Towards non-invasive peripheral stimulation as a treatment for Parkinson's disease gait

Non-invasive coordinated reset stimulation (CRS) to the hands has been shown to improve motor ability in Parkinson's patients, but not specific for gait disturbances. The overall aim of the project is the application of vibrotactile CRS to the feet to improve gait impairments in Parkinson's disease. As a first step towards this objective, we showed that vibrotactile stimulation to the feet can elicit a cortical response and have identified differences in younger and older individuals. Our findings suggest the potential for non-invasive peripheral stimulation as a therapeutic technique.Clinical Relevance- This is an important step towards developing a non-invasive stimulation technique for the management of gait disturbances in Parkinson's disease.

Antipsychotic prescribing choices in patients with First Episode Psychosis

Introduction

As all first line options in treating First Episode Psychosis (FEP) are similarly effective there is a consensus among prescribing guidelines that clinicians and patients should consider side-effect profile as the ‘driver’ of initial choice of antipsychotic. Anecdotally it has been observed that different care teams prescribe particular medications preferentially.

Objectives

To evaluate the patterns of antipsychotic prescribing in patients with FEP at the time of initial treatment and over the first year with the Early Intervention Service (EIS).

Methods

Medical records of all patients who had completed 1 year of follow-up with EIS in Sussex Partnership Foundation Trust (n=274) were reviewed. The first antipsychotic prescribed and antipsychotic prescribed at 12-months was recorded alongside initiating care team (EIS, non-EIS community services, inpatient services).

Results

99% (n=272) of patients were prescribed an antipsychotic. 46% were initiated by inpatient serves, 40% non-EIS community services and 14% EIS. Aripiprazole, olanzapine, quetiapine and risperidone accounted for 95% of initial prescriptions. Different care teams prescribed antipsychotics preferentially (p=<0.005) (Fig.1). Rates at which initial medication was continued at 12-months varied according to initial prescription (P=<0.05) (Fig.2).

Conclusions

The frequency that specialist EIS services prescribed aripiprazole as initial treatment contrasts the preference for olanzapine in other services. Olanzapine has a significant metabolic side effect profile, is sedating and was least likely to be continued at 12 months. This raises questions about why non-FEP specialist services prefer olanzapine and whether EIS services can support these services around initial medication choices more likely to be continued throughout the key first year of treatment.

Disclosure

No significant relationships.

Retrospective Analysis of COVID-19 Conversion Rate Among Anesthesiologists in Acute Care Centers

Brief description of the primary research objective

Among healthcare workers, anesthesiologists are regarded as frequently exposed frontline providers in the fight against COVID-19 due to their proximity to patient airways and involvement in aerosolized procedures. As such, the risk of contracting the COVID-19 virus as an occupational hazard is presumed to be higher. To date, in most published studies, all healthcare workers were grouped together, independent of specialty or profession. At the time that this survey was distributed, we did not find any peer-reviewed articles that differentiated COVID-19 infection rates among frontline, such as anesthesiologists vs. non-frontline healthcare workers. This retrospective survey’s primary research objective was to report the rate of COVID-19 infection among anesthesiologists compared to the general population of healthcare workers.

Methodology

A survey was sent among anesthesiology attendings and residents in Northern New Jersey and Brooklyn, New York hospitals on duty during the peak pandemic from March 2020 to May 2020. Questions in the survey focused on infection rates and adherence to standards of infection precaution and personal protective equipment (PPE) utilization.

Main Findings

This retrospective study highlights the rate of infection among anesthesiologists as a particularly vulnerable subgroup of frontline residents and physicians, as they are called to duty when emergent airway management is required. In our study, the reported rate of contracting COVID-19 among anesthesiologists was 16.7%. This statistic is higher than the infection rates published by studies by New York State and the CDC.

Conclusion

The survey sent to anesthesiologists is useful to understand the impact of COVID-19 on this subgroup of frontline providers and the importance of adhering to standards of infection protocol and the role of PPE.

An open and closed case: timing of closure following laparostomy

INTRODUCTION

Laparostomy is important in the management of patients with intra-abdominal gastrointestinal catastrophe or trauma. It carries significant risk and is resource intensive, both in terms of nursing and surgically. The main goal is to achieve prompt myofascial closure (MFC) in order to minimise morbidity and mortality. Early MFC was initially defined as within 2-3 weeks but there is growing evidence that this should be measured in days.

METHODS

Retrospective analysis was undertaken of laparostomy cases between 2016 and 2018 at an acute trust and trauma centre serving a population of 500,000. Indication, duration of open abdomen (OA), number of relook procedures and consultant presence were examined to see whether they affected MFC rates, morbidity and mortality.

