Arterial dP/dtmax accurately reflects left ventricular contractility during shock when adequate vascular filling is achieved

Background: Peak first derivative of femoral artery pressure (arterial dP/dt max) derived from fluid-filled catheter remains questionable to assess left ventricular (LV) contractility during shock. The aim of this study was to test if arterial dP/dt maxis reliable for assessing LV contractility during various hemodynamic conditions such as endotoxin-induced shock and catecholamine infusion.Methods: Ventricular pressure-volume data obtained with a conductance catheter and invasive arterial pressure obtained with a fluid-filled catheter were continuously recorded in 6 anaesthetized and mechanically ventilated pigs. After a stabilization period, endotoxin was infused to induce shock. Catecholamines were transiently administrated during shock. Arterial dP/dt maxwas compared to end-systolic elastance (Ees), the gold standard method for assessing LV contractility.Results: Endotoxin-induced shock and catecholamine infusion lead to significant variations in LV contractility. Overall, significant correlation (r = 0.51; p < 0.001) but low agreement between the two methods were observed. However, a far better correlation with a good agreement were observed when positive-pressure ventilation induced an arterial pulse pressure variation (PPV) ≤ 11% (r = 0.77; p < 0.001).Conclusion: While arterial dP/dt maxand Ees were significantly correlated during various hemodynamic conditions, arterial dP/dt maxwas more accurate for assessing LV contractility when adequate vascular filling, defined as PPV ≤ 11%, was achieved. © 2012 Morimont et al; licensee BioMed Central Ltd

Improving physical health and reducing substance use in psychosis - randomised control trial (IMPACT RCT): study protocol for a cluster randomised controlled trial

The National Institute for Health Research funds the IMPACT programme at King’s College London and South London and Maudsley NHS Foundation Trust (ref: RP-PG-0606-1049)

SLO-2 Is Cytoprotective and Contributes to Mitochondrial Potassium Transport

Mitochondrial potassium channels are important mediators of cell protection against stress. The mitochondrial large-conductance “big” K+ channel (mBK) mediates the evolutionarily-conserved process of anesthetic preconditioning (APC), wherein exposure to volatile anesthetics initiates protection against ischemic injury. Despite the role of the mBK in cardioprotection, the molecular identity of the channel remains unknown. We investigated the attributes of the mBK using C. elegans and mouse genetic models coupled with measurements of mitochondrial K+ transport and APC. The canonical Ca2+-activated BK (or “maxi-K”) channel SLO1 was dispensable for both mitochondrial K+ transport and APC in both organisms. Instead, we found that the related but physiologically-distinct K+ channel SLO2 was required, and that SLO2-dependent mitochondrial K+ transport was triggered directly by volatile anesthetics. In addition, a SLO2 channel activator mimicked the protective effects of volatile anesthetics. These findings suggest that SLO2 contributes to protection from hypoxic injury by increasing the permeability of the mitochondrial inner membrane to K+

Change in level of productivity in the treatment of schizophrenia with olanzapine or other antipsychotics

<p>Abstract</p> <p>Background</p> <p>When treating schizophrenia, improving patients' productivity level is a major goal considering schizophrenia is a leading cause of functional disability. Productivity level has been identified as the most preferred treatment outcome by patients with schizophrenia. However, little has been done to systematically investigate productivity levels in schizophrenia. We set out to better understand the change in productivity level among chronically ill patients with schizophrenia treated with olanzapine compared with other antipsychotic medications. We also assessed the links between productivity level and other clinical outcomes.</p> <p>Methods</p> <p>This post hoc analysis used data from 6 randomized, double-blind clinical trials of patients with schizophrenia or schizoaffective disorder, with each trial being of approximately 6 months duration. Change in productivity level was compared between olanzapine-treated patients (HGBG, n = 172; HGHJ, n = 277; HGJB, n = 171; HGLB, n = 281; HGGN, n = 159; HGDH, n = 131) and patients treated with other antipsychotic medications (separately vs. haloperidol [HGGN, n = 97; HGDH, n = 132], risperidone [HGBG, n = 167; HGGN, n = 158], quetiapine [HGJB, n = 175], ziprasidone [HGHJ, n = 271] and aripiprazole [HGLB, n = 285]). Productivity was defined as functional activities/work including working for pay, studying, housekeeping and volunteer work. Productivity level in the prior 3 months was assessed on a 5-point scale ranging from no useful functioning to functional activity/work 75% to 100% of the time.</p> <p>Results</p> <p>Chronically ill patients treated with olanzapine (OLZ) experienced significantly greater improvement in productivity when compared to patients treated with risperidone (RISP) (OLZ = 0.22 ± 1.19, RISP = -0.03 ± 1.17, p = 0.033) or ziprasidone (ZIP) (OLZ = 0.50 ± 1.38, ZIP = 0.25 ± 1.27, p = 0.026), but did not significantly differ from the quetiapine, aripiprazole or haloperidol treatment groups. Among first episode patients, OLZ therapy was associated with greater improvements in productivity levels compared to haloperidol (HAL), during the acute phase (OLZ = -0.31 ± 1.59, HAL = -0.69 ± 1.56, p = 0.011) and over the long-term (OLZ = 0.10 ± 1.50, HAL = -0.32 ± 1.91, p = 0.008). Significantly more chronically ill and first episode patients treated with olanzapine showed moderately high (>50%-75% of the time) and high levels of productivity (>75%-100% of the time) at endpoint, when compared to risperidone or haloperidol-treated patients (p < .05), respectively. Higher productivity level was associated with significantly higher study completion rates and better scores on the positive, negative, disorganized thoughts, hostility and depression subscales of the Positive and Negative Symptom Scale (PANSS).</p> <p>Conclusions</p> <p>Some antipsychotic medications significantly differed in beneficial impact on productivity level in the long-term treatment of patients with schizophrenia. Findings further highlight the link between clinical and functional outcomes, showing significant associations between higher productivity, lower symptom severity and better persistence on therapy.</p> <p>Trial Registration</p> <p>clinicaltrials.gov identifier <a href="http://www.clinicaltrials.gov/ct2/show/NCT00088049">NCT00088049</a>; <a href="http://www.clinicaltrials.gov/ct2/show/NCT00036088">NCT00036088</a></p

