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Disease Models (disease + models)
Selected AbstractsDesign and Analysis of Arm-in-Cage Experiments: Inference for Three-State Progressive Disease Models with Common Periodic Observation TimesBIOMETRICS, Issue 2 2008B. A. Griffin Summary We develop statistical methods for designing and analyzing arm-in-cage experiments used to test the efficacy of insect repellents and other topical treatments. In these experiments, a controlled amount of the treatment is applied to a volunteer's forearm, which then is exposed to the insects by being placed into a special cage. Arms are not kept in the cages continuously, but rather placed there periodically for a brief period of time, during which it is noted whether an insect lands (but does not bite) or (lands and) bites. Efficacy of a repellent can be described using a progressive three-state model in which the first two states represent varying degrees of protection (no landing and landing without biting) and the third state occurs once protection is completely lost (biting). Because subjects within a treatment group follow the same cage visit schedule, transition times between states are interval censored into one of several fixed intervals. We develop an approach that uses a mixture of nonparametric and parametric techniques for estimating the parameters of interest when sojourn times are dependent. Design considerations for arm-in-cage experiments are addressed and the proposed methods are illustrated on data from a recent arm-in-cage experiment as well as simulated data. [source] How important are Toll-like receptors for antimicrobial responses?CELLULAR MICROBIOLOGY, Issue 8 2007Susan Carpenter Summary The innate immune system is the primary line of defence against invading pathogenic microbes. Toll-like receptors (TLRs) are a family of membrane receptors which play a pivotal role in sensing a wide range of invading pathogens including bacteria, fungi and viruses. TLR-deficient mice have provided us with immense knowledge on the functioning of individual TLRs. Dysregulation of TLR signalling is linked with a number of disease conditions. Disease models have helped show that targeting components of TLR signalling cascades could lead to novel therapies in the treatment of infectious diseases. In this review we focus on the evidence provided to date to explain just how important TLRs are in host defence against microbial pathogens. [source] Curiosity and cure: Translational research strategies for neural repair-mediated rehabilitationDEVELOPMENTAL NEUROBIOLOGY, Issue 9 2007Bruce H. Dobkin Abstract Clinicians who seek interventions for neural repair in patients with paralysis and other impairments may extrapolate the results of cell culture and rodent experiments into the framework of a preclinical study. These experiments, however, must be interpreted within the context of the model and the highly constrained hypothesis and manipulation being tested. Rodent models of repair for stroke and spinal cord injury offer examples of potential pitfalls in the interpretation of results from developmental gene activation, transgenic mice, endogeneous neurogenesis, cellular transplantation, axon regeneration and remyelination, dendritic proliferation, activity-dependent adaptations, skills learning, and behavioral testing. Preclinical experiments that inform the design of human trials ideally include a lesion of etiology, volume and location that reflects the human disease; examine changes induced by injury and by repair procedures both near and remote from the lesion; distinguish between reactive molecular and histologic changes versus changes critical to repair cascades; employ explicit training paradigms for the reacquisition of testable skills; correlate morphologic and physiologic measures of repair with behavioral measures of task reacquisition; reproduce key results in more than one laboratory, in different strains or species of rodent, and in a larger mammal; and generalize the results across several disease models, such as axonal regeneration in a stroke and spinal cord injury platform. Collaborations between basic and clinical scientists in the development of translational animal models of injury and repair can propel experiments for ethical bench-to-bedside therapies to augment the rehabilitation of disabled patients. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Parasites in food webs: the ultimate missing linksECOLOGY LETTERS, Issue 6 2008Kevin D. Lafferty Abstract Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. [source] Identification of rat urinary glycoproteome captured by three lectins using gel and LC-based proteomicsELECTROPHORESIS, Issue 21 2008Pyong-Gon Moon Abstract Many different types of urine proteome studies have been done, but urine glycoprotein studies are insufficient. Therefore, we studied the glycoproteins from rat urine, which could be used to identify biomarkers in an animal model. First, urinary proteins were prepared by using the dialysis and lyophilizing methods from rat urine. Glycoproteins enriched with lectin affinity purification, concanavalin A, jacalin and wheat germ agglutinin from the urinary proteins were separated by means of reverse-phase fast protein LC (FPLC) or 1-D PAGE. Each FPLC fraction and 1-D PAGE gel band were trypsin-digested and analyzed by means of nanoLC-MS/MS. LC-MS/MS analyses were carried out by using linear ion trap MS. A total of 318 rat urinary glycoproteins were identified from the FPLC fractions and gel bands; approximately 90% of identified proteins were confirmed as glycoproteins in Swiss-Prot. Many glycoproteins, known as biomarkers, including C-reactive protein, uromodulin, amyloid beta A4 protein, alpha-1-inhibitor 3, vitamin D-binding protein, kallikrein 3 and fetuin-A were identified in this study. By studying urinary