Admission patterns in a psychiatric intensive care unit in Ireland: a longitudinal follow-up

OBJECTIVE

This study aims to describe the course of admission and clinical characteristics of admissions to a psychiatric intensive care unit (PICU) in the Phoenix Care Centre (PCC), Dublin, Ireland.

METHODS

This retrospective chart study was conducted at the PCC, Dublin, Ireland. The cohort included all admission episodes (n = 91 complete data) over a three-year study period between January 2014 and January 2017.

RESULTS

The mean age of admitted cases was 37.1 (s.d. = 11.3; range 18-63). The mean length of stay (LOS) was 59.3 days (s.d. = 61.0; median 39.5 days). All patients were admitted under Mental Health Act legislation. Antipsychotic polypharmacy was used in 61% (n = 55) of the admissions. A diagnosis of acute psychotic disorder (B = -1.027, p = 0.003, 95% CI: -1.691, -0.363) was associated with reduced LOS in PICU.

CONCLUSION

Our study describes the cohort of patients admitted as being predominantly male, younger-aged, single, having a diagnosis of schizophrenia and being legally detained. The primary indication for referral is risk of assault, which highlights the need for the intensive and secure treatment model that a PICU can provide.

Adaptations in Visual Search Behaviour as a Function of Expertise in Rugby Union Players Completing Attacking Scenarios

The current study investigated the adaptations which occur in visual search behaviour as a function of expertise in rugby union players when completing attacking scenarios. Ten experienced players (EP) and ten novice players (NP) completed 2 vs. 1 attacking game scenarios. Starting with the ball in hand and wearing a mobile eye tracker throughout, participants were required to score a try against a defender. The scenarios allowed for a pass to their supporting player (Spin Pass or Switch) or trying to run past the defender (Take-Player-On or Dummy Switch). No between group differences were found in fixating on the supporting attacking player (p > 0.05). However, EP increased the length (p = 0.008) and frequency (p = 0.004) looking at the area immediately ahead of the supporting player, particularly when executing a spin pass. NP fixated longer (p = 0.005) and more frequently (p = 0.032) at the defender, whilst EP fixated more frequently in the space the supporting player would run into in Switch and Dummy Switch scenarios (p = 0.025). More successful passes were completed and tries scored by EP compared to NP (p = 0.001). Differences in visual search behaviour between experienced and NP suggest that the experts extract information from areas directly related to guiding the motor action; the space immediately ahead of the support player to pass the ball in. Contrastingly, novices use a more allocentric perspective where the actions from the defender are used to guide their motor actions.

Temporal changes in anticoagulant prescribing and atrial fibrillation: results of interrupted time-series analysis of openly available routine data in England

Introduction

The use of anticoagulants for stroke prevention in patients with atrial fibrillation (AF) has been increasing in England in the recent years (1, 2). The changes in practice coincided with several developments in the area of anticoagulants and AF, including: the emergence of evidence supporting anticoagulant use for stroke prevention in AF, changes in guideline recommendations, and the licensing of direct oral anticoagulants (DOACs) as an alternative to warfarin, which was the mainstay of stroke prevention in AF. Currently, there are four DOACs available for use: dabigatran, rivaroxaban, apixaban, and edoxaban. Recent analyses of time trends of anticoagulant prescribing in England showed an increase in DOACs prescribing and a decrease in warfarin prescribing (1, 2). However, more recent exploration of recent anticoagulant prescribing trends is needed.

Aim

To explore the changes in anticoagulant prescribing for AF in England.

Methods

Interrupted time-series analysis (ITSA) of openly available data on anticoagulant prescribing and AF. Separate analyses were conducted for data from Sentinel Stroke National Audit Programme (SSNAP) and Quality and Outcomes Framework (QOF). The timeframe of the analysis and the length of time intervals depended on the characteristics of each dataset.

Results

Analysis of data from SSNAP showed that the proportion of stroke patients who have a diagnosis of AF who were taking an anticoagulant alone prior to admission increased from 32.51% in the third quarter of 2013 to 62.63% in the third quarter of 2020; this coincided with a decreased proportion of stroke patients who have a diagnosis of AF taking antiplatelets alone from 37.10% to 8.31% during the same period. Analysed QOF data on anticoagulants and AF included information about AF prevalence in QOF datasets, the eligibility of patients with AF for anticoagulant based on stroke risk assessment, and the use of anticoagulants among eligible patients. Prevalence of AF in England in QOF datasets increased from 1.52% in 2012/2013 to 2.05% in 2019/2020 (ITSA gradient=0.08, p-value<.001, 95% confidence interval: 0.07- 0.09). The proportion of patients with AF who are considered eligible for anticoagulation per all patients with AF in QOF datasets increased from 44.95% in 2012/2013 to 80.87% in 2019/2020; there was an increase by 25.24% between 2014/2015 and 2015/2016 which corresponds to modifying risk assessment scores to include additional criteria. The proportion of eligible patients with AF being prescribed anticoagulants also increased in the period between 2012/2013 and 2019/2020 (ITSA gradient = 1.98, p-value<.001, 95% confidence interval: 1.52- 2.44).

