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41.
Marianna D A Ga?a Xiaoying Zhou Razao Issa Kishanee Kiriella John P Iredale R Christopher Benyon 《Matrix biology》2003,22(3):229-239
During liver fibrosis hepatic stellate cells become activated, transforming into proliferative myofibroblastic cells expressing type I collagen and alpha-smooth muscle actin. They become the major producers of the fibrotic neomatrix in injured liver. This study examines if activated stellate cells are a committed phenotype, or whether they can become deactivated by extracellular matrix. Stellate cells isolated from normal rat liver proliferated and expressed mRNA for activation markers, alpha-smooth muscle actin, type I procollagen and tissue inhibitor of metalloproteinases-1 following 5-7 day culture on plastic, but culture on Matrigel suppressed proliferation and mRNA expression. Activated stellate cells were recovered from plastic by trypsinisation and replated onto plastic, type I collagen films or Matrigel. Cells replated on plastic and type I collagen films proliferated and remained morphologically myofibroblastic, expressing alpha-smooth muscle actin and type I procollagen. However, activated cells replated on Matrigel showed <30% of the proliferative rate of these cells, and this was associated with reduced cellular expression of proliferating cell nuclear antigen and phosphorylation of mitogen-activated protein kinase in response to serum. Activated HSC replated on Matrigel for 3-7 days progressively reduced their expression of mRNA for type I procollagen and alpha-smooth muscle actin and both became undetectable after 7 days. We conclude that basement membrane-like matrix induces deactivation of stellate cells. Deactivation represents an important potential mechanism mediating recovery from liver fibrosis in vivo where type I collagen is removed from the liver and stellate cells might re-acquire contact with their normal basement membrane-like pericellular matrix. 相似文献
42.
The sensitivity and accuracy of molecular diagnosis of Salmonella from meat and poultry products using polymerase chain reaction (PCR) was compared with conventional microbiological methods. A total of 212 samples representing the most frequently used fresh and frozen meat and poultry products (whole, cut, ground, and processed) were collected from different locations within the city of Irbid. DNA was extracted directly from each food sample and amplified using Salmonella-specific primers. Samples were also analysed using conventional microbiological methods for the presence of Salmonella spp. Results showed that Salmonella was detected in 185 samples out of 212 (87%) by PCR technique, while 172 (81%) samples were detected Salmonella positive by conventional microbiological methods. On the other hand, 27 (12.7%) samples were negative by PCR and 40 (18.8%) samples were negative by conventional microbiological methods. PCR assay proved to be an effective method for Salmonella detection in meat and poultry products with high specificity and sensitivity and more importantly a less time-consuming procedure. Using PCR, Salmonella spp. detection could be achieved within 24–36 h compared to 3–8 days for the conventional microbiological methods. 相似文献
43.
Sodiomon B. Sirima Alfred B. Tiono Alphonse Ouédraogo Amidou Diarra André Lin Ouédraogo Jean Baptiste Yaro Espérance Ouédraogo Adama Gansané Edith C. Bougouma Amadou T. Konaté Youssouf Kaboré Abdoulaye Traoré Chilengi Roma Issiaka Soulama Adrian J. F. Luty Simon Cousens Issa Nébié 《PloS one》2009,4(10)
Background
A Phase Ia trial in European volunteers of the candidate vaccine merozoite surface protein 3 (MSP3), a Plasmodium falciparum blood stage membrane, showed that it induces biologically active antibodies able to achieve parasite killing in vitro, while a phase Ib trial in semi-immune adult volunteers in Burkina Faso confirmed that the vaccine was safe.The aim of this study was to assess the safety and immunogenicity of this vaccine candidate in children aged 12–24 months living in malaria endemic area of Burkina Faso.Methods
The study was a double-blind, randomized, controlled, dose escalation phase Ib trial, designed to assess the safety, reactogenicity and immunogenicity of three doses of either 15 or 30 µg of MSP3-LSP adsorbed on aluminum hydroxide in 45 children 12 to 24 months of age randomized into three equal groups. Each group received 3 vaccine doses (on days 0, 28 and 56) of either 15 µg of MSP3-LSP, 30 µg of MSP3-LSP or of the Engerix B hepatitis B vaccine. Children were visited at home daily for the 6 days following each vaccination to solicit symptoms which might be related to vaccination. Serious adverse events occurring during the study period (1 year) were recorded. Antibody responses to MSP3-LSP were measured on days 0, 28, 56 and 84.Results
All 45 enrolled children received three MSP3 vaccine doses. No serious adverse events were reported. Most of the adverse events reported were mild to moderate in severity. The only reported local symptoms with grade 3 severity were swelling and induration, with an apparently dose related response. All grade 3 adverse events resolved without any sequelae. Both MSP3 doses regimens were able to elicit high levels of anti-MSP3 specific IgG1 and IgG3 antibodies in the volunteers with very little or no increase in IgG2, IgG4 and IgM classes: i.e. vaccination induced predominantly the isotypes involved in the monocyte-dependent mechanism of P. falciparum parasite-killing.Conclusion
Our results support the promise of MSP3-LSP as a malaria vaccine candidate, both in terms of tolerability and of immunogenicity. Further assessment of the efficacy of this vaccine is recommended.Trial Registration
ClinicalTrials.gov NCT00452088相似文献44.