RESULTS

Overall, 76 laparostomies were performed during the 3-year study period. The most common indication was peritonitis (68.4%). As duration of OA and number of relook procedures increased, the chances of MFC fell significantly. After day 1, MFC rates fell by 20% with each subsequent 24 hours. Leaving the abdomen open primarily at index procedure compared with performing laparostomy following a postoperative complication was associated with significantly higher MFC rates (92.6% vs 68.2%, (p=0.006). The mortality rate was 15.8%.

CONCLUSIONS

If the OA is not closed within five days or by the third relook procedure, then achieving MFC is unlikely. Alternative methods should be employed to close the abdomen rather than continuing to take the patient back to theatre for relook laparotomies while increasing the risk of morbidity and mortality. A proactive strategy to forming primary laparostomy at the index procedure has high closure rates.

353. A Comparison Study of Prevalence and Risk Factors for Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH) by Transient Elastography (TE) in HIV-Infected Patients

Background

There are limited data on the prevalence and risk factors of NAFLD and NASH in HIV-infected individuals receiving ART. A large study on this subject was presented at Glasgow 2018, from the University Hospital of Palermo (UHP).

Methods

We prospectively collected data on epidemiology, comorbidities, CD4, HIV virus load and ART from November 2017 to September 2018 in patients undergoing TE examination with Controlled Attenuation Parameter (CAP) in our HIV clinic at Saint Michael’s Medical Center in Newark, NJ. We used the same parameters to define NAFLD and fibrosis severity that were used for the UHP (CAP >248 dB/m and TE > 7.1 Kpa). We present comparative data between those 2 cohorts.

Results

We enrolled 624 consecutive HIV-infected individuals (group 1) their baseline epidemiologic characteristics were not significantly different from the UHP cohort (group 2) for age and sex. Prevalence of NAFLD was 51.6% in group 1compared with 42.7% in group 2, and the prevalence of significant fibrosis in those with NAFLD was 31% in group 1, and 23% in group 2. The main differences we found between those 2 cohorts were race: group 1, 68% black and group 2, 87% White, incidence of Diabetes mellitus was 20% in group 1, and 6% in group 2, despite the fact that BMI was not significantly higher in group 1. Other important differences were the mean time on ART, it was 5 years longer for group 1. Finally, there was a trend for a higher incidence of hypertension, a lower percentage of patients with Virus load < 20 c/mL, a lower mean CD4 count, and a higher percentage of integrase strand transfer inhibitors current users in group1.

Conclusion

NAFLD prevalence is alarming high in patients with HIV disease, it is of utmost importance to understand its natural history, in order to prevent the potentially severe consequences of NASH. Our study suggests that a longer duration on ART might correlate with higher incidence of NAFLD, which would suggest better monitoring of liver health with new ART.

Disclosures

All authors: No reported disclosures.

Observations on the “Cytoskeleton” of Human Platelets

Structural study of rapidly lysed platelets supports the view that that shape change involves a change in state of the microfilaments which contain actin. The microtubule “bundle” appears to be a continuous coil. Proteolysis of a high molecular weight band is observed in platelets which can no longer form filopodia after suppression by local anesthetics.

Neandertal Introgression Sheds Light on Modern Human Endocranial Globularity

One of the features that distinguishes modern humans from our extinct relatives and ancestors is a globular shape of the braincase [1-4]. As the endocranium closely mirrors the outer shape of the brain, these differences might reflect altered neural architecture [4, 5]. However, in the absence of fossil brain tissue, the underlying neuroanatomical changes as well as their genetic bases remain elusive. To better understand the biological foundations of modern human endocranial shape, we turn to our closest extinct relatives: the Neandertals. Interbreeding between modern humans and Neandertals has resulted in introgressed fragments of Neandertal DNA in the genomes of present-day non-Africans [6, 7]. Based on shape analyses of fossil skull endocasts, we derive a measure of endocranial globularity from structural MRI scans of thousands of modern humans and study the effects of introgressed fragments of Neandertal DNA on this phenotype. We find that Neandertal alleles on chromosomes 1 and 18 are associated with reduced endocranial globularity. These alleles influence expression of two nearby genes, UBR4 and PHLPP1, which are involved in neurogenesis and myelination, respectively. Our findings show how integration of fossil skull data with archaic genomics and neuroimaging can suggest developmental mechanisms that may contribute to the unique modern human endocranial shape.

