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Selected AbstractsPhenotypic analyses of mouse embryos with ubiquitous expression of Oct4: Effects on mid,hindbrain patterning and gene expressionDEVELOPMENTAL DYNAMICS, Issue 1 2005Verónica Ramos-Mejía Abstract Oct4 is a transcription factor that has been associated with pluripotency and fate determination in the initial cell lineages of mammals. On the other hand, Pou2, the ortholog of Oct4 in zebrafish, serves additional later functions during brain development acting as a differentiation switch. In mice, Oct4 is expressed throughout the neural plate of embryos until embryonic day (E) 8.0. In this study, we produced transgenic mouse embryos that ubiquitously express Oct4 and analyzed the consequences during development. We show that, at E8.0, a higher dosage of Oct4 in the neuroectoderm is sufficient to transiently alter mid,hindbrain patterning and produced a strong up-regulation of Pax2, indicating that Oct4 can regulate this gene in vivo. After E9.5, ectopic Oct4 in this region produced cell death and affected the development of the forebrain, suggesting that, at these later stages, Oct4 down-regulation is necessary for normal development to proceed. The phenotype of the transgenic embryos was also accompanied with an increase of Fgf8 expression in several of its endogenous domains, suggesting the possibility that Oct4 can participate in the regulation of expression of this ligand. Our observations support the hypothesis that Oct4, like zebrafish Pou2, has a conserved function during early brain patterning in mouse. Developmental Dynamics 232:180,190, 2005. © 2004 Wiley-Liss, Inc. [source] Two German CINCA (NOMID) patients with different clinical severity and response to anti-inflammatory treatmentEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2003Angela Rösen-Wolff Abstract: Chronic infantile neurologic, cutaneous, articular (CINCA) syndrome is characterized by fever, chronic meningitis, uveitis, sensorineural hearing loss, urticarial skin rash, and a deforming arthritis. In the CIAS1 gene of many but not all CINCA patients, disease-associated mutations have been found recently. We here describe two such patients from Germany. One of them, a 3-yr-old boy, has a 1709A,G, Y570C, mutation, which has previously been described to cause CINCA syndrome. His clinical course is very severe and no satisfying response has been achieved even with high doses of local and systemic steroids. The other patient has a somewhat milder clinical course and considerable improvement could be accomplished with moderate and low doses of steroids. In her CIAS1 gene we have found a 1043C,T, T348M, mutation, which has only been detected in Muckle,Wells syndrome before. Our results suggest that the severity of symptoms in CINCA patients may be influenced by the underlying mutation in the CIAS1 gene. Furthermore, our observations support the view that CINCA syndrome and Muckle,Wells syndrome are essentially the same disease with different degrees of severity. [source] Dynamic light scattering study of an amelogenin gel-like matrix in vitroEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2006Vassiliki Petta Amelogenin self-assembly is critical for the structural organization of apatite crystals during enamel mineralization. The aim of the present study was to investigate the influence of temperature and protein concentration on the aggregation of amelogenin nanospheres at high protein concentrations (> 4.4 mg ml,1) in order to obtain an insight into the mechanism of amelogenin self-assembly to form higher-order structures. Amelogenins were extracted from enamel scrapings of unerupted mandibular pig molars. The dynamics of protein solutions were measured using dynamic light scattering (DLS) as a function of temperature and at acidic pH. At pH 4,5.5, three kinds of particles were observed, ranging in size from 3 to 80 nm. At pH 6, heating the solution above ,,30°C resulted in a drastic change in the solution transparency, from clear to opaque. Low pH showed no aggregation effect, whilst solutions at a slightly acidic pH exhibited diffusion dynamics associated with the onset of aggregation. In addition, at the same temperature range, the hydrodynamic radii of the aggregates increased drastically, by almost one order of magnitude. These observations support the view that hydrophobic interactions are the primary driving force for the pH- and temperature-sensitive self-assembly of amelogenin particles in a ,gel-like' matrix. The trend of self-assembly in a ,gel-like matrix' is similar to that in solution. [source] A TEST OF WORKER POLICING THEORY IN AN ADVANCED EUSOCIAL WASP, VESPULA RUFAEVOLUTION, Issue 6 2005T. Wenseleers Abstract Mutual policing is an important mechanism for maintaining social harmony in group-living organisms. In some ants, bees, and wasps, workers police male eggs laid by other workers in order to maintain the reproductive primacy of the queen. Kin selection theory predicts that multiple mating by the queen is one factor that can selectively favor worker policing. This is because when the queen is mated to multiple males, workers are more closely related to queen's sons than to the sons of other workers. Here we provide an additional test of worker policing theory in Vespinae wasps. We show that the yellowjacket Vespula rufa is characterized by low mating frequency, and that a significant percentage of the males are workers' sons. This supports theoretical predictions for paternities below 2, and contrasts with other Vespula species, in which paternities are higher and few or no adult males are worker produced, probably due to worker policing, which has been shown in one species, Vespula vulgaris. Behavioral observations support the hypothesis that V. rufa has much reduced worker policing compared to other Vespula. In addition, a significant proportion of worker-laid eggs were policed by the queen. [source] Transcriptional regulation of tumor necrosis factor-, in keratinocytes