale (BPRS) (>20% improvement). After a 1-week washout period, CLZ was started at a dose of 25 mg/d, which was increased by the third week up to a maximum of 600 mg/d (mean 365.00 +/- 129.88 mg/d SD) and remained unchanged until the end of the study (week 8). The patients showed a significant improvement in the mean scores of the rating scales for positive (SAPS) and negative symptoms of schizophrenia (Scale for the Assessment of Negative Symptoms, SANS) (P < 0.003, P < 0.02). All of the patients included in the study were BPRS responders; 65% were also SAPS and 75% SANS responders (>20% improvement). The improvement in the SANS score was significantly greater among the female patients (P < 0.05). The SAPS and SANS responders had a significantly higher mean metabolic ratio [MR = (NCLZ/CLZ)] than the nonresponders (P < 0.01), and the percentage of improvement significantly correlated with the increase in MR. This finding suggests that the individual pharmacogenetics indicated by metabolic capacity may be related to clinical response. All of the patients showed a reduction in white blood cell counts, but this was significantly less in the SANS responders than the SANS nonresponders (P = 0.047). The SAPS responders had significantly lower neutrophil counts than the nonresponders (P = 0.03). Our results seem to suggest the importance of pharmacodynamic, constitutional, and genetic data over strict pharmacokinetics in determining the clinical response to CLZ.