Wireless induction coils embedded in diamond for power transfer in medical implants

Wireless power and data transfer to medical implants is a research area where improvements in current state-of-the-art technologies are needed owing to the continuing efforts for miniaturization. At present, lithographical patterning of evaporated metals is widely used for miniature coil fabrication. This method produces coils that are limited to low micron or nanometer thicknesses leading to high impedance values and thus limiting their potential quality. In the present work we describe a novel technique, whereby trenches were milled into a diamond substrate and filled with silver active braze alloy, enabling the manufacture of small, high cross-section, low impedance microcoils capable of transferring up to 10 mW of power up to a distance of 6 mm. As a substitute for a metallic braze line used for hermetic sealing, a continuous metal loop when placed parallel and close to the coil surface reduced power transfer efficiency by 43%, but not significantly, when placed perpendicular to the microcoil surface. Encapsulation of the coil by growth of a further layer of diamond reduced the quality factor by an average of 38%, which can be largely avoided by prior oxygen plasma treatment. Furthermore, an accelerated ageing test after encapsulation showed that these coils are long lasting. Our results thus collectively highlight the feasibility of fabricating a high-cross section, biocompatible and long lasting miniaturized microcoil that could be used in either a neural recording or neuromuscular stimulation device.

The brain anatomy of attention-deficit/hyperactivity disorder in young adults - a magnetic resonance imaging study

Background

This is one of the first studies to examine the structural brain anatomy and connectivity associated with an ADHD diagnosis and child as well as adult ADHD symptoms in young adults. It was hypothesized that an adult ADHD diagnosis and in particular childhood symptoms, are associated with widespread changes in the brain macro- and microstructure, which can be used to develop a morphometric biomarker for ADHD.

Methods

Voxel-wise linear regression models were used to examine structural and diffusion-weighted MRI data in 72 participants (31 young adults with ADHD and 41 controls without ADHD) in relation to diagnosis and the number of self-reported child and adult symptoms.

Results

Findings revealed significant associations between ADHD diagnosis and widespread changes to the maturation of white matter fiber bundles and gray matter density in the brain, such as structural shape changes (incomplete maturation) of the middle and superior temporal gyrus, and fronto-basal portions of both frontal lobes. ADHD symptoms in childhood showed the strongest association with brain macro- and microstructural abnormalities. At the brain circuitry level, the superior longitudinal fasciculus (SLF) and cortico-limbic areas are dysfunctional in individuals with ADHD. The morphometric findings predicted an ADHD diagnosis correctly up to 83% of all cases.

Conclusion

An adult ADHD diagnosis and in particular childhood symptoms are associated with widespread micro- and macrostructural changes. The SLF and cortico-limbic findings suggest complex audio-visual, motivational, and emotional dysfunctions associated with ADHD in young adults. The sensitivity of the morphometric findings in predicting an ADHD diagnosis was sufficient, which indicates that MRI-based assessments are a promising strategy for the development of a biomarker.

Extended interval dosing of natalizumab in multiple sclerosis

BACKGROUND

Natalizumab (NTZ), a monoclonal antibody to human α4β1/β7 integrin, is an effective therapy for multiple sclerosis (MS), albeit associated with progressive multifocal leukoencephalopathy (PML). Clinicians have been extending the dose of infusions with a hypothesis of reducing PML risk. The aim of the study is to evaluate the clinical consequences of reducing NTZ frequency of infusion up to 8 weeks 5 days.

METHODS

A retrospective chart review in 9 MS centres was performed in order to identify patients treated with extended interval dosing (EID) regimens of NTZ. Patients were stratified into 3 groups based on EID NTZ treatment schedule in individual centres: early extended dosing (EED; n=249) every 4 weeks 3 days to 6 weeks 6 days; late extended dosing (LED; n=274) every 7 weeks to 8 weeks 5 days; variable extended dosing (n=382) alternating between EED and LED. These groups were compared with patients on standard interval dosing (SID; n=1093) every 4 weeks.

RESULTS

17% of patients on SID had new T2 lesions compared with 14% in EID (p=0.02); 7% of patients had enhancing T1 lesions in SID compared with 9% in EID (p=0.08); annualised relapse rate was 0.14 in the SID group, and 0.09 in the EID group. No evidence of clinical or radiographic disease activity was observed in 62% of SID and 61% of EID patients (p=0.83). No cases of PML were observed in EID group compared with 4 cases in SID cohort.

CONCLUSIONS

Dosing intervals up to 8 weeks 5 days did not diminish effectiveness of NTZ therapy. Further monitoring is ongoing to evaluate if the risk of PML is reduced in patients on EID.

Epigenetic mechanisms and associated brain circuits in the regulation of positive emotions: A role for transposable elements

Epigenetic programming and reprogramming are at the heart of cellular differentiation and represent developmental and evolutionary mechanisms in both germline and somatic cell lines. Only about 2% of our genome is composed of protein-coding genes, while the remaining 98%, once considered "junk" DNA, codes for regulatory/epigenetic elements that control how genes are expressed in different tissues and across time from conception to death. While we already know that epigenetic mechanisms are at play in cancer development and in regulating metabolism (cellular and whole body), the role of epigenetics in the developing prenatal and postnatal brain, and in maintaining a proper brain activity throughout the various stages of life, in addition to having played a critical role in human evolution, is a relatively new domain of knowledge. Here we present the current state-of-the-art techniques and results of these studies within the domain of emotions, and then speculate on how genomic and epigenetic mechanisms can modify and potentially alter our emotional (limbic) brain and affect our social interactions. J. Comp. Neurol. 524:2944-2954, 2016. © 2016 Wiley Periodicals, Inc.

