Evaluation of the impact of pre- and post-harvest maize handling practices on mycotoxin contamination on smallholder farms in Guatemala

Mycotoxins are secondary metabolites produced by fungi including Aspergillus and Fusarium that commonly contaminate crops, such as maize, resulting in economic losses and food insecurity. Mycotoxins can contaminate crops during pre- and post-harvest stages. Consumption of mycotoxin-contaminated foods has been linked to a variety of negative health outcomes including liver cancer, stunting, and neural tube defects. In countries such as Guatemala where maize constitutes a major portion of the diet, mycotoxins can be a significant contributor to disease burden. This review describes maize pre- and post-harvest practices in Guatemala that can lead to the development of mycotoxins and subsequent exposure to humans and animals, current information gaps, and opportunities for future research. There are specific challenges to minimising fungal growth and subsequent mycotoxin production during storage of maize in Guatemala, including reducing moisture content, minimising pest damage, and controlling temperature. Research on maize-handling practices that are associated with the greatest mycotoxin exposure in Guatemala is needed to prioritise allocation of resources and reduce exposure.

A framework for One Health research

The need for multidisciplinary research to address today's complex health and environmental challenges has never been greater. The One Health (OH) approach to research ensures that human, animal, and environmental health questions are evaluated in an integrated and holistic manner to provide a more comprehensive understanding of the problem and potential solutions than would be possible with siloed approaches. However, the OH approach is complex, and there is limited guidance available for investigators regarding the practical design and implementation of OH research. In this paper we provide a framework to guide researchers through conceptualizing and planning an OH study. We discuss key steps in designing an OH study, including conceptualization of hypotheses and study aims, identification of collaborators for a multi-disciplinary research team, study design options, data sources and collection methods, and analytical methods. We illustrate these concepts through the presentation of a case study of health impacts associated with land application of biosolids. Finally, we discuss opportunities for applying an OH approach to identify solutions to current global health issues, and the need for cross-disciplinary funding sources to foster an OH approach to research.

A multicentre, double-blind, randomized comparison of quetiapine (ICI 204,636, 'Seroquel') and haloperidol in schizophrenia

BACKGROUND

Quetiapine (ICI 204,636, 'Seroquel') is a new atypical antipsychotic agent with a similar binding profile to the original atypical antipsychotic, clozapine. Its clinical efficacy has already been demonstrated at multiple fixed doses (150-750 mg/day) and has been suggested to be comparable with haloperidol (12 mg/day).

METHODS

This international, 6-week, multicentre, double-blind, randomized, parallel-group trial compared quetiapine with haloperidol (455 mg and 8 mg mean total daily doses, respectively) in 448 hospitalized patients with acute exacerbation of chronic or subchronic schizophrenia (DSM-III-R), in order to establish their equivalence in terms of efficacy, and the nature of their tolerability profiles, especially in terms of extrapyramidal symptoms (EPS) and serum prolactin levels.

RESULTS

Both quetiapine and haloperidol produced a clear reduction in the Positive and Negative Syndrome Scale (PANSS) scores and Clinical Global Impression (CGI) Severity of Illness and Global Improvement scores. At day 42, the PANSS total score was reduced by -18.7+/-1.63 in the quetiapine group, and -22.1+/-1.63 in the haloperidol group (P = 0.13, between-treatment). Quetiapine was better tolerated than haloperidol in terms of EPS as demonstrated by the significant differences in the Simpson Scale and Abnormal Involuntary Movement Scale scores (P < 0.05). Although patients in both groups had elevated serum prolactin concentrations at baseline, mean serum prolactin concentration decreased (by 16.5 microg/l) in quetiapine-treated patients, yet increased (by 5.9 microg/l) in patients treated with haloperidol.

CONCLUSION

Quetiapine is an effective and well tolerated antipsychotic of comparable efficacy to haloperidol and lacks the latter compound's effect on prolactin and EPS.

A comparison of bd and tid dose regimens of quetiapine (Seroquel) in the treatment of schizophrenia

Quetiapine (Seroquel, ICI 204,636) is an atypical antipsychotic that is effective in the treatment of both positive and negative symptoms of schizophrenia, and has a low propensity to cause extrapyramidal symptoms. The compound has a relatively short plasma elimination half-life (approximately 7 h). However, since dopamine D2 receptor occupancies correlate poorly with plasma concentrations of antipsychotics, plasma elimination half-life may not predict either duration of clinical effect or dosing frequency. Accordingly, the efficacy and tolerability of three dosing regimens (450 mg/day given in two or three divided doses daily, and 50 mg/day given twice daily) were compared in a 6-week, double-blind, randomized, multicentre, parallel-group study. The study recruited hospitalized men and women aged 18-65 years meeting DSM-IIIR criteria for acute exacerbation of chronic or subchronic schizophrenia. Six hundred and eighteen patients were randomly assigned to treatment with quetiapine 150 mg tid (n = 209), 225 mg bd (n = 200), or a comparator dose of 25 mg bd (n = 209). At day 42, the last day of randomized treatment and the primary timepoint for efficacy, quetiapine 450 mg/day was more effective than 50 mg/day: 225 mg bd was consistently superior to 25 mg bd in all measures of efficacy (total BPRS, P = 0.006; CGI severity, CGI improvement and SANS, P < 0.03), and 150 mg tid was statistically significantly superior to 25 mg bd with respect to BPRS total score (P = 0.05). The 225 mg bd and 150 mg tid groups were not significantly different from each other with respect to any efficacy measure. Quetiapine was generally well tolerated. Extrapyramidal symptom (EPS) adverse events were generally rare, and occurred with similar frequencies in the two 450 mg/day groups. Quetiapine was not associated with sustained increases in plasma prolactin at any dose. These data support the atypical profile developed from preclinical studies and show that quetiapine is an effective, well tolerated antipsychotic that can be given twice daily.