Large-scale serum analysis identifies unique systemic biomarkers in psoriasis and hidradenitis suppurativa

BACKGROUND

Hidradenitis Suppurativa (HS) is now recognized as a systemic inflammatory disease, sharing molecular similarities with psoriasis. Direct comparison of the systemic inflammation in HS with psoriasis is lacking.

OBJECTIVES

To evaluate the serum proteome of HS and psoriasis, and to identify biomarkers associated with disease severity.

METHODS

In this cross-sectional study, 1,536 serum proteins were assessed using the Olink Explore (Proximity Extension Assay/PEA) high-throughput panel in moderate-to-severe HS (n=11), psoriasis (n=10) and age- and BMI-matched healthy controls (n=10).

RESULTS

HS displayed an overall greater dysregulation of circulating proteins, with 434 differentially expressed proteins (|FCH|≥1.2, p-value≤0.05) in HS versus controls, 138 in psoriasis versus controls, and 503 between HS and psoriasis. IL-17A levels and Th1/Th17 pathway enrichment were comparable between diseases, while HS presented greater TNF and IL-1β-related signaling. Th17-associated markers, PI3 and LCN2, were able to accurately differentiate psoriasis from HS. Both diseases presented increases of atherosclerosis-related proteins. Robust correlations between clinical severity scores and immune and atherosclerosis-related proteins were observed across both diseases.

CONCLUSIONS

HS and psoriasis share significant Th1/Th17 enrichment and upregulation of atherosclerosis-related proteins. Nevertheless, despite the greater body surface area involved in psoriasis, HS presents a greater serum inflammatory burden.

A recurrent nova super-remnant in the Andromeda galaxy

The accretion of hydrogen onto a white dwarf star ignites a classical nova eruption^1,2-a thermonuclear runaway in the accumulated envelope of gas, leading to luminosities up to a million times that of the Sun and a high-velocity mass ejection that produces a remnant shell (mainly consisting of insterstellar medium). Close to the upper mass limit of a white dwarf³ (1.4 solar masses), rapid accretion of hydrogen (about 10^-7 solar masses per year) from a stellar companion leads to frequent eruptions on timescales of years^4,5 to decades⁶. Such binary systems are known as recurrent novae. The ejecta of recurrent novae, initially moving at velocities of up to 10,000 kilometres per second⁷, must 'sweep up' the surrounding interstellar medium, creating cavities in space around the nova binary. No remnant larger than one parsec across from any single classical or recurrent nova eruption is known^8-10, but thousands of successive recurrent nova eruptions should be capable of generating shells hundreds of parsecs across. Here we report that the most frequently recurring nova, M31N 2008-12a in the Andromeda galaxy (Messier 31 or NGC 224), which erupts annually¹¹, is indeed surrounded by such a super-remnant with a projected size of at least 134 by 90 parsecs. Larger than almost all known remnants of even supernova explosions¹², the existence of this shell demonstrates that the nova M31N 2008-12a has erupted with high frequency for millions of years.

Brain connectivity changes occurring following cognitive behavioural therapy for psychosis predict long-term recovery

This corrects the article DOI: 10.1038/tp.2016.263.

Comparative study of magnetic resonance defaecography and evacuation proctography in the evaluation of obstructed defaecation

AIM

Obstructed defaecation syndrome is a common condition of multifactorial aetiology and requires specialized evaluation. Accurate and reproducible pelvic floor imaging is imperative for multidisciplinary decision-making. Evacuation proctography (EP) and magnetic resonance defaecography (MRD) are the main imaging modalities used to assess dynamic pelvic floor function. The aim of this prospective study was to compare the findings and acceptability of MRD and EP in the same cohort of patients.

METHOD

This was a prospective comparative study of MRD vs EP in 55 patients with obstructed defaecation syndrome in a single National Health Service Foundation Trust.

RESULTS

Fifty-five patients were recruited and underwent both EP and MRD. Detection rates for rectocoele were similar (82% vs 73%, P = 0.227), but EP revealed a significantly higher number of trapping rectocoeles compared to MRD (75% vs 31%, P < 0.001). EP detected more rectal intussusceptions than MRD (56% vs 35%, P = 0.023). MRD appeared to underestimate the size of the identified rectocoele, although it detected a significant number of anatomical abnormalities in the middle and anterior pelvic compartment not seen on EP (1.8% enterocoele, 9% peritoneocoele and 20% cystocoele). Patients achieved higher rates of expulsion of rectal contrast during EP compared to MRD, but this difference was not significant (76% vs 64% in MRD, P = 0.092). Of the two studies, patients preferred MRD.

CONCLUSIONS

MRD provides a global assessment of pelvic floor function and anatomical abnormality. MRD is better tolerated by patients but it is not as sensitive as EP in detecting trapping rectocoeles and intussusceptions.

Shifting brain inhibitory balance and connectivity of the prefrontal cortex of adults with autism spectrum disorder

Currently, there are no effective pharmacologic treatments for the core symptoms of autism spectrum disorder (ASD). There is, nevertheless, potential for progress. For example, recent evidence suggests that the excitatory (E) glutamate and inhibitory (I) GABA systems may be altered in ASD. However, no prior studies of ASD have examined the 'responsivity' of the E-I system to pharmacologic challenge; or whether E-I modulation alters abnormalities in functional connectivity of brain regions implicated in the disorder. Therefore, we used magnetic resonance spectroscopy ([1H]MRS) to measure prefrontal E-I flux in response to the glutamate and GABA acting drug riluzole in adult men with and without ASD. We compared the change in prefrontal 'Inhibitory Index'-the GABA fraction within the pool of glutamate plus GABA metabolites-post riluzole challenge; and the impact of riluzole on differences in resting-state functional connectivity. Despite no baseline differences in E-I balance, there was a significant group difference in response to pharmacologic challenge. Riluzole increased the prefrontal cortex inhibitory index in ASD but decreased it in controls. There was also a significant group difference in prefrontal functional connectivity at baseline, which was abolished by riluzole within the ASD group. Our results also show, for we believe the first time in ASD, that E-I flux can be 'shifted' with a pharmacologic challenge, but that responsivity is significantly different from controls. Further, our initial evidence suggests that abnormalities in functional connectivity can be 'normalised' by targeting E-I, even in adults.

Brain connectivity changes occurring following cognitive behavioural therapy for psychosis predict long-term recovery

Little is known about the psychobiological mechanisms of cognitive behavioural therapy for psychosis (CBTp) and which specific processes are key in predicting favourable long-term outcomes. Following theoretical models of psychosis, this proof-of-concept study investigated whether the long-term recovery path of CBTp completers can be predicted by the neural changes in threat-based social affective processing that occur during CBTp. We followed up 22 participants who had undergone a social affective processing task during functional magnetic resonance imaging along with self-report and clinician-administered symptom measures, before and after receiving CBTp. Monthly ratings of psychotic and affective symptoms were obtained retrospectively across 8 years since receiving CBTp, plus self-reported recovery at final follow-up. We investigated whether these long-term outcomes were predicted by CBTp-led changes in functional connections with dorsal prefrontal cortical and amygdala during the processing of threatening and prosocial facial affect. Although long-term psychotic symptoms were predicted by changes in prefrontal connections during prosocial facial affective processing, long-term affective symptoms were predicted by threat-related amygdalo-inferior parietal lobule connectivity. Greater increases in dorsolateral prefrontal cortex connectivity with amygdala following CBTp also predicted higher subjective ratings of recovery at long-term follow-up. These findings show that reorganisation occurring at the neural level following psychological therapy can predict the subsequent recovery path of people with psychosis across 8 years. This novel methodology shows promise for further studies with larger sample size, which are needed to better examine the sensitivity of psychobiological processes, in comparison to existing clinical measures, in predicting long-term outcomes.