glycoproteins collected from rat, these results may help to assist in identifying urinary biomarkers regarding various types of disease models. [source] An effective skeletal muscle prefractionation method to remove abundant structural proteins for optimized two-dimensional gel electrophoresisELECTROPHORESIS, Issue 11 2005Bradley Jarrold Abstract Proteomic analysis of biological samples in disease models or therapeutic intervention studies requires the ability to detect and identify biologically relevant proteins present in relatively low concentrations. The detection and analysis of these low-level proteins is hindered by the presence of a few proteins that are expressed in relatively high concentrations. In the case of muscle tissue, highly abundant structural proteins, such as actin, myosin, and tropomyosin, compromise the detection and analysis of more biologically relevant proteins. We have developed a practical protocol which exploits high-pH extraction to reduce or remove abundant structural proteins from skeletal muscle crude membrane preparations in a manner suitable for two dimensional gel electrophoresis. An initial whole-cell muscle lysate is generated by homogenization of powdered tissue in Tris-base. This lysate is subsequently partitioned into a supernatant and pellet containing the majority of structural proteins. Treatment of the pellet with high-pH conditions effectively releases structural proteins from membrane compartments which are then removed through ultracentrifugation. Mass spectrometric identification shows that the majority of protein spots reduced or removed by high-pH treatment were contractile proteins or contractile-related proteins. Removal of these proteins enabled successful detection and identification of minor proteins. Structural protein removal also results in significant improvement of gel quality and the ability to load higher amounts of total protein for the detection of lower abundant protein classes. [source] Obesity predisposes to Th17 biasEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2009Shawn Winer Abstract Obesity is associated with numerous inflammatory conditions including atherosclerosis, autoimmune disease and cancer. Although the precise mechanisms are unknown, obesity-associated rises in TNF-,, IL-6 and TGF-, are believed to contribute. Here we demonstrate that obesity selectively promotes an expansion of the Th17 T-cell sublineage, a subset with prominent pro-inflammatory roles. T-cells from diet-induced obese mice expand Th17 cell pools and produce progressively more IL-17 than lean littermates in an IL-6-dependent process. The increased Th17 bias was associated with more pronounced autoimmune disease as confirmed in two disease models, EAE and trinitrobenzene sulfonic acid colitis. In both, diet-induced obese mice developed more severe early disease and histopathology with increased IL-17+ T-cell pools in target tissues. The well-described association of obesity with inflammatory and autoimmune disease is mechanistically linked to a Th17 bias. [source] Association tests using kernel-based measures of multi-locus genotype similarity between individualsGENETIC EPIDEMIOLOGY, Issue 3 2010Indranil Mukhopadhyay Abstract In a genetic association study, it is often desirable to perform an overall test of whether any or all single-nucleotide polymorphisms (SNPs) in a gene are associated with a phenotype. Several such tests exist, but most of them are powerful only under very specific assumptions about the genetic effects of the individual SNPs. In addition, some of the existing tests assume that the direction of the effect of each SNP is known, which is a highly unlikely scenario. Here, we propose a new kernel-based association test of joint association of several SNPs. Our test is non-parametric and robust, and does not make any assumption about the directions of individual SNP effects. It can be used to test multiple correlated SNPs within a gene and can also be used to test independent SNPs or genes in a biological pathway. Our test uses an analysis of variance paradigm to compare variation between cases and controls to the variation within the groups. The variation is measured using kernel functions for each marker, and then a composite statistic is constructed to combine the markers into a single test. We present simulation results comparing our statistic to the U -statistic-based method by Schaid et al. ([2005] Am. J. Hum. Genet. 76:780,793) and another statistic by Wessel and Schork ([2006] Am. J. Hum. Genet. 79:792,806). We consider a variety of different disease models and assumptions about how many SNPs within the gene are actually associated with disease. Our results indicate that our statistic has higher power than other statistics under most realistic conditions. Genet. Epidemiol. 34: 213,221, 2010. © 2009 Wiley-Liss, Inc. [source] A two-step procedure for constructing confidence intervals of trait loci with application to a rheumatoid arthritis datasetGENETIC EPIDEMIOLOGY, Issue 1 2006Charalampos Papachristou Abstract Preliminary genome screens are usually succeeded by fine mapping analyses focusing on the regions that signal linkage. It is advantageous to reduce the size of the regions where follow-up studies are performed, since this will help better tackle, among other things, the multiplicity adjustment issue associated with them. We describe a two-step approach that uses a confidence set inference procedure as a tool for intermediate mapping (between preliminary genome screening and fine mapping) to further localize disease loci. Apart from the usual Hardy-Weiberg and linkage equilibrium assumptions, the only other assumption of the proposed approach is that each region of interest houses at most one of the disease-contributing loci. Through a simulation study with several two-locus disease models, we demonstrate that our method can isolate the position of trait loci with high accuracy. Application of this two-step procedure to the data from the Arthritis Research Campaign National Repository also led to highly encouraging results. The method not only successfully localized a well-characterized trait contributing locus on chromosome 6, but also placed its position to narrower regions when compared to their LOD support interval counterparts based on the same data. Genet. Epidemiol. 