57 resultados para tissue and cellular pharmacology

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Leptospiral pulmonary haemorrhage syndrome (LPHS) is a particularly severe form of leptospirosis. LPHS is increasingly recognized in both humans and animals and is characterized by rapidly progressive intra-alveolar haemorrhage leading to high mortality. The pathogenic mechanisms of LPHS are poorly understood which hampers the application of effective treatment regimes. In this study a 2-D guinea pig proteome lung map was created and used to investigate the pathogenic mechanisms of LPHS. Comparison of lung proteomes from infected and non-infected guinea pigs via differential in-gel electrophoresis revealed highly significant differences in abundance of proteins contained in 130 spots. Acute phase proteins were the largest functional group amongst proteins with increased abundance in LPHS lung tissue, and likely reflect a local and/or systemic host response to infection. The observed decrease in abundance of proteins involved in cytoskeletal and cellular organization in LPHS lung tissue further suggests that infection with pathogenic Leptospira induces changes in the abundance of host proteins involved in cellular architecture and adhesion contributing to the dramatically increased alveolar septal wall permeability seen in LPHS. BIOLOGICAL SIGNIFICANCE The recent completion of the complete genome sequence of the guinea pig (Cavia porcellus) provides innovative opportunities to apply proteomic technologies to an important animal model of disease. In this study, the comparative proteomic analysis of lung tissue from experimentally infected guinea pigs with leptospiral pulmonary haemorrhage syndrome (LPHS) revealed a decrease in abundance of proteins involved in cellular architecture and adhesion, suggesting that loss or down-regulation of cytoskeletal and adhesion molecules plays an important role in the pathogenesis of LPHS. A publically available guinea pig lung proteome map was constructed to facilitate future pulmonary proteomics in this species.

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The purpose of this study was to assess the expression profile of genes with potential role in the development of insulin resistance (adipokines, cytokines/chemokines, estrogen receptors) in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and placenta of pregnant women with gestational diabetes mellitus (GDM) and age-matched women with physiological pregnancy at the time of Caesarean section. qRT-PCR was used for expression analysis of the studied genes. Leptin gene expression in VAT of GDM group was significantly higher relative to control group. Gene expressions of interleukin-6 and interleukin-8 were significantly increased, whereas the expressions of genes for estrogen receptors alpha and beta were significantly reduced in SAT of GDM group relative to controls, respectively. We found no significant differences in the expression of any genes of interest (LEP, RETN, ADIPOR1, ADIPOR2, TNF-alpha, CD68, IL-6, IL-8, ER alpha, ER beta) in placentas of women with GDM relative to controls. We conclude that increased expression of leptin in visceral adipose depot together with increased expressions of proinflammatory cytokines and reduced expressions of estrogen receptors in subcutaneous fat may play a role in the etiopathogenesis of GDM.

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Plasmalemmal injury is a frequent event in the life of a cell. Physical disruption of the plasma membrane is common in cells that operate under conditions of mechanical stress. The permeability barrier can also be breached by chemical means: pathogens gain access to host cells by secreting pore-forming toxins and phospholipases, and the host's own immune system employs pore-forming proteins to eliminate both pathogens and the pathogen-invaded cells. In all cases, the influx of extracellular Ca(2+) is being sensed and interpreted as an "immediate danger" signal. Various Ca(2+)-dependent mechanisms are employed to enable plasma membrane repair. Extensively damaged regions of the plasma membrane can be patched with internal membranes delivered to the cell surface by exocytosis. Nucleated cells are capable of resealing their injured plasmalemma by endocytosis of the permeabilized site. Likewise, the shedding of membrane microparticles is thought to be involved in the physical elimination of pores. Membrane blebbing is a further damage-control mechanism, which is triggered after initial attempts at plasmalemmal resealing have failed. The members of the annexin protein family are ubiquitously expressed and function as intracellular Ca(2+) sensors. Most cells contain multiple annexins, which interact with distinct plasma membrane regions promoting membrane segregation, membrane fusion and--in combination with their individual Ca(2+)-sensitivity--allow spatially confined, graded responses to membrane injury.