Conclusion

The analysis of data from different sources identified an increase in anticoagulant prescribing for patients with AF in England, which is likely to translate into health gains. However, the use of aggregate data in the analysis did not allow for detailed inspection of patient characteristics, and individual anticoagulants were not specified in the datasets. Therefore, quantitative analyses of primary care data of individual anticoagulant prescribing for different patient groups with AF are needed to further understand whether additional improvements are possible in the prevention of complications from atrial fibrillation.

References

(1) Adderley NJ, Ryan R, Nirantharakumar K, Marshall T. Prevalence and treatment of atrial fibrillation in UK general practice from 2000 to 2016. Heart. 2019;105(1):27-33.

(2) Loo SY, Dell’Aniello S, Huiart L, Renoux C. Trends in the prescription of novel oral anticoagulants in UK primary care. British Journal of Clinical Pharmacology. 2017;83(9):2096-106.

Factors influencing oral anticoagulant prescribing decisions for patients with atrial fibrillation: a systematic review of qualitative and quantitative evidence

Introduction

Despite their efficacy in reducing stroke risk in patients with atrial fibrillation (AF), oral anticoagulants (OACs) remain under-prescribed [1]. Until recently, warfarin has been the dominant OAC. The introduction of direct oral anticoagulants (DOACs) led to changes in anticoagulant prescribing patterns, with an increase in OAC prescribing and a shift towards DOACs [2]. Treatment decisions for OACs are complicated, and require a discussion between clinicians and patients when deciding on a treatment [1].

Aim

To investigate the main factors that influence initial and ongoing OAC prescribing decisions for patients with AF according to patient and health professional views.

Methods

A systematic review was conducted according to the Toolkit for Mixed-Methods Reviews, and was registered on PROSPERO: CRD42019145406. Medline, CINAHL, Scopus, EMBASE, Web of Knowledge and PsychInfo were searched in August, 2019. Primary qualitative and quantitative studies, published between 2009 and 2019, exploring patient and health professional perceptions, views and experiences of OACs in AF were included. McMaster critical appraisal tool for quantitative studies and Critical Appraisal Skills Programme (CASP) checklist for qualitative studies were used for quality assessment. The review followed a convergent integrated approach to data extraction and analysis, which involves extracting and analysing results of quantitative and qualitative studies at the same time using the same method. A data extraction form was adapted from Joanna-Briggs Institute (JBI) mixed-methods extraction form. Study author interpretation of quantitative data was summarised as qualitative statements which were coded together with primary qualitative data using NVIVO 12 software; codes were applied to each sentence in the findings, and were grouped into a hierarchical tree structure

Results

The systematic review included 62 papers (58 studies) discussing clinical and non-clinical factors influencing decisions to initiate OACs, the choice between warfarin and DOACs, and the choice between individual OACs. The balance of stroke and bleeding risks was the most influential when making the decision to initiate anticoagulation according to both patients and health professionals. Convenience-related factors, such as monitoring requirements, dosing regimens, and interactions impacted the choice between warfarin and DOACs, whereas, reversibility and dosing regimen influenced the choice between individual medications according to the views of both groups. Health professional specialty and years of experience affected all aspects of treatments, with specialists and senior clinicians more willing to initiate anticoagulation and choose DOACs. Even though health professionals often expressed that patient views were considered when deciding on a treatment, patients generally said that they followed their physician’s recommendations without questioning.

Conclusion

The review revealed similarities and differences across patient and professional views, experiences, and preferences of anticoagulation. The main discrepancies were related to the decision-making process, and whether patient views are being considered when prescribing. Combining quantitative and qualitative evidence helped explore a wide range of views of OAC and AF, however the review only included published research papers in English, which might have led to exclusion of valuable evidence. More research is needed to explore the factors driving the choice between OACs, especially the choice between individual DOACs.

References

1. Noseworthy PA, Brito JP, Kunneman M, Hargraves IG, Zeballos-Palacios C, Montori VM, Ting HH. Shared decision-making in atrial fibrillation: navigating complex issues in partnership with the patient. Journal of Interventional Cardiac Electrophysiology. 2019;56(2):159–163.

2. Loo, S.Y., Dell'Aniello, S., Huiart, L. and Renoux, C. Trends in the prescription of novel oral anticoagulants in UK primary care. British Journal of Clinical Pharmacology. 2017; 83(9): 2096–2106.

Clozapine in the treatment of refractory schizophrenia: a practical guide for healthcare professionals

BACKGROUND

Clozapine remains the only medication licensed for treating refractory schizophrenia. However, it remains underutilized in part due to concerns regarding adverse events.