30:18,29, 2006. © 2005 Wiley-Liss, Inc. [source] Haplotype interaction analysis of unlinked regionsGENETIC EPIDEMIOLOGY, Issue 4 2005Tim Becker Abstract Genetically complex diseases are caused by interacting environmental factors and genes. As a consequence, statistical methods that consider multiple unlinked genomic regions simultaneously are desirable. Such consideration, however, may lead to a vast number of different high-dimensional tests whose appropriate analysis pose a problem. Here, we present a method to analyze case-control studies with multiple SNP data without phase information that considers gene-gene interaction effects while correcting appropriately for multiple testing. In particular, we allow for interactions of haplotypes that belong to different unlinked regions, as haplotype analysis often proves to be more powerful than single marker analysis. In addition, we consider different marker combinations at each unlinked region. The multiple testing issue is settled via the minP approach; the P value of the "best" marker/region configuration is corrected via Monte-Carlo simulations. Thus, we do not explicitly test for a specific pre-defined interaction model, but test for the global hypothesis that none of the considered haplotype interactions shows association with the disease. We carry out a simulation study for case-control data that confirms the validity of our approach. When simulating two-locus disease models, our test proves to be more powerful than association methods that analyze each linked region separately. In addition, when one of the tested regions is not involved in the etiology of the disease, only a small amount of power is lost with interaction analysis as compared to analysis without interaction. We successfully applied our method to a real case-control data set with markers from two genes controlling a common pathway. While classical analysis failed to reach significance, we obtained a significant result even after correction for multiple testing with our proposed haplotype interaction analysis. The method described here has been implemented in FAMHAP. Genet. Epidemiol. 2005. © 2005 Wiley-Liss, Inc. [source] Affected-sib-pair test for linkage based on constraints for identical-by-descent distributions corresponding to disease models with imprinting,GENETIC EPIDEMIOLOGY, Issue 4 2004Michael Knapp Abstract Holmans' possible triangle test for affected sib pairs has proven to be a powerful tool for linkage analysis. This test is a likelihood-ratio test for which maximization is restricted to the set of possible sharing probabilities. Here, we extend the possible triangle test to take into account genomic imprinting, which is also known as parent-of-origin effect. While the classical test without imprinting looks at whether affected sib pairs share 0, 1, or 2 alleles identical-by-descent, the likelihood-ratio test allowing for imprinting further distinguishes whether the sharing of exactly one allele is through the father or mother. Thus, if the disease gene is indeed subject to imprinting, the extended test presented here can take into account that affecteds will have inherited the mutant allele preferentially from one particular parent. We calculate the sharing probabilities at a marker locus linked to a disease susceptibility locus. Using our formulation, the constraints on these probabilities given by Dudoit and Speed ([1999] Statistics in Genetics; New York: Springer) can easily be verified. Next, we derive the asymptotic distribution of the restricted likelihood-ratio test statistic under the null hypothesis of no linkage, and give LOD-score criteria for various test sizes. We show, for various disease models, that the test allowing for imprinting has significantly higher power to detect linkage if imprinting is indeed present, at the cost of only a small reduction in power in case of no imprinting. Altogether, unlike many methods currently available, our novel model-free sib-pair test adequately models the epigenetic parent-of-origin effect, and will hopefully prove to be a useful tool for the genetic mapping of complex traits. © 2004 Wiley-Liss, Inc. [source] Properties of the transmission-disequilibrium test in the presence of inbreedingGENETIC EPIDEMIOLOGY, Issue 2 2002Emmanuelle Génin Abstract Family-based association tests such as the transmission-disequilibrium test (TDT), which compare alleles transmitted and non-transmitted from parents to affected offspring, are widely used to detect the role of genetic risk factors in diseases. These methods have the advantage of being robust to population stratification and are thus believed to be valid whatever the population context. In different studies of the statistical properties of the TDT, parents of affected offspring are typically assumed to be neither inbred nor related. In many human populations, however, this assumption is false and parental alleles are then no longer independent. It is thus of interest to determine whether the TDT is a valid test of linkage and association in the presence of inbreeding. We present a method to derive the expected value of the TDT statistic under different disease models and for any relationship between the parents of affected offspring. Using this method, we show that in the presence of inbreeding, the TDT is still a valid test for linkage but not for association. The power of the test to detect linkage may, however, be increased in the presence of inbreeding under different modes of inheritance. Genet. Epidemiol. 