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BACKGROUND AND OBJECTIVE: Protease inhibitors are highly bound to orosomucoid (ORM) (alpha1-acid glycoprotein), an acute-phase plasma protein encoded by 2 polymorphic genes, which may modulate their disposition. Our objective was to determine the influence of ORM concentration and phenotype on indinavir, lopinavir, and nelfinavir apparent clearance (CL(app)) and cellular accumulation. Efavirenz, mainly bound to albumin, was included as a control drug. METHODS: Plasma and cells samples were collected from 434 human immunodeficiency virus-infected patients. Total plasma and cellular drug concentrations and ORM concentrations and phenotypes were determined. RESULTS: Indinavir CL(app) was strongly influenced by ORM concentration (n = 36) (r2 = 0.47 [P = .00004]), particularly in the presence of ritonavir (r2 = 0.54 [P = .004]). Lopinavir CL(app) was weakly influenced by ORM concentration (n = 81) (r2 = 0.18 [P = .0001]). For both drugs, the ORM1 S variant concentration mainly explained this influence (r2 = 0.55 [P = .00004] and r2 = 0.23 [P = .0002], respectively). Indinavir CL(app) was significantly higher in F1F1 individuals than in F1S and SS patients (41.3, 23.4, and 10.3 L/h [P = .0004] without ritonavir and 21.1, 13.2, and 10.1 L/h [P = .05] with ritonavir, respectively). Lopinavir cellular exposure was not influenced by ORM abundance and phenotype. Finally, ORM concentration or phenotype did not influence nelfinavir (n = 153) or efavirenz (n = 198) pharmacokinetics. CONCLUSION: ORM concentration and phenotype modulate indinavir pharmacokinetics and, to a lesser extent, lopinavir pharmacokinetics but without influencing their cellular exposure. This confounding influence of ORM should be taken into account for appropriate interpretation of therapeutic drug monitoring results. Further studies are needed to investigate whether the measure of unbound drug plasma concentration gives more meaningful information than total drug concentration for indinavir and lopinavir.

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Endometriosis is an extremely prevalent disorder characterized by the growth of endometrial tissue at ectopic locations. Glycolysis is an energy-producing mechanism that occurs in almost all cells and requires an adequate uptake of glucose mediated by glucose transporter (GLUT) proteins. At present, however, very little is known about their expression in either the endometrium or the endometriotic lesions. The objective of this study was to examine the expression of SLC2A genes in the endometrium of women with and without endometriosis and in the matching ectopic tissue, and to confirm the presence of the GLUT proteins in ectopic lesions. There was a significantly higher expression of SLC2A3 and a significantly lower expression of SLC2A4 in women with endometriosis compared with those without. In women with endometriosis, the ectopic expression of SLC2A3, SLC2A4 and SLC2A5 was significantly higher than that observed in the matching eutopic tissue. GLUT1 protein expression was present in both epithelial and stromal cells and GLUT3 was confined to CD45-positive leukocytes. GLUT4 expression was strong in both ectopic epithelial and stromal cells and localized to the cellular membrane in epithelial cells. These results show that GLUT expression is altered between eutopic and ectopic tissue and between women with and without endometriosis, and that GLUT4 may represent a significant entry route for glucose into the endometriotic epithelial cells. The inducible nature of GLUT4 and its limited cellular expression may make GLUT4 an attractive target for non-hormone-based treatments of endometriosis.

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Recurrent intervertebral disc (IVD) herniation and degenerative disc disease have been identified as the most important factors contributing to persistent pain and disability after surgical discectomy. An annulus fibrosus (AF) closure device that provides immediate closure of the AF rupture, restores disc height, reduces further disc degeneration and enhances self-repair capacities is an unmet clinical need. In this study, a poly(trimethylene carbonate) (PTMC) scaffold seeded with human bone marrow derived mesenchymal stromal cells (MSCs) and covered with a poly(ester-urethane) (PU) membrane was assessed for AF rupture repair in a bovine organ culture annulotomy model under dynamic load for 14 days. PTMC scaffolds combined with the sutured PU membrane restored disc height of annulotomized discs and prevented herniation of nucleus pulposus (NP) tissue. Implanted MSCs showed an up-regulated gene expression of type V collagen, a potential AF marker, indicating in situ differentiation capability. Furthermore, MSCs delivered within PTMC scaffolds induced an up-regulation of anabolic gene expression and down-regulation of catabolic gene expression in adjacent native disc tissue. In conclusion, the combined biomaterial and cellular approach has the potential to hinder herniation of NP tissue, stabilize disc height, and positively modulate cell phenotype of native disc tissue.

