Microbial metabolomic responses to changes in temperature and salinity along the western Antarctic Peninsula.

Seasonal cycles within the marginal ice zones in polar regions include large shifts in temperature and salinity that strongly influence microbial abundance and physiology. However, the combined effects of concurrent temperature and salinity change on microbial community structure and biochemical composition during transitions between seawater and sea ice are not well understood. Coastal marine communities along the western Antarctic Peninsula were sampled and surface seawater was incubated at combinations of temperature and salinity mimicking the formation (cold, salty) and melting (warm, fresh) of sea ice to evaluate how these factors may shape community composition and particulate metabolite pools during seasonal transitions. Bacterial and algal community structures were tightly coupled to each other and distinct across sea-ice, seawater, and sea-ice-meltwater field samples, with unique metabolite profiles in each habitat. During short-term (approximately 10-day) incubations of seawater microbial communities under different temperature and salinity conditions, community compositions changed minimally while metabolite pools shifted greatly, strongly accumulating compatible solutes like proline and glycine betaine under cold and salty conditions. Lower salinities reduced total metabolite concentrations in particulate matter, which may indicate a release of metabolites into the labile dissolved organic matter pool. Low salinity also increased acylcarnitine concentrations in particulate matter, suggesting a potential for fatty acid degradation and reduced nutritional value at the base of the food web during freshening. Our findings have consequences for food web dynamics, microbial interactions, and carbon cycling as polar regions undergo rapid climate change.

Large Diversity in Nitrogen- and Sulfur-Containing Compatible Solute Profiles in Polar and Temperate Diatoms.

Intense bottom-ice algal blooms, often dominated by diatoms, are an important source of food for grazers, organic matter for export during sea ice melt, and dissolved organic carbon. Sea-ice diatoms have a number of adaptations, including accumulation of compatible solutes, that allows them to inhabit this highly variable environment characterized by extremes in temperature, salinity, and light. In addition to protecting them from extreme conditions, these compounds present a labile, nutrient-rich source of organic matter, and include precursors to climate active compounds (e.g., dimethyl sulfide [DMS]), which are likely regulated with environmental change. Here, intracellular concentrations of 45 metabolites were quantified in three sea-ice diatom species and were compared to two temperate diatom species, with a focus on compatible solutes and free amino acid pools. There was a large diversity of metabolite concentrations between diatoms with no clear pattern identifiable for sea-ice species. Concentrations of some compatible solutes (isethionic acid, homarine) approached 1 M in the sea-ice diatoms, Fragilariopsis cylindrus and Navicula cf. perminuta, but not in the larger sea-ice diatom, Nitzschia lecointei or in the temperate diatom species. The differential use of compatible solutes in sea-ice diatoms suggests different adaptive strategies and highlights which small organic compounds may be important in polar biogeochemical cycles.

Correction to: Assessment of individual tumor buds using keratin immunohistochemistry: moderate interobserver agreement suggests a role for machine learning.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Assessment of individual tumor buds using keratin immunohistochemistry: moderate interobserver agreement suggests a role for machine learning.

Tumor budding is a promising and cost-effective biomarker with strong prognostic value in colorectal cancer. However, challenges related to interobserver variability persist. Such variability may be reduced by immunohistochemistry and computer-aided tumor bud selection. Development of computer algorithms for this purpose requires unequivocal examples of individual tumor buds. As such, we undertook a large-scale, international, and digital observer study on individual tumor bud assessment. From a pool of 46 colorectal cancer cases with tumor budding, 3000 tumor bud candidates were selected, largely based on digital image analysis algorithms. For each candidate bud, an image patch (size 256 × 256 µm) was extracted from a pan cytokeratin-stained whole-slide image. Members of an International Tumor Budding Consortium (n = 7) were asked to categorize each candidate as either (1) tumor bud, (2) poorly differentiated cluster, or (3) neither, based on current definitions. Agreement was assessed with Cohen's and Fleiss Kappa statistics. Fleiss Kappa showed moderate overall agreement between observers (0.42 and 0.51), while Cohen's Kappas ranged from 0.25 to 0.63. Complete agreement by all seven observers was present for only 34% of the 3000 tumor bud candidates, while 59% of the candidates were agreed on by at least five of the seven observers. Despite reports of moderate-to-substantial agreement with respect to tumor budding grade, agreement with respect to individual pan cytokeratin-stained tumor buds is moderate at most. A machine learning approach may prove especially useful for a more robust assessment of individual tumor buds.

