Carer-supported home-based exercises designed to target physical activity levels and functional mobility after stroke: a scoping review

PURPOSE

To explore the literature on carer-supported home-based exercise programs for people after stroke, as a form of physical activity. The review focus was to examine the training carers receive, the content of programs, and investigate the physical activity levels and functional mobility of people after stroke.

MATERIALS AND METHODS

A scoping review was undertaken, guided by Joanna Briggs Institute methodology. The concept of home-based carer-supported exercise, in people after stroke, was searched across five databases. Outcomes of interest were physical activity levels and functional mobility.

RESULTS

We screened 2285 references and included 10 studies: one systematic review, five randomised controlled trials, one trial with non-equivalent control, and four uncontrolled studies. Carer training ranged from one to twelve sessions. Exercise interventions commonly including walking, other whole body functional exercises and balance activities. In eight studies interventions were in addition to standard care. Five studies reported significant between-group differences for functional mobility, favouring the intervention. One study reported physical activity levels.

CONCLUSION

There was large variation in the volume and content of training provided to carers. Physical activity levels were infrequently objectively reported. Future studies should include greater details on their protocols to allow for replication and implementation into clinical practice.

Microparticles Decorated with Cell-Instructive Surface Chemistries Actively Promote Wound Healing

Wound healing is a complex biological process involving close crosstalk between various cell types. Dysregulation in any of these processes, such as in diabetic wounds, results in chronic nonhealing wounds. Fibroblasts are a critical cell type involved in the formation of granulation tissue, essential for effective wound healing. 315 different polymer surfaces are screened to identify candidates which actively drive fibroblasts toward either pro- or antiproliferative functional phenotypes. Fibroblast-instructive chemistries are identified, which are synthesized into surfactants to fabricate easy to administer microparticles for direct application to diabetic wounds. The pro-proliferative microfluidic derived particles are able to successfully promote neovascularization, granulation tissue formation, and wound closure after a single application to the wound bed. These active novel bio-instructive microparticles show great potential as a route to reducing the burden of chronic wounds.

Osimertinib and anti-HER3 combination therapy engages immune dependent tumor toxicity via STING activation in trans

Over the past decade, immunotherapy delivered novel treatments for many cancer types. However, lung cancer still leads cancer mortality, and non-small-cell lung carcinoma patients with mutant EGFR cannot benefit from checkpoint inhibitors due to toxicity, relying only on palliative chemotherapy and the third-generation tyrosine kinase inhibitor (TKI) osimertinib. This new drug extends lifespan by 9-months vs. second-generation TKIs, but unfortunately, cancers relapse due to resistance mechanisms and the lack of antitumor immune responses. Here we explored the combination of osimertinib with anti-HER3 monoclonal antibodies and observed that the immune system contributed to eliminate tumor cells in mice and co-culture experiments using bone marrow-derived macrophages and human PBMCs. Osimertinib led to apoptosis of tumors but simultaneously, it triggered inositol-requiring-enzyme (IRE1α)-dependent HER3 upregulation, increased macrophage infiltration, and activated cGAS in cancer cells to produce cGAMP (detected by a lentivirally transduced STING activity biosensor), transactivating STING in macrophages. We sought to target osimertinib-induced HER3 upregulation with monoclonal antibodies, which engaged Fc receptor-dependent tumor elimination by macrophages, and STING agonists enhanced macrophage-mediated tumor elimination further. Thus, by engaging a tumor non-autonomous mechanism involving cGAS-STING and innate immunity, the combination of osimertinib and anti-HER3 antibodies could improve the limited therapeutic and stratification options for advanced stage lung cancer patients with mutant EGFR.

IgM and IgA augmented autoantibody signatures improve early-stage detection of colorectal cancer prior to nodal and distant spread

Objectives

Tumor‐associated autoantibodies (AAbs) in individuals with cancer can precede clinical diagnosis by several months to years. The objective of this study was to determine whether the primary immune response in form of IgM and gut mucosa‐associated IgA can aid IgG AAbs in the detection of early‐stage colorectal cancer (CRC).

Methods

We developed a novel protein array comprising 492 antigens seropositive in CRC. The array was used to profile IgG, IgM and IgA antibody signatures in 99 CRC patients and 99 sex‐ and age‐matched non‐cancer controls. A receiver operating curve (ROC), Kaplan–Meier survival analysis and univariate and multivariate Cox regression analyses were conducted.