Increased brain activity to unpleasant stimuli in individuals with the 7R allele of the DRD4 gene

The aim of the study was to examine functional brain activity in response to unpleasant images in individuals with the 7-repeat (7R) allele compared to individuals with the 4-repeat (4R) allele of the dopamine receptor D4 (DRD4) gene (VNTR in exon 3). Based on the response ready hypothesis, individuals with the DRD4-4R/7R genotype were expected to show greater functional brain activity in response to unpleasant compared to neutral stimuli in specific regions of the frontal, temporal, parietal and limbic lobes, which form the networks involved in attentional, emotional, and preparatory responses. Functional Magnetic Resonance Imaging activity was studied in 26 young adults (13 with the DRD4-4R/7R genotype and 13 with the DRD4-4R/4R genotype). Participants were asked to look at and subjectively rate unpleasant and neutral images. Results showed increased brain activity in response to unpleasant images compared to neutral images in the right temporal lobe in participants with the DRD4-4R/7R genotype versus participants with the DRD4-4R/4R genotype. The increase in right temporal lobe activity in individuals with DRD4-4R/7R suggests greater involvement in processing negative emotional stimuli. Intriguingly, no differences were found between the two genotypes in the subjective ratings of the images. The findings corroborate the response ready hypothesis, which suggests that individuals with the 7R allele are more responsive to negative emotional stimuli compared to individuals with the 4R allele of the DRD4 gene.

An improved cochlear implant electrode array for use in experimental studies

Experimental studies play an important role in establishing the safety and efficacy of cochlear implants and they continue to provide insight into a new generation of electrode arrays and stimulation strategies. One drawback has been the limited depth of insertion of an electrode array in experimental animals. We compared the insertion depth and trauma associated with the insertion of Cochlear Ltd's Hybrid-L (HL) array with a standard 8 ring array in cat cochleae. Both arrays were inserted into cadaver cochleae and an X-ray recorded their anatomical location. The implanted cochlea was serially sectioned and photographed at 300 μm intervals for evidence of electrode insertion trauma. Subsequently two cats were chronically implanted with HL arrays and electrically-evoked potentials recorded over a three month period. Mean insertion depth for the HL arrays was 334.8° (SD = 21°; n = 4) versus 175.5° (SD = 6°; n = 2) for the standard array. This relates to ∼10.5 mm and 6 mm respectively. A similar insertion depth was measured in a chronically implanted animal with an HL array. Histology from each cadaver cochleae showed that the electrode array was always located in the scala tympani; there was no evidence of electrode insertion trauma to the basilar membrane, the osseous spiral lamina or the spiral ligament. Finally, evoked potential data from the chronically implanted animals exhibited significantly lower thresholds compared with animals implanted with a standard 8 ring array, with electrical thresholds remaining stable over a three-month observation period. Cochlear Ltd's HL electrode array can be safely inserted ∼50% of the length of the cat scala tympani, placing the tip of the array close to the 4 kHz place. This insertion depth is considerably greater than is routinely achieved using a standard 8-ring electrode array (∼12 kHz place). The HL array evokes low thresholds that remain stable over three months of implantation. This electrode array has potential application in a broad area of cochlear implant related research.

Enhanced oncolytic potency of vesicular stomatitis virus through vector-mediated inhibition of NK and NKT cells

Recombinant oncolytic viruses represent a promising alternative option for the treatment of malignant cancers. We have reported earlier the safety and efficacy of recombinant vesicular stomatitis virus (VSV) vectors in a rat model of hepatocellular carcinoma (HCC). However, the full potential of VSV therapy is limited by a sudden decline in intratumoral virus replication observed early after viral administration, a phenomenon that coincides with an accumulation of inflammatory cells within infected lesions. To overcome the antiviral function of these cells, we present a recombinant virus, rVSV-UL141, which expresses a protein from human cytomegalovirus known to downregulate the natural killer (NK) cell-activating ligand CD155. The modified vector resulted in an inhibition of NK cell recruitment in vitro, as well as decreased intratumoral accumulations of NK and NKT cells in vivo. Administration of rVSV-UL141 through hepatic artery infusion in immune-competent Buffalo rats harboring orthotopic, multi-focal HCC lesions resulted in a one-log elevation of intratumoral virus replication over a control rVSV vector, which translated to enhance tumor necrosis and substantial prolongation of survival. Moreover, these results were achieved in the absence of apparent toxicities. The present study suggests the applicability of this strategy for the development of effective and safe oncolytic agents to treat multi-focal HCC, and potentially a multitude of other cancers, in the future.