mediated by interleukin-1, and tumor necrosis factor-,EXPERIMENTAL DERMATOLOGY, Issue 6 2002S. Lisby Abstract: Irritant contact dermatitis (ICD) is an inflammatory skin reaction in which cytokines are thought to play a crucial role. In particular, tumor necrosis factor-, (TNF-,) has been implicated in the mechanism of this reaction. We report that interleukin-1, (IL-1,) that has been reported up-regulated in many inflammatory skin conditions is capable of increasing TNF-, mRNA and protein expression in murine keratinocytes. Furthermore, we show that TNF-, is capable of up-regulating itself in keratinocytes most likely in an autocrine manner. The signalling mechanisms involved in both IL-1,- and TNF-,-mediated regulation of TNF-, are critically dependent upon protein kinase C (PKC), as demonstrated by blocking studies using protein kinase inhibitors. Furthermore, the increase in TNF-, mRNA expression seen after stimulation with rTNF-, and rIL-1, involved increased transcription of TNF-, mRNA. This was demonstrated in a chloramphenicol acetyltransferase (CAT) assay using a CAT-construct containing the full-length TNF-, promoter. These observations support the notion of keratinocytes functioning as an amplifier of pro-inflammatory cytokine generation in the epidermis during ICD and other inflammatory skin conditions. [source] Evidence of a functional requirement for a carbamoylated lysine residue in MurD, MurE and MurF synthetases as established by chemical rescue experimentsFEBS JOURNAL, Issue 22 2001Sébastien Dementin Enzymes MurD, MurE, MurF, folylpolyglutamate synthetase and cyanophycin synthetase, which belong to the Mur synthetase superfamily, possess an invariant lysine residue (K198 in the Escherichia coli MurD numbering). Crystallographic analysis of MurD and MurE has recently shown that this residue is present as a carbamate derivative, a modification presumably essential for Mg2+ binding and acyl phosphate formation. In the present work, the importance of the carbamoylated residue was investigated in MurD, MurE and MurF by site-directed mutagenesis and chemical rescue experiments. Mutant proteins MurD K198A/F, MurE K224A and MurF K202A, which displayed low enzymatic activity, were rescued by incubation with short-chain carboxylic acids, but not amines. The best rescuing agent was acetate for MurD K198A, formate for K198F, and propionate for MurE K224A and MurF K202A. In the last of these, wild-type levels of activity were recovered. A complementarity between the volume of the residue replacing lysine and the length of the carbon chain of the acid was noted. These observations support a functional role for the carbamate in the three Mur synthetases. Experiments aimed at recovering an active enzyme by introducing an acidic residue in place of the invariant lysine residue were also undertaken. Mutant protein MurD K198E was weakly active and was rescued by formate, indicating the necessity of correct positioning of the acidic function with respect to the peptide backbone. Attempts at covalent rescue of mutant protein MurD K198C failed because of its lack of reactivity towards haloacids. [source] Constitutive activation of the neuregulin-1/ErbB receptor signaling pathway is essential for the proliferation of a neoplastic Schwann cell lineGLIA, Issue 2 2003Paul W. Frohnert Abstract Neuregulin-1 (NRG-1) proteins promote Schwann cell survival, differentiation and proliferation during development. High levels of an NRG-like activity are also present in some human peripheral nerve sheath tumors, suggesting that NRG-1 isoforms may be involved in the development of these neoplasms. We examined the expression of NRG-1 and its receptors, the erbB membrane tyrosine kinases, in JS1 cells, a rapidly proliferating line derived from a chemically induced rat malignant peripheral nerve sheath tumor (MPNST). Relative to nontransformed Schwann cells, JS1 cells overexpress the NRG-1 receptor erbB3 and its erbB2 coreceptor; JS1 erbB2 transcripts show no evidence of the activating mutation commonly found in N-ethyl-N-nitrosourea-induced neoplasms. JS1 cells do not express the epidermal growth factor receptor (EGFR), a kinase implicated in the pathogenesis of a major subset of MPNSTs. JS1 cells also express mRNAs encoding multiple , and , isoforms from the glial growth factor and sensory and motor neuron-derived factor NRG-1 subfamilies. Stimulation with NRG-1, in the presence of forskolin produces a dose-dependent increase in JS1 DNA synthesis. Even in unstimulated JS1 cells, however, erbB2 and erbB3 are constitutively tyrosine phosphorylated. Reducing this constitutive phosphorylation with the specific erbB inhibitor PD158780 markedly impairs JS1 DNA synthesis. These observations support the hypothesis that NRG-1 isoforms and erbB kinases act in an autocrine and/or paracrine fashion to promote mitogenesis in JS1 cells. The absence of EGFR expression in JS1 cells suggests that constitutive activation of the NRG-1/erbB signaling pathway is an alternative means of inducing Schwann cell neoplasia. © 2003 Wiley-Liss, Inc. [source] Constitutive androstane receptor (CAR) ligand, TCPOBOP, attenuates Fas-induced murine liver injury by altering Bcl-2 proteins,HEPATOLOGY, Issue 1 2006Edwina S. Baskin-Bey The constitutive androstane receptor (CAR) modulates xeno- and endobiotic hepatotoxicity by regulating detoxification pathways. Whether activation of CAR may also protect against liver injury by directly blocking apoptosis is unknown. To address this question, CAR wild-type (CAR+/+) and CAR knockout (CAR,/,) mice were treated with the CAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) and then with the Fas agonist Jo2 or with concanavalin A (ConA). Following the administration of Jo2, hepatocyte apoptosis, liver injury, and animal fatalities were abated in TCPOBOP-treated CAR+/+ but not in CAR,/, mice. Likewise, acute and chronic ConA-mediated liver injury and fibrosis were also reduced in wild-type versus CAR,/, TCPOBOP-treated mice. The proapoptotic proteins