SOURCES OF DATA

Published literature.

AREAS OF AGREEMENT

Common adverse events during clozapine treatment include sedation, hypersalivation, postural hypotension, dysphagia, gastrointestinal hypomotility, weight gain, diabetes mellitus and dyslipidaemia. Rare but serious events include agranulocytosis, cardiomyopathy, myocarditis, pneumonia, paralytic ileus and seizure.

AREAS OF CONTROVERSY

It remains unclear how best to minimize clozapine-induced morbidity/mortality (i) during dose titration, (ii) from hypersalivation and (iii) from gastrointestinal hypomotility. It is also unclear how clozapine pharmacokinetics are affected by (i) gastrointestinal hypomotility, (ii) systemic infection and (iii) passive exposure to cigarette smoke. Whether monthly haematological monitoring needs to continue after 12 months of uninterrupted therapy is also a subject of debate.

GROWING POINTS

There is a need for better management of serious clozapine-related adverse events in addition to agranulocytosis. There is also a need for better education of patients and carers, general practitioners, A&E and ITU staff and others of the problems posed in using clozapine safely.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is a need for more research on assessing clozapine dosage (i) as patients get older, (ii) with respect to exposure to cigarette smoke and (iii) optimizing response if adverse events or other factors limit dosage.

Remission and recovery from first-episode psychosis in adults: A systematic review and meta-analysis of long-term outcome studies

Introduction

Remission and recovery rates for people who have had a first episode psychosis (FEP) remain uncertain.

Objectives

We conducted a systematic review and meta-analysis to assess pooled prevalence rates of remission and recovery in FEP in longitudinal studies and conducted meta regression analyses to investigate potential moderators.

Methods

A systematic literature search of major electronic databases without language restrictions was conducted from database inception until July 1, 2016. Longitudinal studies with follow up greater than 1 year reporting data on remission or recovery rates in FEP were included.

Results

Seventy-nine studies were included representing 19,072 FEP patients (mean age = 26.9 years, male = 59.5%). The pooled rate of remission among 12,301 individuals with FEP was 57.9% (95%CI: 52.7–62.9, Q = 1536.3, P< 0.001, n = 60 studies, mean follow up = 5.5 years). Restricting the analysis to studies, which used the remission in schizophrenia working group (RSWG) criteria (n = 25 studies, n = 6909 patients), the pooled remission rate was 56.9% (95%CI: 48.9–64.5, Q = 656.9). Higher remission rates were moderated by studies from more recent years. The pooled prevalence of recovery among 9642 individuals with FEP was 37.9% (95%CI: 30.0–46.5, Q = 1450.8, studies = 35, P = 0.006, average follow up = 7.2 years). Recovery rates were higher (P< 0.05) in North America compared to other regions.

Conclusions

Our data suggest that remission and recovery rates in FEP may be more favorable than previously thought. We observed stability of recovery rates after the first two years, suggesting that a progressive deteriorating course of illness is not typical. While remission rates have improved over time, recovery rates have not, raising questions about the effectiveness of specialist early intervention services in achieving improved recovery.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Systemic Review: High Dose Olanzapine Treatment for Treatment Resistant Schizophrenia

Objectives

Schizophrenia is a major mental illness with a progressive course. Thirty percent of cases of patients with schizophrenia do not respond to adequate trials of at least 2 different groups of antipsychotics are currently classified as having treatment resistant schizophrenia (TRS). Clozapine remains the gold standard, treatment of choice for TRS. However, clozapine does not come without its own challenges. Its risk profile, particularly agranulocytosis, reported in 1% of cases, has led to the necessity of weekly blood counts within the first 18 weeks of treatment and subsequently every month with slow dose titration. Clinically, sedation, weight gain and hypersalivation may further hamper the compliance of patients. Non-compliance has been reported to cause rebound psychosis. Recent studies have raised questions as to which antipsychotic is most efficacious for TRS. Thus, we conducted a systematic review of high dose olanzapine treatment for people with TRS.

Method

A systematic review of prospective studies found through search of PubMed, Scopus and hand-searched key papers which included randomized controlled trials and open-label studies which looked at high dose of olanzapine treatment response for TRS.

Results

The study is currently ongoing and preliminary results will be presented at the conference in April 2017.