Sex differences in brain activity during aversive visceral stimulation and its expectation in patients with chronic abdominal pain: a network analysis

Differences in brain responses to aversive visceral stimuli may underlie previously reported sex differences in symptoms as well as perceptual and emotional responses to such stimuli in patients with irritable bowel syndrome (IBS). The goal of the current study was to identify brain networks activated by expected and delivered aversive visceral stimuli in male and female patients with chronic abdominal pain, and to test for sex differences in the effective connectivity of the circuitry comprising these networks. Network analysis was applied to assess the brain response of 46 IBS patients (22 men and 24 women) recorded using [15O] water positron emission tomography during rest/baseline and expected and delivered aversive rectal distension. Functional connectivity results from partial least squares analyses provided support for the hypothesized involvement of 3 networks corresponding to: 1) visceral afferent information processing (thalamus, insula and dorsal anterior cingulate cortex, orbital frontal cortex), 2) emotional-arousal (amygdala, rostral and subgenual cingulate regions, and locus coeruleus complex) and 3) cortical modulation (frontal and parietal cortices). Effective connectivity results obtained via structural equation modeling indicated that sex-related differences in brain response are largely due to alterations in the effective connectivity of emotional-arousal circuitry rather than visceral afferent processing circuits. Sex differences in the cortico-limbic circuitry involved in emotional-arousal, pain facilitation and autonomic responses may underlie the observed differences in symptoms, and in perceptual and emotional responses to aversive visceral stimuli.

Visualizing whole-brain DTI tractography with GPU-based Tuboids and LoD management

Diffusion Tensor Imaging (DTI) of the human brain, coupled with tractography techniques, enable the extraction of large-collections of three-dimensional tract pathways per subject. These pathways and pathway bundles represent the connectivity between different brain regions and are critical for the understanding of brain related diseases. A flexible and efficient GPU-based rendering technique for DTI tractography data is presented that addresses common performance bottlenecks and image-quality issues, allowing interactive render rates to be achieved on commodity hardware. An occlusion query-based pathway LoD management system for streamlines/streamtubes/tuboids is introduced that optimizes input geometry, vertex processing, and fragment processing loads, and helps reduce overdraw. The tuboid, a fully-shaded streamtube impostor constructed entirely on the GPU from streamline vertices, is also introduced. Unlike full streamtubes and other impostor constructs, tuboids require little to no preprocessing or extra space over the original streamline data. The supported fragment processing levels of detail range from texture-based draft shading to full raycast normal computation, Phong shading, environment mapping, and curvature-correct text labeling. The presented text labeling technique for tuboids provides adaptive, aesthetically pleasing labels that appear attached to the surface of the tubes. Furthermore, an occlusion query aggregating and scheduling scheme for tuboids is described that reduces the query overhead. Results for a tractography dataset are presented, and demonstrate that LoD-managed tuboids offer benefits over traditional streamtubes both in performance and appearance.

Lipid rafts are involved in C95 (4,8) agrin fragment-induced acetylcholine receptor clustering

During development of the neuromuscular junction, high densities of acetylcholine receptors accumulate beneath the overlying nerve terminal. A defining feature of mature synapses is the sharp demarcation of acetylcholine receptor density, which is approximately 1000-fold higher in the postsynaptic as compared with the contiguous extrasynaptic muscle membrane. These high densities of receptors accumulate by at least four mechanisms, re-distribution of existing surface receptors, local synthesis of new receptors, decreased turnover of synaptic receptors, and limitation of diffusion of sub-neural, aggregated receptors. The limitation of receptor diffusion within the membrane is likely in part due to the anchoring of acetylcholine receptor complexes to components of the cytoskeleton. Here we have tested the idea that lipid rafts--mobile, cholesterol enriched microdomains within the lipid bilayer--are another mechanism by which acetylcholine receptors are clustered in the postsynaptic apparatus. Using mouse C2C12 cells, a muscle cell line, we show that a carboxy terminal 95 amino acid fragment [C95 (4,8)] of the extracellular matrix molecule agrin that is essential for nerve-induced postsynaptic differentiation, promotes the redistribution of acetylcholine receptors into lipid rafts. Disruption of lipid rafts before agrin treatment largely inhibits de novo agrin-induced acetylcholine receptor clustering. Moreover, mature acetylcholine receptor clusters are destabilized if lipid rafts are disrupted. These results show that lipid rafts are important in both the initial clustering and later stabilization of agrin-induced acetylcholine receptor clusters and also suggest that lipid rafts may contribute to the postsynaptic localization of acetylcholine receptors in vivo.

