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71.
Kogen Okita Hideki Yamazaki Kazutaka Sakiyama Hikaru Yamane Shinya Niina Tomohiro Takatani Osamu Arakawa Yoshitaka Sakakura 《Ichthyological Research》2013,60(4):386-389
Behavioral observation was conducted to test whether olfaction is functional to detect tetrodotoxin (TTX) in tiger puffer Takifugu rubripes using Y-maze. We placed either agarose carrier or one agarose and one agarose containing TTX (200 MU) at each head of the channel of Y-maze. Then three non-toxic hatchery-reared juveniles (body length, 5.6 ± 0.4 cm; n = 18) were released into the Y-maze and pecking behavior to carrier was observed for 3 h. The same procedure was tested for olfactory-ablated juveniles and for juveniles taht received sham operation. Juveniles showed significant selectivity to TTX, except for olfactory-ablated juveniles. These results indicate that pufferfish detects TTX by olfactory organ. 相似文献
72.
Lienemann T Pitkänen T Antikainen J Mölsä E Miettinen I Haukka K Vaara M Siitonen A 《Current microbiology》2011,62(4):1239-1244
In November 2007, 450 m3 of treated wastewater leaked into the drinking water distribution system contaminating the drinking water of over 10,000
inhabitants of Nokia, Southern Finland. Nearly 1,000 people visited the health centre because of gastroenteritis during the
following 5 weeks. A wide range of enteric pathogens was found in the patients. The authors used the 16-plex PCR to investigate
whether the five major diarrheagenic Escherichia coli pathotypes (EPEC, ETEC, STEC, EIEC or EAEC) were present in the contaminated drinking water and in the patients’ stool samples.
The contaminated drinking water was positive for genes characteristic of various E. coli pathotypes: pic, invE, hlyA, ent, escV, eae, aggR, stx
2
, estIa and astA. These genes, except stx
2
, hlyA and invE, were also detected in the stool samples of the patients linked to this outbreak. A sorbitol positive, streptomycin resistant
STEC strain was isolated from the drinking water, and belonged to the serotype O100:H
–
, produced Stx2 toxin (titre 1:8 by reversed-passive latex agglutination method), and carried the genes stx
2e,
estIa and irp2. 相似文献
73.
Case RJ Longford SR Campbell AH Low A Tujula N Steinberg PD Kjelleberg S 《Environmental microbiology》2011,13(2):529-537
Host-pathogen interactions have been widely studied in humans and terrestrial plants, but are much less well explored in marine systems. Here we show that a marine macroalga, Delisea pulchra, utilizes a chemical defence - furanones - to inhibit colonization and infection by a novel bacterial pathogen, Ruegeria sp. R11, and that infection by R11 is temperature dependent. Ruegeria sp. R11 formed biofilms, invaded and bleached furanone-free, but not furanone-producing D. pulchra thalli, at high (24°C) but not low (19°C) temperatures. Bleaching is commonly observed in natural populations of D. pulchra near Sydney, Australia, during the austral summer when ocean temperatures are at their peak and the chemical defences of the alga are reduced. Furanones, produced by D. pulchra as a chemical defence, inhibit quorum sensing (QS) in bacteria, and this may play a role in furanone inhibition of R11 infection of furanone-free thalli as R11 produces QS signals. This interplay between temperature, an algal chemical defence mechanism and bacterial virulence demonstrates the complex impact environmental change can have on an ecosystem. 相似文献
74.
Human papillomavirus (HPV) infection is a prerequisite of developing cervical cancer, approximately half of which are associated with HPV type 16. HPV 16 encodes three oncogenes, E5, E6, and E7, of which E5 is the least studied so far. Its roles in regulating replication and pathogenesis of HPV are not fully understood. Here we utilize high-throughput screening to coordinately investigate the effect of E5 on the expression of host protein-coding and microRNA genes. MicroRNAs form a class of 22nt long noncoding RNAs with regulatory activity. Among the altered cellular microRNAs we focus on the alteration in the expression of miR-146a, miR-203 and miR-324-5p and their target genes in a time interval of 96 hours of E5 induction. Our results indicate that HPV infection and subsequent transformation take place through complex regulatory patterns of gene expression in the host cells, part of which are regulated by the E5 protein. 相似文献
75.