Conclusions

The gravity of burden TRS brings to patients extends itself to their families, carers and clinicians. Further evidence on which antipsychotic is more efficacious for patients with TRS would have huge implications in terms of health benefits for the patients, better informed clinical decisions and also health economics in general.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Systemic Review: High Dose Olanzapine Treatment for Treatment Resistant Schizophrenia

Objectives

Schizophrenia is a major mental illness with a progressive course. Thirty percent of cases of patients with schizophrenia do not respond to adequate trials of at least 2 different groups of antipsychotics,are currently classified as having treatment resistant schizophrenia (TRS). Clozapine remains the gold standard, treatment of choice for TRS. However, clozapine does not come without its own challenges. Its risk profile, particularly agranulocytosis, reported in 1% of cases, has led to the necessity of weekly blood counts within the first 18 weeks of treatment and subsequently every month with slow dose titration. Clinically, sedation, weight gain and hypersalivation may further hamper the compliance of patients. Non-compliance has been reported to cause rebound psychosis. Recent studies have raised questions as to which antipsychotic is most efficacious for TRS. Thus, we conducted a systematic review of high dose olanzapine treatment for people with TRS.

Method

A systematic review of prospective studies found through search of PubMed, Scopus and hand-searched key papers which included randomized controlled trials and open-label studies which looked at high dose of olanzapine treatment response for TRS.

Results

The study is currently ongoing and preliminary results will be presented at the conference in April 2017.

Conclusions

The gravity of burden TRS brings to patients extends itself to their families, carers and clinicians. Further evidence on which antipsychotic is more efficacious for patients with TRS would have huge implications in terms of health benefits for the patients, better informed clinical decisions and also health economics in general.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Two distinct patterns of treatment resistance: clinical predictors of treatment resistance in first-episode schizophrenia spectrum psychoses

BACKGROUND

Clozapine remains the only evidence-based antipsychotic for treatment-resistant schizophrenia (TRS). The ability to predict which patients with their first onset of schizophrenia would subsequently meet criteria for treatment resistance (TR) could help to diminish the severe functional disability which may ensue if TR is not recognized and correctly treated.

METHOD

This is a 5-year longitudinal assessment of clinical outcomes in a cohort of 246 first-episode schizophrenia spectrum patients recruited as part of the NIHR Genetics and Psychosis (GAP) study conducted in South London from 2005 to 2010. We examined the relationship between baseline demographic and clinical measures and the emergence of TR. TR status was determined from a review of electronic case records. We assessed for associations with early-, and late-onset TR, and non-TR, and differences between those TR patients treated with clozapine and those who were not.

RESULTS

Seventy per cent (n = 56) of TR patients, and 23% of the total study population (n = 246) were treatment resistant from illness onset. Those who met criteria for TR during the first 5 years of illness were more likely to have an early age of first contact for psychosis (<20 years) [odds ratio (OR) 2.49, 95% confidence interval (CI) 1.25-4.94] compared to those with non-TR. The relationship between an early age of first contact (<20 years) and TR was significant in patients of Black ethnicity (OR 3.71, 95% CI 1.44-9.56); and patients of male gender (OR 3.13 95% CI 1.35-7.23).

CONCLUSIONS

For the majority of the TR group, antipsychotic TR is present from illness onset, necessitating increased consideration for the earlier use of clozapine.

Clinical correlates of vitamin D deficiency in established psychosis

BACKGROUND

Suboptimal vitamin D levels have been identified in populations with psychotic disorders. We sought to explore the relationship between vitamin D deficiency, clinical characteristics and cardiovascular disease risk factors among people with established psychosis.

METHODS

Vitamin D levels were measured in 324 community dwelling individuals in England with established psychotic disorders, along with measures of mental health, cardiovascular risk and lifestyle choices. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D (25-OHD) levels below 10 ng/ml (equivalent to <25 nmol/L) and "sufficient" Vitamin D as above 30 ng/ml (>50 nmol/L).

RESULTS

The mean 25-OHD serum level was 12.4 (SD 7.3) ng/ml, (range 4.0-51.7 ng/ml). Forty nine percent (n = 158) were vitamin D deficient, with only 14 % (n = 45) meeting criteria for sufficiency. Accounting for age, gender, ethnicity and season of sampling, serum 25-OHD levels were negatively correlated with waist circumference (r = -0.220, p < 0.002), triglycerides (r = -0.160, p = 0.024), total cholesterol (r = -0.144, p = 0.043), fasting glucose (r = -0.191, p = 0.007), HbA1c (r = -0.183, p = 0.01), and serum CRP levels (r = -0.211, p = 0.003) and were linked to the presence of metabolic syndrome.

CONCLUSIONS

This is the largest cross sectional study of serum 25-OHD levels in community dwelling individuals with established psychosis, indicating a high level of vitamin D deficiency. Lower vitamin D levels are associated with increased cardiovascular disease risk factors and in particular metabolic syndrome. Further research is needed to define appropriate protocols for vitamin D testing and supplementation in practice to see if this can improve cardiovascular disease risk.

TRIAL REGISTRATION

ISRCTN number is ISRCTN58667926 Date of registration: 23/04/2010.

Patient-reported factors influencing return to work after joint replacement

BACKGROUND

An increasing number of patients in the working population are undergoing total hip and knee replacement for osteoarthritis and the timing and success of return to work (RTW) is becoming increasingly important as a measure of success for these patients. There is limited understanding of the patient variables that determine the ability to RTW.

