Plasmablast and plasma cell production and distribution in trout immune tissues

These studies describe the in vitro and ex vivo generation of plasmablasts and plasma cells in trout (Oncorhynchus mykiss) peripheral blood and splenic and anterior kidney tissues. Cells were derived either from naive trout and cultured with the polyclonal activator, Escherichia coli LPS, or from trout that had been immunized with trinitrophenyl-keyhole limpet hemocyanin. Hydroxyurea was used to resolve populations of replicating (plasmablast) and nonreplicating (plasma cell) Ab-secreting cells (ASC). Complete inhibition of Ig secretion was only observed within the PBL. Both anterior kidney and splenic lymphocytes possessed a subset of ASCs that were hydroxyurea resistant. Thus, in vitro production of plasma cells appears to be restricted to the latter two tissues, whereas peripheral blood is exclusively restricted to the production of plasmablasts. After immunization with trinitrophenyl-keyhole limpet hemocyanin, specific ASC could be isolated from all immune organs; however, the anterior kidney contained 98% of all ASC. Late in the response (\u3e 10 wk), anterior kidney ASC secreted specific Ab for at least 15 days in culture, indicating that they were long-lived plasma cells. Cells from spleen and peripheral blood lost all capacity to secrete specific Ab in the absence of Ag. Late in the Ab response, high serum titer levels are solely the result of Ig secretion from anterior kidney plasma cells

Hengailua ruutujen välityksellä:yhteisöllisyys ja striimien katsomisen syitä Twitch-sivustolla

Tiivistelmä. Kulttuuriantropologian graduaiheeni on online-yhteisöllisyys ja siihen liittyvien motiivien syistä katsojan näkökulmasta Twitch-sivustolla, sillä haluan saada selville, että mitä erilaisia syitä striimien katsomisen takaa löytyy. Tämän lisäksi tutkin myös sitä, että millä tavalla yhteisöt muodostuvat Twitch.tv-sivustolla sekä millainen luonne online-yhteisöillä on verrattuna yhteisöihin ns. offline-maailmassa. Livestriimaaminen eli reaaliaikainen suoratoistaminen on internetissä tapahtuvaa videokuvan lähettämistä suorana. Nykyisin videoiden suoratoistaminen pyörii paljolti videopelaamisen ympärillä, joista eräs suosituimmista suoratoistopalveluista on Twitch.tv. Livestriimaaminen on yleistynyt huimasti viimeisen 10 vuoden aikana. Tutkimukseni tavoitteena on selvittää syitä sille, että miksi ihmiset katsovat livestriimejä. Tämän lisäksi tutkin online-yhteisöjen ilmenemisen luonnetta sekä striimaajan ja katsojien välisiä vuorovaikutustapoja. Tutkimuksessani minua kiinnostaa myös se, että mitkä tekijät vaikuttavat siihen, että striimaaja on kiinnostava. Aineiston keruun aloitin ensimmäisenä havainnoimalla Twitch.tv-sivuston livestriimejä. En kohdistanut havainnointiani kehenkään tiettyyn striimaajaan saatikka mihinkään tiettyyn striimiin, vaan valitsin striimit, jotka lukeutuivat videopelistriimeiksi ja toisaalta sellaisia, jotka olivat Chatti-kategoriassa. Toisena aineistonkeruumenetelmänä käytin puolistrukturoituja haastatteluita. Haastattelin viittä 20—29-vuotiaita henkilöitä, jotka aktiivisesti katsovat striimejä Twitch.tv-sivustolla. Osa haastatteluista suoritin kasvotusten, osan videohaastatteluna Zoomissa ja sähköpostihaastatteluna. Haastatteluiden teemoiksi nousivat erilaiset syyt sille, että mitkä tekijät saavat heidät hakeutumaan sivustolle ja viettämään aikaa striimejä katsellessa sekä kyselin heiltä siitä, että millä tavoin striimi-yhteisöt ja striimaajan ja katsojien välinen kanssakäyminen ilmenevät ja millä tavalla he itse määrittelisivät roolinsa katsojana. Online-yhteisöt Twitchissä ovat hyvinkin samankaltaisia verrattuna perinteiseen käsitykseen yhteisöistä. Vertasin Twitchiä online-ympäristönä myös Oldenburgin kolmannen tilan -käsitteeseen, jollaisena Twitch toimii myös eräänlaisena kokoontumispaikkana, johon ihmisillä on vapaa pääsy. Haastatteluissa kävi ilmi, että striimejä katsoessa striimaajan persoonallisuus näyttäisi olevan tärkeämmässä roolissa kuin itse striimattava sisältö. Tämän lisäksi aineistosta nousi esiin striimien viihteellisyys, joka koettiin tärkeänä osana katsomisen kokemusta