Results

We identified a panel of 16 multi‐isotype AAbs with a cumulative sensitivity of 91% and specificity of 74% (AUC 0.90, 95% CI: 0.850–0.940) across all CRC stages. IgM and IgG isotypes were conversely associated with disease stage with IgM contributing significantly to improved stage I and II sensitivity of 96% at 78% specificity (AUC 0.928, 95% CI: 0.884–0.973). A single identified IgA AAb reached an overall sensitivity of 5% at 99% specificity (AUC 0.520, 95% CI: 0.440–0.601) balanced across all CRC stages. Kaplan–Meier analysis revealed that se33‐1 (ZNF638) IgG AAbs were associated with reduced 5‐year overall survival (log‐rank test, P = 0.012), whereas cumulative IgM isotype signatures were associated with improved 5‐year overall survival (log‐rank test, P = 0.024).

Conclusion

IgM AAbs are associated with early‐stage colorectal cancer. Combining IgG, IgM and IgA AAbs is a novel strategy to improve early diagnosis of cancers.

Dynamic metabolic patterns tracking neurodegeneration and gliosis following 26S proteasome dysfunction in mouse forebrain neurons

Metabolite profiling is an important tool that may better capture the multiple features of neurodegeneration. With the considerable parallels between mouse and human metabolism, the use of metabolomics in mouse models with neurodegenerative pathology provides mechanistic insight and ready translation into aspects of human disease. Using 400 MHz nuclear magnetic resonance spectroscopy we have carried out a temporal region-specific investigation of the metabolome of neuron-specific 26S proteasome knockout mice characterised by progressive neurodegeneration and Lewy-like inclusion formation in the forebrain. An early significant decrease in N-acetyl aspartate revealed evidence of neuronal dysfunction before cell death that may be associated with changes in brain neuroenergetics, underpinning the use of this metabolite to track neuronal health. Importantly, we show early and extensive activation of astrocytes and microglia in response to targeted neuronal dysfunction in this context, but only late changes in myo-inositol; the best established glial cell marker in magnetic resonance spectroscopy studies, supporting recent evidence that additional early neuroinflammatory markers are needed. Our results extend the limited understanding of metabolite changes associated with gliosis and provide evidence that changes in glutamate homeostasis and lactate may correlate with astrocyte activation and have biomarker potential for tracking neuroinflammation.

Validity and reliability of eye healthcare professionals in the assessment of glaucoma - a systematic review

OBJECTIVE(S)

To explore the validity and reliability of eye healthcare professionals with different levels of training in diagnosing and/or identifying glaucomatous progression.

CLINICAL RELEVANCE

Substantial pressure is being placed on our current eye healthcare workforce by chronic diseases such as glaucoma. Shared care schemes and role expansion of professionals other than ophthalmologists are being proposed to alleviate this pressure. A sound evidence base is imperative to determine whether other allied health professionals are skilled and clinically competent, when it comes to taking on these new roles in glaucoma management.

METHODS

A systematic review of research articles identified in MEDLINE, CINAHL, Embase, Scopus and Cochrane Library was performed. Studies which investigated rater reliability of various health professionals in diagnosing and/or identifying glaucoma progression against a reference standard were included.

RESULTS

Of the 4088 publications identified by the initial database search, 32 met the inclusion criteria. The majority of studies demonstrated positive results, with most finding moderate to substantial agreement for inter- and intra-rater reliability across all testing modalities. The eye health professionals with ophthalmology training consistently attained the greatest agreement. When allied health professionals with different levels of training were compared, those who had completed residency training were significantly better than those who had not.

CONCLUSION

The studies included in this review show promising results, including those raters without ophthalmology training. A lack of power calculations, unequal sample sizes in some studies and the diversity of the testing procedures used make it difficult to make sound inferences.

The use of molecular imaging combined with genomic techniques to understand the heterogeneity in cancer metastasis

Tumour heterogeneity has, in recent times, come to play a vital role in how we understand and treat cancers; however, the clinical translation of this has lagged behind advances in research. Although significant advancements in oncological management have been made, personalized care remains an elusive goal. Inter- and intratumour heterogeneity, particularly in the clinical setting, has been difficult to quantify and therefore to treat. The histological quantification of heterogeneity of tumours can be a logistical and clinical challenge. The ability to examine not just the whole tumour but also all the molecular variations of metastatic disease in a patient is obviously difficult with current histological techniques. Advances in imaging techniques and novel applications, alongside our understanding of tumour heterogeneity, have opened up a plethora of non-invasive biomarker potential to examine tumours, their heterogeneity and the clinical translation. This review will focus on how various imaging methods that allow for quantification of metastatic tumour heterogeneity, along with the potential of developing imaging, integrated with other in vitro diagnostic approaches such as genomics and exosome analyses, have the potential role as a non-invasive biomarker for guiding the treatment algorithm.

