81 research outputs found
Evaluation of Lionex TB kits and mycobacterial antigens for IgG and IgA detection in cerebrospinal fluid from tuberculosis meningitis patients
To evaluate commercial Lionex TB together with four antigens of Mycobacterium tuberculosis (MPT-64, MT10.3, 16 kDa and 38 kDa) for IgG and IgA cerebrospinal fluid (CSF) detection in the diagnosis of tuberculosis meningitis (TBM) with CSF negative acid-fast bacilli staining, 19 cases of TBM, 64 cases of other infectious meningoencephalitis and 73 cases of other neurological disorders were tested by enzyme linked immunosorbent assay. IgA-MPT-64 and IgG Lionex showed the highest sensitivities, specificities, positive predictive value and negative predictive value (63.2%, 47.4%; 95%, 93.7%; 40%, 98% and 28.4%, 97.1%, respectively). However, while grey zone was 12.7% and 6%, respectively, lowering sensitivity but maintains high specificity (> 95%). High protein concentration in CSF was associated with antibody positivity CSF/HIV+ which did not influence the sensitivity of both tests. To our knowledge, this is the first description of IgA-MPT-64 and IgG Lionex antibodies in CSF-TBM and, although there is good specificity, adjustments are needed based on antigen composition to enhance sensitivity
Light-evoked Somatosensory Perception of Transgenic Rats That Express Channelrhodopsin-2 in Dorsal Root Ganglion Cells
In vertebrate somatosensory systems, each mode of touch-pressure, temperature or pain is sensed by sensory endings of different dorsal root ganglion (DRG) neurons, which conducted to the specific cortical loci as nerve impulses. Therefore, direct electrical stimulation of the peripheral nerve endings causes an erroneous sensation to be conducted by the nerve. We have recently generated several transgenic lines of rat in which channelrhodopsin-2 (ChR2) transgene is driven by the Thy-1.2 promoter. In one of them, W-TChR2V4, some neurons were endowed with photosensitivity by the introduction of the ChR2 gene, coding an algal photoreceptor molecule. The DRG neurons expressing ChR2 were immunohistochemically identified using specific antibodies to the markers of mechanoreceptive or nociceptive neurons. Their peripheral nerve endings in the plantar skin as well as the central endings in the spinal cord were also examined. We identified that ChR2 is expressed in a certain population of large neurons in the DRG of W-TChR2V4. On the basis of their morphology and molecular markers, these neurons were classified as mechanoreceptive but not nociceptive. ChR2 was also distributed in their peripheral sensory nerve endings, some of which were closely associated with CK20-positive cells to form Merkel cell-neurite complexes or with S-100-positive cells to form structures like Meissner's corpuscles. These nerve endings are thus suggested to be involved in the sensing of touch. Each W-TChR2V4 rat showed a sensory-evoked behavior in response to blue LED flashes on the plantar skin. It is thus suggested that each rat acquired an unusual sensory modality of sensing blue light through the skin as touch-pressure. This light-evoked somatosensory perception should facilitate study of how the complex tactile sense emerges in the brain
Matrix Metalloproteinase Gene Delivery for Liver Fibrosis
The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs
Insulin-like growth factor binding protein 5 enhances survival of LX2 human hepatic stellate cells
ABSTRACT: BACKGROUND: Expression of insulin-like growth factor binding protein 5 (IGFBP5) is strongly induced upon activation of hepatic stellate cells and their transdifferentiation into myofibroblasts in vitro. This was confirmed in vivo in an animal model of liver fibrosis. Since IGFBP5 has been shown to promote fibrosis in other tissues, the aim of this study was to investigate its role in the progression of liver fibrosis. METHODS: The effect of IGFBP5 was studied in LX2 cells, a model for partially activated hepatic stellate cells, and in human primary liver myofibroblasts. IGFBP5 signalling was modulated by the addition of recombinant protein, by lentiviral overexpression, and by siRNA mediated silencing. Furthermore, the addition of IGF1 and silencing of the IGF1R was used to investigate the role of the IGF-axis in IGFBP5 mediated effects. RESULTS: IGFBP5 enhanced the survival of LX2 cells and myofibroblasts via a >50% suppression of apoptosis. This effect of IGFBP5 was not modulated by the addition of IGF1, nor by silencing of the IGF1R. Additionally, IGFBP5 was able to enhance the expression of established pro-fibrotic markers, such as collagen Ialpha1, TIMP1 and MMP1. CONCLUSION: IGFBP5 enhances the survival of (partially) activated hepatic stellate cells and myofibroblasts by lowering apoptosis via an IGF1-independent mechanism, and enhances the expression of profibrotic genes. Its lowered expression may, therefore, reduce the progression of liver fibrosi
Expression of ECM proteins fibulin-1 and -2 in acute and chronic liver disease and in cultured rat liver cells
Fibulin-2 has previously been considered as a marker to distinguish rat liver myofibroblasts from hepatic stellate cells. The function of other fibulins in acute or chronic liver damage has not yet been investigated. The aim of this study has been to evaluate the expression of fibulin-1 and -2 in models of rat liver injury and in human liver cirrhosis. Their cellular sources have also been investigated. In normal rat liver, fibulin-1 and -2 were both mainly present in the portal field. Fibulin-1-coding transcripts were detected in total RNA of normal rat liver, whereas fibulin-2 mRNA was only detected by sensitive, real-time quantitative polymerase chain reaction. In acute liver injury, the expression of fibulin-1 was significantly increased (17.23-fold after 48 h), whereas that of fibulin-2 was not modified. The expression of both fibulin-1 and -2 was increased in experimental rat liver cirrhosis (19.16- and 26.47-fold, respectively). At the cellular level, fibulin-1 was detectable in hepatocytes, “activated” hepatic stellate cells, and liver myofibroblasts (2.71-, 122.65-, and 469.48-fold over the expression in normal rat liver), whereas fibulin-2 was restricted to liver myofibroblasts and was regulated by transforming growth factor beta-1 (TGF-β1) in 2-day-old hepatocyte cultures and in liver myofibroblasts. Thus, fibulin-1 and -2 respond differentially to single and repeated damaging noxae, and their expression is differently present in liver cells. Expression of the fibulin-2 gene is regulated by TGF-β1 in liver myofibroblasts
