Translocation of Helicobacter pylori CagA into gastric epithelial cells by type IV secretion     

Odenbreit S  Püls J  Sedlmaier B  Gerland E  Fischer W  Haas R 《Science (New York, N.Y.)》2000,287(5457):1497-1500

The Gram-negative bacterium Helicobacter pylori is a causative agent of gastritis and peptic ulcer disease in humans. Strains producing the CagA antigen (cagA(+)) induce strong gastric inflammation and are strongly associated with gastric adenocarcinoma and MALT lymphoma. We show here that such strains translocate the bacterial protein CagA into gastric epithelial cells by a type IV secretion system, encoded by the cag pathogenicity island. CagA is tyrosine-phosphorylated and induces changes in the tyrosine phosphorylation state of distinct cellular proteins. Modulation of host cells by bacterial protein translocation adds a new dimension to the chronic Helicobacter infection with yet unknown consequences.  相似文献   

Marine polysaccharides: a source of bioactive molecules for cell therapy and tissue engineering     

Senni K  Pereira J  Gueniche F  Delbarre-Ladrat C  Sinquin C  Ratiskol J  Godeau G  Fischer AM  Helley D  Colliec-Jouault S 《Marine drugs》2011,9(9):1664-1681

The therapeutic potential of natural bioactive compounds such as polysaccharides, especially glycosaminoglycans, is now well documented, and this activity combined with natural biodiversity will allow the development of a new generation of therapeutics. Advances in our understanding of the biosynthesis, structure and function of complex glycans from mammalian origin have shown the crucial role of this class of molecules to modulate disease processes and the importance of a deeper knowledge of structure-activity relationships. Marine environment offers a tremendous biodiversity and original polysaccharides have been discovered presenting a great chemical diversity that is largely species specific. The study of the biological properties of the polysaccharides from marine eukaryotes and marine prokaryotes revealed that the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans. Marine polysaccharides present a real potential for natural product drug discovery and for the delivery of new marine derived products for therapeutic applications.  相似文献   

Genotype-by-environment interactions for grain yield associated with water availability at flowering in rainfed lowland rice     

M. Ouk  J. Basnayake  M. Tsubo  S. Fukai  K.S. Fischer  S. Kang  S. Men  V. Thun  M. Cooper 《Field Crops Research》2007

While a large genotype-by-environment (G × E) interaction component of variance for grain yield (GY) has been widely reported for rainfed lowland rice, the reasons for such large interactions are not well known. A random reference population of 34 genotypes taken from the Cambodian rice improvement program was used to examine the magnitude and nature of G × E interactions for GY in Cambodia. These genotypes were evaluated in a multi-environment trial (MET) conducted across 3 years (2000–2002) and eight locations in the rainfed lowlands. The G × E interaction was partitioned into components attributed to genotype-by-location (G × L), genotype-by-year (G × Y) and genotype-by-location-by-year (G × L × Y) interactions. The G × L × Y interaction was the largest component of variance for GY. The G × L interaction was also significant and comparable in size to the genotypic component (G). The significant G component was partly explained by a group of four genotypes that were broadly adapted to different environmental conditions represented by three environmental groups. The three environmental groups were identified from a pattern analysis, and the grouping was partly related to the time of sowing, and hence water availability at flowering. A major factor contributing to the large G × L × Y interactions for GY was late maturing genotypes being affected greatly when soil water availability at flowering was reduced greatly, compared to earlier maturing genotype groups. While the differential genotypic responses to the water availability environment explained part of a large G × E interaction for GY, other non-water related environmental conditions also appeared to have contributed to the interaction. Three target environments were identified for focusing efforts of the breeding programs in Cambodia, and four putative genotypes were selected for their high yield and wide adaptation in the rainfed lowlands.  相似文献   

Unilateral and Bilateral Congenital Sensorineural Deafness in Client-Owned Pure-Breed White Cats     

D. Cvejic  T.A. Steinberg  M.S. Kent  A. Fischer 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(2):392-395

Background: Congenital sensorineural deafness has been reported frequently in experimental mixed-breed white cats but there is a paucity of data on occurrence of deafness in client-owned pure-breed white cats.
Objective: To describe hearing status in client-owned pure-breed white cats.
Animals: Eighty-four pure-breed client-owned cats with white coat color of 10 registered breeds presented for routine hearing evaluation before breeding (1995–2008).
Methods: Hearing was assessed by click-evoked brainstem auditory evoked response.
Results: Overall deafness prevalence was 20.2%; 9 cats (10.7%) were bilaterally deaf and 8 cats (9.5%) were unilaterally deaf. There was no association between sex and deafness status ( P = .85). Deafness status was associated with iris color ( P = .04).
Conclusions and Clinical Importance: Congenital sensorineural deafness frequently occurs in pure-breed cats with white coat color. Unilateral sensorineural deafness was as common as bilateral deafness.  相似文献   

A comparison of epidural buprenorphine plus detomidine with morphine plus detomidine in horses undergoing bilateral stifle arthroscopy     

Berit L Fischer DVM  Diplomate ACVA    John W Ludders DVM  Diplomate  ACVA    Makoto Asakawa BVSc    Lisa A Fortier DVM  PhD  Diplomate ACVS    Susan L Fubini DVM  Diplomate ACVS    Alan J Nixon DVM  PhD  Diplomate ACVS    Rolfe M Radcliffe DVM  Diplomate ACVS  & Hollis N Erb† DVM  MS  PhD 《Veterinary anaesthesia and analgesia》2009,36(1):67-76