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Percutaneous needle intervention based on PET/CT images is effective, but exposes the patient to unnecessary radiation due to the increased number of CT scans required. Computer assisted intervention can reduce the number of scans, but requires handling, matching and visualization of two different datasets. While one dataset is used for target definition according to metabolism, the other is used for instrument guidance according to anatomical structures. No navigation systems capable of handling such data and performing PET/CT image-based procedures while following clinically approved protocols for oncologic percutaneous interventions are available. The need for such systems is emphasized in scenarios where the target can be located in different types of tissue such as bone and soft tissue. These two tissues require different clinical protocols for puncturing and may therefore give rise to different problems during the navigated intervention. Studies comparing the performance of navigated needle interventions targeting lesions located in these two types of tissue are not often found in the literature. Hence, this paper presents an optical navigation system for percutaneous needle interventions based on PET/CT images. The system provides viewers for guiding the physician to the target with real-time visualization of PET/CT datasets, and is able to handle targets located in both bone and soft tissue. The navigation system and the required clinical workflow were designed taking into consideration clinical protocols and requirements, and the system is thus operable by a single person, even during transition to the sterile phase. Both the system and the workflow were evaluated in an initial set of experiments simulating 41 lesions (23 located in bone tissue and 18 in soft tissue) in swine cadavers. We also measured and decomposed the overall system error into distinct error sources, which allowed for the identification of particularities involved in the process as well as highlighting the differences between bone and soft tissue punctures. An overall average error of 4.23 mm and 3.07 mm for bone and soft tissue punctures, respectively, demonstrated the feasibility of using this system for such interventions. The proposed system workflow was shown to be effective in separating the preparation from the sterile phase, as well as in keeping the system manageable by a single operator. Among the distinct sources of error, the user error based on the system accuracy (defined as the distance from the planned target to the actual needle tip) appeared to be the most significant. Bone punctures showed higher user error, whereas soft tissue punctures showed higher tissue deformation error.

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For centuries the science of pharmacognosy has dominated rational drug development until it was gradually substituted by target-based drug discovery in the last fifty years. Pharmacognosy stems from the different systems of traditional herbal medicine and its "reverse pharmacology" approach has led to the discovery of numerous pharmacologically active molecules and drug leads for humankind. But do botanical drugs also provide effective mixtures? Nature has evolved distinct strategies to modulate biological processes, either by selectively targeting biological macromolecules or by creating molecular promiscuity or polypharmacology (one molecule binds to different targets). Widely claimed to be superior over monosubstances, mixtures of bioactive compounds in botanical drugs allegedly exert synergistic therapeutic effects. Despite evolutionary clues to molecular synergism in nature, sound experimental data are still widely lacking to support this assumption. In this short review, the emerging concept of network pharmacology is highlighted, and the importance of studying ligand-target networks for botanical drugs is emphasized. Furthermore, problems associated with studying mixtures of molecules with distinctly different pharmacodynamic properties are addressed. It is concluded that a better understanding of the polypharmacology and potential network pharmacology of botanical drugs is fundamental in the ongoing rationalization of phytotherapy.

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The synthesis and incorporation into oligodeoxynucleotides of two novel derivatives of bicyclothymidine carrying a cationic diaminopropyl or lysine unit in the C(6′)-β position is described. Compared to unmodified DNA these oligonucleotides show Tm-neutral behavior when paired against complementary DNA and are destabilizing when paired against RNA. Unaided uptake experiments of a decamer containing five lys-bcT units into HeLa and HEK293T cells showed substantial internalization with mostly cytosolic distribution which was not observed in the case of an unmodified control oligonucleotide.