Bak (Bcl-2 antagonistic killer) and Bax (Bcl-2-associated X protein) were depleted in livers from TCPOBOP-treated CAR+/+ mice. In contrast, mRNA expression of the antiapoptotic effector myeloid cell leukemia factor-1 (Mcl-1) was increased fourfold. Mcl-1 promoter activity was increased by transfection with CAR and administration of TCPOBOP in hepatoma cells, consistent with a direct CAR effect on Mcl-1 transcription. Indeed, site-directed mutagenesis of a putative CAR consensus binding sequence on the Mcl-1 promoter decreased Mcl-1 promoter activity. Mcl-1 transgenic animals demonstrated little to no acute liver injury after administration of Jo2, signifying Mcl-1 cytoprotection. In conclusion, these observations support a prominent role for CAR cytoprotection against Fas-mediated hepatocyte injury via a mechanism involving upregulation of Mcl-1 and, likely, downregulation of Bax and Bak. (HEPATOLOGY 2006;44:252,262.) [source] Plasticity in the adult rat pancreas: Transdifferentiation of exocrine to hepatocyte-like cells in primary cultureHEPATOLOGY, Issue 6 2004Jessy Lardon Under certain experimental conditions, hepatocytes can arise in the pancreas. It has been suggested that the pancreas retains a source of hepatocyte progenitor cells. However, such cells have not been yet identified in the adult pancreas. We describe here the transdifferentiation of primary rat pancreatic exocrine cells into hepatocyte-like cells during 5 days of tissue culture in the presence of dexamethasone (DX). Using reverse-transcription polymerase chain reaction and immunocytochemistry, it was observed that DX treatment induced albumin RNA and protein expression in the cells. Coexpression of albumin and amylase, and the absence of cell proliferation, demonstrated a direct transdifferentiation of acinar cells to hepatocytic cells. CCAAT enhancer-binding protein-ß protein, a liver-enriched transcription factor that is considered to be the master switch in pancreatohepatic transdifferentiation, and ,-fetoprotein were markedly upregulated in the cells after treatment with DX. We compared transcriptional profiles of freshly isolated exocrine cells and DX-treated cells using oligonucleotide microarrays and found that multiple liver-specific genes are induced along with albumin, and that certain pancreatic genes are downregulated in the DX-treated cells. In conclusion, these observations support the notion of plasticity in the adult pancreas and that exocrine cells can be reprogrammed to transdifferentiate into other cell types such as hepatocytes. (HEPATOLOGY 2004;39:1499,1507.) [source] Interferon-alpha regulates the dynamic balance between human activated regulatory and effector T cells: implications for antiviral and autoimmune responsesIMMUNOLOGY, Issue 1 2010Amit Golding Summary An adequate effector response against pathogens and its subsequent inactivation after pathogen clearance are critical for the maintenance of immune homeostasis. This process involves an initial phase of T-cell effector (Teff) activation followed by the expansion of regulatory T cells (Tregs), a unique cell population that limits Teff functions. However, significant questions remain unanswered about the mechanisms that regulate the balance between these cell populations. Using an in vitro system to mimic T-cell activation in human peripheral blood mononuclear cells (PBMC), we analysed the patterns of Treg and Teff activation, with special attention to the role of type I interferon (IFN-I). Interestingly, we found that IFN-,, either exogenously added or endogenously induced, suppressed the generation of CD4+ FoxP3HI IFN-,Neg activated Tregs (aTregs) while simultaneously promoting propagation of CD4+ FoxP3Low/Neg IFN-,Pos activated Teffs (aTeffs). We also showed that IFN-,-mediated inhibition of interleukin (IL)-2 production may play an essential role in IFN-,-induced suppression of aTregs. In order to test our findings in a disease state with chronically elevated IFN-,, we investigated systemic lupus erythematosus (SLE). Plasma from patients with SLE was found to contain IFN-I activity that suppressed aTreg generation. Furthermore, anti-CD3 activated SLE PBMCs exhibited preferential expansion of aTeffs with a very limited increase in aTreg numbers. Together, these observations support a model whereby a transient production of IFN-, (such as is seen in an early antiviral response) may promote CD4 effector functions by delaying aTreg generation, but a chronic elevation of IFN-, may tip the aTeff:aTreg balance towards aTeffs and autoimmunity. [source] Innate immune responses induced by CpG oligodeoxyribonucleotide stimulation of ovine blood mononuclear cellsIMMUNOLOGY, Issue 2 2003Angelo Mena Summary Examples exist in the literature that demonstrate that treatment with immunostimulatory cytosine,phosphate,guanosine (CpG)-DNA can protect mice against infection by intracellular pathogens. There are, however, few studies reporting that CpG-DNA offers similar disease protection in other species. In this study, we assessed the potential of a class A and class B CpG oligodeoxynucleotide (ODN) to induce innate immune responses in sheep, an outbred species. Using peripheral blood mononuclear cells, we have for the first time demonstrated CpG-ODN-induced innate immune responses, including natural-killer-like activity [non-major histocompatibility complex (MHC)-restricted cytotoxicity], interferon-, secretion and 2,-5,A oligoadenylate synthetase activity, that could contribute to immune protection in sheep. The type and magnitude of these responses were dependent on ODN class and non-MHC-restricted killing was not associated with interferon-, production. The latter observation is in contrast with observations reported for mice and humans. These observations support the conclusion that differences in CpG-ODN-induced responses exist among species and that specific ODN sequences can significantly influence innate immune responses. [source] The haemopoietic growth factor, Flt3L, alters the immune