Single crystal growth from separated educts and its application to lithium transition-metal oxides

Thorough mixing of the starting materials is the first step of a crystal growth procedure. This holds true for almost any standard technique, whereas the intentional separation of educts is considered to be restricted to a very limited number of cases. Here we show that single crystals of α-Li₂IrO₃ can be grown from separated educts in an open crucible in air. Elemental lithium and iridium are oxidized and transported over a distance of typically one centimeter. In contrast to classical vapor transport, the process is essentially isothermal and a temperature gradient of minor importance. Single crystals grow from an exposed condensation point placed in between the educts. The method has also been applied to the growth of Li₂RuO₃, Li₂PtO₃ and β-Li₂IrO₃. A successful use of this simple and low cost technique for various other materials is anticipated.

The Analgesic Effect of Oxytocin in Humans: A Double-Blind, Placebo-Controlled Cross-Over Study Using Laser-Evoked Potentials

Oxytocin is a neuropeptide regulating social-affiliative and reproductive behaviour in mammals. Despite robust preclinical evidence for the antinociceptive effects and mechanisms of action of exogenous oxytocin, human studies have produced mixed results regarding the analgesic role of oxytocin and are yet to show a specific modulation of neural processes involved in pain perception. In the present study, we investigated the analgesic effects of 40 IU of intranasal oxytocin in 13 healthy male volunteers using a double-blind, placebo-controlled, cross-over design and brief radiant heat pulses generated by an infrared laser that selectively activate Aδ- and C-fibre nerve endings in the epidermis, at the same time as recording the ensuing laser-evoked potentials (LEPs). We predicted that oxytocin would reduce subjective pain ratings and attenuate the amplitude of the N1, N2 and P2 components. We observed that oxytocin attenuated perceived pain intensity and the local peak amplitude of the N1 and N2 (but not of P2) LEPs, and increased the latency of the N2 component. Importantly, for the first time, the present study reports an association between the analgesic effect of oxytocin (reduction in subjective pain ratings) and the oxytocin-induced modulation of cortical activity after noxious stimulation (attenuation of the N2 LEP). These effects indicate that oxytocin modulates neural processes contributing to pain perception. The present study reports preliminary evidence that is consistent with electrophysiological studies in rodents showing that oxytocin specifically modulates Aδ/C-fibre nociceptive afferent signalling at the spinal level and provides further specificity to evidence obtained in humans indicating that oxytocin may be modulating pain experience by modulating activity in the cortical areas involved in pain processing.

Regulation of fibrinolysis by C-terminal lysines operates through plasminogen and plasmin but not tissue-type plasminogen activator

BACKGROUND

Binding of tissue-type plasminogen (Pgn) activator (t-PA) and Pgn to fibrin regulates plasmin generation, but there is no consistent, quantitative understanding of the individual contribution of t-PA finger and kringle 2 domains to the regulation of fibrinolysis. Kringle domains bind to lysines in fibrin, and this interaction can be studied by competition with lysine analogs and removal of C-terminal lysines by carboxypeptidase B (CPB).

METHODS

High-throughput, precise clot lysis assays incorporating the lysine analog tranexamic acid (TA) or CPB and genetically engineered variants of t-PA were performed. In particular, wild-type (WT) t-PA (F-G-K1-K2-P) and a domain-switched variant K1K1t-PA (F-G-K1-K1-P) that lacks kringle 2 but retains normal t-PA structure were compared to probe the importance of fibrin lysine binding by t-PA kringle 2.

RESULTS

WT t-PA showed higher rates of fibrinolysis than K1K1t-PA, but the inhibitory effects of TA or CPB were very similar for WT t-PA and the variant t-PA (< 10% difference). Urokinase plasminogen activator (u-PA)-catalyzed fibrinolysis was also inhibited by TA, even though Pgn activation could be stimulated. Fibrin treated with factor XIIIa (FXIIIa) generates crosslinked degradation products, but these did not affect the results obtained with WT t-PA and K1K1t-PA.

CONCLUSIONS

t-PA kringle 2 has a minor role in the initial interaction of t-PA and fibrin, but stimulation of fibrinolysis by C-terminal lysines (or inhibition by carboxypeptidases or TA) operates through Pgn and plasmin binding, not through t-PA. This is also true when fibrin is crosslinked by treatment with FXIIIa.

Proton magnetic resonance spectroscopy of the striatum in Parkinson's disease patients with motor response fluctuations

We have performed proton magnetic resonance spectroscopy centred on the putamen contralateral to the worst affected side in 10 patients with idiopathic Parkinson's disease (PD) and motor response fluctuations and seven age matched healthy controls. In PD, there was striking reduction in the N-acetylaspartate (NAA) and creatine and NAA/choline ratios compared to controls. This pilot study provides in vivo evidence of striatal neuronal dysfunction in PD and further studies are in progress to establish if the observed changes are due to the disease process itself or due to chronic levodopa therapy.

Does the use of a "track and trigger" warning system reduce mortality in trauma patients?

INTRODUCTION

Despite the lack of robust evidence, numerous different "track and trigger" warning systems have been implemented. These have only been validated in an emergency medical admissions setting. The Modified Early Warning Score (MEWS) is the chosen track and trigger system used in the University Hospitals of Leicester trauma unit, but has not been validated in trauma patients. A considerable proportion of all trauma admissions are elderly patients with proximal femoral fractures and significant co-morbidities. Early recognition of physiological deterioration and prompt action could therefore be lifesaving in this patient group.

AIM

To identify whether the implementation of the MEWS system coupled with a critical care outreach service resulted in a reduction in mortality in a busy trauma unit.

METHOD

A retrospective study. The MEWS system was implemented in all trauma and orthopaedic wards at the Leicester Royal Infirmary in the summer of 2005. The numbers of emergency trauma inpatient admissions and deaths from January 2002 to December 2009 were obtained. The diagnosis, primary procedures and cause of death, if known, were noted. Comparisons were made pre- and post-MEWS. Student's t-test was used for statistical analysis.

RESULTS

32,149 patients were admitted (55% male; 45% female). Overall there were 889 deaths (77% female; 33% male, P<0.0001). The in-hospital mortality rate for orthopaedic trauma patients was 2.8% throughout the 7-year study period. 61% of those who died were admitted with proximal femoral fractures. The modal age group with the highest mortality was 81-90 years. Overall, females had a considerably greater mortality rate than males. The mortality rate was lower post-MEWS in males (1.82-1.418%; P=0.214), females (4.871-3.364%; P=0.108) and all patients (3.215-2.294%; P=0.092), but this was not statistically significant.

CONCLUSION

The use of a track and trigger warning system has not led to a statistically significant reduction in mortality in trauma patients. In view of the apparent lack of clinical effectiveness of the MEWS/outreach partnership, the cost effectiveness of this initiative needs to be questioned. Possible reasons for these findings include: failure of the MEWS to be correctly applied, inadequate action once the threshold is triggered, or unsuitability of this tool for this patient population. A better system for identifying and treating elderly, medically unwell trauma patients with co-morbidities needs to be developed.

Altered brain function directly related to structural abnormalities in people at ultra high risk of psychosis: longitudinal VBM-fMRI study

BACKGROUND

Several studies have indicated that people with prodromal signs of psychosis show alterations in the structure and function of the brain when they first present to clinical services. However, the longitudinal course of these abnormalities, and how they relate to subsequent clinical and functional outcome is relatively unclear.