Potential clinical scenarios of tumour budding in colorectal cancer.

Tumour budding, defined as single tumour cells or clusters of 4 tumour cells or less detached from the main tumour body, is a wellestablished indicator of aggressive tumour biology in colorectal cancer. As a marker of tumour dissemination, evidence points towards tumour budding as a morphological correlate of epithelialmesenchymal type changes in the tumour microenvironment. Despite many studies in the literature going back decades, tumour budding has not been systematically integrated in colorectal cancer reporting protocols. The recently published proceedings of the International Tumour Budding Consensus Conference (ITBCC) have sparked the systematic implementation of tumour budding in routine reporting of colorectal cancer. Tumour budding may be particularly relevant to patient management in endoscopically resected pT1 colorectal cancer, stage II tumour and pre-operative biopsies. The present review focuses mainly on these three potential clinical scenarios with the aim to provide a concise and updated overview on tumour budding in CRC.

The Mutational Profile of Unicystic Ameloblastoma.

BRAF V600E is the most common mutation in conventional ameloblastoma (AM) of the mandible. In contrast, maxillary AMs appear to harbor more frequently RAS, FGFR2, or SMO mutations. Unicystic ameloblastoma (UAM) is considered a less aggressive variant of ameloblastoma, amenable to more conservative treatment, and classified as a distinct entity. The aim of this study was to characterize the mutation profile of UAM ( n = 39) and to compare it to conventional AM ( n = 39). The associations between mutation status and recurrence probability were also analyzed. In the mandible, 94% of UAMs (29/31, including 8/8 luminal, 6/8 intraluminal, and 15/15 mural subtypes) and 74% of AMs (28/38) revealed BRAF V600E mutations. Among the BRAF wild-type cases, 1 UAM showed a missense SMO mutation (p.L412F), whereas 2 NRAS (p.Q61R), 2 HRAS (p.Q61R), and 2 FGFR2 (p.C383R) activating mutations were identified in AM. Of the 3 maxillary UAMs, only 1 revealed a BRAF V600E mutation. Taken together, our findings demonstrate high frequency of activating BRAF V600E mutations in both UAM and AM of the mandible. In maxillary UAMs, the BRAF V600E mutation prevalence appears to be lower as was shown for AM previously. It could therefore be argued that UAM and AM are part of the spectrum of the same disease. AMs without BRAF V600E mutations were associated with an increased rate of local recurrence ( P = 0.0003), which might indicate that routine mutation testing also has an impact on prognosis.

Femoral osteochondroplasty can be performed effectively without the risk of avascular necrosis or femoral neck fractures in an experimental ovine FAI model.

OBJECTIVE: The experimental induction of cam-type femoroacetabular impingement (FAI) in sheep is established. To tap the full potential of this ovine model, one should be able to perform a femoral osteochondroplasty safely. This study was based on previous cadaver experiments on the blood supply to the ovine femoral head and on the biomechanical strength of the proximal femur following offset creation. We hypothesized that offset creation in this ovine FAI model does not lead to (1) avascular necrosis (AVN) of the ovine femoral head or (2) iatrogenic femoral neck fractures and (3) can be performed effectively. DESIGN: In this experimental, controlled, prospective study nine sheep underwent unilateral FAI induction through an intertrochanteric, varus osteotomy. Seventy days following FAI induction, femoral osteochondroplasty was performed. Sheep were sacrificed after another 140 days. Radiographs, computed tomography (CT) scans and MRI were acquired. Histologic samples were stained with hematoxylin-eosin. (1) The multimodal Association Research Circulation Osseous (ARCO) classification was used for assessment of AVN. (2) Femoral neck fractures were assessed with the multimodal imaging approach. (3) Pre- and postoperative (=after sacrifice) alpha angles and femoral neck diameters were compared. RESULTS: (1) No signs for AVN according to the ARCO classification or (2) for femoral neck fractures were detected. (3) Mean alpha angles and femoral neck diameters decreased significantly (p < 0.001) superiorly by at least 30° respectively 4 mm after the offset creation. CONCLUSIONS: Femoral osteochondroplasty can be performed effectively and without the risk of AVN or femoral neck fractures in this ovine FAI model.