Effect of APOE genotype on microvascular basement membrane in Alzheimer's disease

APOE4 homozygosity has been associated with an increased risk of sporadic Alzheimer's disease through a mechanism, which has yet to be defined. Recent evidence has suggested that microvascular basement membrane injury may be a critical factor in the pathogenesis of AD-related dementia. In previous studies, we have shown that the synaptic organizing protein agrin can be found in neurons, and is a major component of the brain microvascular basement membrane. Here, we compare the basement membrane surface area of cortical microvasculature in AD brains by staining with an anti-agrin antibody. Quantitative morphometric analysis was used to determine the mean basement area (micro(2)) of prefrontal cortical microvessels. An average of 10 capillaries was measured in each of 35 cases of AD genotyped for APOE status. APOE4,4 homozygotes had smaller capillary basement membrane areas (17.4 micro(2))+/-6.2) than APOE3,3 homozygotes (26.9 micro(2)+/-6.5), p<0.001. The capillary basement membrane areas (CBMA) of heterozygotes APOE3,4 did not differ significantly from APOE3,3 or APOE4,4. Braak stage did not contribute significantly to CBMA. However, a preliminary analysis suggests an interaction between APOE4,4 and Braak V-VI producing smaller CBMA, a finding which needs to be confirmed with a larger sample. These data support the hypothesis that APOE4,4 is associated with thinning of the microvascular basement membrane in Alzheimer's disease.

Sex-related difference in amygdala activity during emotionally influenced memory storage

We tested the possibility suggested by previous imaging studies that amygdala participation in the storage of emotionally influenced memory is differentially lateralized in men and women. Male and female subjects received two PET scans for regional cerebral glucose-one while viewing a series of emotionally provocative (negative) films, and a second while viewing a series of matched, but emotionally more neutral, films. Consistent with suggestions from several previously published studies, enhanced activity of the right, but not the left, amygdala in men was related to enhanced memory for the emotional films. Conversely, enhanced activity of the left, but not the right, amygdala in women was related to enhanced memory for the emotional films. These results demonstrate a clear gender-related lateralization of amygdala involvement in emotionally influenced memory, and indicate that theories of the neurobiology of emotionally influenced memory must begin to account for the influence of gender.

In vivo induction of massive proliferation, directed migration, and differentiation of neural cells in the adult mammalian brain

The development of an in vivo procedure for the induction of massive proliferation, directed migration, and neurodifferentiation (PMD) in the damaged adult central nervous system would hold promise for the treatment of human neurodegenerative disorders such as Parkinson's disease. We investigated the in vivo induction of PMD in the forebrain of the adult rat by using a combination of 6-hydroxydopamine lesion of the substantia nigra dopaminergic neurons and infusions of transforming growth factor alpha (TGFalpha) into forebrain structures. Only in animals with both lesion and infusion of TGFalpha was there a rapid proliferation of forebrain stem cells followed by a timed migration of a ridge of neuronal and glial progenitors directed toward the region of the TGFalpha infusion site. Subsequently, increasing numbers of differentiated neurons were observed in the striatum. In behavioral experiments, there was a significant reduction of apomorphine-induced rotations in animals receiving the TGFalpha infusions. These results show that the brain contains stem cells capable of PMD in response to an exogenously administered growth factor. This finding has significant implications with respect to the development of treatments for both acute neural trauma and neurodegenerative diseases.

Correlation of intellectual impairment in Parkinson's disease with FDG PET scan

This study investigated the relationship between regional glucose metabolism with intellectual impairment in patients with Parkinson's disease using statistical parametric mapping. Regional cerebral glucose metabolism using [18F]deoxyglucose (FDG) PET scans were performed on 10 patients with Parkinson's disease. We used the intellectual impairment score from the UPDRS. PET scans were analyzed with SPM96. Patients showed significant positive correlations with left limbic structures such as the cingulate gyrus, parahippocampal gyrus, and medial frontal gyrus. Patients showed significant negative correlations with associative neocortical posterior structures such as bilateral parietal and occipital gyrus. There were significant relationships between regional glucose metabolism and intellectual impairment.

Inhibition of intimal thickening after balloon angioplasty in porcine coronary arteries by targeting regulators of the cell cycle

BACKGROUND

Although percutaneous transluminal coronary angioplasty (PTCA) is a highly effective procedure to reduce the severity of stenotic coronary atherosclerotic disease, its long-term success is significantly limited by the high rate of restenosis. Several cellular and molecular mechanisms have been implicated in the development of restenosis post-PTCA, including vascular smooth muscle cell (VSMC) activation, migration, and proliferation. Recently, our group demonstrated that rapamycin, an immunosuppressant agent with antiproliferative properties, inhibits both rat and human VSMC proliferation and migration in vitro. In the present study, we investigated (1) whether rapamycin administration could reduce neointimal thickening in a porcine model of restenosis post-PTCA and (2) the mechanism by which rapamycin inhibits VSMCs in vivo.