METHODS

A cohort of subjects at ultra high risk of psychosis were studied using functional magnetic resonance imaging (fMRI) in conjunction with the N-Back task, and volumetric MRI at first clinical presentation and again after one year. Levels of psychopathology and global functioning were assessed at the same time points using the CAARMS, PANSS, and the GAF scale.

RESULTS

At baseline, the high risk group showed reduced activation during the task in the left middle frontal gyrus, supramarginal gyrus and inferior parietal lobule, and reduced gray matter volume in the left middle and medial frontal gyri, left insula and the right anterior cingulate gyrus. Within the high-risk group, there was a positive correlation between the magnitude of the functional and structural alterations in the left middle frontal gyrus. Between presentation and follow up, the severity of perceptual disorder and thought disorder (rated by the CAARMS), and of general psychopathology (rated by the PANSS general score) decreased, and the level of global functioning improved. This clinical and functional improvement was associated with a longitudinal increase in activation in the anterior cingulate and right parahippocampal gyrus. The change in anterior cingulate response was directly correlated with the improvement in the GAF score.

CONCLUSIONS

In subjects presenting with prodromal signs of psychosis, reduced prefrontal activation during a working memory task is associated with a reduction in gray matter volume in the same area. Changes in anterior cingulate activation were correlated with functional improvement in this group, consistent with the role of this region in multiple cognitive and social processes.

Spatial working memory in individuals at high risk for psychosis: longitudinal fMRI study

BACKGROUND

Neurocognitive impairments in executive and mnemonic domains are already evident in the pre-psychotic phases. The longitudinal dynamic course of the neurofunctional abnormalities underlying liability to psychosis and their relation to clinical outcomes is unknown.

METHODS

In this study we used functional magnetic resonance imaging (fMRI) in a cohort of subjects at ultra high clinical risk for psychosis (with an "At Risk Mental State", ARMS) and in healthy controls. Images were acquired at baseline and again after one year on a 1.5 Tesla Signa, while patients were performing a visuospatial working memory task. Psychopathological assessment of the prodromal symptoms was conducted at the same time points by using the CAARMS and the PANSS instruments.

RESULTS

There were no significant differences between the ARMS and control groups with respect to age or IQ. Although both groups performed the PAL task with a high degree of accuracy, the ARMS showed an increased latency in answers during the most demanding level of the task. At baseline, such cognitive impairment was associated with reduced activation in the left precuneus, left superior parietal lobule, right middle temporal gyrus in the ARMS as compared to controls. In addition, the ARMS failed to activate parietal areas with increasing difficulty of the task. Between presentation and follow-up the overall clinical status of the ARMS sample improved, despite 2 out of the 15 subjects having developed a full-blown psychosis: the CAARMS (perceptual disorder and thought disorder subscales) and the PANNS general scores decreased, while the GAF score increased. Such clinical amelioration was associated with a longitudinal compensatory increase in occipitoparietal regions.

CONCLUSIONS

The prodromal phase of psychosis is associated with functional alterations in parietal and temporal networks subserving visuospatial working memory which are more evident under high cognitive loads. The clinical improvement at one year is associated with a compensatory increase in occipitoparietal regions.

A new musculoskeletal curriculum: has it made a difference?

This study assessed whether undergraduate performance improved following the introduction in 2006 of a musculoskeletal teaching programme lasting for seven weeks. Different methods were used to deliver knowledge and skills in trauma and orthopaedic surgery, rheumatology and allied specialties. The programme combined four main elements: traditional firm-based teaching, weekly plenary sessions, a task-based workbook and additional specialist clinics. The block of 139 students who attended in its first year were assessed using a multiple choice question examination just before their final examinations in 2008. They showed a 6% improvement in performance over a control group of 130 students assessed in 2005 before the programme had commenced. There was no difference in performance between the students assessed in 2005 and a second group of 46 students from 2008 who did not attend the new teaching programme. Performance was improved by providing more focused musculoskeletal training using available resources, as well as increasing the length of the programme.

The adoption of smoke-free hospital campuses in the United States

BACKGROUND

The adoption of a smoke-free hospital campus policy is often a highly publicised local event. National media coverage suggests that the trend towards adopting these policies is growing, and this publicity can frequently lead hospital administrators to consider the adoption of such policies within their own institutions. Little is actually known, however, about the prevalence of these policies or their impact.

OBJECTIVES

To determine the national prevalence of smoke-free hospital campus policies and the relation between these policies and performance on nationally standardised measures for smoking cessation counselling in US hospitals.

METHODS

4494 Joint Commission-accredited hospitals were invited to complete a web-based questionnaire assessing current smoking policies and future plans. Smoking cessation counselling rates were assessed through nationally standardised measures.

RESULTS

The 1916 hospitals responding to the survey (43%) were statistically similar to non-responders with respect to performance measure rates, smoking policies and demographic characteristics. Approximately 45% of responders reported an existing smoke-free hospital campus policy. With respect to demographics, higher proportions of smoke-free campus policies were reported in non-teaching and non-profit hospitals. Smoke-free campus hospitals were also more likely to provide smoking cessation counselling to patients with acute myocardial infarction, heart failure and pneumonia who smoke (p<0.001).

CONCLUSIONS

By February 2008, 45% of US hospitals (up from approximately 3% in 1992) had adopted a smoke-free campus policy; another 15% reported actively pursuing the adoption of such a policy. By the end of 2009, it is likely that the majority of US hospitals will have a smoke-free campus.

Enhanced orexin receptor-2 signaling prevents diet-induced obesity and improves leptin sensitivity

The hypothalamic orexin neuropeptide acutely promotes appetite, yet orexin deficiency in humans and mice is associated with obesity. Prolonged effects of increased orexin signaling upon energy homeostasis have not been fully characterized. Here, we examine the metabolic effects of orexin gain of function utilizing genetic and pharmacologic techniques in mice. Transgenic orexin overexpression confers resistance to high-fat diet-induced obesity and insulin insensitivity by promoting energy expenditure and reducing consumption. Genetic studies indicate that orexin receptor-2 (OX2R), rather than OX1R signaling, predominantly mediates this phenotype. Likewise, prolonged central administration of an OX2R-selective peptide agonist inhibits diet-induced obesity. While orexin overexpression enhances the anorectic-catabolic effects of central leptin administration, obese leptin-deficient mice are completely resistant to the metabolic effects of orexin overexpression or OX2R agonist infusion. We conclude that enhanced orexin-OX2R signaling confers resistance to diet-induced features of the metabolic syndrome through negative energy homeostasis and improved leptin sensitivity.

Developing a robust and efficient pathway for the referral and investigation of women with post-menopausal bleeding using a cut-off of < or =4 mm for normal thickness

The majority of women with post-menopausal bleeding (PMB) do not have endometrial cancer, and transvaginal ultrasound (TVUS) is accepted as the screening tool of choice to identify those at highest risk of malignancy. A new referral pathway was instigated in 2000, with patients only being referred to a gynaecologist following an abnormal TVUS result. An initial audit revealed a low positive predictive value for TVUS and a low incidence of detected malignancy. The cut-off value for a normal endometrium was increased from 3 mm to 4 mm in line with published data. This re7hyphen;audit evaluated the effectiveness of implemented changes and identified other areas for improvement. Of the 277 women referred during the study period, 193 had an abnormal or unseen endometrium and were subsequently seen by a gynaecologist. For patients without a histological diagnosis, clinical notes were reviewed and the hospital cancer database scrutinized for all endometrial cancers. Despite a 15.4% increase in referrals, only an additional 2.9% were assessed by gynaecologists. 14 cases of malignancy were identified with a mean endometrial thickness (ET) of 15.7 mm. Failed endometrial sampling was more prevalent with a minimally thickened endometrium. 80 patients with abnormal TVUS had no recorded histological diagnosis. Increasing the ET cut-off value has reduced unnecessary investigations in women at low risk of malignancy. No woman discharged back to her GP has been diagnosed with an endometrial malignancy within 1 year of initial referral. An algorithm has been proposed to further improve the investigation of women with PMB following an abnormal TVUS.