response induced by transcutaneous immunizationIMMUNOLOGY, Issue 1 2002Maria E. Baca-Estrada Summary Topical application of antigen induces antigen-specific humoral and cellular immune responses. In this study we examined whether expansion of dendritic cells (DC) by Flt3 ligand (Flt3L) treatment influences the induction of immune responses following transcutaneous immunization. Mice were treated intraperitoneally with Flt3L or phosphate-buffered saline (PBS) and immunized transcutaneously with hen egg lysozyme (HEL). Flt3L-treated mice developed lower HEL-specific cellular and humoral immune responses than PBS-treated mice. However, in the presence of cholera toxin (CT), a potent adjuvant for mucosal and transcutaneous immunization, Flt3L-treated mice developed significantly higher cellular and humoral immune responses to HEL when compared to PBS-treated mice. We assessed whether the immunomodulatory effects of CT were a result of activation of epidermal dendritic cells (Langerhans' cells; LC). Our results indicate that within 8,12 hr of topical application of CT, epidermal LC cells lose their dendritic morphology and become rounder in appearance. In addition, we observed enhanced expression of major histocompatibility complex (MHC) class II, and of adhesion molecules CD11c and intracellular adhesion molecule-1 (ICAM-1). Our observations support the concept that the state of activation of DC in the skin is central to the regulation of immune responses. This information is relevant to the design of effective transcutaneous vaccination strategies. [source] Irreversible Perforations in Vertebral Trabeculae?,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2003X Banse In human cancellous bone, osteoclastic perforations resulting from normal remodeling were generally considered irreversible. In human vertebral samples, examined by backscatter electron microscopy, there was clear evidence of bridging of perforation defects by new bone formation. Hence trabecular perforations may not be irreversible. Introduction: Preservation of the trabecular bone microarchitecture is essential to maintain its load-bearing capacity and prevent fractures. However, during bone remodeling, the osteoclasts may perforate the platelike trabeculae and disconnect the structure. Large perforations (>100 ,m) are generally considered irreversible because there is no surface on which new bone can be laid down. In this work, we investigated the outcome of these perforations on human vertebral cancellous bone. Materials and Methods: Using backscatter electron microscopy, we analyzed 264 vertebral bone samples from the thoracic and lumbar spine of nine subjects (44,88 years old). Nine fields (2 × 1.5 mm) were observed on each block. Several bone structural units (BSUs) were visible on a single trabecula, illustrating a dynamic, historical aspect of bone remodeling. A bridge was defined as a single and recent BSU connecting two segments of trabeculae previously separated by osteoclastic resorption. They were counted and measured (length and breadth, ,m). Results and Conclusion: We observed 396 bridges over 2376 images. By comparison, we found only 15 microcalluses on the same material. The median length of the bridge was 165 ,m (range, 29,869 ,m); 86% being longer than 100 ,m and 35% longer than 200 ,m. Their breadth was 56 ,m (range, 6,255 ,m), but the thinnest were still in construction. Bridges were found in all nine subjects included in the study, suggesting that it is a common feature of normal vertebral bone remodeling. These observations support the hypothesis that perforation could be repaired by new bone formation. and hence, might not be systematically irreversible. [source] Expression of FGFR3 with the G380R Achondroplasia Mutation Inhibits Proliferation and Maturation of CFK2 Chondrocytic CellsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2000Janet E. Henderson Abstract A G380R substitution in the transmembrane-spanning region of FGFR3 (FGFR3Ach) results in constitutive receptor kinase activity and is the most common cause of achondroplastic dwarfism in humans. The epiphyseal growth plates of affected individuals are disorganized and hypocellular and show aberrant chondrocyte maturation. To examine the molecular basis of these abnormalities, we used a chondrocytic cell line, CFK2, to stably express the b variant of wild-type FGFR3 or the the constitutively active FGFR3Ach. Overexpression of FGFR3 had minimal effects on CFK2 proliferation and maturation compared with the severe growth retardation found in cells expressing FGFR3Ach. Cells expressing the mutant receptor also showed an abnormal apoptotic response to serum deprivation and failed to undergo differentiation under appropriate culture conditions. These changes were associated with altered expression of integrin subunits, which effectively led to a switch in substrate preference of the immature cell from fibronectin to type II collagen. These in vitro observations support those from in vivo studies indicating that FGFR3 mediates an inhibitory influence on chondrocyte proliferation. We now suggest that the mechanism is related to altered integrin expression. [source] Irregular Atrial Activation During Atrioventricular Nodal Reentrant Tachycardia:JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2003Evidence of an Upper Common Pathway Controversy continues regarding the precise nature of the reentrant circuit of AV nodal reentrant tachycardia, especially the existence of an upper common pathway. In this case report, we show that marked variation and irregularity in atrial activation (maximum AA interval variation of 80 msec) can exist with fixed and constant activation of the His bundle and ventricles during AV nodal reentrant tachycardia in a 45-year-old female patient. We propose that irregular atrial activation is due to variable and inconsistent conduction from the AV node to the atria through the perinodal transitional cell envelope extrinsic to the reentrant circuit. Our observations support the concept of an upper common pathway, at least in some patients with AV nodal reentrant tachycardia.