Recommendations for reporting tumor budding in colorectal cancer based on the International Tumor Budding Consensus Conference (ITBCC) 2016

Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer. The ITBCC included nine sessions with presentations, a pre-meeting survey and an e-book covering the key publications on tumor budding in colorectal cancer. The 'Grading of Recommendation Assessment, Development and Evaluation' method was used to determine the strength of recommendations and quality of evidence. The following 10 statements achieved consensus: tumor budding is defined as a single tumor cell or a cell cluster consisting of four tumor cells or less (22/22, 100%). Tumor budding is an independent predictor of lymph node metastases in pT1 colorectal cancer (23/23, 100%). Tumor budding is an independent predictor of survival in stage II colorectal cancer (23/23, 100%). Tumor budding should be taken into account along with other clinicopathological features in a multidisciplinary setting (23/23, 100%). Tumor budding is counted on H&E (19/22, 86%). Intratumoral budding exists in colorectal cancer and has been shown to be related to lymph node metastasis (22/22, 100%). Tumor budding is assessed in one hotspot (in a field measuring 0.785 mm2) at the invasive front (22/22, 100%). A three-tier system should be used along with the budding count in order to facilitate risk stratification in colorectal cancer (23/23, 100%). Tumor budding and tumor grade are not the same (23/23, 100%). Tumor budding should be included in guidelines/protocols for colorectal cancer reporting (23/23, 100%). Members of the ITBCC were able to reach strong consensus on a single international, evidence-based method for tumor budding assessment and reporting. It is proposed that this method be incorporated into colorectal cancer guidelines/protocols and staging systems.

[Hereditary colorectal cancer : An update on genetics and entities in terms of differential diagnosis]. / Hereditäres Dickdarmkarzinom : Ein Update zu Genetik und Entitäten aus differenzialdiagnostischer Sicht.

The pathologist can contribute to recognizing hereditary causes of colorectal cancer via morphology. By identifying so-called index patients, it is possible to take preventive measures in affected families. The precise definition of the clinical presentation and the histopathological phenotype help to narrow the spectrum of expected genetic alterations. Novelties within Lynch syndrome include the recognition of EPCAM as a fifth gene locus, as well as the newly defined Lynch-like syndrome with evidence of somatic mismatch repair (MMR) mutations. With regard to polyposis-associated syndromes, the spectrum of polyps, whether serrated, hamartomatous or classic adenoma, is of crucial importance. The resulting differential diagnosis includes (attenuated) familial adenomatous polyposis ([a]FAP), MUTYH-associated polyposis (MAP), polymerase proofreading-associated polyposis (PPAP), phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS), Peutz-Jeghers syndrome and juvenile polyposis, each with a specific genetic background.

Intratumoural budding (ITB) in preoperative biopsies predicts the presence of lymph node and distant metastases in colon and rectal cancer patients.

BACKGROUND: In colorectal cancer (CRC), tumour budding at the invasion front is associated with lymph node (LN) and distant metastasis. Interestingly, tumour budding can also be detected in biopsies (intratumoural budding; ITB) and may have similar clinical importance. Here we investigate whether ITB in preoperative CRC biopsies can be translated into daily diagnostic practice. METHODS: Preoperative biopsies from 133 CRC patients (no neoadjuvant therapy) underwent immunohistochemistry for pan-cytokeratin marker AE1/AE3. Across all biopsies for each patient, the densest region of buds at × 40 (high-power field; HPF) was identified and buds were counted. RESULTS: A greater number of tumour buds in the biopsy was associated with pT stage (P=0.0143), LN metastasis (P=0.0007), lymphatic (P=0.0065) and venous vessel invasion (P=0.0318) and distant metastasis (cM1) (P=0.0013). Using logistic regression, a 'scale' was developed to estimate the probability of LN and distant metastasis using the number of tumour buds (e.g. 10 buds per HPF: 64% chance of LN metastasis; 30 buds per HPF: 86% chance). Inter-observer agreement for ITB was excellent (intraclass correlation coefficient: 0.813). CONCLUSION: Tumour budding can be assessed in the preoperative biopsy of CRC patients. It is practical, reproducible and predictive of LN and distant metastasis. Intratumoural budding qualifies for further investigation in the prospective setting.

MR imaging in Crohn's disease: correlation of MR motility measurement with histopathology in the terminal ileum.