22:116,127, 2002. © 2002 Wiley-Liss, Inc. [source] Lymphotoxin and LIGHT signaling pathways and target genesIMMUNOLOGICAL REVIEWS, Issue 1 2004Kirsten Schneider Summary:, Lymphotoxins (LT, and LT,), LIGHT [homologous to LT, inducible expression, competes with herpes simplex virus (HSV) glycoprotein D for HSV entry mediator (HVEM), a receptor expressed on T lymphocytes], tumor necrosis factor (TNF), and their specific receptors LT,R, HVEM, and TNF receptor 1 (TNFR1) and TNFR2, form the immediate family of the larger TNF superfamily. These cytokines establish a critical communication system required for the development of secondary lymphoid tissues; however, knowledge of the target genes activated by these signaling pathways is limited. Target genes regulated by the LT,,-LT,R pathway include the tissue-organizing chemokines, CXCL13, CCL19, and CCL21, which establish cytokine circuits that regulate LT expression on lymphocytes, leading to organized lymphoid tissue. Infectious disease models have revealed that LT,, pathways are also important for innate and adaptive immune responses involved in host defense. Here, regulation of interferon-, by LT,R and TNFR signaling may play a crucial role in certain viral infections. Regulation of autoimmune regulator in the thymus via LT,R implicates LT/LIGHT involvement in central tolerance. Dysregulated expression of LIGHT overrides peripheral tolerance leading to T-cell-driven autoimmune disease. Blockade of TNF/LT/LIGHT pathways as an intervention in controlling autoimmune diseases is attractive, but such therapy may have risks. Thus, identifying and understanding the target genes may offer an opportunity to fine-tune inhibitory interventions. [source] Genetic analysis of collagen-induced arthritis in rats: a polygenic model for rheumatoid arthritis predicts a common framework of cross-species inflammatory/autoimmune disease lociIMMUNOLOGICAL REVIEWS, Issue 1 2001Marie M. Griffiths Summary: Collagen-induced arthritis (CIA) is a useful model for dissecting the genetic patterns underlying susceptibility to rheumatoid arthritis (RA) and related chronic/inflammatory autoimmune diseases. CIA exhibits three phenotypes characteristic of autoimmune disease pathogenesis: abnormal levels of immune reactivity to self antigens; chronic inflammation of target organs expressing that specific autoantigen; activation and direct participation of invading mononuclear cells and resident tissue fibroblasts in organ damage. Over 25 different quantitative trait loci (QTL) regulating arthritis severity and autoantibody in rats with CIA are mapped. QTL-congenic strains show that certain CIA,QTLs can modulate arthritis independently. These monogenic models are proving to be highly informative for fine mapping and function studies, revealing gender effects and evidence of gene clusters. Recent genome scans of RA populations identified RA-susceptibility loci in chromosome regions homologous to rat chromosomal segments housing CIA,QTLs. Also, CIA,QTLs frequently co-localize with susceptibility QTLs mapped in other rat arthritis models induced with non-immunogenic adjuvant oils and/or in rat autoimmune models of multiple sclerosis and diabetes. Common autoimmunity genes and inflammation genes important to several human diseases are likely being detected in the various rat disease models. Continued dissection of the genetic underpinnings of rat arthritis models should provide candidate genes for investigation in human patients and lead to a clearer understanding of the complex genetics of RA. [source] Stepwise regulation of TH1 responses in autoimmunity: IL-12-related cytokines and their receptorsINFLAMMATORY BOWEL DISEASES, Issue 8 2005Christoph Becker PhD Abstract Interleukin (IL)-12 is a key cytokine of cell-mediated immune responses. Until recently, IL-12 was believed to be unique in its ability to induce the differentiation of naive T cells toward the TH1 phenotype and in its pathogenic activity, as shown in various disease models including inflammatory bowel disease. However, recently, 2 additional cytokines closely related to IL-12, IL-23 and IL-27, were discovered. Until then, the role of IL-12 was overestimated because it was believed that the p40 subunit was unique to IL-12. The discovery that IL-12 shares p40 with IL-23 and that IL-23 but not IL-12 is essential in models of chronic inflammation and autoimmunity led to a model in which IL-12 is essential to induce interferon-,-producing TH1 cells, whereas IL-23 mediates effector functions. The latest cytokine added to this cytokine family is IL-27. IL-27 has the unique feature to act on naive T cells, rendering them susceptible to IL-12 signaling. Thus, IL-27 may be essential for the early events of a cell-mediated immune response. This review focuses on these novel cytokines and their role in cell-mediated immune responses and discusses differences and common features within the family of IL-12-related cytokines. [source] Monoclonal and polyclonal humoral immune response to EC HER-2/NEU peptides with low similarity to the host's proteomeINTERNATIONAL JOURNAL OF CANCER, Issue 5 2002Abraham Mittelman Abstract We are studying peptide immunogenicity as a function of the similarity level to the host's proteome. By using as a model the breast/prostate cancer-associated HER-2/neu antigen, we analyzed the monoclonal and polyclonal humoral immune responses against HER-2/neu peptide motifs not shared with the host proteome. We show here that (i) a mouse monoclonal antibody (MAb) raised against the extracellular domain (EC) of human HER-2/neu oncoprotein recognized a linear peptide motif endowed with low similarity level to the mouse proteome; (ii) likewise, human sera from breast/prostate cancer patients