(J Cardiovasc Electrophysiol, Vol. 14, pp. 309-313, March 2003) [source] An unusual ostensible example of intraoral basal cell carcinomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2009Ioannis G. Koutlas An example of oral basal cell carcinoma is presented originating on the posterior mandibular mucosa and gingiva of a 67-year-old female. Histologically, it featured a multifocal pattern. It recurred eight times in a period of 20 years. Tissue samples of the tumor were evaluated with monoclonal antibody Ber-EP4 and were compared with examples of oral mucosa, skin, oral and cutaneous squamous cell carcinoma, peripheral ameloblastoma, ameloblastoma and cutaneous basal cell carcinoma (BCC). Only neoplastic basal cells showed positive immunohistochemical staining. Additionally, microdissected neoplastic areas were evaluated for loss of heterozygosity (LOH) of the PTCH gene with markers D9S303, D9S252 and D9S287. PTCH gene mutations are reported in patients with Gorlin syndrome and sporadic cutaneous BCCs. Loss of one allele was observed with all three markers. Examples of conventional ameloblastomas did not show evidence of LOH. These observations support the inclusion of BCC in the differential diagnosis of appropriate oral mucosal neoplasms. [source] Differential Expression of Vasoactive Intestinal Polypeptide Receptor 1 and 2 mRNA in Murine Intestinal T Lymphocyte SubtypesJOURNAL OF NEUROENDOCRINOLOGY, Issue 9 2001B.-F. Qian Abstract Neuropeptides may exert a variety of effects on the immune cells at both systemic and mucosal immune sites. The immunoregulatory properties refer to the ability of physiological signals and pathways to influence various immune functions. Vasoactive intestinal polypeptide (VIP), a neuropeptide present in high concentration in gut, was studied for its production and receptor expression in intraepithelial and lamina propria T lymphocytes of mouse intestine. Using reverse transcription-polymerase chain reaction (RT-PCR) analysis, it was demonstrated that VIP receptor 1 (VIPR1) was constantly expressed in intraepithelial and lamina propria T lymphocytes from both small and large intestine. In contrast, VIPR2 was identified only in T cells from small intestine. Further studies on purified subpopulations of T lymphocytes indicated the existence of VIPR2 in CD8+ T cells, but not CD4+ and CD4CD8 double negative T cells, although all these three subpopulations displayed VIPR1. In addition, VIPR1 mRNA was detected in splenic T lymphocytes, but no signal was obtained for VIPR2 mRNA, even after stimulation of the cells with anti-CD3,-chain mAb, phorbol 12-myristate 13-acetate (PMA) and/or VIP. The presence of VIP receptor(s) on intestinal T lymphocytes was supported by the detection of VIP on the cell surface using dual colour immunoflowcytometry. In-vitro treatment with VIP resulted in a tendency towards an increased size of the VIP immunoreactive T cell population and significantly enhanced the average immunofluorescence intensity of the surface labelling. This indicates that the receptors are partially occupied by locally produced VIP in vivo and that more peptide molecules can be bound on the lymphocytes when needed, released and accumulated in higher concentration at the action sites. We failed to detect the expression of VIP mRNA in T lymphocytes, from either intestine or spleen. These observations support that VIP may be an important immune modulator in gut acting through specific receptors on T lymphocytes. The differential mRNA expression of VIP receptor subtypes in cells with different phenotypes and in different immune compartments may suggest diverse regulatory roles of the neuropeptide in immune responses. [source] Synaptic mRNAs are modulated by learningJOURNAL OF NEUROSCIENCE RESEARCH, Issue 9 2009Eugenia Ferrara Abstract We have recently demonstrated that brain plastic events significantly modify synaptic protein synthesis measured by the incorporation of [35S]methionine in brain synaptosomal proteins. Notably, in rats learning a two-way active avoidance task, the local synthesis of two synaptic proteins was selectively enhanced. Because this effect may be attributed to transcriptional modulation, we used reverse transcriptase,polymerase chain reaction methods to determine the content of discrete synaptosomal mRNAs in rats exposed to the same training protocol. Correlative analyses between behavioral responses and synaptosomal mRNA content showed that GAT-1 mRNA (a prevalent presynaptic component) correlates with avoidances and escapes in rat cerebellum, while glial fibrillary acid protein mRNA (an astrocytic component) correlates with freezings in cerebellum and cerebral cortex. These observations support the hypothesis that synaptic protein synthesis may be transcriptionally regulated. The cellular origin of synaptic transcripts is briefly discussed, with special regard to those present at large distances from neuron somas. © 2009 Wiley-Liss, Inc. [source] Effect of anesthetic structure on inhalation anesthesia: Implications for the mechanismJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2008Michael H. Abraham Abstract Many previous attempts (e.g., the Meyer,Overton hypothesis) to provide a single set of physical or chemical characteristics that accurately predict anesthetic potency have failed. A finding of a general predictive correlation would support the notion of a unitary theory of narcosis. Using the Abraham solvation parameter model, the minimum alveolar concentration, MAC, of 148 varied anesthetic agents can be fitted to a linear equation in log (1/MAC) with R2,=,0.985 and a standard deviation, SD,=,0.192 log units. Division of the 148 compounds into a training set and a test set shows that log (1/MAC) values can be predicted with no bias and with SD,=,0.20 log units. The two main factors that determine MAC values are compound size and compound hydrogen bond acidity, both of