Abstract P5-01-01: Lymphoid tissue inducer cells: Identification of a novel immune cell within the breast tumour microenvironment and its role in promoting tumour cell invasion

Within breast cancers, trans-endothelial migration of tumour cells through lymphatic vessels is the first step to tumour dissemination and lympho-vascular invasion has been shown to stratify breast cancer phenotypes into distinct prognostic groups. The exact molecular mechanisms mediating tumor cell entry and persistence within the lymphatic system remain unclear. Lymphoid tissue inducer (LTi) cells are members of the emerging family of retinoic acid related orphan receptor (ROR)gt+ innate lymphoid cells (ILCs), and their interaction with stromal cells induces production by the stromal cells of VEGF-C and “lymphoid” chemokines, essential for lymphoid organogenesis. We hypothesized that tumour cells manipulate the normal processes that govern chemokine-dependent, trans-lymphatic migration of immune cells, including LTi cells; shaping its microenvironment. Results: We analyzed the expression of lymphoid chemokines genes (CXCL12, CXCL13, CCL19, CCL20 and CCL21) and their corresponding receptors (CXCR4, CXCR5, CCR6 and CCR7) within the METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) Tissue Bank. An unsupervised hierarchical cluster analysis revealed co-expression of these genes, categorizing breast tumors as relatively high/low expressors. Tumors exhibiting relatively high expression of these genes were found to be enriched for “basal-like” breast cancers according to PAM50 intrinsic subtype assignments. Immunofluorescence of the primary tumour sections identified cells that were comparable in phenotype to LTi cells. In a blinded study, we observed that patients with high LTi counts within the tumour microenvironment were also likely to have a gene expression corresponding to high expression for the lymphoid chemokines. IHC for the lymphatic marker, podoplanin found that the LTi count correlated with both an increased lymphatic vessel density and tumor invasion into lymphatic vessels. Within the basal and HER2+ve subtypes, patients with more than 4 lymph nodes were found to exhibit higher numbers of intratumoural LTi cells. In vitro studies, alongside multi-photon in vivo imaging were performed to investigate the interaction between intra-tumoural LTi and mesenchymal stromal cells. CXCL13 was shown to be essential for LTi clustering around stromal cells in vitro, and, the administration of a blocking antibody in vivo delayed the onset of lymph node metastasis in a murine mammary tumour (4T1.2) model. CXCLl3 has been identified as having independent prognostic significance in breast cancer, but we and others report that breast cancer cell lines are not the source of CXCL13. We show that an increase in stromal CXCL13 concentration within the tumour microenvironment following LTi recruitment promotes an EMT phenotype in the 4T1.2 cancer cell line, possibly via activation of the RANKL/RANK axis promoting tumorigenesis. We report for the first time, the identification of LTi cells within the human breast cancer tumour microenvironment and propose a pivotal role for these cells, through stromal cell interactions in the tumour microenvironment, in facilitating lymphatic invasion of tumour cells by modulation of the local lymphoid chemokine profile.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-01-01.

Implications for oxidative stress and astrocytes following 26S proteasomal depletion in mouse forebrain neurones

Neurodegenerative diseases are characterized by progressive degeneration of selective neurones in the nervous system, but the underlying mechanisms involved in neuroprotection and neurodegeneration remain unclear. Dysfunction of the ubiquitin proteasome system is one of the proposed hypotheses for the cause and progression of neuronal loss. We have performed quantitative two-dimensional fluorescence difference in-gel electrophoresis combined with peptide mass fingerprinting to reveal proteome changes associated with neurodegeneration following 26S proteasomal depletion in mouse forebrain neurones. Differentially expressed proteins were validated by Western blotting, biochemical assays and immunohistochemistry. Of significance was increased expression of the antioxidant enzyme peroxiredoxin 6 (PRDX6) in astrocytes, associated with oxidative stress. Interestingly, PRDX6 is a bifunctional enzyme with antioxidant peroxidase and phospholipase A2 (PLA2) activities. The PLA2 activity of PRDX6 was also increased following 26S proteasomal depletion and may be involved in neuroprotective or neurodegenerative mechanisms. This is the first in vivo report of oxidative stress caused directly by neuronal proteasome dysfunction in the mammalian brain. The results contribute to understanding neuronal-glial interactions in disease pathogenesis, provide an in vivo link between prominent disease hypotheses and importantly, are of relevance to a heterogeneous spectrum of neurodegenerative diseases.