preferentially recognized peptide fragments from the EC of the HER-2/neu oncoprotein having sequences that are not present in the human proteome. Together with previous results obtained in other disease models (cervical cancer-associated HPV16 E7 oncoprotein and Pemphigus vulgaris auto-antigen desmoglein-3), the present data suggest that a low level of sequence similarity to the host's proteome might be an important factor in shaping the pool of B cell epitopes. © 2002 Wiley-Liss, Inc. [source] A subpopulation of mesenchymal stromal cells with high osteogenic potentialJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009Hua Liu Abstract Current bone disease therapy with bone marrow-derived mesenchymal stromal cells (MSC) is hampered by low efficiency. Advanced allogeneic studies on well-established mouse genetic and disease models are hindered by difficulties in isolating murine MSC (mMSC). And mMSC prepared from different laboratories exhibit significant heterogeneity. Hence, this study aimed to identify and isolate a sub-population of mMSC at an early passage number with high osteogenic potential. Enrichment of mMSC was achieved by 1-hr silica incubation and negative selection. Approximately 96% of these cells synthesized osteocalcin after 28 days of osteogenic induction in vitro, and displayed a complete dynamic alteration of alkaline phosphatase (ALP) activity with increasing osteogenic maturation and strong mineralization. Moreover, the cells displayed uniform and stable surface molecular profile, long-term survival, fast proliferation in vitro with maintenance of normal karyotype and distinct immunological properties. CD73 was found to be expressed exclusively in osteogenesis but not in adipogenesis. These cells also retained high osteogenic potential upon allogeneic transplantation in an ectopic site by the detection of bone-specific ALP, osteopontin, osteocalcin and local mineralization as early as 12 days after implantation. Hence, these cells may provide a useful source for improving current strategies in bone regenerative therapy, and for characterizing markers defining the putative MSC population. [source] Defective calcium homeostasis in the cerebellum in a mouse model of Niemann,Pick A diseaseJOURNAL OF NEUROCHEMISTRY, Issue 6 2005Luba Ginzburg Abstract We recently demonstrated that calcium homeostasis is altered in mouse models of two sphingolipid storage diseases, Gaucher and Sandhoff diseases, owing to modulation of the activities of a calcium-release channel (the ryanodine receptor) and of the sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA) respectively, by the accumulating sphingolipids. We now demonstrate that calcium homeostasis is also altered in a mouse model of Niemann,Pick A disease, the acid sphingomyelinase (A-SMase)-deficient mouse (ASM,/,), with reduced rates of calcium uptake via SERCA in the cerebellum of 6,7-month-old mice. However, the mechanism responsible for defective calcium homeostasis is completely different from that observed in the other two disease models. Thus, levels of SERCA expression are significantly reduced in the ASM,/, cerebellum by 6,7 months of age, immediately before death of the mice, as are levels of the inositol 1,4,5-triphosphate receptor (IP3R), the major calcium-release channel in the cerebellum. Systematic analyses of the time course of loss of SERCA and IP3R expression revealed that loss of the IP3R preceeded that of SERCA, with essentially no IP3R remaining by 4 months of age, whereas SERCA was still present even after 6 months. Expression of zebrin II (aldolase C), a protein found in about half of the Purkinje cells in the adult mouse cerebellum, was essentially unchanged during development. We discuss possible pathological mechanisms related to calcium dysfunction that may cause Purkinje cell degeneration, and as a result, the onset of neuropathology in Niemann,Pick A disease. [source] Altered sensitivity to excitotoxic cell death and glutamate receptor expression between two commonly studied mouse strainsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 12 2010Rozzy Finn Abstract Alterations in glutamatergic synapse function have been implicated in the pathogenesis of many different neurological disorders, including ischemia, epilepsy, Parkinson's disease, Alzheimer's disease, and Huntington's disease. While studying glutamate receptor function in juvenile Batten disease on the C57BL/6J and 129S6/SvEv mouse backgrounds, we noticed differences unlikely to be due to mutation difference alone. We report here that primary cerebellar granule cell cultures from C57BL/6J mice are more sensitive to N-methyl-D-aspartate (NMDA)-mediated cell death. Moreover, sensitivity to AMPA-mediated excitotoxicity is more variable and is dependent on the treatment conditions and age of the cultures. Glutamate receptor surface expression levels examined in vitro by in situ ELISA and in vivo by Western blot in surface cross-linked cerebellar samples indicated that these differences in sensitivity likely are due to strain-dependent differences in cell surface receptor expression levels. We propose that differences in glutamate receptor expression and in excitotoxic vulnerability should be taken into consideration in the context of characterizing disease models on the C57BL/6J and 129S6/SvEv mouse backgrounds. © 2010 Wiley-Liss, Inc. [source] The cardiac patient: a gender comparison via illness narrativesJOURNAL OF NURSING AND HEALTHCARE OF CHRONIC ILLNE SS: AN INTERNATIONAL INTERDISCIPLINARY JOURNAL, Issue 1 2009Michal Rassin PhD Aims., To compare responses to heart disease between women and men, aged 30,50 years, and to identify the factors influencing them in health and illness. Background., The quality of life and prognosis for women with heart disease are worse than for men. Methods., Participants were 30 men and 30 women who had