which increase anesthetic activity. Shape has little or no effect on anesthetic activity. Our observations support a unitary theory of narcosis by inhalation anesthetics. A two-stage mechanism for inhalation anesthesia accounts for the observed structural effects of anesthetics. In this mechanism, the first main step is transfer of the anesthetic to the site of action, and the second step is interaction of the anesthetic with a receptor(s). © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:2373,2384, 2008 [source] Leukocyte Adhesion in Capillary-Sized, P-Selectin-Coated MicropipettesMICROCIRCULATION, Issue 2 2008Prithu Sundd ABSTRACT Objective: Leukocyte retention in lung capillaries is observed in normal physiology and following a bacterial infection. It has been hypothesized that cells either become mechanically trapped or adhere to capillary endothelial cells via adhesion molecules. We propose that retention involves both mechanical and adhesive forces and that the biochemical adhesive force is modulated by mechanical forces that alter the area of contact between leukocytes and endothelium. Methods: To probe this hypothesis, an adhesion assay has been developed in which individual HL-60 cells were aspirated into micropipettes pre-coated with P-selectin. Following aspiration, cells were exposed to physiological pressure differences. Results: Little adhesion was seen in micropipettes coated with BSA, whereas significant adhesion was observed in micropipettes coated with P-selectin. The frequency of cell arrest on P-selectin in the micropipette was much greater than on P-selectin in a parallel plate flow chamber even though the disruptive force in the micropipette assay exceeds that in the parallel plate flow chamber. These results demonstrate that receptor,ligand interactions can enhance adhesion in a capillary geometry and that differences in capillary geometry vs. venule geometry can significantly influence the adhesive phenotype. Conclusions: Taken together, these observations support the hypothesis that an interplay between mechanical and biochemical adhesive forces can play a major role in retention. [source] Beta-helix model for the filamentous haemagglutinin adhesin of Bordetella pertussis and related bacterial secretory proteinsMOLECULAR MICROBIOLOGY, Issue 2 2001Andrey V. Kajava Bordetella pertussis establishes infection by attaching to epithelial cells of the respiratory tract. One of its adhesins is filamentous haemagglutinin (FHA), a 500-Ĺ-long secreted protein that is rich in ,-structure and contains two regions, R1 and R2, of tandem 19-residue repeats. Two models have been proposed in which the central shaft is (i) a hairpin made up of a pairing of two long antiparallel ,-sheets; or (ii) a ,-helix in which the polypeptide chain is coiled to form three long parallel ,-sheets. We have analysed a truncated variant of FHA by electron microscopy (negative staining, shadowing and scanning transmission electron microscopy of unstained specimens): these observations support the latter model. Further support comes from detailed sequence analysis and molecular modelling studies. We applied a profile search method to the sequences adjacent to and between R1 and R2 and found additional ,covert' copies of the same motifs that may be recognized in overt form in the R1 and R2 sequence repeats. Their total number is sufficient to support the tenet of the ,-helix model that the shaft domain , a 350 Ĺ rod , should consist of a continuous run of these motifs, apart from loop inserts. The N-terminus, which does not contain such repeats, was found to be weakly homologous to cyclodextrin transferase, a protein of known immunoglobulin-like structure. Drawing on crystal structures of known ,-helical proteins, we developed structural models of the coil motifs putatively formed by the R1 and R2 repeats. Finally, we applied the same profile search method to the sequence database and found several other proteins , all large secreted proteins of bacterial provenance , that have similar repeats and probably also similar structures. [source] Postural responses to continuous unilateral neck muscle vibration in standing patients with cervical dystoniaMOVEMENT DISORDERS, Issue 4 2007Marco Bove MD Abstract Several observations support the notion that integration of neck proprioceptive input is impaired in cervical dystonia (CD). An example is the inconsistent or opposite to normal effect of lateral neck muscle vibration on body rotation during stepping. We hypothesized that lateral neck vibration produces abnormal responses also in a static task. Normal subjects and patients with CD stood quietly with eyes closed, without or with vibration applied to the sternocleidomastoid muscle, and center of foot pressure and body sway were recorded by a dynamometric platform. Patients had a larger than normal sway under control condition. They showed little or no postural responses to vibration. When body tilt occurred, it was rarely in the frontal plane as in normal subjects, but in the sagittal plane. No relationship existed between vibration-induced tilt during stance and body rotation during stepping. Therefore, in CD, proprioceptive neck input is less used for the construction of the postural vertical during quiet stance than it is used for the definition of the subjective straight ahead during a dynamic task. © 2007 Movement Disorder Society [source] A Gene Knockout Corroborates the Integral Function of Cellular Retinol-binding Protein in Retinoid MetabolismNUTRITION REVIEWS, Issue 8 2000Joseph L. Napoli Ph.D. Continually expanding evidence has moved inexorably toward establishing key functions for cellular retinol-binding protein (CRBP) in retinoid metabolism. These experimental data integrate into a model of CRBP as a chaperone that protects retinol from the cellular milieu and interacts with certain retinoid-metabolizing enzymes. Mutant mice with an inactivated CRBP gene show decreased liver retinyl ester storage, a shorter elimination half-life of liver