Pale body-like inclusion formation and neurodegeneration following depletion of 26S proteasomes in mouse brain neurones are independent of α-synuclein

Parkinson's disease (PD) is characterized by the progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurones and the formation of Lewy bodies (LB) in a proportion of the remaining neurones. α-synuclein is the main component of LB, but the pathological mechanisms that lead to neurodegeneration associated with LB formation remain unclear. Three pivotal elements have emerged in the development of PD: α-synuclein, mitochondria and protein degradation systems. We previously reported a unique model, created by conditional genetic depletion of 26S proteasomes in the SNpc of mice, which mechanistically links these three elements with the neuropathology of PD: progressive neurodegeneration and intraneuronal inclusion formation. Using this model, we tested the hypothesis that α-synuclein was essential for the formation of inclusions and neurodegeneration caused by 26S proteasomal depletion. We found that both of these processes were independent of α-synuclein. This provides an important insight into the relationship between the proteasome, α-synuclein, inclusion formation and neurodegeneration. We also show that the autophagy-lysosomal pathway is not activated in 26S proteasome-depleted neurones. This leads us to suggest that the paranuclear accumulation of mitochondria in inclusions in our model may reflect a role for the ubiquitin proteasome system in mitochondrial homeostasis and that neurodegeneration may be mediated through mitochondrial factors linked to inclusion biogenesis.

Abstract P2-10-29: Time dependent breast cancer metastasis prediction using novel biological imaging, clinico-pathological and genomic data combined with Bayesian modeling to reduce over-fitting and improve on inter-cohort reproducibility

Background: Breast cancer heterogeneity demands that prognostic models must be biologically driven and recent clinical evidence indicates that future prognostic signatures need evaluation in the context of early versus late metastatic risk prediction. The aim of our work was to identify biologically validated quantitative imaging parameters with improved correlation to clinical outcome, and to address some of the remaining obstacles for a truly robust prognostic model in clinical use.

Method: We identified 4 seed proteins (ezrin/radixin/moesin-cofilin), along with several kinases as biologically relevant subnetwork of proteins that control tumor cell motility and metastasis. Patient-derived breast cancer tumour samples were used to perform a combination of imaging methods such as Fluoresecence lifetime imaging microscopy, automated segmentation and co-localisation intensity analysis. A complexity optimized Bayesian proportional hazard regression model was performed on a total of 419 breast cancer patients to validate time dependent predictions using traditional clinicopathological, genomic and our novel optical imaging-derived parameters. An independent dataset of 300 patient samples from the Leeds Institute of Molecular Medicine is currently being evaluated, representing a large cross centre validation of our integrated model.

Results: We demonstrate that the traditional gold standard clinico-pathological variables are poor predictors for patients that survive long periods, and that their predictive significance (in terms of hazard ratios) varies significantly between two temporal cohorts where the adjuvant treatments are vastly different. Moreover, we investigate the predictive accuracy of a combined imaging/clinicopathological model compared with genomic/clinicopathological models. We demonstrate how to reduce over-fitting to help improve the performance of prognostic models. Results of an integrated model combining genomic and imaging parameters are still awaited.

Discussion: We have produced the first optical imaging-derived multivariate tumour metastatic signature, which measures underlying key biological variables involved in regulating cancer cell motility. Using Bayesian proportional hazards regression in a time-dependent manner, we highlight the inadequacies of existing prediction tools and present a model combining the clinicopathological parameters with our imaging-based metastatic signature, as an integrative reproducible prognostic tool across different temporal cohorts.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-29.

The ATP-binding cassette proteins of the deep-branching protozoan parasite Trichomonas vaginalis

The ATP binding cassette (ABC) proteins are a family of membrane transporters and regulatory proteins responsible for diverse and critical cellular process in all organisms. To date, there has been no attempt to investigate this class of proteins in the infectious parasite Trichomonas vaginalis. We have utilized a combination of bioinformatics, gene sequence analysis, gene expression and confocal microscopy to investigate the ABC proteins of T. vaginalis. We demonstrate that, uniquely among eukaryotes, T. vaginalis possesses no intact full-length ABC transporters and has undergone a dramatic expansion of some ABC protein sub-families. Furthermore, we provide preliminary evidence that T. vaginalis is able to read through in-frame stop codons to express ABC transporter components from gene pairs in a head-to-tail orientation. Finally, with confocal microscopy we demonstrate the expression and endoplasmic reticulum localization of a number of T. vaginalis ABC transporters.

The parasite Trichomonas vaginalis infects in excess of 100 million people per year, and is a contributory factor to enhanced transmission rates of HIV, the causative virus in AIDS. As such, T. vaginalis infection is an important public health concern. Understanding the biology of the organism is important to determine aspects of the response to drug treatment, host:parasite interactions and so on. We have investigated an important family of proteins – the ATP binding cassette transporters – which are present in the membranes of all cells, and which contribute to a diverse spectrum of important cellular processes. The ABC transporters of T. vaginalis were identified by analysis of primary amino acid sequence data, and examined by subsequent protein and gene expression studies. Our most important conclusion is that – uniquely amongst eukaryotes - T. vaginalis has no ABC transporters capable of acting as monomers. In other words, its ABC transporters must all act by forming functional complexes with other ABC proteins. This has implications for our understanding not just of the parasite's biology, but also its evolution. In summary our analysis opens up the path for future research of individual members of the ABC protein family in T. vaginalis.