Significance of hip rotation on measurement of 'Tip Apex Distance' during fixation of extracapsular proximal femoral fractures

The Tip Apex Distance (TAD) is defined as the sum of the distance, in millimetres, from the tip of the lag screw to the apex of the femoral head, as measured on an antero-posterior radiograph and lateral radiograph, after correction has been made for magnification. The relationship between the degree of rotation of the hip joint and its implication on measuring TAD during fixation of a proximal femoral fracture was studied. This relationship has not been previously explored in the English literature. This study involved radiographs of a lag screw placed in a synthetic femur specimen taken in neutral and varying degrees of rotation and adduction/abduction. The lag screw was placed anteriorly in the femoral head. Measurements were taken for each radiograph after correction for magnification.

RESULTS

Statistical analysis between measurements showed statistically significant differences (P<0.05) of TAD in AP and lateral (abduction and adduction) views. A graph to show the relationship between hip rotation and TAD was conducted and demonstrates a linear correlation.

CONCLUSION

If an anteriorly placed hip screw is not seen to be breaching the articular surface on a view taken in internal rotation, the screw is definitely not in the joint. Beware of a hip screw appearing very close to the joint surface on a view taken in external rotation or abduction as it could be within the joint. The converse may apply to a posteriorly placed screw.

Cellular multiparametric MRI of neural stem cell therapy in a rat glioma model

Cellular multiparametric magnetic resonance imaging (MRI) provided an in vivo visualisation of neural stem cells' (NSCs) tropism for gliomas in the rat brain. NSCs were magnetically labelled in vitro with the bimodal gadolinium-based contrast agent, gadolinium rhodamine dextran (GRID), and injected into the contralateral hemisphere to the developing tumour. Contrast-to-noise measurements showed that GRID-labelled cells induced a signal attenuation on both T2-, T2(*)-weighted images, and a modest signal gain on T1-weighted images. Tumour development and progression were longitudinally monitored in vivo by serial MR scanning. Measurements of tumour volume and tumour progression over time in terms of tumour doubling time showed a tendency towards a reduced tumour growth in NSC-treated animals. MR findings of migration and infiltration of tumours by labelled NSCs were corroborated with immunohistopathology, where labelled cells were detected in the corpus callosum at the tumour border and dispersed in the solid tumour tissue. Immunohistopathology also revealed that macrophages invaded the tumour tissue and in some cases engulfed GRID-labelled stem cells. No significant difference in macrophage recruitment between NSC-treated and vehicle-treated animals were detected, indicating that magnetically labelled NSC do not increase macrophage invasion of tumour tissue. Our findings demonstrate that cellular multiparametric MRI provides a valuable tool for in vivo dynamic monitoring of tumour-directed neural stem cell migration as well as therapeutic efficacy.

Pseudomonas aeruginosa autoinducer modulates host cell responses through calcium signalling

The opportunistic pathogen Pseudomonas aeruginosa utilizes a cell density-dependent signalling phenomenon known as quorum sensing (QS) to regulate several virulence factors needed for infection. Acylated homoserine lactones, or autoinducers, are the primary signal molecules that mediate QS in P. aeruginosa. The autoinducer N-3O-dodecanoyl-homoserine lactone (3O-C12) exerts effects on mammalian cells, including upregulation of pro-inflammatory mediators and induction of apoptosis. However, the mechanism(s) by which 3O-C12 affects mammalian cell responses is unknown. Here we report that 3O-C12 induces apoptosis and modulates the expression of immune mediators in murine fibroblasts and human vascular endothelial cells (HUVEC). The effects of 3O-C12 were accompanied by increases in cytosolic calcium levels that were mobilized from intracellular stores in the endoplasmic reticulum (ER). Calcium release was blocked by an inhibitor of phospholipase C, suggesting that release occurred through inositol triphosphate (IP3) receptors in the ER. Apoptosis, but not immunodulatory gene activation, was blocked when 3O-C12-exposed cells were co-incubated with inhibitors of calcium signalling. This study indicates that 3O-C12 can activate at least two independent signal transduction pathways in mammalian cells, one that involves increases in intracellular calcium levels and leads to apoptosis, and a second pathway that results in modulation of the inflammatory response.

The dorsomedial hypothalamic nucleus as a putative food-entrainable circadian pacemaker

Temporal restriction of feeding can phase-shift behavioral and physiological circadian rhythms in mammals. These changes in biological rhythms are postulated to be brought about by a food-entrainable oscillator (FEO) that is independent of the suprachiasmatic nucleus. However, the neural substrates of FEO have remained elusive. Here, we carried out an unbiased search for mouse brain region(s) that exhibit a rhythmic expression of the Period genes in a feeding-entrainable manner. We found that the compact part of the dorsomedial hypothalamic nucleus (DMH) demonstrates a robust oscillation of mPer expression only under restricted feeding. The oscillation persisted for at least 2 days even when mice were given no food during the expected feeding period after the establishment of food-entrained behavioral rhythms. Moreover, refeeding after fasting rapidly induced a transient mPer expression in the same area of DMH. Taken in conjunction with recent findings (i) that behavioral expression of food-entrainable circadian rhythms is blocked by cell-specific lesions of DMH in rats and (ii) that DMH neurons directly project to orexin neurons in the lateral hypothalamus, which are essential for proper expression of food-entrained behavioral rhythms, the present study suggests that DMH plays a key role as a central FEO in the feeding-mediated regulation of circadian behaviors.

Distribution of neuropeptide W immunoreactivity and mRNA in adult rat brain

Neuropeptide W (NPW) is a recently identified neuropeptide that binds to G-protein-coupled receptor (GPR) 7, which is highly expressed in several discrete regions of the rodent brain including the central amygdaloid nucleus and bed nucleus of the stria terminalis. Although several reports suggested that NPW is implicated in the regulation of energy homeostasis and nociception, the precise physiological role of NPW has remained unclear. In this study, we examined distribution of NPW messenger RNA and NPW immunoreactivity in the adult rat brain. NPW-immunoreactive (ir) cells were detected in the ventral tegmental area, periaqueductal gray, and Edinger-Westphal nucleus. NPW-ir fibers were observed in several brain regions, including the lateral septum, bed nucleus of the stria terminalis, dorsomedial and posterior hypothalamus, central amygdaloid nucleus, CA1 field of hippocampus, interpeduncular nucleus, inferior colliculus, lateral parabrachial nucleus, facial nucleus, and hypoglossal nucleus. NPW-ir fibers were most abundantly observed in the central amygdaloid nucleus and the bed nucleus of the stria terminalis, which are regions implicated in fear and anxiety. These results suggest that NPW might be involved in the regulation of stress and emotive responses, especially in fear and anxiety-related physiological and behavioral functions.