retinoids, and predisposition to vitamin A deficiency. No morphologic phenotype was observed until vitamin A was exhausted. Although the mechanisms underlying diminished vitamin A in the CRBP-null mice have not been elucidated, the observations support the model of CRBP as a chaperone of retinoid metabolism. [source] Relationship between Amplitude and Timing of Heart Sounds and Endocardial AccelerationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2009AUDE TASSIN M.D. Objective: To study the correlation between heart sounds and peak endocardial acceleration (PEA) amplitudes and timings, by modulation of paced atrioventricular (AV) delay in recipients of dual chamber pacemakers. Methods: Ten recipients of dual chamber pacemakers implanted for high-degree AV block were studied. Endocardial acceleration (EA) and phonocardiographic and electrocardiographic signals were recorded during performance of an AV delay scan in VDD and DDD modes. Results: First PEA (PEA I) and first heart sound (S1) changed similarly with the AV delay. A close intrapatient correlation was observed between S1 and PEA I amplitudes in all patients (P < 0.0001). The interpatient normalized PEA I to S1 amplitudes correlation was r = 0.89 (P < 0.0001) in DDD mode, and r = 0.81 (P < 0.0001) in VDD mode. The mean cycle-by-cycle PEA I to S1 delay was ,4.3 ± 22 ms and second PEA (PEA II) to second heart sound (S2) delay was ,7.7 ± 15 ms. Conclusions: A close correlation was observed between PEA I and S1 amplitudes and timings, and between PEA II and S2 timings. These observations support the hypothesis that PEA and heart sounds are manifestations of the same phenomena. EA might be a useful tool to monitor cardiac function. [source] Age distributions, birth weights, nephrogenic rests, and heterogeneity in the pathogenesis of Wilms tumorPEDIATRIC BLOOD & CANCER, Issue 3 2006Norman E. Breslow PhD Abstract Background The National Wilms Tumor Study (NWTS) constitutes a unique resource for study of clinical, pathologic, and epidemiologic features of Wilms tumor (WT). Procedure Data from NWTS-3,4,5 were compiled for 7,455 patients with tumors of favorable (FH) or anaplastic (AH) histology. The associations of birth weight (BW) and age-at-onset with gender, intralobar (ILNR), and perilobar (PLNR) nephrogenic rests, tumor focality, congenital malformation syndromes, and tumor histology were analyzed using descriptive statistics and linear regression. Results Mean BWs for male and female patients without PLNR were 3.52 and 3.36 kg, respectively, and for those with PLNR were 0.12 kg and 0.15 kg heavier. Mean age was 45 months for males with no rests whose tumors were unifocal and of triphasic favorable histology. ILNR or multifocality decreased the mean age by 18 and 10 months, respectively, whereas female gender, blastemal/FH or AH increased it by 3, 10, and 16 months. Over 90% of multifocal tumors occurred in the presence of demonstrated ILNR or PLNR or both. The apparent bimodality of the age distributions and later mean ages-at-onset for females with both unifocal and multifocal tumors were explained in part by the relative deficit in females of ILNR versus PLNR-associated tumors. Conclusions These observations support the view that there are multiple pathways to Wilms tumorigenesis. They will facilitate selection of informative subgroups of patients for molecular analysis that may serve to identify the putative pathway for the majority of patients who cannot be classified provisionally on the basis of ILNR or PLNR. Pediatr Blood Cancer 2006;47:260,267. © 2006 Wiley-Liss, Inc. [source] Hydroclathrus (Scytosiphonaceae, Phaeophyceae): Conspectus of the genus and proposal of new species from Australia and HawaiiPHYCOLOGICAL RESEARCH, Issue 4 2003Gerald T. Kraft SUMMARY Representatives of the two current species of Hydroclathrus, Hydroclathrus clathratus (C. Agardh) Howe (the generitype) and Hydroclathrus tenuis Tseng et Lu, are compared to recent collections of the genus from isolated localities in the central and south Pacific: Necker Island and Lord Howe Island, respectively. Although published descriptions of the virtually pan-tropical/warm-temperate H. clathratus portray a species highly variable in the habits and soral distribution patterns of the macro-phases of its life history, our observations support the hypothesis that the newly discovered Pacific island populations represent new species. Hydroclathrus steph-anosorus Kraft, sp. nov., from Lord Howe Island, differs from seemingly typical H. clathratus by the low-domed profiles of its surface cortical cells, aggregates of moniliform hair primordia that are almost always associated with plurangial sori, and particularly by the configurations of the sori themselves, which form discrete, nearly circular rings around the central hair tufts. Hydroclathrus tumulis Kraft et Abbott, sp. nov., from two deep-water localities in the northwestern Hawaiian Islands, has subacutely papillate cortical cells, scattered single, paired or laxly aggregated hair primordia of distinctive obcuneate morphology, and discrete, angular plurangial sori with no predetermined relationship to hairs, the plurangia being relatively laxly aggregated by virtue of their often arising on pedicels formed by the peaked crests of the cortical bearing cells. H. tenuis, although making the most striking visual impression of any of the species because of its exceedingly narrow, fibrous membranes, seems otherwise closest to H. clathratus in cortical cell, hair and soral features, absolute morphological boundaries between the two species being perhaps difficult to draw at times. [source] Strategy differences of two potato species in response to nitrogen starvation.PLANT CELL & ENVIRONMENT, Issue 7 2000Do plants have a genetic switch for nitrogen signalling? ABSTRACT Survival responses to nitrogen starvation are well known in micro-organisms but little studied in plants. To construct a framework for study of the plant responses, we investigated the strategy differences