BACKGROUND: The objective of the study was to correlate MR-detectable motility alterations of the terminal ileum with biopsy-documented active and chronic changes in Crohn's disease. METHODS: This IRB approved retrospective analysis of 43 patients included magnetic resonance enterography (MRE) and terminal ileum biopsies (<2 weeks apart). Motility was measured at the terminal ileum using coronal 2D trueFISP pulse sequences (1.5T MRI,TR 83.8,TE1.89) and dedicated motility assessment software. Motility grading (hypermotility, normal, hypomotility, complete arrest) was agreed by two experienced readers. Motility was compared and correlated with histopathology using two-tailed Kruskal-Wallis test and paired Spearman Rank-Order Correlation tests. KEY RESULTS: Motility abnormalities were present in 27/43 patients: nine hypomotility and 18 complete arrest. Active disease was diagnosed on 15 biopsies: eight moderate and seven severe inflammatory activity. Chronic changes were diagnosed on 17 biopsies: 13 moderate and four severe cases. In four patients with normal motility alterations on histopathology were diagnosed. Histopathology correlated with presence (P = 0.0056 for hypomotility and P = 0.0119 for complete arrest) and grade (P < 0.0001; P = 0.0004) of motility alterations. A significant difference in the motility was observed in patients with active or chronic CD compared with patients without disease (P < 0.001; P = 0.0024). CONCLUSIONS & INFERENCES: MR-detectable motility changes of the terminal ileum correlate with histopathological findings both in active and chronic CD. Motility changes may indicate the presence pathology, but do not allow differentiation of active and chronic disease.

Geographic analysis of RKIP expression and its clinical relevance in colorectal cancer.

BACKGROUND: This study evaluates the geographic expression pattern of Raf-1 Kinase Inhibitor Protein (RKIP) in colorectal cancer (CRC) in correlation with clinicopathological and molecular features, markers of epithelial-mesenchymal transition (EMT) and survival outcome. METHODS: Whole-tissue sections of 220 well-characterised CRCs were immunostained for RKIP. NF-κB and E-Cadherin expression was assessed using a matched multi-punch tissue microarray. Analysis of mismatch repair (MMR) protein expression, B-Raf and KRAS mutations was performed. RKIP expression in normal mucosa, tumour centre, invasion front and tumour buds was each assessed for clinical relevance. RESULTS: RKIP was diffusely expressed in normal mucosa and progressively lost towards tumour centre and front (P<0.0001). Only 0.9% of tumour buds were RKIP-positive. In the tumour centre, RKIP deficiency predicted metastatic disease (P=0.0307), vascular invasion (P=0.0506), tumour budding (P=0.0112) and an invasive border configuration (P=0.0084). Loss of RKIP correlated with NF-κB activation (P=0.0002) and loss of E-Cadherin (P<0.0001). Absence of RKIP was more common in MMR-deficient cancers (P=0.0191), while no impact of KRAS and B-Raf mutation was observed. RKIP in the tumour centre was identified as a strong prognostic indicator (HR (95% CI): 2.13 (1.27-3.56); P=0.0042) independently of TNM classification and therapy (P=0.0474). CONCLUSION: The clinical relevance of RKIP expression as an independent prognostic factor is restricted to the tumour centre. Loss of RKIP predicts features of EMT and correlates with frequent distant metastasis.

Loss of tau elicits axonal degeneration in a mouse model of Alzheimer's disease.

A central issue in the pathogenesis of tauopathy is the question of how tau protein dysfunction leads to neurodegeneration. We have previously demonstrated that the absence of tau protein is associated with destabilization of microtubules and impaired neurite outgrowth (Dawson et al., 2001; Rapoport et al., 2002). We now hypothesize that the absence of functional tau protein may render the central nervous system more vulnerable to secondary insults such as the overexpression of mutated beta amyloid precursor protein (APP) and traumatic brain injury. We therefore crossed tau knockout mice (Dawson et al., 2001) to mice overexpressing a mutated human APP (APP(670,671), A(sw)) (Hsiao et al., 1996) and created a mouse model (A(sw)/mTau(-/-)) that provides evidence that the loss of tau function causes degeneration of neuronal processes. The overexpression of APP(670,671) in tau knockout mice, elicits the extensive formation of axonal spheroids. While spheroids are only found associated with Abeta plaques in mice expressing APP(670,671) on an endogenous mouse tau background (Irizarry et al., 1997), A(sw)/mTau(-/-) mice have spheroids not only surrounding Abeta plaques but also in white matter tracks and in the neuropil. Plaque associated and neuropil dystrophic neurites and spheroids are prominent features of Alzheimer's disease (Masliah et al., 1993; Terry, 1996; Stokin et al., 2005), and our current data suggests that loss of tau function may lead to neurodegeneration.