coronary heart disease. The study was conducted using a qualitative method based on narrative investigation. Narratives were gathered using in-depth interviews and were analyzed by thematic analysis. Data were collected in 2006. Results., Women often delayed seeking treatment. When they did seek treatment they were often not initially diagnosed as having heart disease. The recovery period for women was characterised by their quick return to daily home making before their physical condition permitted it. Conversely, men extended their recovery period and received family support. Men were strict in following the instructions of the health regimen, whereas most women ignored it. The women, compared to the men, received less support from their spouses and families, and they noted that social expectations concerning their role were high. Conclusions., The role of the cardiac patient is socially formed based on male characteristics and, as a result, men are legitimised and receive social support in all that relates to the disease. Consequently, men adhere to the health regimen, whereas women are less inclined to. Relevance to clinical practice., Improved disease models for women with heart disease are needed, as are specifically design rehabilitation programmes to meet the needs of women with heart disease. [source] Intracellular readthrough of nonsense mutations by aminoglycosides in coagulation factor VIIJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2006M. PINOTTI Summary.,Background: Nonsense mutations in coagulation factor (F) VII potentially cause a lethal hemorrhagic diathesis. Readthrough of nonsense mutations by aminoglycosides has been studied in a few human disease models with variable results. Objectives: We investigated the K316X and W364X FVII mutations, associated with intracranial hemorrhage, and their correction by aminoglycosides. The rare nonsense mutations in FVII represent favorite models to test this strategy, because even tiny increases in the amount of functional full-length protein in patients could ameliorate hemorrhagic phenotypes. Results: A FVII,green fluorescent protein (GFP) chimaera provided us with a fluorescent model of FVII expression in living cells. Appreciable fluorescence in cells transfected with nonsense FVII,GFP mutants was detected upon geneticin treatment, thus demonstrating suppression of premature translation termination. To investigate the rescue of FVII function, nonsense variants of the native FVII without GFP (p316X,FVII and p364X,FVII) were transfected and found to secrete low amounts of FVII (,1% of Wt,FVII activity), thus suggesting a spontaneous stop codon readthrough. Geneticin treatment of cells resulted in a significant and dose-dependent increase of secreted FVII molecules (p316X,FVII, 24 ± 12 ng mL,1, 3.6 ± 0.8% of Wt,FVII activity; p364X,FVII, 26 ± 10 ng mL,1, 3.7±0.6%) characterized by reduced specific activity, thus indicating the synthesis of dysfunctional proteins. Similar results were observed with gentamicin, a commonly used aminoglycoside of potential interest for patient treatment. Conclusions: Our approach, extendable to other coagulation factors, represents an effective tool for a systematic study of the effects of aminoglycosides and neighboring sequences on nonsense codon readthrough. These results provide the rationale for a mutation-specific therapeutic approach in FVII deficiency. [source] Nuclear factor-,B inhibition improves myocardial contractility in rats with cirrhotic cardiomyopathyLIVER INTERNATIONAL, Issue 5 2008Hongqun Liu Abstract Background/Aims: Cytokines such as tumour necrosis factor (TNF-,) contribute to the pathogenesis of cirrhotic cardiomyopathy. Nuclear factor-,B (NF-,B) is crucial for cytokine regulation, and induces cardiac dysfunction in several heart disease models. We aimed to elucidate possible NF-,B involvement in cirrhotic cardiomyopathy. Methods: Rats were bile duct ligated (BDL) to produce cirrhosis; controls received sham operation. Animals were studied 4 weeks later. Two NF-,B inhibitors were used: pyrrolidine dithiocarbamate (PDTC) and Bay 11-7082. Four groups were studied in most protocols: sham control, sham+PDTC, BDL and BDL+PDTC. Additional contractility studies were performed with Bay 11-7082. Myocardial NF-,B and TNF-, expression was measured by Western blot and ELISA. The contractility of isolated cardiomyocytes was observed under direct microscopy. Results: Nuclear factor-,B and TNF-, levels were increased in cirrhotic hearts compared with controls. PDTC significantly reduced NF-,B activity and TNF-, expression in cirrhotic hearts; controls were unaffected. Cirrhotic cardiomyocytes showed decreased systolic and diatolic velocity compared with sham controls. Both PDTC and Bay 11-7082 restored contractile function in cirrhotic cardiomyocytes, but did not affect controls. Conclusions: Inhibition of the increased NF-,B activity in cirrhotic hearts was associated with improvement of attenuated cardiomyocyte contractility. NF-,B, via effects on cytokine expression, may contribute to the pathogenesis of cirrhotic cardiomyopathy. [source] Apoptosis and necrosis in liver diseaseLIVER INTERNATIONAL, Issue 2 2004Hartmut Jaeschke Abstract: Liver cell injury and cell death is a prominent feature in all liver disease processes. During the last 5,10 years, most research activities focused almost exclusively on evaluating apoptotic cell death and the corresponding intracellular signaling pathways. Although this effort led to substantial progress in our understanding of the mechanisms of apoptosis, it also created substantial confusion regarding the predominant mode of cell death and the relevance of apoptosis in a variety of liver disease models, as discussed in this review for acetaminophen and troglitazone hepatotoxicity, obstructive cholestasis and viral hepatitis. Part of the problem is