METHODS AND RESULTS

PTCA was performed on a porcine model at a balloon/vessel ratio of 1.7+/-0.2. Coronary arteries were analyzed for neointimal formation 4 weeks after PTCA. Intramuscular administration of rapamycin started 3 days before PTCA at a dose of 0.5 mg/kg and continued for 14 days at a dose of 0.25 mg/kg. Cyclin-dependent kinase inhibitor (CDKI) p27(kip1) protein levels and pRb phosphorylation within the vessel wall were determined by immunoblot analysis. PTCA in the control group was associated with the development of significant luminal stenosis 4 weeks after the coronary intervention. Luminal narrowing was a consequence of significant neointimal formation in the injured areas. Rapamycin administration was associated with a significant inhibition in coronary stenosis (63+/-3.4% versus 36+/-4.5%; P<0.001), resulting in a concomitant increase in luminal area (1.74+/-0.1 mm2 versus 3. 3+/-0.4 mm2; P<0.001) after PTCA. Inhibition of proliferation was associated with markedly increased concentrations of the p27(kip1) levels and inhibition of pRb phosphorylation within the vessel wall.

CONCLUSIONS

Rapamycin administration significantly reduced the arterial proliferative response after PTCA in the pig by increasing the level of the CDKI p27(kip1) and inhibition of the pRb phosphorylation within the vessel wall. Therefore, pharmacological interventions that elevate CDKI in the vessel wall and target cyclin-dependent kinase activity may have a therapeutic role in the treatment of restenosis after angioplasty in humans.

Cooperation between VEGF and TNF-alpha is necessary for exposure of active tissue factor on the surface of human endothelial cells

This study was undertaken to characterize tissue factor (TF) induction, localization, and functional activity in cultured human umbilical vein endothelial cells (HUVECs) exposed to recombinant vascular endothelial growth factor (rVEGF) and recombinant tumor necrosis factor-alpha (rTNF-alpha). rVEGF (1 nmol/L) and rTNF-alpha (500 U/mL) synergistically increased TF mRNA, protein, and total activity, as measured in cell lysates. To examine surface TF expression, living cells were treated with antibody to TF and examined microscopically. Almost no staining was seen in control cells or cells treated with a single agent. In contrast, cells treated with both agonists showed intense membrane staining with surface patches, appearing as buds by confocal microscopy. To determine surface TF activity, studies were performed using a parallel-plate flow chamber, which allows detection of factor Xa generation on living cells. rVEGF and rTNF-alpha induced little surface TF activity (0.032+/-0.008 and 0.014+/-0.008 fmol/cm2, respectively). In combination, they significantly increased TF expression on the cell surface (0.429+/-0.094 fmol/cm2, P<0.05). These data indicate that the synergistic effect of rVEGF and rTNF-alpha is necessary to generate functional TF on the surface of endothelial cells. The requirement for multiple agonists to expose active TF may serve to protect endothelial cells from acting as a procoagulant surface, even under conditions of cell perturbation.

The Fibromyalgia Impact Questionnaire: a useful tool in evaluating patients with post-Lyme disease syndrome

OBJECTIVE

To determine the reliability and validity of a modified version of the Fibromyalgia Impact Questionnaire (FIQ) in evaluating patients with post-Lyme disease syndrome (PLDS).

METHODS

In this cross-sectional analysis 13 PLDS, 18 fibromyalgia (FM), and 16 healthy controls (n = 47) completed a modified FIQ containing items to evaluate physical impairment, symptom severity, and global well-being. Comparisons between groups were done using analysis of variance with a significance level set at 0.05.

RESULTS

PLDS patients demonstrated statistically significantly greater levels of impairment than controls in physical functioning, FIQ total score, global well-being, joint pain, fatigue, depression, ability to perform activities of daily living, and memory/concentration. FM patients demonstrated a statistically significantly greater level of impairment than the control group in all categories, and the scores were significantly higher than the PLDS group in the measurement of physical impairment, FIQ total score, muscle pain, and joint pain. Overall, the instrument possesses good reliability and validity, although adequacy of this instrument to measure impairment in the male PLDS population needs further elucidation.

CONCLUSION

The results of this study suggest that the modified FIQ may be a useful tool in evaluating PLDS patients. The findings suggest that there may be some differences in the etiopathology of the symptoms experienced by PLDS and FM patients.

Decreasing striatal 6-FDOPA uptake with increasing duration of cocaine withdrawal

It has been hypothesized that a decrease in dopaminergic presynaptic activity during abstinence or withdrawal is related to relapse in cocaine-dependent subjects (Dackis and Gold 1985; Markou and Koob 1991). This study measured striatal 6-fluorodopa (6-FDOPA) uptake, an index of dopaminergic presynaptic activity, using positron emission tomography (PET) in 11 drug-free cocaine addicts compared to eight normal subjects. Middle abstinence cocaine addicts (n = 5, off cocaine 11-30 days) had significantly lower striatal 6-FDOPA uptake compared to normal controls or early abstinence cocaine addicts (n = 6, off cocaine 1-10 days). The cocaine-dependent subjects (n = 11) showed a significant negative correlation between days off cocaine and striatal 6-FDOPA uptake. The results suggest that during abstinence from cocaine there is a delayed decrease in dopamine terminal activity in the striatum.