Augmentation of venous, arterial and microvascular blood supply in the leg by isometric neuromuscular stimulation via the peroneal nerve.

BACKGROUND: Deep vein thrombosis (DVT) is the formation of a blood clot within the deep veins. During periods of sitting, blood flow is decreased and this contributes to an increased risk of DVT. Trials have shown that 5% to 10% of passengers undertaking long-haul flights develop asymptomatic calf DVT. AIM: To investigate the safety and efficacy of a novel neuromuscular device that augments peripheral blood flow. METHODS: Thirty healthy volunteers were assessed while seated. Each subject had one leg connected to the stimulator and the other leg immobile acting as control. Fifteen sequential electrical stimulations were applied for 5 min each followed by a 10 min recovery phase. The following noninvasive measurements were performed before, during and after the stimulation programs: photoplethysmography, strain gauge plethysmography, laser Doppler fluxmetry, transcutaneous oxygen tension, pulse oximetry, superficial femoral vein blood flow and vessel diameter (ultrasound); discomfort questionnaires were also administered. RESULTS: During neuromuscular stimulation, significant increases in blood volume flow and velocity and skin capillary blood flow were found; transdermal skin oxygen levels were maintained. No changes were observed in heart rate, blood pressure, oxygen saturation or femoral vein vessel diameter. CONCLUSIONS: Using a newly developed device, electrical nerve stimulation of the lower leg significantly increased blood flow; the device in the present study is, therefore, a promising tool for the development of a novel DVT prevention device. Because this method of electrical nerve stimulation is virtually pain free, the present study has significant implications for the prevention of DVT in hospitals, outpatient settings and community care settings, as well as in preventing travel-related thrombosis.

Transcriptome profile and cytogenetic analysis of immortalized neuronally restricted progenitor cells derived from the porcine olfactory bulb.

Recently, we established and phenotypically characterized an immortalized porcine olfactory bulb neuroblast cell line, OBGF400 (1). To facilitate the future application of these cells in studies of neurological dysfunctions and neuronal pathogen interactions, a comprehensive knowledge of their genomic variability and overall gene expression capacity was pursued. Accordingly, the OBGF400 cells were subjected to karyotyping and more extensive transcriptome analyses. Cytogenetic characterization of these cells revealed a genetic mosaicism of neuronal hyperdiploidy. A direct comparison of the OBGF400 cell transcriptome pattern, generated by utilizing the Affymetrix GeneChip(R) Porcine Genome Array, to that of a non-neural, porcine epithelial cell line facilitated the identification of 831 probe sets preferentially hybridized by the neuroblast transcripts. Subsequent functional annotation of these OBGF400 RNAs using the Database for Annotation, Visualization and Integrated Discovery 2008 enabled their allocation to the corresponding gene ontology biological process term, thereby assisting the recognition of key elements involved in the regulation of neuronal signal transduction and neurogenesis.

Cinnamon extract attenuates TNF-alpha-induced intestinal lipoprotein ApoB48 overproduction by regulating inflammatory, insulin, and lipoprotein pathways in enterocytes.

We have previously reported that the obesity-associated proinflammatory cytokine, TNF-alpha, stimulates the overproduction of intestinal apolipoprotein (apo) B48 containing lipoproteins. In the current study, we have evaluated whether a water-soluble cinnamon extract [CE (Cinnulin PF)] attenuates the dyslipidemia induced by TNF-alpha in Triton WR-1339 treated hamsters, and whether CE inhibits the oversecrection of apoB48-induced by TNF-alpha in enterocytes in a 35S labeling study. In vivo, oral treatment of Cinnulin PF (50 mg per kg BW), inhibited the postprandial overproduction of apoB48-containing lipoproteins and serum triglyceride levels. In ex vivo 35S labeling studies, CE (10 and 20 microg/ml) inhibited the oversecretion of apoB48 induced by TNF-alpha treated enterocytes into the media. To determine the molecular mechanisms, TNF-alpha treated primary enterocytes isolated from chow-fed hamsters, were incubated with CE (10 microg/ml), and the expression of the inflammatory factor genes, IL1-beta, IL-6, and TNF-alpha, insulin signaling pathway genes, insulin receptor (IR), IRS1, IRS2, phosphatidylinositol 3-kinase (PI3-K), Akt1 and phosphatase and tensin homology (PTEN), as well as the key regulators of lipid metabolism, cluster of differentiation (CD)36, microsomal triglyceride transfer protein (MTTP), and sterol regulatory element binding protein (SREBP)-1c were evaluated. Quantitative real-time PCR assays showed that CE treatment decreased the mRNA expression of IL-1beta, IL-6 and TNF-alpha, improved the mRNA expression of IR, IRS1, IRS2, PI3K and Akt1, inhibited CD36, MTTP, and PTEN, and enhanced the impaired SREBP-1c expression in TNF-alpha treated enterocytes. These data suggest that a water extract of cinnamon reverses TNF-alpha-induced overproduction of intestinal apoB48 by regulating gene expression involving inflammatory, insulin, and lipoprotein signaling pathways. In conclusion, Cinulin PF improves inflammation related intestinal dyslipidemia.