Effect Of Homogenate From Different Oyster Species On Perkinsus Marinus Proliferation And Subtilisin Gene Transcription

The modulation of Perkinsus marinus proliferation and subtilisin gene transcription by host (oyster) tissue was examined. Perkinsus rnarinus cells were cultured for 4 weeks in media supplemented with extract from either one of four different Crassostrea virginica stocks or with extract from one of two other Crassostrea species, C. ariakensis and C. gigas. After 4 weeks in culture, we determined cell counts and relative subtilisin gene transcription levels using quantitative real-time polymerise chain reaction (qRTPCR). Cell proliferation and subtilisin gene transcription were significantly lower when P. marinus\u27 cells were grown in the presence of homogenate from any of the three oyster species than in unsupplemented media. Perkinstrs marinas subtilisin gene transcription was also significantly lower in cells cultured in media supplemented with homogenate from either C. ariakensis or C. gigas, than in media containing extract from the native oyster host, C. virginica. Gene transcription levels among cells grown in media supplemented with homogenate from the different stocks of C. virginica were not significantly different from one another

Histopathology of the renal and splenic haemopoietic tissues of coho salmon Oncorhynchus kisutch experimentally infected with Renibacterium salmoninarum

We report the histopathological changes occurring in the renal and splenic haemopoietic tissues of coho salmon Oncorhynchus kisutch experimentally infected with renibacterium salmoninarum. In both tissues we were able by light microscopy to distinguish 3 different grades in the progression of the infection. The grades of infection were characterized according to the location of the bacteria and the tissue injuries. Ultrastructural observation revealed sinusoidal cells, macrophages, reticular and barrier cells to be infected by the pathogen, and necrosis of the tissue to be general in advanced stages of the infection. Despite destruction of the haemopoietic tissue, plasmacytopoietic foci were frequently observed in both organs. Other major changes were the appearance of epithelioid cells and an increase in the number of barrier cells. These 2 cell types might be involved in the local defence response to the pathogen, but they may also act as a reservoir and proliferation locus for R. salmoninarum

Research needs for the risk assessment of health and environmental effects of endocrine disruptors: A report of the US EPA-sponsored workshop

The hypothesis has been put forward that humans and wildlife species have suffered adverse health effects after exposure to endocrine-disrupting chemicals. Reported adverse effects include declines in populations, increases in cancers, and reduced reproductive function. The U.S. Environmental Protection Agency sponsored a workshop in April 1995 to bring together interested parties in an effort to identify research gaps related to this hypothesis and to establish priorities for future research activities. Approximately 90 invited participants were organized into work groups developed around the principal reported health effects-carcinogenesis, reproductive toxicity, neurotoxicity, and immunotoxicity--as well as along the risk assessment paradigm--hazard identification, dose-response assessment, exposure assessment, and risk characterization. Attention focused on both ecological and human health effects. In general, the group felt that the hypothesis warranted a concerted research effort to evaluate its validity and that research should focus primarily on effects on development of reproductive capability, on improved exposure assessment, and on the effects of mixtures. This report summarizes the discussions of the work groups and details the recommendations for additional research

Mycobacterium shottsii sp nov., a slowly growing species isolated from Chesapeake Bay striped bass (Morone saxatilis)

Slowly growing, non-pigmented mycobacteria were isolated from striped bass (Morone saxatilis) during an epizootic of mycobacteriosis in the Chesapeake Bay. Growth characteristics, acid-fastness and results of 16S rRNA gene sequencing were consistent with those of the genus Mycobacterium. A unique profile of biochemical reactions was observed among the 21 isolates. A single cluster of eight peaks identified by analysis of mycolic acids (HPLC) resembled those of reference patterns but differed in peak elution times from profiles of reference species of the Mycobacterium tuberculosis complex. One isolate (M175(T)) was placed within the slowly growing mycobacteria by analysis of aligned 16S rRNA gene sequences and was proximate in phylogeny to Mycobacterium ulcerans and Mycobacterium marinum. However, distinct nucleoticle differences were detected in the 16S rRNA gene sequence among M175(T), M. ulcerans and M. marinum (99-2% similarity). Isolate IM175(T) could be differentiated from other slowly growing, nonpigmented mycobacteria by its inability to grow at 37degreesC, production of niacin and urease, absence of nitrate reductase and resistance to isoniazid (1 mug ml(-1)), thiacetazone and thiophene-2-carboxylic hydrazide. Based upon these genetic and phenotypic differences, isolate IM175T (= ATCC 700981(T) = NCTC 13215(T)) is proposed as the type strain of a novel species, Mycobacterium shottsii sp. nov