AIMS

To explore the factors influencing RTW following hip and knee replacement from the patient's perspective.

METHODS

A cross-sectional population-based postal survey carried out with patients of working age after hip and knee replacement surgery in a UK teaching hospital. Free text comments were collected regarding the experiences of patients returning to work following hip and knee replacement. Qualitative thematic analysis was undertaken to identify the factors influencing RTW from the patient's perspective.

RESULTS

From the patients' perspective three key factors were identified that influenced RTW. Patients reported an improved physical and psychological performance at work after surgery in comparison to pre-operative functioning, although there was a lack of informed advice regarding RTW after surgery. Workplace support and adaptation of the job role enhanced the experience of RTW.

CONCLUSIONS

Return to work is influenced by a combination of patient, clinician and occupational factors. The relationship between each of these needs to be explored in greater depth through further qualitative work to gain a wider understanding of the variables influencing patients' RTW following hip and knee replacement.

Cardiovascular risk factors and metabolic syndrome in people with established psychotic illnesses: baseline data from the IMPaCT RCT study--Corrigendum

The author regrets to announce that affiliation 8, in the above article (Gardner-Sood et al. 2015), contained an error in the author affiliation address and author surname, which were published in the approved article. The correct surname and affiliation address are given below. J. Eberhard, Clinical Psychiatric Research Center, Lund University, Skåne, Sweden

Cardiovascular risk factors and metabolic syndrome in people with established psychotic illnesses: baseline data from the IMPaCT randomized controlled trial

BACKGROUND

The aims of the study were to determine the prevalence of cardiometabolic risk factors and establish the proportion of people with psychosis meeting criteria for the metabolic syndrome (MetS). The study also aimed to identify the key lifestyle behaviours associated with increased risk of the MetS and to investigate whether the MetS is associated with illness severity and degree of functional impairment.

METHOD

Baseline data were collected as part of a large randomized controlled trial (IMPaCT RCT). The study took place within community mental health teams in five Mental Health NHS Trusts in urban and rural locations across England. A total of 450 randomly selected out-patients, aged 18-65 years, with an established psychotic illness were recruited. We ascertained the prevalence rates of cardiometabolic risk factors, illness severity and functional impairment and calculated rates of the MetS, using International Diabetes Federation (IDF) and National Cholesterol Education Program Third Adult Treatment Panel criteria.

RESULTS

High rates of cardiometabolic risk factors were found. Nearly all women and most men had waist circumference exceeding the IDF threshold for central obesity. Half the sample was obese (body mass index ≥ 30 kg/m2) and a fifth met the criteria for type 2 diabetes mellitus. Females were more likely to be obese than males (61% v. 42%, p < 0.001). Of the 308 patients with complete laboratory measures, 57% (n = 175) met the IDF criteria for the MetS.

CONCLUSIONS

In the UK, the prevalence of cardiometabolic risk factors in individuals with psychotic illnesses is much higher than that observed in national general population studies as well as in most international studies of patients with psychosis.

TBC1D1 reduces palmitate oxidation by inhibiting β-HAD activity in skeletal muscle

In skeletal muscle the Rab-GTPase-activating protein TBC1D1 has been implicated in the regulation of fatty acid oxidation by an unknown mechanism. We determined whether TBC1D1 altered fatty acid utilization via changes in protein-mediated fatty acid transport and/or selected enzymes regulating mitochondrial fatty acid oxidation. We also determined the effects of TBC1D1 on glucose transport and oxidation. Electrotransfection of mouse soleus muscles with TBC1D1 cDNA increased TBC1D1 protein after 2 wk (P<0.05), without altering its paralog AS160. TBC1D1 overexpression decreased basal palmitate oxidation (-22%) while blunting 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR)-stimulated palmitate oxidation (-18%). There was a tendency to increase fatty acid esterification (+10 nmol·g(-1)·60 min(-1), P=0.07), which reflected the reduction in fatty acid oxidation (-12 nmol·g(-1)·60 min(-1)). Concomitantly, basal (+21%) and AICAR-stimulated glucose oxidation (+8%) were increased in TBC1D1-transfected muscles relative to their respective controls (P<0.05), independent of changes in GLUT4 and glucose transport. The reductions in TBC1D1-mediated fatty acid oxidation could not be attributed to changes in the transporter FAT/CD36, muscle mitochondrial content, CPT1 expression or the expression and phosphorylation of AS160, acetyl-CoA carboxylase, or AMPK. However, TBC1D1 overexpression reduced β-HAD enzyme activity (-18%, P<0.05). In conclusion, TBC1D1-mediated reduction of muscle fatty acid oxidation appears to occur via inhibition of β-HAD activity.