Abstract 4301: Shear stress induces Rac1/Rab5 circular ruffling/endosomes at the apical surface of metastatic esophageal tumor cells enhancing spreading and motility responses

A coordinated mode of motility is required for dissemination and invasion of esophageal metastases through the vasculature. This motility is largely driven by the activation of GTPases Rac1 and Rab5 which regulate 2 and 3-dimensional motility respectively; however, little is known about the localization and activation of these GTPases under hydrodynamic flow. In this study, the effect of Rac1 activation on tumor motility was investigated in a controlled microfluidic chip that simulates venous flow conditions. A metastatic esophageal cell line derived from the ascites of a male patient with squamous cell cancer of the esophagus (OC-1), was transiently transfected with cDNA encoding active (L61), dominant negative (N17) and wild type (WT) Rac1 fused to GFP to enable visual localization of Rac1 in real time under static and fluid flow conditions. Transfected OC-1 cells were allowed to adhere to fibronectin (Fn) for 30 minutes under static conditions or allowed to adhere to Fn for 5 minutes followed by exposure to a continuous venous shear rate of 200 s-1 for 25 minutes. Cell motility and Rac1 localization was monitored over a 30-minute period followed by cell fixation and co-staining with a polyclonal antibody directed against Rab5 to visualize endosomal trafficking within the cells. The results of our study show that the over-expression of constitutively active Rac1 enhances circular ruffling, pseudopodia formation and motility in OC-1 cells under static conditions when compared to N17 and WT Rac1. Moreover, this activation response in L61-transfected cells is significantly increased in the presence of venous shear rates, (p<0.0013) and completely inhibited in cells expressing the N17 active mutant which display rounded quiescent morphology states. Co-localization studies confirmed that both Rac1 and Rab5 GTPases are recruited to distinct populations of endosomes containing actin at the apical membrane of OC-1 cells under shear, measuring between 0.6 and 1.5 μm. These results suggest that Rab5/Rac1 circular ruffling/endosomal recruitment at the apical surface is an important adaptive response to enhance motility under fluid flow conditions. Moreover, this study may offer insight into mechano-receptor signaling and how metastatic cells adapt and disseminate in circulation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4301. doi:1538-7445.AM2012-4301

The challenges of integrating molecular imaging into the optimization of cancer therapy

We review novel, in vivo and tissue-based imaging technologies that monitor and optimize cancer therapeutics. Recent advances in cancer treatment centre around the development of targeted therapies and personalisation of treatment regimes to individual tumour characteristics. However, clinical outcomes have not improved as expected. Further development of the use of molecular imaging to predict or assess treatment response must address spatial heterogeneity of cancer within the body. A combination of different imaging modalities should be used to relate the effect of the drug to dosing regimen or effective drug concentration at the local site of action. Molecular imaging provides a functional and dynamic read-out of cancer therapeutics, from nanometre to whole body scale. At the whole body scale, an increase in the sensitivity and specificity of the imaging probe is required to localise (micro)metastatic foci and/or residual disease that are currently below the limit of detection. The use of image-guided endoscopic biopsy can produce tumour cells or tissues for nanoscopic analysis in a relatively patient-compliant manner, thereby linking clinical imaging to a more precise assessment of molecular mechanisms. This multimodality imaging approach (in combination with genetics/genomic information) could be used to bridge the gap between our knowledge of mechanisms underlying the processes of metastasis, tumour dormancy and routine clinical practice. Treatment regimes could therefore be individually tailored both at diagnosis and throughout treatment, through monitoring of drug pharmacodynamics providing an early read-out of response or resistance.

Hydroxylase inhibition attenuates colonic epithelial secretory function and ameliorates experimental diarrhea

Hydroxylases are oxygen-sensing enzymes that regulate cellular responses to hypoxia. Transepithelial Cl(-) secretion, the driving force for fluid secretion, is dependent on O(2) availability for generation of cellular energy. Here, we investigated the role of hydroxylases in regulating epithelial secretion and the potential for targeting these enzymes in treatment of diarrheal disorders. Ion transport was measured as short-circuit current changes across voltage-clamped monolayers of T(84) cells and mouse colon. The antidiarrheal efficacy of dimethyloxallyl glycine (DMOG) was tested in a mouse model of allergic disease. Hydroxylase inhibition with DMOG attenuated Ca(2+)- and cAMP-dependent secretory responses in voltage-clamped T(84) cells to 20.2 ± 2.6 and 38.8 ± 6.7% (n=16; P≤0.001) of those in control cells, respectively. Antisecretory actions of DMOG were time and concentration dependent, being maximal after 18 h of DMOG (1 mM) treatment. DMOG specifically inhibited Na(+)/K(+)-ATPase pump activity without altering its expression or membrane localization. In mice, DMOG inhibited agonist-induced secretory responses ex vivo and prevented allergic diarrhea in vivo. In conclusion, hydroxylases are important regulators of epithelial Cl(-) and fluid secretion and present a promising target for development of new drugs to treat transport disorders.