Mycobacterium pseudoshottsii sp nov., a slowly growing chromogenic species isolated from Chesapeake Bay striped bass (Morone saxatilis)

A group of slowly growing photochromogenic mycobacteria was isolated from Chesapeake Bay striped bass (Morone saxatilis) during an epizootic of mycobacteriosis. Growth characteristics, acid-fastness and 16S rRNA gene sequencing results were consistent with those of the genus Mycobacterium, Biochemical reactions, growth characteristics and mycolic acid profiles (HPLC) resembled those of Mycobacterium shottsii, a non-pigmented mycobacterium also isolated during the same epizootic. Sequencing of the 16S rRNA genes, the gene encoding the exported repeated protein (erp) and the gene encoding the 65 kDa heat-shock protein (hsp65) and restriction enzyme analysis of the hsp65 gene demonstrated that this group of isolates is unique. Insertion sequences associated with Mycobacterium ulcerans, IS2404 and IS2606, were detected by PCR. These isolates could be differentiated from other slowly growing pigmented mycobacteria by their inability to grow at 37 degrees C, production of niacin and urease, absence of nitrate reductase, negative Tween 80 hydrolysis and resistance to isoniazid (1 mu g ml(-1)), p-nitrobenzoic acid, thiacetazone and thiophene-2-carboxylic hydrazide. On the basis of this polyphasic study, it is proposed that these isolates represent a novel species, Mycobacterium pseudoshottsii sp. nov. The type strain, L15(T), has been deposited in the American Type Culture Collection as ATCC BAA-883(T) and the National Collection of Type Cultures (UK) as NCTC 13318(T)

CXCL8 Chemokines in Teleost Fish: Two Lineages with Distinct Expression Profiles during Early Phases of Inflammation

Contains fulltext : 126584.pdf (publisher's version ) (Open Access

“The mind is not a vessel to be filled but a fire to be kindled”:teachers’ perceptions of bridging schools and working life with ICT

Globalization, digitalization and ubiquitous technology have changed the way people work, play, live and learn. The vast changes in society and working life make meeting the needs of the 21st century challenging for education systems. Despite information technology is providing various sources to receive information about working life, insecurity is increasing among youngsters in the moment when they should decide about their future professions. The aim of this research was to investigate the teachers’ own perceptions and main challenges related to this matter, and the goal was to find out if ICT can bring schools and working life closer to one another. This was a mixed-method research using grounded theory as a research approach, and the quantitative and qualitative data was collected by online survey. The theoretical framework combined the concepts of educational usage of ICT and digital media. Also the altering needs of working life and the 21st century skills built an essential part of the theoretical frame, as well as teachers’ and learners’ views about the needs of working life. The informants of this research were high school and upper secondary school teachers, student counselors and principals working in the Oulu area. They were chosen by using simple random sampling, and in total 31 informants participated in this research. Based on the findings, teachers agree schools’ cooperation with working life is important, but the shortages of educators and learners ICT skills, also the lack of information about the existing digital tools, are often preventing the educational usage of ICT in bridging schools with working life. In the findings teachers also address the ways they would most like to receive ICT training and information about school and working life cooperation. The limitations of this research lie in the fact that it was limited to 31 participants. However, as the data was collected with an online survey containing multiple quantitative and qualitative questions with open-ended answers, the responses gave diverse insights and provided local perspective about current issues relating to the topic of this research. The conclusions of this research highlight that even though ICT is just one tool in education and learning processes, ubiquitous technology is everywhere and it should not be neglected neither in teaching nor learning. The majority of teachers feel positively about using ICT in education, but they wish to train those skills, and to learn more about the existing digital tools for school and working life cooperation. Conclusions suggest that the goal of teaching and learning should enhance skills such as collaboration, communication, creativity and critical thinking to meet the needs of the 21st century and working life, and to build individuals’ career paths. Future research is recommended to focus on investigating the existing procedures in ICT skills for mapping out the current gaps in education. Another suggested topic for further research is to investigate the importance of individuals’ passion for learning, and how the current education system could enhance it