Prevalence of hypercalcaemia in patients on maintenance lithium therapy monitored in primary care

The purpose of this study was to ascertain the prevalence of hypercalcaemia and hyperparathyroidism in individuals on long term lithium therapy who were monitored by their general practitioners and living within the West Galway mental health catchment area. We also wished to assess the extent of screening for calcium dysfunction in this patient cohort.Current guidelines do not specify the need for calcium monitoring in patients on lithium therapy. We conducted a retrospective analysis of clinical and laboratory data collected as part of regular monitoring for patients on long term lithium treatment. Three hundred and thirty three patients had serum lithium levels monitored over a 2 year period. Fifteen patients (5.3%) had lithium associated hypercalcaemia. The mean duration of lithium treatment for those with hypercalcaemia was 15 years and these patients had a mean serum calcium level of 2.7mmol/L. Eighty six (14%) patients did not have a calcium level monitored over the 2 year period. Three patients (1%) were found to have hyperparathyroidism. This survey supports the need for regular monitoring of serum calcium levels in patients on maintenance lithium treatment.

Increasing skeletal muscle fatty acid transport protein 1 (FATP1) targets fatty acids to oxidation and does not predispose mice to diet-induced insulin resistance

AIMS/HYPOTHESIS

We examined in skeletal muscle (1) whether fatty acid transport protein (FATP) 1 channels long-chain fatty acid (LCFA) to specific metabolic fates in rats; and (2) whether FATP1-mediated increases in LCFA uptake exacerbate the development of diet-induced insulin resistance in mice. We also examined whether FATP1 is altered in insulin-resistant obese Zucker rats.

METHODS

LCFA uptake, oxidation and triacylglycerol esterification rates were measured in control and Fatp1-transfected soleus muscles to determine FATP1-mediated lipid handling. The effects of FATP1 on insulin sensitivity and triacylglycerol accumulation were determined in high-fat diet-fed wild-type mice and in muscle-specific Fatp1 (also known as Slc27a1) overexpressing transgenic mice driven by the muscle creatine kinase (Mck [also known as Ckm]) promoter. We also examined the relationship between FATP1 and both fatty acid transport and metabolism in insulin-resistant obese Zucker rats.

RESULTS

Transient Fatp1 overexpression in soleus muscle increased (p < 0.05) palmitate transport (24%) and oxidation (35%), without altering triacylglycerol esterification or the intrinsic rate of palmitate oxidation in isolated mitochondria. In Mck/Fatp1 animals, Fatp1 mRNA and 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid uptake in skeletal muscle were upregulated (75%). However, insulin sensitivity and intramuscular triacylglycerol content did not differ between wild-type and Mck/Fatp1 mice following a 16 week high-fat diet. In insulin-resistant obese Zucker rats, LCFA transport and triacylglycerol accumulation were increased (85% and 24%, respectively), but this was not attributable to Fatp1 expression, as neither total cellular nor sarcolemmal FATP1 content were altered.

CONCLUSIONS/INTERPRETATION

Overexpression of Fatp1 in skeletal muscle increased the rate of LCFA transport and channelled these lipids to oxidation, not to intramuscular lipid accumulation. Therefore, skeletal muscle FATP1 overabundance does not predispose animals to diet-induced insulin resistance.

Increased levels of peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1alpha) improve lipid utilisation, insulin signalling and glucose transport in skeletal muscle of lean and insulin-resistant obese Zucker rats

AIMS/HYPOTHESIS

Reductions in peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1alpha) levels have been associated with the skeletal muscle insulin resistance. However, in vivo, the therapeutic potential of PGC-1alpha has met with failure, as supra-physiological overexpression of PGC-1alpha induced insulin resistance, due to fatty acid translocase (FAT)-mediated lipid accumulation. Based on physiological and metabolic considerations, we hypothesised that a modest increase in PGC-1alpha levels would limit FAT upregulation and improve lipid metabolism and insulin sensitivity, although these effects may differ in lean and insulin-resistant muscle.

METHODS

Pgc-1alpha was transfected into lean and obese Zucker rat muscles. Two weeks later we examined mitochondrial biogenesis, intramuscular lipids (triacylglycerol, diacylglycerol, ceramide), GLUT4 and FAT levels, insulin-stimulated glucose transport and signalling protein phosphorylation (thymoma viral proto-oncogene 2 [Akt2], Akt substrate of 160 kDa [AS160]), and fatty acid oxidation in subsarcolemmal and intermyofibrillar mitochondria.

RESULTS

Electrotransfection yielded physiologically relevant increases in Pgc-1alpha (also known as Ppargc1a) mRNA and protein ( approximately 25%) in lean and obese muscle. This induced mitochondrial biogenesis, and increased FAT and GLUT4 levels, insulin-stimulated glucose transport, and Akt2 and AS160 phosphorylation in lean and obese animals, while bioactive intramuscular lipids were only reduced in obese muscle. Concurrently, PGC-1alpha increased palmitate oxidation in subsarcolemmal, but not in intermyofibrillar mitochondria, in both groups. In obese compared with lean animals, the PGC-1alpha-induced improvement in insulin-stimulated glucose transport was smaller, but intramuscular lipid reduction was greater.