related to the fact that there is no specific assay or parameter, with the exception of morphological changes in vivo, which allows the unequivocal distinction between apoptosis and oncotic necrosis. In addition, some aspects of the signaling pathways are similar. Therefore, to make progress in identifying relevant pharmacological intervention strategies to prevent or attenuate human liver disease processes, it is of critical importance to apply several different experimental approaches and analyze as many parameters as possible. In addition, positive controls for the assumed process should be used whenever possible and mechanisms of cell injury should only be investigated in model systems relevant for the human pathophysiology. [source] Mesangial cell proliferation inhibitors for the treatment of proliferative glomerular diseaseMEDICINAL RESEARCH REVIEWS, Issue 1 2003Yasuhisa Kurogi Abstract Mesangial cells (MC) serve a number of functions in the renal glomerular capillary including structural support of the capillary tuft, modulation of glomerular hemodynamics, and a phagocytic function allowing removal of macromolecules and immune complexes. The proliferation of MC is a prominent feature of glomerular disease including IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, and diabetic nephropathy. In experimental animal models of nephritis, MC proliferation frequently precedes and is linked to the increase of extracellular matrix in the mesangium and glomerulosclerosis. Reduction of MC proliferation in glomerular disease models by treatment with heparin, low-protein diet, or antibodies to platelet-derived growth factor (PDGF), have been shown to reduce extracellular matrix expansion and glomerulosclerotic changes. Therefore, MC proliferation inhibitors may offer therapeutic opportunities for the treatment of proliferative glomerular disease. It is also known that the MC proliferation is inhibited by many kinds of pharmacological drugs, for example, angiotensin converting enzyme (ACE) inhibitors, leukotriene D4 (LTD4) antagonists, PDGF inhibitors, matrix metalloproteinases (MMP) inhibitors, 3-hydroxy-3 methyl glutaryl-coenzymeA (HMG-CoA) inhibitors, cyclin-dependent kinases (CDK) inhibitors, and others. This review summarizes the recently reported MC proliferation inhibitors with their pharmacological properties on the basis of their chemical structures. © 2002 Wiley Periodicals, Inc. Med Res Rev, 23, No. 1, 15,31, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/med.10028 [source] Cytoskeletal response of microvessel endothelial cells to an applied stress force at the submicrometer scale studied by atomic force microscopyMICROSCOPY RESEARCH AND TECHNIQUE, Issue 10 2006Wanyun Ma Abstract Cytoskeleton fibers form an intricate three-dimensional network to provide structure and function to microvessel endothelial cells. During accommodation to blood flowing, stress fiber bundles become more prominent and align with the direction of blood flow. This network either mechanically resists the applied shear stress (lateral force) or, if deformed, is dynamically remodeled back to a preferred architecture. However, the detailed response of these stress fiber bundles to applied lateral force at submicrometer scales are as yet poorly understood. In our in vitro study, the tip, topography probe in lateral force microscopy of atomic force microscopy, acted as a tool for exerting quantitative vertical and lateral force on the filaments of the cytoskeleton. Moreover, the authors developed a formula to calculate the value of lateral force exerted on every point of the filaments. The results show that cytoskeleton fibers of healthy tight junctions in rat cerebral microvessel endothelial cells formed a cross-type network, and were reinforced and elongated in the direction of scanning under lateral force of 15,42 nN. Under peroxidation (H2O2 of 300 ,mol/L), the cytoskeleton remodeled at intercellular junctions, and changed over the meshwork structures into a dense bundle, that redistributed the stress. Once mechanical forces were exerted on an area, the cells shrank and lost morphologic tight junctions. It would be useful in our understanding of certain pathological processes, such as cerebral ischemia/reperfusion injury, which maybe caused by biomechanical forces and which are overlooked in current disease models. Microsc. Res. Tech., 2006. © 2006 Wiley-Liss, Inc. [source] Glia cells in amyotrophic lateral sclerosis: New clues to understanding an old disease?MUSCLE AND NERVE, Issue 6 2007Clemens Neusch MD Abstract In classic neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), the pathogenic concept of a cell-autonomous disease of motor neurons has been challenged increasingly in recent years. Macro- and microglial cells have come to the forefront for their role in multistep degenerative processes in ALS and respective disease models. The activation of astroglial and microglial cells occurs early in the pathogenesis of the disease and seems to greatly influence disease onset and promotion. The role of oligodendrocytes and Schwann cells remains elusive. In this review we highlight the impact of nonneuronal cells in ALS pathology. We discuss diverse glial membrane proteins that are necessary to control neuronal activity and neuronal cell survival, and summarize the contribution of these proteins to motor neuron death in ALS. We also describe recently discovered glial mechanisms that promote motor neuron degeneration using state-of-the-art genetic mouse technology. Finally, we provide an outlook on the extent to which these new pathomechanistic insights may offer novel therapeutic approaches. Muscle Nerve, 2007 [source] A method for the isolation of glomerular and tubulointerstitial endothelial cells and a comparison of characteristics with the human umbilical vein endothelial cell modelNEPHROLOGY, Issue 