A neuropeptide ligand of the G protein-coupled receptor GPR103 regulates feeding, behavioral arousal, and blood pressure in mice

Here, we report the isolation and characterization of an endogenous peptide ligand of GPR103 from rat brains. The purified peptide was found to be the 43-residue RF-amide peptide QRFP. We also describe two mouse homologues of human GPR103, termed mouse GPR103A and GPR103B. QRFP binds and activates the human GPR103, as well as mouse GPR103A and GPR103B, with nanomolar affinities in transfected cells. Systematic in situ hybridization analysis in mouse brains showed that QRFP is expressed exclusively in the periventricular and lateral hypothalamus, whereas the two receptor mRNAs are distinctly localized in various brain areas without an overlap to each other. When administered centrally in mice, QRFP induced feeding behavior, accompanied by increased general locomotor activity and metabolic rate. QRFP-induced food intake was abolished by preadministration of BIBP3226, a specific antagonist for the Y1 neuropeptide Y receptor. Hypothalamic prepro-QRFP mRNA expression was up-regulated upon fasting and in genetically obese ob/ob and db/db mice. Central QRFP administration also evoked highly sustained elevation of blood pressure and heart rate. Our findings suggest that QRFP and GPR103A/B may regulate diverse neuroendocrine and behavioral functions and implicate this neuropeptide system in metabolic syndrome.

Comparison of accuracy of lag screw placement in cephalocondylic nails and sliding hip screw plate fixation for extracapsular fractures of the neck of femur

This study compared the accuracy of lag screw placement between extracapsular femoral fractures fixed with sliding hip screw plate systems and those fixed with cephalocondylic nails. It involved 75 retrospective radiographs of fractures fixed with either a cephalocondylic nail (32) or a sliding hip screw plate system (43). Postoperative anteroposterior and lateral radiographs of the hip were scanned using a digital X-ray scanner and measured using computer software. Measurements were conducted by two independent observers, and the radiographs were calibrated to correct for magnification. Accuracy of lag screw placement was determined by "tip apex distance," described by Baumgaertner et al., and by the ratio method described by Parker. The mean tip apex distance was 24.0 mm in sliding hip screw plate systems and 21.1 mm in cephalocondylic nails. This was found to be statistically significant. Lag screw placement through cephalocondylic nails is more accurate and therefore has less chance of cut-out compared with sliding hip screw plate systems. There was no statistically significant difference using Parker's ratio method because this method quantifies the direction of the screw rather than the depth of penetration.

APOE-epsilon4 predisposes to cognitive dysfunction following uncomplicated carotid endarterectomy

BACKGROUND

Between 9% and 23% of patients undergoing otherwise uncomplicated carotid endarterectomy (CEA) develop subtle cognitive decline 1 month postoperatively. The APOE-epsilon4 allele has been associated with worse outcome following stroke.

OBJECTIVE

To investigate the ability of APOE-epsilon4 to predict post-CEA neurocognitive dysfunction.

METHODS

Seventy-five patients with CEA undergoing elective CEA were prospectively recruited in this nested cohort study and demographic variables were recorded. Patients were evaluated before and 1 month after surgery with a standard battery of five neuropsychological tests. APOE genotyping was performed by restriction fragment length polymorphism analysis in all patients. Neuropsychological deficits were identified by comparing changes (before to 1 month post-operation) in individual performance on the test battery. Logistic regression was performed for APOE-epsilon4 and previously identified risk factors.

RESULTS

Twelve of 75 (16%) CEA patients possessed the APOE-epsilon4 allele. Eight of 75 (11%) patients experienced neurocognitive dysfunction on postoperative day 30. One month post-CEA, APOE-epsilon4-positive patients were more likely to be cognitively injured (42%) than APOE-epsilon4-negative patients (5%) (p = 0.002). In multivariate analysis, the presence of the APOE-epsilon4 allele increased the risk of neurocognitive dysfunction at 1 month 62-fold (62.28, 3.15 to 1229, p = 0.007). Diabetes (51.42, 1.94 to 1363, p = 0.02), and obesity (24.43, 1.41 to 422.9, p = 0.03) also predisposed to injury.

CONCLUSION

The APOE-epsilon4 allele is a robust independent predictor of neurocognitive decline 1 month following CEA.

Neuropeptide B-deficient mice demonstrate hyperalgesia in response to inflammatory pain

Neuropeptide B (NPB) and neuropeptide W (NPW) have been recently identified as ligands for the G protein-coupled receptor (GPR) 7 and GPR8. The precise in vivo role of this neuropeptide-receptor pathway has not been fully demonstrated. In this paper, we report that NPB-deficient mice manifest a mild adult-onset obesity, similar to that reported in GPR7-null mice. NPB-deficient mice also exhibit hyperalgesia in response to inflammatory pain. Hyperalgesia was not observed in response to chemical pain, thermal pain, or electrical stimulation. NPB-deficient mice demonstrated intact behavioral responses to pain, and learning from the negative reinforcement of electrical stimulation was unaltered. Baseline anxiety was also unchanged as measured in both the elevated plus maze and time spent immobile in a novel environment. These data support the idea that NPB is a factor in the modulation of responses to inflammatory pain and body weight homeostasis.

Orexin neurons function in an efferent pathway of a food-entrainable circadian oscillator in eliciting food-anticipatory activity and wakefulness

Temporal restriction of feeding can entrain circadian behavioral and physiological rhythms in mammals. Considering the critical functions of the hypothalamic orexin (hypocretin) neuropeptides in promoting wakefulness and locomotor activity, we examined the role of orexin neurons in the adaptation to restricted feeding. In orexin neuron-ablated transgenic mice, the food-entrained rhythmicity of mPer2 expression in the brain and liver, the reversal of the sleep-wake cycle, and the recovery of daily food intake were unaltered compared with wild-type littermates. In contrast, orexin neuron-ablated mice had a severe deficit in displaying the normal food-anticipatory increases in wakefulness and locomotor activity under restricted feeding. Moreover, activity of orexin neurons markedly increased during the food-anticipatory period under restricted feeding in wild-type mice. Orexin neurons thus convey an efferent signal from putative food-entrainable oscillator or oscillators to increase wakefulness and locomotor activity.

Extrarenal ETBPlays a Significant Role in Controlling Cardiovascular Responses to High Dietary Sodium in Rats

Endothelin-B receptor (ET(B))-deficient rats have low-renin, salt-sensitive hypertension. We hypothesized this was caused by an absence of renal ET(B) signaling and performed a series of experiments to examine the effect of dietary sodium (Na) on endothelin-1 (ET1) expression and renal function in wild-type (WT) and ET(B)-deficient rats. We found that ET(B) deficiency, but not dietary Na, increases circulating and tissue (kidney and aorta) ET1 levels. Quantitative reverse-transcription polymerase chain reaction reveals that aortic and renal ET1 and endothelin-A receptor (ET(A)) mRNA, however, are similarly increased by dietary Na in ET(B)-WT and ET(B)-deficient rats. We then determined the effect of chronic ET(A) blockade on blood pressure (direct conscious measurements), urinary protein excretion, and creatinine clearance (Crcl). On a Na-deficient diet, ET(B)-deficient rats have mild proteinuria and impaired Crcl. On a high-Na diet, severe hypertension and renal dysfunction develop in ET(B)-deficient rats. Chronic ET(A) blockade prevents hypertension and renal injury. To determine the role of the renal versus the extrarenal endothelin system, we performed renal cross-transplantation. We found that ET(B) deficiency in the body is associated with renal injury and an impaired ability to excrete an Na load. We also found that ET(B) deficiency in the body affects blood pressure response to dietary Na. Expression of ET1 and ET(A) are regulated by dietary Na. ET(B) receptors outside of the kidney, likely by functioning as a clearance receptor for ET1, limit salt-sensitivity in rats.

