NRN1 Gene as a Potential Marker of Early-Onset Schizophrenia: Evidence from Genetic and Neuroimaging Approaches

Included in the neurotrophins family, the Neuritin 1 gene (NRN1) has emerged as an attractive candidate gene for schizophrenia (SZ) since it has been associated with the risk for the disorder and general cognitive performance. In this work, we aimed to further investigate the association of NRN1 with SZ by exploring its role on age at onset and its brain activity correlates. First, we developed two genetic association analyses using a family-based sample (80 early-onset (EO) trios (offspring onset ≤ 18 years) and 71 adult-onset (AO) trios) and an independent case–control sample (120 healthy subjects (HS), 87 EO and 138 AO patients). Second, we explored the effect of NRN1 on brain activity during a working memory task (N-back task; 39 HS, 39 EO and 39 AO; matched by age, sex and estimated IQ). Different haplotypes encompassing the same three Single Nucleotide Polymorphisms(SNPs, rs3763180–rs10484320–rs4960155) were associated with EO in the two samples (GCT, TCC and GTT). Besides, the GTT haplotype was associated with worse N-back task performance in EO and was linked to an inefficient dorsolateral prefrontal cortex activity in subjects with EO compared to HS. Our results show convergent evidence on the NRN1 association with EO both from genetic and neuroimaging approaches, highlighting the role of neurotrophins in the pathophysiology of SZ.

First-episode psychosis is characterized by failure of deactivation but not by hypo- or hyperfrontality

BACKGROUND

It is not known whether first-episode psychosis is characterized by the same prefrontal cortex functional imaging abnormalities as chronic schizophrenia.

METHOD

Thirty patients with a first episode of non-affective functional psychosis and 28 healthy controls underwent functional magnetic resonance imaging (fMRI) during performance of the n-back working memory task. Voxel-based analyses of brain activations and deactivations were carried out and compared between groups. The connectivity of regions of significant difference between the patients and controls was also examined.

RESULTS

The first-episode patients did not show significant prefrontal hypo- or hyperactivation compared to controls. However, they showed failure of deactivation in the medial frontal cortex. This area showed high levels of connectivity with the posterior cingulate gyrus/precuneus and parts of the parietal cortex bilaterally. Failure of deactivation was significantly greater in first-episode patients who had or went on to acquire a DSM-IV diagnosis of schizophrenia than in those who did not, and in those who met RDC criteria for schizophrenia compared to those who did not.

CONCLUSIONS

First-episode psychosis is not characterized by hypo- or hyperfrontality but instead by a failure of deactivation in the medial frontal cortex. The location and connectivity of this area suggest that it is part of the default mode network. The failure of deactivation seems to be particularly marked in first-episode patients who have, or progress to, schizophrenia.

Clinical characteristics and legal consequences of violent behavior: a case of bipolar disorder

The main subject of criminal proceedings is that of criminal responsibility, from this point of view bipolar disorders sometimes seem to be a neglected subject in legal scholarship. Yet they may affect decision-making across the spectrum of the law, especially when manic and psychotic symptoms are implicated. This case studies a 37-year-old woman, diagnosed with bipolar affective in disorder, who attacked the neighbour of her ex-husband during a manic episode with psychotic symptoms. Two groups of those psychotic symptoms are especially remarkable: delusions and experiences of influences playing on her body and thought insertion (threat/control–override symptoms). Hostility against her ex-husband was also implicated in the attack. Researchers have pointed all those symptoms as important predictors of violence, and they have determinant legal correlates.

Accidental removal of endotracheal and nasogastric tubes and intravascular catheters

OBJECTIVES

To characterize the rates of accidental removal of endotracheal tubes, nasogastric tubes, central venous catheters, and arterial catheters. To assess the efficacy of corrective measures aimed at reducing the accidental removal of these devices.

DESIGN

Prospective, observational, and interventional study.

SETTING

Eighteen-bed medical-surgical intensive care unit of a 650-bed tertiary care hospital.

PATIENTS

Patients admitted to the intensive care unit who had any of the following devices in place for more than 24 hrs: endotracheal tube, nasogastric tube, central venous catheter, arterial catheter.

MEASUREMENTS AND INTERVENTIONS

Data were collected on the date of placement of tubes and catheters, position of vascular catheters, date of removal, and reason for removal. The study involved three consecutive 6-month periods. At the end of the first and the second periods, information about rates of accidental removal was provided to the physicians and nurses. In addition, the personnel were instructed to be more vigilant and specific measures aimed at reducing the accidental removal were introduced.

MAIN RESULTS

In the first period, 289 endotracheal tubes were placed and 13.1% (24.7 per 1000 days) were removed accidentally. In the second and third periods, 17.1% (25.5 per 1000 days) and 11.4% (15.1 per 1000 days) were removed accidentally, respectively. In the first period, 368 nasogastric tubes were placed and 41% (73.9 per 1000 days) were removed accidentally. In both the second and the third period, a significant reduction in the rate of accidental removal was observed (32.4% or 41.2 per 1000 days and 25.8% or 29.8 per 1000 days, respectively). A significant decrease was observed in the rates of accidental removal of central venous catheters from 7.5% (12.4 per 1000 days) in the first period to 3.6% (5.4 per 1000 days) in the second period. The rate of arterial catheters accidentally removed expressed according to the time at risk significantly decreased from 46.5 per 1000 days in the first period to 19.1 per 1000 days in the second period and 25.3 per 1000 days in the third period.

CONCLUSIONS

The information provided by the rates of accidental removal expressed by patient-days is helpful to compare results obtained in populations with different times of follow-up. Education of medical personnel and limiting upper-extremity access to within 20 cm from any catheter or tube resulted in a significant reduction of patient-related removal of tubes and catheters.

[Design of a program of quality control of nursing in an intensive care unit]

Although in the last few years care quality programs have started to be used in services, these are still few in nursing equipment. Our aim is to show the process we have followed to design a nursing care quality program in ICU. We developed the stages of process, where a list of general activities performed in the service was created to establish a priority later, as it was necessary, due to the high number of aspects or activities to monitor, to choose those we would use to start the quality control program. The ultimate order was settled with the following activities: 1. Surveillance of the infection. 2. Accidental withdrawal of tubes and catheters. 3. Pressure ulcers.