Variability in Working Memory Performance Explained by Epistasis vs Polygenic Scores in the ZNF804A Pathway

Importance: We investigated the variation in neuropsychological function explained by risk alleles at the psychosis susceptibility gene ZNF804A and its interacting partners using single nucleotide polymorphisms (SNPs), polygenic scores, and epistatic analyses. Of particular importance was the relative contribution of the polygenic score vs epistasis in variation explained. Objectives To (1) assess the association between SNPs in ZNF804A and the ZNF804A polygenic score with measures of cognition in cases with psychosis and (2) assess whether epistasis within the ZNF804A pathway could explain additional variation above and beyond that explained by the polygenic score. Design, Setting, and Participants: Patients with psychosis (n = 424) were assessed in areas of cognitive ability impaired in schizophrenia including IQ, memory, attention, and social cognition. We used the Psychiatric GWAS Consortium 1 schizophrenia genome-wide association study to calculate a polygenic score based on identified risk variants within this genetic pathway. Cognitive measures significantly associated with the polygenic score were tested for an epistatic component using a training set (n = 170), which was used to develop linear regression models containing the polygenic score and 2-SNP interactions. The best-fitting models were tested for replication in 2 independent test sets of cases: (1) 170 individuals with schizophrenia or schizoaffective disorder and (2) 84 patients with broad psychosis (including bipolar disorder, major depressive disorder, and other psychosis). Main Outcomes and Measures: Participants completed a neuropsychological assessment battery designed to target the cognitive deficits of schizophrenia including general cognitive function, episodic memory, working memory, attentional control, and social cognition. Results: Higher polygenic scores were associated with poorer performance among patients on IQ, memory, and social cognition, explaining 1% to 3% of variation on these scores (range, P = .01 to .03). Using a narrow psychosis training set and independent test sets of narrow phenotype psychosis (schizophrenia and schizoaffective disorder), broad psychosis, and control participants (n = 89), the addition of 2 interaction terms containing 2 SNPs each increased the R2 for spatial working memory strategy in the independent psychosis test sets from 1.2% using the polygenic score only to 4.8% (P = .11 and .001, respectively) but did not explain additional variation in control participants. Conclusions and Relevance: These data support a role for the ZNF804A pathway in IQ, memory, and social cognition in cases. Furthermore, we showed that epistasis increases the variation explained above the contribution of the polygenic score

Suicide risk in schizophrenia: learning from the past to change the future

Suicide is a major cause of death among patients with schizophrenia. Research indicates that at least 5–13% of schizophrenic patients die by suicide, and it is likely that the higher end of range is the most accurate estimate. There is almost total agreement that the schizophrenic patient who is more likely to commit suicide is young, male, white and never married, with good premorbid function, post-psychotic depression and a history of substance abuse and suicide attempts. Hopelessness, social isolation, hospitalization, deteriorating health after a high level of premorbid functioning, recent loss or rejection, limited external support, and family stress or instability are risk factors for suicide in patients with schizophrenia. Suicidal schizophrenics usually fear further mental deterioration, and they experience either excessive treatment dependence or loss of faith in treatment. Awareness of illness has been reported as a major issue among suicidal schizophrenic patients, yet some researchers argue that insight into the illness does not increase suicide risk. Protective factors play also an important role in assessing suicide risk and should also be carefully evaluated. The neurobiological perspective offers a new approach for understanding self-destructive behavior among patients with schizophrenia and may improve the accuracy of screening schizophrenics for suicide. Although, there is general consensus on the risk factors, accurate knowledge as well as early recognition of patients at risk is still lacking in everyday clinical practice. Better knowledge may help clinicians and caretakers to implement preventive measures. This review paper is the results of a joint effort between researchers in the field of suicide in schizophrenia. Each expert provided a brief essay on one specific aspect of the problem. This is the first attempt to present a consensus report as well as the development of a set of guidelines for reducing suicide risk among schizophenia patients