of tubers from two closely related potato species. Solanum tuberosum conserves tuber nitrogen by inhibiting shoot growth, but S. phureja mobilizes tuber nitrogen to grow shoots, flowers and seeds. Genetic analysis of progeny from S. phureja,haploid S. tuberosum crosses uncovered segregation of a single dominant gene for the S. tuberosum inhibition strategy. Within S. tuberosum, haploid progeny closely resembled their tetraploid parents, suggesting strong genetic control of the inhibition. Growth of the inhibited shoots was proportional to sub-optimal levels of added nitrate, and was triggered by exogenous gibberellic acid (GA3). These observations support the notion that potato plants can closely tie shoot growth to ambient nitrogen levels , probably by a root,shoot nitrogen signal transduction pathway, and that this can be overridden by emergency mobilization of nitrogen reserves, perhaps by GA signalling from the tuber. Furthermore, genes for such developmental switches can be identified by classical genetic analysis of closely related species, such as S. tuberosum and S. phureja, that exhibit opposite survival strategies. [source] Crystal structure of calcium-free human sorcin: A member of the penta-EF-hand protein familyPROTEIN SCIENCE, Issue 12 2001Xiaoling Xie Abstract Sorcin is a 22 kD calcium-binding protein that is found in a wide variety of cell types, such as heart, muscle, brain and adrenal medulla. It belongs to the penta-EF-hand (PEF) protein family, which contains five EF-hand motifs that associate with membranes in a calcium-dependent manner. Prototypic members of this family are the calcium-binding domains of calpain, such as calpain dVI. Full-length human sorcin has been crystallized in the absence of calcium and the structure determined at 2.2 Ĺ resolution. Apart from an extended N-terminal portion, the sorcin molecule has a globular shape. The C-terminal domain is predominantly ,-helical, containing eight ,-helices and connecting loops incorporating five EF hands. Sorcin forms dimers through the association of the unpaired EF5, confirming this as the mode of association in the dimerization of PEF proteins. Comparison with calpain dVI reveals that the general folds of the individual EF-hand motifs are conserved, especially that of EF1, the novel EF-hand motif characteristic of the family. Detailed structural comparisons of sorcin with other members of PEF indicate that the EF-hand pair EF1,EF2 is likely to correspond to the two physiologically relevant calcium-binding sites and that the calcium-induced conformational change may be modest and localized within this pair of EF-hands. Overall, the results derived from the structural observations support the view that, in sorcin, calcium signaling takes place through the first pair of EF-hands. [source] The effectiveness of nonverbal symbolic signs and metaphors in advertisements: An experimental inquiryPSYCHOLOGY & MARKETING, Issue 3 2008Eric D. DeRosia This research investigates the effectiveness of nonverbal symbolic signs and rhetorical metaphors in advertisements. Hypotheses are made based on appeals to both interpretive and psychological theoretical perspectives. In contrast to previous research that has assumed nonverbal ad elements are effortlessly and automatically processed, it is proposed here that consumers must devote a nontrivial level of cognitive effort if they are to comprehend nonverbal symbolic signs and metaphors. The hypotheses suggest boundary conditions for the effectiveness of nonverbal elements in advertising. An experiment is conducted as a test of the hypotheses, and the observations support the hypotheses. © 2008 Wiley Periodicals, Inc. [source] Social stress, visceral obesity, and coronary artery atherosclerosis: product of a primate adaptationAMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2009Carol A. Shively Abstract Abdominal obesity is prevalent and often accompanied by an array of metabolic perturbations including elevated blood pressure, dyslipidemia, impaired glucose tolerance or insulin resistance, a prothrombotic state, and a proinflammatory state, together referred to as the metabolic syndrome. The metabolic syndrome greatly increases coronary heart disease (CHD) risk. Social stress also increases CHD although the mechanisms through which this occurs are not completely understood. Chronic stress may result in sustained glucocorticoid production, which is thought to promote visceral obesity. Thus, one hypothesis is that social stress may cause visceral fat deposition and the metabolic syndrome, which, in turn increases CHD. CHD is caused by coronary artery atherosclerosis (CAA) and its sequelae. Cynomolgus monkeys (Macaca fascicularis) are a well-established models of CAA. Social subordination may be stressful to cynomolgus monkeys and result in hypercortisolemia and exacerbated CAA in females. Herein is reviewed a body of literature which suggests that social stress increases visceral fat deposition in cynomolgus monkeys, that subordinate females are more likely than dominants to have visceral obesity, that females with visceral obesity have behavioral and physiological characteristics consistent with a stressed state, and that females with high ratios of visceral to subcutaneous abdominal fat develop more CAA. While these relationships have been most extensively studied in cynomolgus macaques, obesity-related metabolic disturbances are also observed in other primate species. Taken together, these observations support the view that the current obesity epidemic is the result of a primate adaptation involving the coevolution with encephalization of elaborate physiological systems to protect against starvation and defend stored body fat in order to feed a large and metabolically demanding brain. Social stress may be engaging these same physiological systems, increasing the visceral deposition of fat and its sequelae, which increase CHD risk. Am. J. Primatol. 71:742,751, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||