ObjectiveTo compare the analgesic efficacy of buprenorphine plus detomidine with that of morphine plus detomidine when administered epidurally in horses undergoing bilateral stifle arthroscopy.Study designProspective, randomized, blinded clinical trial.AnimalsTwelve healthy adult horses participating in an orthopedic research study. Group M (n = 6) received morphine (0.2 mg kg^?1) and detomidine (0.15 mg kg^?1) epidurally; group B (n = 6) received buprenorphine (0.005 mg kg^?1) and detomidine (0.15 mg kg^?1) epidurally.MethodsHorses received one of two epidural treatments following induction of general anesthesia for bilateral stifle arthroscopy. Heart rate (HR), mean arterial blood pressure (MAP), end-tidal CO₂ (Pe’CO₂), and end-tidal isoflurane concentrations (E’Iso%) were recorded every 15 minutes following epidural administration. Post-operative assessment was performed at 1, 2, 3, 6, 9, 12, and 24 hours after standing; variables recorded included HR, respiratory rate (f_R), abdominal borborygmi, defecation, and the presence of undesirable side effects. At the same times post-operatively, each horse was videotaped at a walk and subsequently assigned a lameness score (0-4) by three ACVS diplomates blinded to treatment and who followed previously published guidelines. Nonparametric data were analyzed using Wilcoxon’s rank-sum test. Inter- and intra-rater agreement were determined using weighted kappa coefficients. Statistical significance was set at p = 0.05.ResultsNo statistically significant differences were found between groups with respect to intra-operative HR, MAP, E’Iso%, or post-operative HR, gastrointestinal function and cumulative median lameness scores. Post-operative f_R in group B [24 (12-30), median (range)] breaths per minute was significantly higher than in group M [18 (15-20)] breaths per minute, p = 0.04.Conclusions and clinical relevanceIn horses undergoing bilateral stifle arthroscopy, these doses of buprenorphine plus detomidine injected epidurally produced analgesia similar in intensity and duration to that of morphine plus detomidine injected epidurally.  相似文献   

Modelling relative abundance of Oligoryzomys flavescens,an Orthohantavirus reservoir,in an endemic hantavirus pulmonary syndrome zone     

María Victoria Vadell  Carlos González Fischer  Mariano Codesido  Aníbal Carbajo  David Bilenca  Isabel E. Gómez Villafañe 《Zoonoses and public health》2023,70(1):13-21

Hantavirus pulmonary syndrome (HPS) is a zoonotic emerging infectious disease caused by New World orthohantaviruses (family Hantaviridae) hosted by rodents of the family Cricetidae. In Argentina, one of its main hosts is the sigmodontine rodent Oligoryzomys flavescens, a widely distributed mouse of the Pampas, Delta and Espinal ecoregions of central-east Argentina. Because the abundance of the reservoir and its proportion in the rodent community affects both virus prevalence and human exposure risk, its estimation throughout its known geographical distribution is of key importance for the design of public health strategies to prevent HPS. The aim of this study was therefore to model the relative abundance of O. flavescens in most of the Pampas ecoregion within Buenos Aires Province, Argentina, where hantavirus pulmonary syndrome is endemic. To do this we used owl-pellet samples collected between 2006 and 2008 from 51 sites distributed throughout most of Buenos Aires province. Mammalian prey in each pellet was identified to the lowest possible taxonomic level by examination of the skulls, dentaries and molars. We modelled the frequency of O. flavescens found in each sample as a function of climatic, environmental, and topographic data of each site. The two best models were applied to a Geo referential Information System to build maps of estimated frequency (as a proxy of relative abundance) within Buenos Aires province. Estimated relative abundance of O. flavescens in Buenos Aires province was significantly associated with annual mean temperature, annual precipitation and presence of freshwater bodies, and varied among sub-regions, with the Inland and Rolling Pampas being the regions with highest frequencies. Knowing in which areas O. flavescens abundance is expected to be higher can be used to concentrate limited sanitary efforts in those areas that are most needed in order to reduce transmission and increase detection.  相似文献   

Extraction and Activation of Wheat Polyphenol Oxidase by Detergents: Biochemistry and Applications     

Aravind K. Jukanti  Phil L. Bruckner  Debra K. Habernicht  Curt R. Foster  John M. Martin  Andreas M. Fischer 《Cereal Chemistry》2003,80(6):712-716

Polyphenol oxidases (PPOs) from several plant species, including wheat, have been implicated in undesirable brown discolorations of food products. It has been demonstrated that these enzymes are often present in a latent form or are membrane‐associated, necessitating detergent or other treatments to obtain fully active preparations. Here, the influence of different detergents on wheat meal and flour PPOs was investigated. Extraction in presence of 50 mM SDS led to a 5‐ to 15‐fold increase in PPO activity, making quantitative assays in flour from low‐PPO lines more robust. Among a series of additional nonionic, anionic, and cationic detergents tested, only n ‐lauroylsarcosine increased extractable PPO activity to a degree comparable to that of SDS. Additional experiments suggested that a large fraction of wheat meal PPOs may be membrane‐associated and that SDS is able to activate PPOs extracted from high‐activity but not from low‐activity wheat lines. PPO activities assayed after SDS extraction of meal and flour were highly correlated with each other and with activity determined in whole (intact) kernels in absence of SDS. Correlation coefficients between PPO activities measured with all these methods and noodle brightness were about equal, indicating that activities assayed after SDS extraction are useful for germplasm screening and quality prediction.  相似文献