Expression of a poly-glutamine-ataxin-3 transgene in orexin neurons induces narcolepsy-cataplexy in the rat

The sleep disorder narcolepsy has been linked to loss of hypothalamic neurons producing the orexin (hypocretin) neuropeptides. Here, we report the generation of transgenic rats expressing a human ataxin-3 fragment with an elongated polyglutamyl stretch under control of the human prepro-orexin promoter (orexin/ataxin-3 rats). At 17 weeks of age, the transgenic rats exhibited postnatal loss of orexin-positive neurons in the lateral hypothalamus, and orexin-containing projections were essentially undetectable. The loss of orexin production resulted in the expression of a phenotype with fragmented vigilance states, a decreased latency to rapid eye movement (REM) sleep and increased REM sleep time during the dark active phase. Wakefulness time was also reduced during the dark phase, and this effect was concentrated at the photoperiod boundaries. Direct transitions from wakefulness to REM sleep, a defining characteristic of narcolepsy, occurred frequently. Brief episodes of muscle atonia and postural collapse resembling cataplexy were also noted while rats maintained the electroencephalographic characteristics of wakefulness. These findings indicate that the orexin/ataxin-3 transgenic rat could provide a useful model of human narcolepsy.

Reducing unnecessary skull radiographs in children: a multidisciplinary audit

AIM

To review guidelines on the indications for skull radiographs with a view to improving compliance and reducing unnecessary irradiation of children.

METHODS

Three audits on the indications, compliance and effect on practice of differing sets of guidelines for skull radiographs following paediatric head trauma were performed. After each audit, alterations in clinical practice with modifications of the guidelines were implemented. The effect of these changes on radiological practice and patient care were recorded. Audits were performed for 3 months (February-April) in 1999, 2001 and 2003.

RESULTS

The number of children with head injuries presenting was unchanged. The number of skull radiographs performed fell from 146 in 1999 to 95 in 2001 and 50 in 2003. Compliance with hospital guidelines increased from 85% in 1999 to 100% in 2003. No neurosurgical problems were missed.

CONCLUSION

The implementation of guidelines that are acceptable to all specialties will improve compliance and reduce unnecessary radiographs being performed. The involvement of the radiography staff will help maintain compliance. The training of junior staff and maintaining good communication with involved departments will improve patient care.

Lower limb arthroplasty complicated by deep venous thrombosis. Prevalence and subjective outcome

The aim of this study was to determine the prevalence of deep venous thrombosis (DVT) following lower limb arthroplasty and to assess whether this adversely affected satisfaction, relief from pain, or the level of mobility as perceived by patients. Six hundred and ten consecutive recipients of primary total hip replacement (THR) or total knee replacement (TKR) underwent routine post-operative venography. The functional outcome had already been assessed at one year by using the Regional Arthroplasty Database questionnaire, the results of which were correlated to venographic records. The combined prevalence of DVT after THR and TKR in the patients, who did not receive chemical thromboprophylaxis, was 46.4%. Thrombus was identified in 57.6% of those with a TKR and in 33.5% of patients with a THR. Proximal thrombus was found in 11.0% of TKRs and in 14.8% of THRs. One year after surgery, patients who had a DVT established by venography did not report higher levels of immobility (p = 0.07), discomfort (p = 0.12) or dissatisfaction (p = 0.23) when compared to those with patent venous systems. This suggests that the prevalence of DVT following TKR/THR without chemical thromboprophylaxis is high and these findings are consistent with the literature. However, patients did not perceive thrombosis to compromise their overall outcome. This challenges the belief that DVT is associated with morbidity and calls for further comprehensive research in this area. The low morbidity of the lower limb associated with DVT in these patients does not support the use of chemical thromboprophylaxis.

Cell-autonomous and nonautonomous actions of endothelin-A receptor signaling in craniofacial and cardiovascular development

Craniofacial and cardiac development relies on the proper patterning of the neural crest-derived ectomesenchyme of the pharyngeal arches, from which many craniofacial and great vessel structures arise. One of the intercellular signaling molecules that is involved in this process, endothelin-1 (ET-1), is expressed in the arch epithelium and influences arch development by binding to its cognate receptor, the endothelin A (ET(A)) receptor, found on ectomesenchymal cells. We have previously shown that absence of ET(A) signaling in ET(A)(-/-) mouse embryos disrupts neural crest cell development, resulting in craniofacial and cardiovascular defects similar in many aspects to those in mouse models of DiGeorge syndrome. These changes may reflect a cell-autonomous requirement for ET(A) signaling during crest cell development because the ET(A) receptor is an intracellular signaling molecule. However, it is also possible that some of the observed defects in ET(A)(-/-) embryos could arise from the absence of downstream signaling that act in a non-cell-autonomous manner. To address this question, we performed chimera analysis using ET(A)(-/-) embryonic stem cells. We observe that, in almost all early ET(A)(-/-) --> (+/+) chimeric embryos, ET(A)(-/-) cells are excluded from the caudoventral aspects of the pharyngeal arches, suggesting a cell-autonomous role for ET(A) signaling in crest cell migration and/or colonization. Interestingly, in the few embryos in which mutant cells do reach the ventral arch, structures derived from this area are either composed solely of wild type cells or are missing, suggesting a second cell-autonomous role for ET(A) signaling in postmigratory crest cell differentiation. In the cardiac outflow tract and great vessels, ET(A)(-/-) cells are excluded from the walls of the developing pharyngeal arch arteries, indicating that ET(A) signaling also acts cell-autonomously during cardiac neural crest cell development.

Distinct narcolepsy syndromes in Orexin receptor-2 and Orexin null mice: molecular genetic dissection of Non-REM and REM sleep regulatory processes

Narcolepsy-cataplexy, a neurological disorder associated with the absence of hypothalamic orexin (hypocretin) neuropeptides, consists of two underlying problems: inability to maintain wakefulness and intrusion of rapid eye movement (REM) sleep into wakefulness. Here we document, using behavioral, electrophysiological, and pharmacological criteria, two distinct classes of behavioral arrests exhibited by mice deficient in orexin-mediated signaling. Both OX2R(-/-) and orexin(-/-) mice are similarly affected with behaviorally abnormal attacks of non-REM sleep ("sleep attacks") and show similar degrees of disrupted wakefulness. In contrast, OX2R(-/-) mice are only mildly affected with cataplexy-like attacks of REM sleep, whereas orexin(-/-) mice are severely affected. Absence of OX2Rs eliminates orexin-evoked excitation of histaminergic neurons in the hypothalamus, which gate non-REM sleep onset. While normal regulation of wake/non-REM sleep transitions depends critically upon OX2R activation, the profound dysregulation of REM sleep control unique to the narcolepsy-cataplexy syndrome emerges from loss of signaling through both OX2R-dependent and OX2R-independent pathways.