4 2004STELLA MCGINN SUMMARY: Background: Abnormalities in the structure and function of glomerular endothelial cells play a pivotal role in the development of progressive renal disease. The vascular abnormalities observed in the renal tubulointerstitium, however, correlate more strongly with progressive renal failure. Therefore, the successful isolation and culture of human renal microvascular endothelial cells from both the glomerulus and tubulointerstitium are paramount in studying renal disease models. Methods and Results: This study describes a simple and reproducible method for the isolation of human tubulointerstitial and glomerular endothelial cells by using immunomagnetic separation with anti-platelet endothelial-cell adhesion (anti-PECAM-1) Dyna beads, followed by manual weeding of mesangial and fibroblast contamination. No significant changes in morphological or immunohistochemical characteristics were observed up to passage two of culture. The in vitro characteristics of the endothelial cells were compared to the renal cortical endothelial cells in vivo and the standard human umbilical vein endothelial cell model (HUVECs). Similar to HUVECs, both populations of renal microvascular endothelial cells had a classical cobblestone appearance, stained positively for von Willebrand Factor and PECAM-1 and negatively for antifibroblast surface antigen and anticytokeratin. Differences in the expression of von Willebrand Factor, Wiebel Palade bodies and Flk-1 staining were observed between glomerular and tubulointerstitial endothelial cells. These immunohistochemical characteristics suggested that tubulointerstital endothelial cells were more closely aligned to HUVECS than to the glomerular endothelial cells. This observation indicated that HUVECs may be a suitable model for determining the tubulointerstitial endothelial response to systemic injury. Conclusion: In conclusion, a unique and novel method for the differential isolation of both glomerular and tubulointerstitial endothelial cells has been developed. Significantly, characterization of these populations suggests a role for HUVECS in the study of renal tubulointerstitial disease. [source] Tissue culture methods to study neurological disorders: Establishment of immortalized Schwann cells from murine disease modelsNEUROPATHOLOGY, Issue 1 2003Kazuhiko Watabe Previously, the authors have established spontaneously immortalized cell lines from long-term cultures of normal adult mouse Schwann cells. Establishment of such Schwann cell lines derived from murine disease models may greatly facilitate studies of the cellular mechanisms of their peripheral nervous system lesions in the relevant diseases. Recently, the authors have established immortalized Schwann cell lines derived from Niemann,Pick disease type C mice (NPC; spm/spm) and globoid cell leukodystrophy mice (twitcher). In the present study, long-term cultures were maintained of Schwann cells derived from dorsal root ganglia and consecutive peripheral nerves of another NPC mouse (npcnih/npcnih, npcnih/+), myelin P0 protein-deficient mice (P0,/,, P0+/,) with their wild-type littermates (P0+/+), and neurofibromatosis type 1 gene (NF1)-deficient mice (Nf1Fcr/+) for 8,10 months, and immortalized cell lines from all these animals established spontaneously. These cell lines had spindle-shaped Schwann cell morphology and distinct Schwann cell phenotypes and retained genomic and biochemical abnormalities, sufficiently representing the in vivo pathological features of the mutant mice. These immortalized Schwann cell lines can be useful in studies of nervous system lesions in these mutant mice and relevant human disorders. [source] In Vivo mouse imaging and spectroscopy in drug discoveryNMR IN BIOMEDICINE, Issue 3 2007Nicolau Beckmann Abstract Imaging modalities such as micro-computed tomography (micro-CT), micro-positron emission tomography (micro-PET), high-resolution MRI, optical imaging, and high-resolution ultrasound have become invaluable tools in preclinical pharmaceutical research. They can be used to non-invasively investigate, in vivo, rodent biology and metabolism, disease models, and pharmacokinetics and pharmacodynamics of drugs. The advantages and limitations of each approach usually determine its application, and therefore a small-rodent imaging laboratory in a pharmaceutical environment should ideally provide access to several techniques. In this paper we aim to illustrate how these techniques may be used to obtain meaningful information for the phenotyping of transgenic mice and for the analysis of compounds in murine models of disease. Copyright © 2007 John Wiley & Sons, Ltd. [source] Amelioration of Airway Stenosis in Rabbit Models by Photodynamic Therapy with Talaporfin Sodium (NPe6)PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2009Yoshinori Nakagishi It is difficult to treat patients with acquired airway stenosis, and the quality of life of such patients is therefore lowered. We have suggested the application of photodynamic therapy (PDT) as a new treatment for airway stenosis and have determined the efficacy of PDT in animal disease models using a second-generation photosensitizer with reduced photosensitivity. An airway stenosis rabbit model induced by scraping of the tracheal mucosa was administered NPe6 (5 mg kg,1), and the stenotic lesion was irradiated with 670 nm light emitted from a cylindrical diffuser tip at 60 J cm,2 under bronchoscopic monitoring. PDT using NPe6 improved airway stenosis (P = 0.043) and respiratory stridor. A significant prolongation of survival time was seen in the PDT-treated animals compared to that in the untreated animals (P = 0.025) and 44% of the treated animals achieved long-term survival (>60 days). In conclusion, PDT using NPe6 is effective for improvement in airway stenosis. [source] | ||||||||||||||||||||||||||||