Cognitive-behavioural therapy for adolescents with bulimic symptomatology: the acceptability and effectiveness of internet-based delivery.

BACKGROUND: The evidence base for the treatment of adolescents with bulimia nervosa (BN) is limited. AIMS: To assess the feasibility, acceptability, and clinical outcomes of a web-based cognitive-behavioural (CBT) intervention for adolescents with bulimic symptomatology. METHOD: 101 participants were recruited from eating disorders clinics or from beat, a UK-wide eating disorders charity. The programme consisted of online CBT sessions ('Overcoming Bulimia Online'), peer support via message boards, and email support from a clinician. Participants' bulimic symptomatology and service utilisation were assessed by interview at baseline and at three and six months. Participants' views of the treatment package were also determined. RESULTS: There were significant improvements in eating disorder symptoms and service contacts from baseline to three months, which were maintained at six months. Participants' views of the intervention were positive. CONCLUSIONS: The intervention has the potential for use as a first step in the treatment of adolescents with bulimic symptomatology.

Innate immune defenses induced by CpG do not promote vaccine-induced protection against foot-and-mouth disease virus in pigs.

Emergency vaccination as part of the control strategies against foot-and-mouth disease virus (FMDV) has the potential to limit virus spread and reduce large-scale culling. To reduce the time between vaccination and the onset of immunity, immunostimulatory CpG was tested for its capacity to promote early protection against FMDV challenge in pigs. To this end, CpG 2142, an efficient inducer of alpha interferon, was injected intramuscularly. Increased transcription of Mx1, OAS, and IRF-7 was identified as a sensitive measurement of CpG-induced innate immunity, with increased levels detectable to at least 4 days after injection of CpG formulated with Emulsigen. Despite this, CpG combined with an FMD vaccine did not promote protection. Pigs vaccinated 2 days before challenge had disease development, which was at least as acute as that of unvaccinated controls. All pigs vaccinated 7 days before challenge were protected without a noticeable effect of CpG. In summary, our results demonstrate the caution required when translating findings from mouse models to natural hosts of FMDV.

Quantitative measurement of postural sway in mouse models of human neurodegenerative disease.

Detection of motor dysfunction in genetic mouse models of neurodegenerative disease requires reproducible, standardized and sensitive behavioral assays. We have utilized a center of pressure (CoP) assay in mice to quantify postural sway produced by genetic mutations that affect motor control centers of the brain. As a positive control for postural instability, wild type mice were injected with harmaline, a tremorigenic agent, and the average areas of the 95% confidence ellipse, which measures 95% of the CoP trajectory values recorded in a single trial, were measured. Ellipse area significantly increased in mice treated with increasing doses of harmaline and returned to control values after recovery. We also examined postural sway in mice expressing mutations that mimic frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) (T-279, P301L or P301L-nitric oxide synthase 2 (NOS2)(-/-) mice) and that demonstrate motor symptoms. These mice were then compared with a mouse model of Alzheimer's disease (APPSwDI mice) that demonstrates cognitive, but not motor deficits. T-279 and P301L-NOS2(-/-) mice demonstrated a significant increase in CoP ellipse area compared with appropriate wild type control mice or to mice expressing the P301L mutation alone. In contrast, postural instability was significantly reduced in APPSwDI mice that have cognitive deficits but do not have associated motor deficits. The CoP assay provides a simple, sensitive and quantitative tool to detect motor deficits resulting from postural abnormalities in mice and may be useful in understanding the underlying mechanisms of disease.