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Dairy cows with high and low plasma non-esterified fatty acid (NEFA) concentrations in early lactation were compared for plasma parameters and mRNA expression of genes in liver and subcutaneous adipose tissue. The study involved 16 multiparous dairy cows with a plasma NEFA concentration of >500 mumol/l [n = 8, high NEFA (HNEFA)] and <140 mumol/l [n = 8, low NEFA (LNEFA)] in the first week post-partum (pp). Blood samples, adipose and liver tissues were collected on day 1 (+1d) and at week 3 pp (+3wk). Blood plasma was assayed for concentrations of metabolites and hormones. Subcutaneous adipose and liver tissues were analysed for mRNA abundance by real-time qRT-PCR encoding parameters related to lipid metabolism. Results showed that mean daily milk yield and milk fat quantity were higher in HNEFA than in LNEFA cows (p < 0.01), and the NEB was more negative in HNEFA than in LNEFA in +3wk too (p < 0.05). HNEFA cows had slightly lower (p < 0.1) insulin concentrations than LNEFA cows across the study period, and the body condition score decreased more from +1d to +3wk in HNEFA than in LNEFA (p = 0.09). The mRNA abundance of genes in the liver related to fatty acid oxidation (carnitine palmitoyltransferase 2 and very long chain acyl-coenzyme A dehydrogenase) and ketogenesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 2) were lower in HNEFA than in LNEFA cows. No differences between the two groups were observed for mRNA expression of genes in adipose tissue. The number of calculated significant correlation coefficients (moderately strong) between parameters in the liver and in adipose tissue was nearly similar on +1d, and higher for HNEFA compared with LNEFA cows in +3wk. In conclusion, dairy cows with high compared with low plasma NEFA concentrations in early lactation show differentially synchronized mRNA expression of genes in adipose tissue and liver in +3wk that suggests a different orchestrated homeorhetic regulation of lipid metabolism.

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The central nervous system (CNS) comprises the brain, spinal cord, optic nerves and retina, and contains post-mitotic, delicate cells. As the rigid coverings of the CNS render swelling dangerous and destructive, inflammatory reactions must be carefully controlled in CNS tissues. Nevertheless, effector immune responses that protect the host during CNS infection still occur in the CNS. Here, we describe the anatomical and cellular basis of immune surveillance in the CNS, and explain how this shapes the unique immunology of these tissues. The Review focuses principally on insights gained from the study of autoimmune responses in the CNS and to a lesser extent on models of infectious disease. Furthermore, we propose a new model to explain how antigen-specific T cell responses occur in the CNS.

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Combustion-derived and synthetic nano-sized particles (NSP) have gained considerable interest among pulmonary researchers and clinicians for two main reasons: 1) Inhalation exposure to combustion-derived NSP was associated with increased pulmonary and cardiovascular morbidity and mortality as suggested by epidemiological studies. Experimental evidence has provided a mechanistic picture of the adverse health effects associated with inhalation of combustion-derived and synthetic NSP. 2) The toxicological potential of NSP contrasts with the potential application of synthetic NSP in technological as well as medicinal settings with the latter including the use of NSP as diagnostics or therapeutics. In order to shed light on this paradox, this article aims to highlight recent findings about the interaction of inhaled NSP with the structures of the respiratory tract including surfactant and alveolar macrophages and epithelial cells. Cellular responses to NSP exposure include the generation of reactive oxygen species and the induction of an inflammatory response. Furthermore, this review places special emphasis on methodological differences between experimental studies and the caveats associated with the dose metrics and points out ways to overcome inherent methodological problems. Key words: electron tomography, surfactant, translocation, oxidative stress, inflammation.

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The penetration, translocation, and distribution of ultrafine and nanoparticles in tissues and cells are challenging issues in aerosol research. This article describes a set of novel quantitative microscopic methods for evaluating particle distributions within sectional images of tissues and cells by addressing the following questions: (1) is the observed distribution of particles between spatial compartments random? (2) Which compartments are preferentially targeted by particles? and (3) Does the observed particle distribution shift between different experimental groups? Each of these questions can be addressed by testing an appropriate null hypothesis. The methods all require observed particle distributions to be estimated by counting the number of particles associated with each defined compartment. For studying preferential labeling of compartments, the size of each of the compartments must also be estimated by counting the number of points of a randomly superimposed test grid that hit the different compartments. The latter provides information about the particle distribution that would be expected if the particles were randomly distributed, that is, the expected number of particles. From these data, we can calculate a relative deposition index (RDI) by dividing the observed number of particles by the expected number of particles. The RDI indicates whether the observed number of particles corresponds to that predicted solely by compartment size (for which RDI = 1). Within one group, the observed and expected particle distributions are compared by chi-squared analysis. The total chi-squared value indicates whether an observed distribution is random. If not, the partial chi-squared values help to identify those compartments that are preferential targets of the particles (RDI > 1). Particle distributions between different groups can be compared in a similar way by contingency table analysis. We first describe the preconditions and the way to implement these methods, then provide three worked examples, and finally discuss the advantages, pitfalls, and limitations of this method.