Heterologous expression of a membrane-spanning auxin importer: implications for functional analyses of auxin transporters

Biochemical studies of plant auxin transporters in vivo are made difficult by the presence of multiple auxin transporters and auxin-interacting proteins. Furthermore, the expression level of most such transporters in plants is likely to be too low for purification and downstream functional analysis. Heterologous expression systems should address both of these issues. We have examined a number of such systems for their efficiency in expressing AUX1 from Arabidopsis thaliana. We find that a eukaryotic system based upon infection of insect cells with recombinant baculovirus provides a high level, easily scalable expression system capable of delivering a functional assay for AUX1. Furthermore, a transient transfection system in mammalian cells enables localization of AUX1 and AUX1-mediated transport of auxin to be investigated. In contrast, we were unable to utilise P. pastoris or L. lactis expression systems to reliably express AUX1.

Shear stress induces internalization of E-cadherin and invasiveness in metastatic oesophageal cancer cells by a Src-dependent pathway

Metastatic disease is dependent on tumor cell migration through the venous and lymphatic systems and requires dynamic rearrangement of adherens junctions. Endocytosis of cadherins is a key mechanism to dynamically arrange adherens junctions, signaling, and motility in tumor cells; however, the role of shear in regulating this process in metastatic cells is unknown. In this study, the role of shear in regulating cell surface expression of E-cadherin was investigated. We found that exposure to venous shear (shear rate, 200/s) induced internalization of E-cadherin in adherent metastatic oesophageal tumor cells (OC-1 tumor cell line). Internalized E-cadherin was found localized to Rab5-positive endosomes and was not present in lysosomes. As the Src family of tyrosine kinase have been implicated in regulating cadherin expression, we investigated the role of shear in regulating E-cadherin through Src activity. Pretreatment of OC-1 cells with the specific Src kinase inhibitor 4-amino-5- (4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1) prevented shear-induced internalization of E-cadherin. Direct measurement of Src activity (phosphorylation on Y416) showed that Src is activated in sheared OC-1 cells and that the shear-induced increase in phospho-Src is inhibited by the presence of PP1. Moreover, we show that shear stress significantly increased the invasive capacity of OC-1 cells (P < 0.001), a process inhibited by the presence of PP1. These results indicate a novel role for shear in regulating the endocytosis of E-cadherin and invasiveness in metastatic cells.

Mobility and invasiveness of metastatic esophageal cancer are potentiated by shear stress in a ROCK- and Ras-dependent manner

To metastasize, tumor cells must adopt different morphological responses to resist shear forces encountered in circulating blood and invade through basement membranes. The Rho and Ras GTPases play a critical role in regulating this dynamic behavior. Recently, we demonstrated shear-induced activation of adherent esophageal metastatic cells, characterized by formation of dynamic membrane blebs. Although membrane blebbing has only recently been characterized as a rounded mode of cellular invasion promoted through Rho kinase (ROCK), the role of shear forces in modulating membrane blebbing activity is unknown. To further characterize membrane blebbing in esophageal metastatic cells (OC-1 cell line), we investigated the role of shear in cytoskeletal remodeling and signaling through ROCK and Ras. Our results show that actin and tubulin colocalize to the cortical ring of the OC-1 cell under static conditions. However, under shear, actin acquires a punctuate distribution and tubulin localizes to the leading edge of the OC-1 cell. We show for the first time that dynamic bleb formation is induced by shear alone independent of integrin-mediated adhesion ( P < 0.001, compared with OC-1 cells). Y-27632, a specific inhibitor of ROCK, causes a significant reduction in shear-induced bleb formation and inhibits integrin αvβ3-Ras colocalization at the leading edge of the cell. Direct measurement of Ras activation shows that the level of GTP-bound Ras is elevated in sheared OC-1 cells and that the shear-induced increase in Ras activity is inhibited by Y-27632. Finally, we show that shear stress significantly increases OC-1 cell invasion ( P < 0.007), an effect negated by the presence of Y-27632. Together our findings suggest a novel physiological role for ROCK and Ras in metastatic cell behavior.