MPP+ induced substantia nigra degeneration is attenuated in nNOS knockout mice

Recent studies showed that neuronal nitric oxide synthase (nNOS) plays a role in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity. In the present study we examined the effects of striatal injection of 1-methyl-4-phenylpyridinium (MPP+) on substantia nigra degeneration in mutant mice lacking the nNOS gene or the endothelial nitric oxide synthase (eNOS) gene. Both striatal lesion volume and substantia nigra degeneration were significantly attenuated in the nNOS mutant mice but not in the eNOS mutant mice. The mice lacking nNOS showed a significant attenuation of MPP+(-) induced increases of 3-nitrotyrosine concentrations in the striatum. In a separate experiment administration of 7-nitroindazole for 48 h after MPP+ injections significantly attenuated substantia nigra degeneration in rats. Immunohistochemical studies showed apposition of nNOS-positive neuronal processes on tyrosine hydroxylase-positive neurons. These results provide further evidence that neuronally derived NO and peroxynitrite play a role in MPP+ neurotoxicity.

MPP+ produces progressive neuronal degeneration which is mediated by oxidative stress

The neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which produces Parkinsonism, is mediated by its metabolite 1-methyl-4-phenylpyridinium ion (MPP+). When injected into the striatum MPP+ is accumulated by dopaminergic nerve terminals and is then retrogradely transported to the substantia nigra compacta. The mechanism by which it mediates cell death involves both inhibition of complex I of the electron transport chain and free radical generation. In the present experiments we found that administration of the free radical spin trap N-tert-butyl-alpha-(2-sulfophenyl) nitrone (S-PBN) significantly attenuated substantia nigra cell loss produced by MPP+ administration into rat striatum. We also found that coadministration of coenzyme Q10 with nicotinamide, which attenuates energy depletion, significantly blocked MPP(+)-induced substantia nigra damage. Last, we found that a single administration of MPP+ into rat striatum can produce progressive cell loss in the substantia nigra and that administration of S-PBN starting 7 days after administration of MPP+ can block the ensuing neuronal damage. These observations suggest that a one-time exposure to a neurotoxic agent may result in progressive neuronal degeneration mediated by oxidative stress.

Increased dopamine activity associated with stuttering

Position emission tomography using 6-FDOPA as a marker of presynaptic dopaminergic activity was used to investigate the role of the dopamine system in stuttering. Three patients with moderate to severe developmental stuttering were compared with six normal controls. Stuttering subjects showed significantly higher 6-FDOPA uptake than normal controls in medial prefrontal cortex, deep orbital cortex, insular cortex, extended amygdala, auditory cortex and caudate tail. Elevated 6-FDOPA uptake in ventral limbic cortical and subcortical regions is compatible with the hypothesis that stuttering is associated with an overactive presynaptic dopamine system in brain regions that modulate verbalization.

Amygdala activity at encoding correlated with long-term, free recall of emotional information

Positron emission tomography of cerebral glucose metabolism in adult human subjects was used to investigate amygdaloid complex (AC) activity associated with the storage of long-term memory for emotionally arousing events. Subjects viewed two videos (one in each of two separate positron emission tomography sessions, separated by 3-7 days) consisting either of 12 emotionally arousing film clips ("E" film session) or of 12 relatively emotionally neutral film clips ("N" film session), and rated their emotional reaction to each film clip immediately after viewing it. Three weeks after the second session, memory for the videos was assessed in a free recall test. As expected, the subjects' average emotional reaction to the E films was higher than that for the N films. In addition, the subjects recalled significantly more E films than N films. Glucose metabolic rate of the right AC while viewing the E films was highly correlated with the number of E films recalled. AC activity was not significantly correlated with the number of N films recalled. The findings support the view derived from both animal and human investigations that the AC is selectively involved with the formation of enhanced long-term memory associated with emotionally arousing events.

Planimetry study of the percent of body surface represented by the hand and palm: sizing irregular burns is more accurately done with the palm

Sizing irregular burns is commonly done with use of the patient's hand as a template representing 1% of the body surface. To verify that this is accurate over a broad range of ages or to see if the surface of the palm is a more consistent template, a planimetry study was done. This revealed that the surface area of the palm averaged 0.52% total body surface area (+/- 0.07) and the palmar surface of the hand 0.85% total body surface area (+/- 0.08). The surface of the palm was a more consistent template and represented 0.5% of the body surface over a broad range of ages.