Characterization of a family of endogenous neuropeptide ligands for the G protein-coupled receptors GPR7 and GPR8

GPR7 and GPR8 are orphan G protein-coupled receptors that are highly similar to each other. These receptors are expressed predominantly in brain, suggesting roles in central nervous system function. We have purified an endogenous peptide ligand for GPR7 from bovine hypothalamus extracts. This peptide, termed neuropeptide B (NPB), has a C-6-brominated tryptophan residue at the N terminus. It binds and activates human GPR7 or GPR8 with median effective concentrations (EC(50)) of 0.23 nM and 15.8 nM, respectively. In situ hybridization shows distinct localizations of the prepro-NPB mRNA in mouse brain, i.e., in paraventricular hypothalamic nucleus, hippocampus, and several nuclei in midbrain and brainstem. Intracerebroventricular (i.c.v.) injection of NPB in mice induces hyperphagia during the first 2 h, followed by hypophagia. Intracerebroventricular injection of NPB produces analgesia to s.c. formalin injection in rats. Through EST database searches, we identified a putative paralogous peptide. This peptide, termed neuropeptide W (NPW), also has an N-terminal tryptophan residue. Synthetic human NPW binds and activates human GPR7 or GPR8 with EC(50) values of 0.56 nM and 0.51 nM, respectively. The expression of NPW mRNA in mouse brain is confined to specific nuclei in midbrain and brainstem. These findings suggest diverse physiological functions of NPB and NPW in the central nervous system, acting as endogenous ligands on GPR7 andor GPR8.

Improving the quality of patient care: patient satisfaction with a nurse-led fracture clinic service

A prospective study was conducted to assess nurse-led follow-up of patients with fracture.

Neuroglobin, a novel member of the globin family, is expressed in focal regions of the brain

Hemoproteins are widely distributed among unicellular eukaryotes, plants, and animals. In addition to myoglobin and hemoglobin, a third hemoprotein, neuroglobin, has recently been isolated from vertebrate brain. Although the functional role of this novel member of the globin family remains unclear, neuroglobin contains a heme-binding domain and may participate in diverse processes such as oxygen transport, oxygen storage, nitric oxide detoxification, or modulation of terminal oxidase activity. In this study we utilized in situ hybridization (ISH) and RT-PCR analyses to examine the expression of neuroglobin in the normoxic and hypoxic murine brain. In the normoxic adult mouse, neuroglobin expression was observed in focal regions of the brain, including the lateral tegmental nuclei, the preoptic nucleus, amygdala, locus coeruleus, and nucleus of the solitary tract. Using ISH and RT-PCR techniques, no significant changes in neuroglobin expression in the adult murine brain was observed in response to chronic 10% oxygen. These results support the hypothesis that neuroglobin is a hemoprotein that is expressed in the brain and may have diverse functional roles.

Depersonalization disorder: thinking without feeling

Patients with depersonalization disorder (DP) experience a detachment from their own senses and surrounding events, as if they were outside observers. A particularly common symptom is emotional detachment from the surroundings. Using functional magnetic resonance imaging (fMRI), we compared neural responses to emotionally salient stimuli in DP patients, and in psychiatric and healthy control subjects. Six patients with DP, 10 with obsessive-compulsive disorder (OCD), and six volunteers were scanned whilst viewing standardized pictures of aversive and neutral scenes, matched for visual complexity. Pictures were then rated for emotional content. Both control groups rated aversive pictures as much more emotive, and demonstrated in response to these scenes significantly greater activation in regions important for disgust perception, the insula and occipito-temporal cortex, than DP patients (covarying for age, years of education and total extent of brain activation). In DP patients, aversive scenes activated the right ventral prefrontal cortex. The insula was activated only by neutral scenes in this group. Our findings indicate that a core phenomenon of depersonalization--absent subjective experience of emotion--is associated with reduced neural responses in emotion-sensitive regions, and increased responses in regions associated with emotion regulation.

Normal-appearing white matter in ischemic leukoaraiosis: a diffusion tensor MRI study

Ischemic leukoaraiosis is a consistent concomitant of vascular dementia. Conventional MRI provides little information about underlying white matter tract disruption and correlates poorly with cognitive dysfunction. Diffusion tensor MRI may provide better markers of tract integrity. Changes in the normal-appearing white matter were demonstrated in 30 patients with ischemic leukoaraiosis compared with 17 age-matched control subjects. These changes correlated with executive dysfunction assessed by the Wisconsin Card Sorting Test.

Functional magnetic resonance imaging of odor identification: the effect of aging

BACKGROUND

Sense of smell declines with age and impairment in olfaction has been observed in some neurodegenerative disorders such as Alzheimer's disease. Functional neuroimaging techniques enable researchers to observe brain regions activated by olfactory stimuli.

METHODS

We gave three mainly olfactory-mediated odors (limonene, methylsalicylate, and eugenol) to six young and six elderly subjects and observed the areas activated by using blood oxygen level dependent contrast functional magnetic resonance imaging.

RESULTS

The group mapping of young subjects showed extensive activation in the orbitofrontal cortex, commonly believed to be the olfactory cortex, some limbic areas (the hippocampus and the thalamus), regions involved with gustatory sensation (the anterior insula and the inferior postcentral gyrus), superior and inferior temporal gyri, and cerebellum. In the elderly group, only the left inferior temporal gyrus and the primary visual cortex reached accepted significance levels.

CONCLUSIONS

We have therefore confirmed previous reports of brain regions involved in olfactory processing in young volunteers and demonstrated decreased activation in elderly volunteers.

Delaying the initiation of progesterone supplementation results in decreased pregnancy rates after in vitro fertilization: a randomized, prospective study

OBJECTIVE

To compare IVF outcome between two protocols for luteal phase supplementation, one beginning on day 3 after oocyte retrieval and the other beginning on day 6 after retrieval.

DESIGN

Prospective, randomized study.

SETTING

University-based assisted reproductive technology center.

PATIENT(S)

One hundred twenty-six consecutive patients undergoing IVF between January and July 2000.

INTERVENTION(S)

Patients were randomized to begin luteal phase support using vaginal progesterone beginning either on day 3 after oocyte retrieval or on day 6 after oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rates and implantation rates.

RESULT(S)

All patients randomized underwent transfer. There were no differences in age, oocytes retrieved, or embryos transferred between the two groups. Those patients receiving luteal phase support with progesterone beginning on day 6 after retrieval had a significantly lower clinical pregnancy rate per transfer compared with those beginning support on day 3 after retrieval (44.8% vs. 61.0%, respectively). This difference in pregnancy rates was greater in those patients undergoing a luteal gonadotropin releasing hormone (GnRH) agonist down-regulation protocol (47.5% vs. 71.4%, day 6 vs. day 3, respectively). Beginning support on day 6 also significantly decreased implantation rates in the GnRH agonist group (21.0% vs. 34.0%, day 6 vs. day 3, respectively).

CONCLUSION(S)

Pregnancy rates are significantly decreased by initiating luteal-phase progesterone supplementation on day 6 after oocyte retrieval during in vitro fertilization cycles.

Neuroimaging correlates of negative priming

Many theoretical accounts of selective attention and memory retrieval include reference to active inhibitory processes, such as those argued to underlie the negative priming effect. fMRI was used in order to investigate the areas of cortical activation associated with Stroop interference, Stroop facilitation and Stroop negative priming tasks. The most significant activation within the negative priming task was within the inferior parietal lobule, left temporal lobe and frontal lobes. Areas of cortical activation are discussed with reference to theoretical accounts of the negative priming effect.

Volumetric analysis reveals corticospinal tract degeneration and extramotor involvement in ALS

BACKGROUND

Pathologic changes in the motor cortex and corticospinal tracts in ALS may be reflected by abnormal signal intensities on conventional MRI. The sensitivity of these changes in detecting underlying pathology remains unclear.