Caudate blood flow and volume are reduced in HIV+ neurocognitively impaired patients

OBJECTIVE

To evaluate the effects of HIV-associated neurocognitive impairment on caudate blood flow and volume.

METHODS

The authors performed continuous arterial spin labeled MRI on 42 HIV+ patients (23 subsyndromic and 19 HIV neurosymptomatic) on highly active antiretroviral therapy and 17 seronegative controls. They compared caudate blood flow and volume among groups.

RESULTS

A stepwise decrease in both caudate blood flow and volume was observed with increasing HIV-associated neurocognitive impairment. Compared with seronegative controls, baseline caudate blood flow was reduced in HIV+ neurosymptomatic patients (p = 0.001) with a similar decreasing trend for subsyndromic HIV+ patients (p = 0.070). Differences in caudate volume were observed only for neurosymptomatic HIV+ patients compared with controls (p = 0.010). A Jonckheere-Terpstra test for trends was significant for both caudate blood flow and volume for each of the three subgroups. Pearson product moment correlation coefficients were not significant between caudate blood flow and volume for each group.

CONCLUSIONS

Decreasing trends in caudate blood flow and volume were associated with significantly increasing HIV-associated neurocognitive impairment (HNCI), with the greatest decreases observed for more severely impaired patients. However, reductions in caudate blood flow and volume were poorly correlated. Changes in residual caudate blood flow may act as a surrogate biomarker for classifying the degree of HNCI.

Shear stress modulates the interaction of platelet-secreted matrix proteins with tumor cells through the integrin alphavbeta3

Interaction of tumor cells with the vascular wall is required for metastasis from the bloodstream. The precise interaction among metastatic cells, circulating platelets, the vessel wall, and physiological flow conditions remains to be determined. In this study, we investigated the interaction of shear on metastatic cell lines adherent to lipopolysaccharide (LPS)-treated endothelium. Tumor cells were perfused over LPS-treated human umbilical vein endothelial cells (HUVECs) at incremental venous shear rates from 50 to 800 s(-1). At a venous shear rate of 400 s(-1), 3% of adherent tumor cells formed pseudopodia under shear, a process we termed shear-induced activation. Because platelets promote tumor dissemination, we then investigated the effect of pretreating tumor cells with platelet releasate collected from activated platelet concentrate. We found that in the presence of platelet releasate, the number of tumor cells adhering to HUVECs increased and tumor "activation" occurred at a significantly lower shear rate of 50 s(-1). This was inhibited with acetylsalicylic acid. Depletion of fibronectin or vitronectin from the platelet releasate resulted in significantly less adhesion at higher venous shear rates of 600 and 800 s(-1). The integrin alphavbeta3 has been shown to mediate cell adhesion primarily through vitronectin and fibronectin proteins. Inhibition of alphavbeta3, followed by the addition of platelet releasate to the tumor cells, resulted in significantly less adhesion at higher venous shear rates of 600 and 800 s(-1). Collectively, our data suggest that alphavbeta3 promotes the metastatic phenotype of tumor cells through interactions with the secreted platelet proteins vitronectin and fibronectin under venous shear conditions.

How audit can improve provision of in-patient pain services

Clinical governance makes it necessary for the cycle of clinical audit to be refined, encouraging a continuous process of quality improvement. This is achieved through the monitoring of practice and benchmarking, and supported by continuing practice development. Reliable information is essential if pain services are to be improved in line with patients' needs.

Medication use among children with asthma in East Harlem

PURPOSE

To examine daily use of antiinflammatory medication among children with asthma in East Harlem, where hospitalization rates for asthma are among the highest in the United States.

METHODS

We analyzed parent/guardian reports of medications used by children with current asthma (defined as physician diagnosis and wheezing during the previous 12 months) identified from a cross-sectional survey conducted in 2 elementary schools.

RESULTS

From an overall sample of 1319 children, 298 with current asthma were included in this analysis. Most of those with asthma were Puerto Rican (136 [46%]) or black (98 [33%]), 168 (57%) were boys, and the median age was 8 years old. Overall, 65 (22%) were using antiinflammatory medication on a daily basis. A subgroup of 107 children with asthma had been hospitalized during the previous 12 months or had used beta(2)-agonist on a daily basis, suggesting persistent or severe asthma. Of these 107 children, 42 (39%) were taking antiinflammatory medication on a daily basis. Multivariate analysis of these 107 children revealed that daily use of antiinflammatory medication was associated with using a spacer tube (adjusted odds ratio [AOR]: 3. 08; 95% confidence interval [CI]: 1.27,7.47) and having seen a physician in the past 6 months (AOR: 3.46; CI: 1.01,11.9). Compared with Puerto Ricans, blacks (AOR:.32; CI:.12,.89) or children of other races/ethnicities (AOR:.27; CI:.09,.85) were less likely to use antiinflammatory medication on a daily basis.