45.
Brockschmidt A Filippi A Charbel Issa P Nelles M Urbach H Eter N Driever W Weber RG 《Human genetics》2011,130(5):645-655
In this study, we performed an in-depth analysis of the neurologic and ophthalmologic phenotype in a patient with Pitt–Hopkins
syndrome (PTHS), a disorder characterized by severe mental and motor retardation, carrying a uniallelic TCF4 deletion, and studied a zebrafish model. The PTHS-patient was characterized by high-resolution magnetic resonance imaging
(MRI) with diffusion tensor imaging to analyze the brain structurally, spectral-domain optical coherence tomography to visualize
the retinal layers, and electroretinography to evaluate retinal function. A zebrafish model was generated by knockdown of
tcf4-function by injection of morpholino antisense oligos into zebrafish embryos and the morphant phenotype was characterized
for expression of neural differentiation genes neurog1, ascl1b, pax6a, zic1, atoh1a, atoh2b. Data from PTHS-patient and zebrafish morphants were compared. While a cerebral MRI-scan showed markedly delayed myelination
and ventriculomegaly in the 1-year-old PTHS-patient, no structural cerebral anomalies including no white matter tract alterations
were detected at 9 years of age. Structural ocular examinations showed highly myopic eyes and an increase in ocular length,
while retinal layers were normal. Knockdown of tcf4-function in zebrafish embryos resulted in a developmental delay or defects in terminal differentiation of brain and eyes,
small eyes with a relative increase in ocular length and an enlargement of the hindbrain ventricle. In summary, tcf4-knockdown in zebrafish embryos does not seem to affect early neural patterning and regionalization of the forebrain, but
may be involved in later aspects of neurogenesis and differentiation. We provide evidence for a role of TCF4/E2-2 in ocular
growth control in PTHS-patients and the zebrafish model. 相似文献
46.
Complement regulation at necrotic cell lesions is impaired by the age-related macular degeneration-associated factor-H His402 risk variant 总被引:1,自引:0,他引:1
Lauer N Mihlan M Hartmann A Schlötzer-Schrehardt U Keilhauer C Scholl HP Charbel Issa P Holz F Weber BH Skerka C Zipfel PF 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(8):4374-4383
Age-related macular degeneration is a leading form of blindness in Western countries and is associated with a common SNP (rs 1061170/Y402H) in the Factor H gene, which encodes the two complement inhibitors Factor H and FHL1. However, the functional consequences of this Tyr(402) His exchange in domain 7 are not precisely defined. In this study, we show that the Tyr(402) His sequence variation affects Factor H surface recruitment by monomeric C-reactive protein (mCRP) to specific patches on the surface of necrotic retinal pigment epithelial cells. Enhanced attachment of the protective Tyr(402) variants of both Factor H and FHL1 by mCRP results in more efficient complement control and further provides an anti-inflammatory environment. In addition, we demonstrate that mCRP is generated on the surface of necrotic retinal pigment epithelial cells and that this newly formed mCRP colocalizes with the cell damage marker annexin V. Bound to the cell surface, Factor H-mCRP complexes allow complement inactivation and reduce the release of the proinflammatory cytokine TNF-α. This mCRP-mediated complement inhibitory and anti-inflammatory activity at necrotic membrane lesions is affected by residue 402 of Factor H and defines a new role for mCRP, for Factor H, and also for the mCRP-Factor H complex. The increased protective capacity of the Tyr(402) Factor H variant allows better and more efficient clearance and removal of cellular debris and reduces inflammation and pathology. 相似文献
47.
Miguel A. Bedoya-Pérez Daniel D. Issa Peter B. Banks Clare McArthur 《Oecologia》2014,175(4):1167-1177
While trying to achieve their nutritional requirements, foraging herbivores face the costs of plant defenses, such as toxins. Teasing apart the costs and benefits of various chemical constituents in plants is difficult because their chemical defenses and nutrient concentrations often co-vary. We used an approach derived from predator–prey studies to quantitatively compare the foraging response of a free-ranging mammalian herbivore, the swamp wallaby (Wallabia bicolor), through three feeding trials with artificial diets that differed in their concentrations of (1) the terpene 1,8-cineole, (2) primary constituents (including nitrogen and fiber), and (3) both the terpene and the primary constituents. Applying the giving-up density (GUD) framework, we demonstrated that the foraging cost of food patches increases with higher dietary cineole concentration and decreases with higher dietary nutrient concentration. The effect of combined differences in nutrients and cineole concentrations on GUD was interactive, and high nutrient food required more cineole to achieve the same patch value as low nutrient food. Our results indicate that swamp wallabies equate low nutrient, poorly defended food with high nutrient, highly defended food, providing two contrasting diets with similar cost–benefit outcomes. This behavior suggests that equal concentrations of chemical defenses provide nutrient-poor plants with relatively greater protection as nutrient-rich plants. Nutrient-rich plants may therefore face the exacerbated problem of being preferred by herbivores and therefore need to produce more defense compounds to achieve the same level of defense as nutrient-poor plants. Our findings help explain the difference in anti-herbivore strategy of nutrient-poor and rich plants, i.e., tolerance versus defense. 相似文献
48.