Lower respiratory tract infections (LRTI) are the leading cause of death world-wide, with Streptococcus pneumoniae (Pnc) as the most prevalent pathogen. Local immune mechanisms appear central to protection against the disease, yet they are poorly characterized. Infections at other, non-respiratory mucosal sites are associated with a transient circulation of mucosa-originating lymphocytes from the mucosal site to blood and back to the mucosa. The present study explored whether pathogen-specific plasmablasts appear in the circulation also in patients with infection of the lower respiratory tract. 16 patients with bacteremic Pnc pneumonia and 14 healthy volunteers were explored for circulating plasmablasts secreting antibodies against their own pathogenic Pnc strain isolated in blood cultures (patients) or against several pathogenic strains from pneumonia patients (14 controls) or a mixture of nine different purified pneumococcal polysaccharides (8 controls). Both patients and volunteers were studied for all plasmablasts. The cells were identified with ELISPOT as Pnc-specific antibody-secreting cells (ASC) and as all immunoglobulin-secreting cells (ISC). High numbers of circulating Pnc-specific ASC were found in the acute phase of the disease in all patients with pneumonia (median 97 ASC/10(6) PBMC), but in none of the controls. IgG isotype predominated in 9/16 patients. The numbers of ISC were significantly higher in the patients than in the healthy controls, yet Pnc-specific ASC only accounted for 0.7% of all the patients' ISC.The present study is the first to show that antigen-specific plasmablasts appear in the circulation in pneumonia, suggesting that pulmonary lypmhocytes recirculate in humans. Assessing these cells provides a novel tool for studying immune response to antigens encountered at the LRT. 相似文献
76.
N Kanerva E Kronholm T Partonen ML Ovaskainen NE Kaartinen H Konttinen U Broms S Männistö 《Chronobiology international》2012,29(7):920-927
Subjects with higher preference for evening hours in daily activities (eveningness) have been repeatedly shown to practice adverse health behaviors as compared to those preferring morning hours (morningness). However, associations between chronotype and dietary intake have not been explored intensively. The authors explored whether the human chronotype is associated with food and nutrient intakes in a random sample of the population aged 25 to 74 yrs. The cross-sectional study included 4493 subjects from the National FINRISK 2007 Study. Chronotype was assessed using a shortened version of Horne and ?stberg's Morningness-Eveningness Questionnaire. Diet was assessed using a validated food frequency questionnaire. Associations between morningness-eveningness (ME) score and dietary intakes were analyzed by linear regression and difference between lowest (eveningness) and highest (morningness) ME score quintiles by Tukey's test. In the multivariable model, intakes of whole grain, rye, potatoes, and vegetables and roots decreased, whereas those of wine and chocolate increased with lower ME scores. Participants in the lowest ME score quintile consumed less fish (p .001) and fruits (p =?.025) and more chocolate (p =?.001) and soft drinks (p =?.015) compared to the highest quintile. No linear association was found between ME score and total energy intake. In regression analyses, intake of alcohol (as a percentage of total energy intake; E%) and sucrose (E%) increased, whereas intake of carbohydrates (E%), protein (E%), fiber, folic acid, and sodium decreased with lower ME scores. Furthermore, participants in the lowest ME score quintile ingested more fat (E%) (p .001) and less vitamin D (p .001) compared to the highest quintile, even though no linear trend between ME score and these nutrients emerged. In conclusion, these results support existing evidence that individuals with circadian preference toward eveningness have less healthy lifestyles, such as unfavorable dietary habits, than those with tendency toward morningness, which could put them at higher risk of several chronic diseases. 相似文献
77.
Benjamin Weigel Niina Kotamäki Olli Malve Kristiina Vuorio Otso Ovaskainen 《Global Ecology and Biogeography》2023,32(2):295-309
Aim
We use lake phytoplankton community data to quantify the spatio-temporal and scale-dependent impacts of eutrophication, land-use and climate change on species niches and community assembly processes while accounting for species traits and phylogenetic constraints.Location
Finland.Time period
1977–2017.Major taxa
Phytoplankton.Methods
We use hierarchical modelling of species communities (HMSC) to model metacommunity trajectories at 853 lakes over four decades of environmental change, including a hierarchical spatial structure to account for scale-dependent processes. Using a “region of common profile” approach, we evaluate compositional changes of species communities and trait profiles and investigate their temporal development.Results
We demonstrate the emergence of novel and widespread community composition clusters in previously more compositionally homogeneous communities, with cluster-specific community trait profiles, indicating functional differences. A strong phylogenetic signal of species responses to the environment implies similar responses among closely related taxa. Community cluster-specific species prevalence indicates lower taxonomic dispersion within the current dominant clusters compared with the historically dominant cluster and an overall higher prevalence of smaller species sizes within communities. Our findings denote profound spatio-temporal structuring of species co-occurrence patterns and highlight functional differences of lake phytoplankton communities.Main conclusions
Diverging community trajectories have led to a nationwide reshuffling of lake phytoplankton communities. At regional and national scales, lakes are not single entities but metacommunity hubs in an interconnected waterscape. The assembly mechanisms of phytoplankton communities are strongly structured by spatio-temporal dynamics, which have led to novel community types, but only a minor part of this reshuffling could be linked to temporal environmental change. 相似文献78.
79.
80.
Nga Nguyen Peter J. Fashing Derek A. Boyd Tyler S. Barry Ryan J. Burke C. Barret Goodale Sorrel C.Z. Jones Jeffrey T. Kerby Bryce S. Kellogg Laura M. Lee Carrie M. Miller Niina O. Nurmi Malcolm S. Ramsay Jason D. Reynolds Kathrine M. Stewart Taylor J. Turner Vivek V. Venkataraman Yvonne Knauf Christian Roos Sascha Knauf 《American journal of primatology》2015,77(5):579-594