CONCLUSION

Daily use of antiinflammatory medication for children with persistent or severe asthma in East Harlem was underused. Differences in access to care may explain some findings; however, reasons for ethnic differences in use remain unclear. Both community interventions and additional provider education are needed.

The transition to managed care: experiences of planned parenthood patients

A review of the findings from a 1996 survey of women visiting a Planned Parenthood clinic reveals that some members of managed care organizations (MCOs) may not be receiving appropriate preventive services and information from their primary care providers. This article details the results of a survey of 115 women who attended a Planned Parenthood of New York City clinic for reproductive health services. Based on these survey findings, the authors provide recommendations for MCOs and traditional providers of reproductive health to improve service delivery.

Pain assessment

Pain assessment is fundamental to planning pain relief and is an area of nursing accountability. It allows diagnosis of the cause of pain, accurately evaluates the effect of analgesia and provides a framework for the setting of standards. Pain assessment should be a collaborative process involving the patient.

A controlled trial of fluoxetine in nondepressed patients with Huntington's disease

To examine the antidepressant specificity of fluoxetine in Huntington's disease (HD), we carried out a randomized, double-blind, placebo-controlled trial of this medication in nondepressed HD patients. Thirty patients with early HD who were depressed (Hamilton Depression Inventory < 16) were randomized to placebo (N = 13) or fluoxetine 20 mg/day (N = 17) and were followed up for 4 months. Outcome measures included changes in total functional capacity (TFC) and in standardized neurological, cognitive, and behavioral ratings. After adjustment for the higher education level found in the placebo group at baseline, no differences between the treatment groups were found in TFC, neurological, or cognitive ratings. Fluoxetine-treated patients did show a slight reduction in agitation and in the need for routine. Although fluoxetine may be a useful antidepressant in depressed HD patients, it failed to exert substantial clinical benefits in nondepressed HD patients.

Lifestyle correlates of Carpal Tunnel Syndrome

The potential for predicting membership in a Carpal Tunnel Syndrome group (CTS) vs. a non-CTS group was evaluated for five psychological variables (i.e., life events stress, perceived stress, self-management habits, cognitive self-control skills, and lifestyle organization) and three physical variables (i.e., general physical symptoms, suspected medical risk for CTS, and generic musculoskeletal problems). The subjects included 50 pairs of workers, with each pair having one worker who had CTS and the other who had not. A logistic regression analysis indicated that five of the measures (three psychological and two physical) were significant single model predictors of membership in CTS and non-CTS groups. The most efficient multifactor model in predicting CTS appeared to be a combination of measures reflecting generic musculoskeletal problems and lifestyle organization.

Cortical and subcortical afferent connections of a posterior division of feline area 7 (area 7p)

Area 7 of the cat, as identified cytoarchitecturally, includes cortex both on the middle suprasylvian gyrus and on the anterior lateral gyrus. The aim of the experiments reported here was to determine whether within this zone there are subdivisions with qualitatively different patterns of afferent connectivity. Deposits of distinguishable retrograde tracers were placed at 29 sites in and around area 7 of 15 cats; cortical and subcortical telencephalic structures were then scanned for retrograde labeling. Our results indicate that cortex on the anterior lateral gyrus, although often included in area 7, is indistinguishable on connectional grounds from adjacent somesthetic cortex (area 5b). Cortex with strong links to visual, oculomotor, and association areas is confined to the middle suprasylvian gyrus and the adjacent lateral bank of the lateral sulcus. We refer to this discrete, connectionally defined zone as posterior area 7 (area 7p). Area 7p receives input from visual areas 19, 20a, 20b, 21a, 21b, AMLS, ALLS, and PLLS; from frontal oculomotor cortex (areas 6m and 6l); and from cortical association areas (posterior cingulate cortex, the granular insula, the posterior ectosylvian gyrus, and posterior area 35). Thalamic projections to area 7p arise from three specific nuclei (pulvinar; nucleus lateralis intermedius, pars caudalis; nucleus ventralis anterior) and from the intralaminar complex (nuclei centralis lateralis, paracentralis and centralis medialis). Neurons in a division of the claustrum immediately beneath the somatosensory and visual zones project to area 7p. Within area 7p, anterior-posterior regional differentiation is present, as indicated by the spatial ordering of projections from cingulate and frontal cortex, the thalamus, and the claustrum. Area 7p, as delineated by connectional analysis in this study, resembles cortex of the primate inferior parietal lobule both in its location relative to other cortical districts and in its pattern of neural connectivity.