Homing in on the hepatic scar:recent advances in cell-specific targeting of liver fibrosis
Despite the high prevalence of liver disease globally, there are currently no approved anti-fibrotic therapies to treat patients with liver fibrosis. A major goal in anti-fibrotic therapy is the development of drug delivery systems that allow direct targeting of the major pro-scarring cell populations within the liver (hepatic myofibroblasts) whilst not perturbing the homeostatic functions of other mesenchymal cell types present within both the liver and other organ systems. In this review we will outline some of the recent advances in our understanding of myofibroblast biology, discussing both the origin of myofibroblasts and possible myofibroblast fates during hepatic fibrosis progression and resolution. We will then discuss the various strategies currently being employed to increase the precision with which we deliver potential anti-fibrotic therapies to patients with liver fibrosis
The Precarious State of the Liver After a Fontan Operation: Summary of a Multidisciplinary Symposium
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A Global Baltic - Potential Gains from Trade Liberalisation in the Baltic Sea States
What would a “Global Baltic”, liberalised to the rest of the world, mean for national income and trade patterns of the Baltic Sea region? Although the countries have displayed substantial economic growth and relatively high trading activity over the last decade, facilitated by politicoeconomic reforms, significant trade barriers still exist in the region. Their removal might further boost the economies of the region. The aim of this study is to analyse the potential effects from unilateral trade liberalisation, using a CGE-model with monopolistic competition in most aggregate sectors. Besides addressing the “usual suspects” (tariffs, subsidies and tariffequivalents for restrictions to services trade) as well as trade facilitation in the main simulation, we also address some core non-tariff-measures (NTM) in a separate simulation. The NTMsimulation is based on recently released data. The effect of a “Global Baltic” would be a substantial boost to national income and trade of the region: a 1 and 0.9 percent increase in regional income, in the main and the NTM-scenario, respectively. In other words, liberalisation would sustain growth in the area. Particularly strong results are found for the group of emerging market economies of the region. The largest income gains stem from a country’s own liberalisation. With respect to the different simulation elements, trade facilitation and reductions in NTMs bring the major sources of gains. In the main as well as the NTM scenario, effects on national income are primarily due to elimination of dead-weight losses caused by rules and regulations at, or behind the border and more efficient allocation of resources. The income effects from scale economies are slightly negative in both scenarios on an aggregate level. On a country level, the results show that different reforms create different incentives for production, and that the net-effect on a country’s national income will to a large extent be related to which sectors are expanding/contracting. Structurally, the expected joint effect of the two simulation scenarios is a move towards services and industrial production and export
Economic implications of the Doha round
In this study the key elements of the WTO Doha round are simulated and the main implications for international trade and national income are analysed. Based on negotiation positions at the recent Hong Kong ministerial conference, a number of Doha scenarios are carefully designed and implemented. All scenarios encompass goods, services and agricultural liberalisation as well as trade facilitation. For goods liberalisation, a socalled Swiss formula with two coefficients is used to cut bound tariff rates. Agricultural tariffs are cut according to a tiered linear formula with four bands. Considerable attention has been given to the modelling of trade facilitation. Indirect as well as direct trade transaction costs are modelled, using detailed cross-country data. For simulation of the services liberalisation we use quantitative estimates of the indirect trade barriers for each region and sector. The simulation results show that all regions in the aggregation gain in the simulated Doha scenarios, with a particularly strong result for developing countries. In this respect, the Doha round can be called a development round. A conservative estimate is that global income increases with 0.2-0.7 percent of initial GDP per year, depending on the level of liberalisation. Trade facilitation contributes the most to these results, with increased market access for non-agricultural goods coming in second place. However, services reforms contribute the least, as small real market openings are expected. Overall, simulations indicate the importance of countries’ own liberalisation for their national income gains. Therefore, a “round for free” does not seem to be a valid concept. Furthermore, the importance of a broad-based round is underlined. Excluding some elements of liberalisation from the round may turn potential gains into losses, for some countries
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