CONCLUSIONS/INTERPRETATIONS

Increases in PGC-1alpha levels, similar to those that can be induced by physiological stimuli, altered intramuscular lipids and improved fatty acid oxidation, insulin signalling and insulin-stimulated glucose transport, albeit to different extents in lean and insulin-resistant muscle. These positive effects are probably attributable to limiting the PGC-1alpha-induced increase in FAT, thereby preventing bioactive lipid accumulation as has occurred in transgenic PGC-1alpha animals.

Prediction of response and progression in multiple myeloma (MM) with serum-free light chains (sFLC): Corroboration of the International Myeloma Working Group (IMWG) criteria

8047

Background: The sFLC assay was proposed as a tool for the assessment of response in patients with non-secretory or oligosecretory MM and patients with primary amyloidosis. Response and progression criteria have been proposed by the IMWG, but have not been thoroughly validated. Methods: Electronic records of patients (pts) with MM enrolled in various clinical trials at the Cleveland Clinic between 4/2004 and 12/2006 were reviewed. Response to treatment and progression were assessed using the European Blood and Bone Marrow Transplantation (EBMT) criteria for all pts. sFLC responses were defined per IMWG criteria: response (R, decrease in the difference between the involved and uninvolved light chain by greater than 50%), progression (P, increase in the difference between the involved and uninvolved light chain by greater than 25%), and stable disease (SD, not meeting the criteria for either R or P). sFLC responses were assessed in pts with involved FLC =10 mg/dL (=100mg/L) per the IMWG criteria. Results: 89 pts were identified. The median age was 61 years (range 41–87) and 58 pts were males. The involved light chain was kappa in 67 pts (75%), and lambda in the remainder. By EBMT criteria, 4 pts had a complete response, 22 a partial response, 34 stable disease, 26 progressive disease and 3 were inevaluable. Only 43/89 pts (48%) had an involved sFLC=10mg/dL; of which 14 had R, 8 had SD, 18 had P, and 3 were inevaluable. Table 1 reviews the test characteristics for sFLC assay for the prediction of response or progression. Conclusions: sFLC reliably predicts response and progression in MM pts. However, half the pts had an involved sFLC that would not be considered evaluable by IMWG, which limits its potential use.

No significant financial relationships to disclose.

[Table: see text]

Solution structure and interaction surface of the C-terminal domain from p47: a major p97-cofactor involved in SNARE disassembly

p47 is the major protein identified in complex with the cytosolic AAA ATPase p97. It functions as an essential cofactor of p97-regulated membrane fusion, which has been suggested to disassemble t-t-SNARE complexes and prepare them for further rounds of membrane fusion. Here, we report the high-resolution NMR structure of the C-terminal domain from p47. It comprises a UBX domain and a 13 residue long structured N-terminal extension. The UBX domain adopts a characteristic ubiquitin fold with a betabetaalphabetabetaalphabeta secondary structure arrangement. Three hydrophobic residues from the N-terminal extension pack closely against a cleft in the UBX domain. We also identify, for the first time, the p97 interaction surface using NMR chemical shift perturbation studies.

Structure of the AAA ATPase p97

p97, an abundant hexameric ATPase of the AAA family, is involved in homotypic membrane fusion. It is thought to disassemble SNARE complexes formed during the process of membrane fusion. Here, we report two structures: a crystal structure of the N-terminal and D1 ATPase domains of murine p97 at 2.9 A resolution, and a cryoelectron microscopy structure of full-length rat p97 at 18 A resolution. Together, these structures show that the D1 and D2 hexamers pack in a tail-to-tail arrangement, and that the N domain is flexible. A comparison with NSF D2 (ATP complex) reveals possible conformational changes induced by ATP hydrolysis. Given the D1 and D2 packing arrangement, we propose a ratchet mechanism for p97 during its ATP hydrolysis cycle.

20S human proteasomes bind with a specific orientation to lipid monolayers in vitro

20S Proteasomes are non-lysosomal, high molecular weight proteinases implicated in the degradation of misfolded proteins and several short-lived regulatory proteins. They have a well established role, as the core of the 26S proteasome complex, in the ubiquitin-dependent proteolytic pathway and in antigen processing. While correctly folded proteins are not degraded by the 20S proteasome, unfolding, for example by oxidation, may render them degradable. The 20S proteasome is a 700-kDa cylindrical particle, composed of 14 subunits of molecular masses 20-35 kDa. There is evidence that 20S proteasomes are in close proximity to or associate with the endoplasmic reticulum and nuclear and plasma membranes in vivo. To better understand the lipid association of 20S proteasomes in vitro, we used a lipid monolayer system as a simple model system for biological membranes. The structure and orientation of the monolayer lipid bound 20S proteasomes has been determined by electron microscopy. 20S proteasomes associated in an "end-on' configuration specifically on PI lipid monolayers forming large arrays, with their channels opposite the lipid headgroups. On ER and Golgi lipid films 20S proteasomes were oriented in the same way as on the PI lipid film but were monodisperse. Protein molecules were randomly oriented in the presence of PA, PG, PS, PC and mitochondrial lipid monolayers. We show that 20S proteasomes bind to phospholipids in vitro in a preferred orientation which places the proteasome channel perpendicular to the membrane.