Maroya Spalding Walters Janell Routh Matthew Mikoleit Samuel Kadivane Caroline Ouma Denis Mubiru Ben Mbusa Amos Murangi Emmanuel Ejoku Absalom Rwantangle Uziah Kule John Lule Nancy Garrett Jessica Halpin Nikki Maxwell Atek Kagirita Fred Mulabya Issa Makumbi Molly Freeman Kevin Joyce Vince Hill Robert Downing Eric Mintz 《PLoS neglected tropical diseases》2014,8(3)
Background
Salmonella enterica serovar Typhi is transmitted by fecally contaminated food and water and causes approximately 22 million typhoid fever infections worldwide each year. Most cases occur in developing countries, where approximately 4% of patients develop intestinal perforation (IP). In Kasese District, Uganda, a typhoid fever outbreak notable for a high IP rate began in 2008. We report that this outbreak continued through 2011, when it spread to the neighboring district of Bundibugyo.Methodology/Principal Findings
A suspected typhoid fever case was defined as IP or symptoms of fever, abdominal pain, and ≥1 of the following: gastrointestinal disruptions, body weakness, joint pain, headache, clinically suspected IP, or non-responsiveness to antimalarial medications. Cases were identified retrospectively via medical record reviews and prospectively through laboratory-enhanced case finding. Among Kasese residents, 709 cases were identified from August 1, 2009–December 31, 2011; of these, 149 were identified during the prospective period beginning November 1, 2011. Among Bundibugyo residents, 333 cases were identified from January 1–December 31, 2011, including 128 cases identified during the prospective period beginning October 28, 2011. IP was reported for 507 (82%) and 59 (20%) of Kasese and Bundibugyo cases, respectively. Blood and stool cultures performed for 154 patients during the prospective period yielded isolates from 24 (16%) patients. Three pulsed-field gel electrophoresis pattern combinations, including one observed in a Kasese isolate in 2009, were shared among Kasese and Bundibugyo isolates. Antimicrobial susceptibility was assessed for 18 isolates; among these 15 (83%) were multidrug-resistant (MDR), compared to 5% of 2009 isolates.Conclusions/Significance
Molecular and epidemiological evidence suggest that during a prolonged outbreak, typhoid spread from Kasese to Bundibugyo. MDR strains became prevalent. Lasting interventions, such as typhoid vaccination and improvements in drinking water infrastructure, should be considered to minimize the risk of prolonged outbreaks in the future. 相似文献49.
Mapping stakeholder viewpoints in biodiversity management: an application in Niger using Q methodology 总被引:1,自引:0,他引:1
Issa Hamadou Nassim Moula Seyni Siddo Moumouni Issa Hamani Marichatou Pascal Leroy Nicolas Antoine-Moussiaux 《Biodiversity and Conservation》2016,25(10):1973-1986
The purpose of this paper is to examine the viewpoints of stakeholders in the management and conservation of farm animal biodiversity in Niger. The research applies Q methodology in order to reveal consensual and divergent discourses. After the development of the set of items on the topic of biodiversity (Q sample), the statements were sorted by the respondents through a 7-grade scale, from ?3 to +3. The analysis of Q-sort data with the qmethod package under the R software highlighted three distinct stakeholder viewpoints on the importance of biodiversity in agriculture and animal husbandry, the balance between progress and preservation and the effectiveness of different methods of conservation. The study shows an apparent consensus on the importance of biodiversity that is obviously a promoted topic in the country. Behind the consensus, different discourses are defined that all appear divided by the same dilemma between conservation and economic development. Understanding the different answers and weight attributed to each of the components of the dilemma will guide awareness-raising campaigns and help to pinpoint divergent interests among stakeholders. 相似文献
50.
Helicobacter pylori infection reduces the risk of Barrett's esophagus: A meta‐analysis and systematic review
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Bálint Erőss Nelli Farkas Áron Vincze Benedek Tinusz László Szapáry András Garami Márta Balaskó Patrícia Sarlós László Czopf Hussain Alizadeh Zoltán Rakonczay Jr Tamás Habon Péter Hegyi 《Helicobacter》2018,23(4)