METHOD

The authors used automated image analysis to quantify volumes of cerebral gray and white matter in 16 patients with ALS (eight limb onset, eight bulbar onset) and eight normal controls. Previously they had demonstrated a reduction in N-acetyl aspartate/creatine + phosphocreatine (NAA/[Cr + PCr]) measured by (1)H-MRS in the subcortical white matter in the motor cortex region in the patients with bulbar-onset ALS. To determine whether this resulted from axonal degeneration, they also compared gray and white matter volumes in the patients with limb- and bulbar-onset ALS.

RESULTS

There were no differences in the total brain volumes of gray or white matter for the three subject groups (p > 0.23). Comparison of the total ALS group and controls revealed localized deficits in gray matter volume centered on Brodmann areas 8, 9, and 10 bilaterally. Comparison of the patients with limb- and bulbar-onset ALS revealed deficits in the white matter volume in the bulbar-onset group, extending bilaterally from the precentral gyrus into the internal capsule and brainstem, consistent with the course of the corticospinal tract. There was no loss in gray matter volume in the precentral gyri.

CONCLUSIONS

The loss of gray matter in the frontal regions (total ALS group) provides further support that ALS is a multisystem disorder. In addition, there is in vivo evidence of axonal degeneration in the subcortical white matter in the motor region in patients with bulbar-onset ALS. This is consistent with a "dying back" process affecting cortical motoneurons in bulbar-onset ALS.

Brain activation during automatic and controlled processing of semantic relations: a priming experiment using lexical-decision

Semantic relations may be studied using the experimental technique known as semantic priming, in which a word 'primes' the processing of a related target (e.g. lion-tiger), following a short delay. Priming may be automatic or, with longer delays, under more controlled processing. This study used functional magnetic resonance imaging (fMRI) to examine the cerebral activation during two lexical-decision semantic priming experiments, with a short and long delay, representing automatic and controlled processing, respectively. A further two un-primed lexical-decision tasks were performed to distinguish cerebral activation specific to semantic priming itself from those utilised during lexical-decision processes. Distinct regions of anterior cingulate cortex (ACC) were critical to automatic and controlled semantic priming, whilst the putamen and hippocampal complex responded differently to unrelated and semantically related prime-target pairs. Lexical-decision alone revealed activation in posterior temporal cortex especially on the left, in agreement with previous neuroimaging studies. The results provide a plausible neural substrate for common semantic relations independent of task demands and further emphasise the regional functional specialisation of the ACC.

Distributed grey and white matter deficits in hyperkinetic disorder: MRI evidence for anatomical abnormality in an attentional network

BACKGROUND

Previous neuroimaging studies of children with attention deficit hyperactivity disorder (ADHD) have demonstrated anatomic and functional abnormalities predominantly in frontal and striatal grey matter. Here we report the use of novel image analysis methods, which do not require prior selection of regions of interest, to characterize distributed morphological deficits of both grey and white matter associated with ADHD.

METHODS

Eighteen children with a refined phenotype of ADHD, who also met ICD-10 criteria for hyperkinetic disorder (mean age 10.4 years), and 16 normal children (mean age 10.3 years) were compared using magnetic resonance imaging. The groups were matched for handedness, sex, height, weight and head circumference. Morphological differences between groups were estimated by fitting a linear model at each voxel in standard space, applying a threshold to the resulting voxel statistic maps to generate clusters of spatially contiguous suprathreshold voxels, and testing cluster 'mass', or the sum of suprathreshold voxel statistics in each 2D cluster, by repeated random resampling of the data.

RESULTS

The hyperkinetic children had significant grey matter deficits in right superior frontal gyrus (Brodmann area (BA) 8/9), right posterior cingulate gyrus (BA 30) and the basal ganglia bilaterally (especially right globus pallidus and putamen). They also demonstrated significant central white matter deficits in the left hemisphere anterior to the pyramidal tracts and superior to the basal ganglia.

CONCLUSIONS

This pattern of spatially distributed grey matter deficit in the right hemisphere is compatible with the hypothesis that ADHD is associated with disruption of a large scale neurocognitive network for attention. The left hemispheric white matter deficits may be due to dysmyelination.

Widespread anatomical abnormalities of grey and white matter structure in tuberous sclerosis

BACKGROUND

Neuroimaging studies of tuberous sclerosis complex (TSC) have previously focused mainly on tubers or subependymal nodules. Subtle pathological changes in the structure of the brain have not been studied in detail. Computationally intensive techniques for reliable morphometry of brain structure are useful in disorders like TSC, where there is little prior data to guide selection of regions of interest.

METHODS

Dual-echo, fast spin-echo MRI data were acquired from 10 TSC patients of normal intelligence and eight age-matched controls. Between-group differences in grey matter, white matter and cerebrospinal fluid were estimated at each intracerebral voxel after registration of these images in standard space; a permutation test based on spatial statistics was used for inference. CSF-attenuated FLAIR images were acquired for neuroradiological rating of tuber number.

RESULTS

Significant deficits were found in patients, relative to comparison subjects, of grey matter volume bilaterally in the medial temporal lobes, posterior cingulate gyrus, thalamus and basal ganglia, and unilaterally in right fronto-parietal cortex (patients -20%). We also found significant and approximately symmetrical deficits of central white matter involving the longitudinal fasciculi and other major intrahemispheric tracts (patients -21%); and a bilateral cerebellar region of relative white matter excess (patients +28%). Within the patient group, grey matter volume in limbic and subcortical regions of deficit was negatively correlated with tuber count.

CONCLUSIONS

Neuropathological changes associated with TSC may be more extensive than hitherto suspected, involving radiologically normal parenchymal structures as well as tubers, although these two aspects of the disorder may be correlated.

Modality specific neural correlates of auditory and somatic hallucinations

Somatic hallucinations occur in schizophrenia and other psychotic disorders, although auditory hallucinations are more common. Although the neural correlates of auditory hallucinations have been described in several neuroimaging studies, little is known of the pathophysiology of somatic hallucinations. Functional magnetic resonance imaging (fMRI) was used to compare the distribution of brain activity during somatic and auditory verbal hallucinations, occurring at different times in a 36 year old man with schizophrenia. Somatic hallucinations were associated with activation in the primary somatosensory and posterior parietal cortex, areas that normally mediate tactile perception. Auditory hallucinations were associated with activation in the middle and superior temporal cortex, areas involved in processing external speech. Hallucinations in a given modality seem to involve areas that normally process sensory information in that modality.

Differential frontal activation in schizophrenia and bipolar illness during verbal fluency

INTRODUCTION

The precise nature of frontal lobe dysfunction in schizophrenia remains unclear. We have previously demonstrated, using fMRI, a task-specific attenuation of frontal activation in schizophrenic patients. By using an identical methodology in matched bipolar subjects, we sought to determine whether this finding is specific to schizophrenia or a correlate of psychosis in general.

METHOD

Five dextral male bipolar patients and matching groups of schizophrenic subjects and controls were studied using fMRI. Echoplanar images were acquired while subjects performed two paced tasks: covert verbal fluency and a semantic decision task. Generic brain activation maps were constructed from individual images by sinusoidal regression analysis. Between-group differences in the mean power of experimental response were identified on a voxel-wise basis by an analysis of variance (ANOVA).

RESULTS

The bipolar patients showed extensive prefrontal activation during verbal fluency which was significantly greater than in controls. There was no difference in the prefrontal BOLD response during the semantic decision task.

CONCLUSIONS

These data indicate that bipolar patients show a strikingly different pattern of frontal responses compared to those with schizophrenia and provide further evidence that abnormal frontal activation in psychotic disorders is more apparent during verbal fluency than semantic decision.