The solution structure of the RING finger domain from the acute promyelocytic leukaemia proto-oncoprotein PML

Acute promyelocytic leukaemia (APL) has been ascribed to a chromosomal translocation event which results in a fusion protein comprising the PML protein and the retinoic acid receptor alpha. PML is normally a component of a nuclear multiprotein complex (termed ND10, Kr bodies, nuclear bodies, PML oncogenic domains or PODs) which is disrupted in the APL disease state. PML contains a number of characterized motifs including a Zn2+ binding domain called the RING or C3HC4 finger. Here we describe the solution structure of the PML RING finger as solved by 1H NMR methods at physiological pH with r.m.s. deviations for backbone atoms of 0.88 and 1.39 A for all atoms. Additional biophysical studies including CD and optical spectroscopy, show that the PML RING finger requires Zn2+ for autonomous folding and that cysteines are used in metal ligation. A comparison of the structure with the previously solved equine herpes virus IE110 RING finger, shows significant differences suggesting that the RING motif is structurally diverse. The role of the RING domain in PML nuclear body formation was tested in vivo, by using site-directed mutagenesis and immunofluorescence on transiently transfected NIH 3T3 cells. Independently mutating two pairs of cysteines in each of the Zn2+ binding sites prevents PML nuclear body formation, suggesting that a fully folded RING domain is necessary for this process. These results suggest that the PML RING domain is probably involved in protein-protein interactions, a feature which may be common to other RING finger domains.

Inflammatory pseudotumor of the spleen: MR findings

Inflammatory pseudotumor of the spleen is an unusual lesion often mistaken preoperatively for other masses. Isolated inflammatory pseudotumors of the spleen are rare. We report a proven case examined with ultrasound, CT, single photon emission CT, and MRI.

Morphological studies of an ion-dependent perinuclear cataract model

The perinuclear region of the rabbit lens is susceptible to alterations in the ionic composition of incubation medium. Rabbit lenses and a comparable cell type, red blood cells, were stressed during ex vivo incubations in isotonic modified Earle's medium with 131 mM NaCl replaced by either 232 mM sucrose or 131 mM choline chloride at pH 7.2 (normal) or 9.2. Our parallel NMR study revealed that these experimental media maintain normal intracellular pH and phosphorus metabolite levels. The present study demonstrates that lens transparency, normal fiber cell ultrastructure and volume were maintained in either sodium chloride or choline chloride containing media at normal or elevated pH. Similarly, normal morphology, mean cell volume (MCV) and mean cell hemoglobin concentration (MCHC), 86.8 +/- 0.03 micron 3 and 33.2 +/- 1.0 g dl-1, respectively, were maintained in red blood cells in either sodium chloride or choline chloride containing media. In sodium chloride deficient media at both normal and elevated pH the lens developed a nuclear cataract based on slit-lamp examination; however, SEM examination showed that fiber cell morphological abnormalities were confined to a narrow band, 50 micron wide, in the perinuclear region of the transition zone. Damage consisted of ruptured cell membranes and an absence of identifiable interdigitations with the combination of sodium chloride deficiency and elevated pH. The major abnormality produced during incubation in sodium chloride deficient medium at normal pH was the presence of numerous smooth-surfaced cellular protrusions along the vertices of the perinuclear fiber cells. In addition, the sodium chloride deficient medium, pH 9.2, produced a volume loss both in the lens and RBC (4.5 +/- 1.5% and 5.6 +/- 1.1%, respectively). The sodium chloride deficient medium, pH 7.4, produced no volume loss in the lens or red blood cells (MCV 86.0 +/- 0.05 micron 3). Further studies indicated that the cataract induced by sodium chloride deficiency (pH 9.2) is irreversible. The mechanism for perinuclear opacification due to ion deficiency remains to be elucidated.

The Canberra mental health survey: further analysis of the adult sample

Secondary analysis of the Canberra Mental Health Survey (adult sample) extends the results of earlier analysis. New relationships between independent and dependent variables are revealed. Marital status previously not associated with mental health proves important when sex and socioeconomic status are controlled. Participation in organizations is strongly associated with social variables and mental health adjustment, suggesting explanations of mental health in relation to social support.