Lesion mimic mutants (LMMs) are a class of mutants in which hypersensitive cell death and defence responses are constitutively activated in the absence of pathogen attack. Various signalling molecules, such as salicylic acid (SA), reactive oxygen species (ROS), nitric oxide (NO), Ca2+, ethylene, and jasmonate, are involved in the regulation of multiple pathways controlling hypersensitive response (HR) activation, and LMMs are considered useful tools to understand the role played by the key elements of the HR cell death signalling cascade. Here the characterization of an Arabidopsis LMM lacking the function of the FZL gene is reported. This gene encodes a membrane-remodelling GTPase playing an essential role in the determination of thylakoid and chloroplast morphology. The mutant displayed alteration in chloroplast number, size, and shape, and the typical characteristics of an LMM, namely development of chlorotic lesions on rosette leaves and constitutive expression of genetic and biochemical markers associated with defence responses. The chloroplasts are a major source of ROS, and the characterization of this mutant suggests that their accumulation, triggered by damage to the chloroplast membranes, is a signal sufficient to start the HR signalling cascade, thus confirming the central role of the chloroplast in HR activation.

Calmodulin (CAM) is an ubiquitous calcium binding protein whose function is to translate the signals, perceived as calcium concentration variations, into the appropriate cellular responses. In Arabidopsis thaliana there are 4 CAM isoforms which are highly similar, encoded by 7 genes, and one possible explanation proposed for the evolutionary conservation of the CAM gene family is that the different genes have acquired different functions so that they play possibly overlapping but non-identical roles. Here we report the characterization of the Arabidopsis mutant cam2-2, identified among the lines of the gene-trapping collection EXOTIC because of a distorted segregation of kanamycin resistance. Phenotypic analysis showed that in normal growth conditions cam2-2 plants were indistinguishable from the wild type while genetic analysis showed a reduced transmission of the cam2-2 allele through the male gametophyte and in vitro pollen germination revealed a reduced level of germination in comparison with the wild type. These results provide genetic evidence of the involvement of a CAM gene in pollen germination and support the theory of functional diversification of the CAM gene family.

The increased risk of violence in schizophrenia has been linked to several environmental, clinical and neuropsychological factors, including executive dysfunction.However, data about the nature of these effects are mixed and controversial. The main aim of this study was to investigate the relationship between clinical and neuropsychological factors with violence risk in patients with schizophrenia, taking into account current psychopathology and lifetime alcohol use. We compared a sample of patients living inResidential Facilities (RFs) with schizophrenia and a past history of interpersonal violence (vSZ, N=50) to patients with schizophrenia matched on age, gender and alcohol abuse/dependence but with no violence history (nvSZ, N=37). We then established the association between the clinical and neuropsychological factors that predicted violence over a 1 year follow-up period. The results revealed that vSZ patients living in RFs were characterized by greater compulsory hospital admissions, higher anger and less negative symptoms as compared to nvSZ patients. vSZ patients performed better on executive and motor tasks than nvSZ; however, these differences appeared to be explained by the lower negative psychotic symptom in the vSZ group. Both groups were involved in episodes of violence during the follow-up period; among the two, the vSZ patients were more likely to be violent. Negative symptoms predicted less verbal aggression at 1 year follow-up.Overall, these findings support a key role of negative rather than positive symptoms in driving violence risk among SZ patients living in RFs, in a manner that negative symptoms are linked to a lower risk of violence.

a b s t r a c tBackground: Most people with mental disorders are not violent. However, the lack of specific studies in this area and recent radical changes in Italy, including the closure of six Forensic Mental Hospitals, has prompted a more detailed investigation of patients with aggressive behaviour. Aims: To compare socio-demographic, clinical and treatment-related characteristics of long-term inpatients with a lifetime history of serious violence with controls; to identify predictors of verbal and physical aggressive behaviour during 1-year follow-up. Methods: In a prospective cohort study, patients living in Residential Facilities (RFs) with a lifetime history of serious violence were assessed with a large set of standardized instruments and compared to patients with no violent history. Patients were evaluated bi-monthly with MOAS in order to monitor any aggressive behaviour. Results: The sample included 139 inpatients, 82 violent and 57 control subjects; most patients were male. The bi-monthly monitoring during the 1-year follow-up did not show any statistically significant differences in aggressive behaviour rates between the two groups. The subscale explaining most of the MOAS total score was aggression against objects, although verbal aggression was the most common pattern. Furthermore, verbal aggression was significantly associated with aggression against objects and physical aggression. Conclusions: Patients with a history of violence in RFs, where treatment and clinical supervision are available, do not show higher rates of aggressiveness compared to patients with no lifetime history of violence. Since verbal aggression is associated with more severe forms of aggression, prompt intervention is warranted to reduce the risk of escalation.

The aims of this study were (a) to investigate the presence of clinically significant personality traits and personality disorders (PD) in patients living in residential facilities, with or without a history of violence (69 and 46, respectively); and (b) to investigate any associations between clinically significant personality traits and PDs, aggression, impulsivity, hostility, and violent behavior during a 1-year follow-up. The most frequent primary diagnoses were schizophrenia (58.3%) and PD (20.9%). Those with a history of violence demonstrated more antisocial and alcohol dependence features and lower depressive PD symptoms than the control group. Hostility levels, antisocial symptoms, and drug dependence, as well as a Structured Clinical Interview for DSM-IV Axis II diagnosis of PD, predicted aggressive and violent behavior during follow-up. The study confirms the relevance of assessing PDs both to evaluate the risk of violent behavior and to plan appropriate preventive and treatment intervention.