144 research outputs found
A comprehensive transcriptional body map of Atlantic salmon unveils the vital role of the intestine in the immune system and highlights functional specialization within its compartments
The intestine is a barrier organ that plays an important role in the immune system of Atlantic salmon. The immune functions are distributed among the diffuse gut lymphoid tissue containing diverse immune cells, and other cell types. Comparison of intestinal transcriptomes with those of other organs and tissues offers an opportunity to elucidate the specific roles of the intestine and its relationship with other parts of the body. In this work, a meta-analysis was performed on a large volume of data obtained using a genome-wide DNA oligonucleotide microarray. The intestine ranks third by the expression level of immune genes after the spleen and head kidney. The activity of antigen presentation and innate antiviral immunity is higher in the intestine than in any other tissue. By comparing transcriptome profiles, intestine shows the greatest similarity with the gill, head kidney, spleen, epidermis, and olfactory rosette (descending order), which emphasizes the integrity of the peripheral mucosal system and its strong connections with the major lymphoid organs. T cells-specific genes dominate among the genes co-expressed in these tissues. The transcription signature of CD8+ (86 genes, r > 0.9) includes a master gene of immune tolerance foxp3 and other negative regulators. Different segments of the intestine were compared in a separate experiment, in which expression gradients along the intestine were found across several functional groups of genes. The expression of luminal and intracellular (lysosome) proteases is markedly higher in pyloric caeca and distal intestine respectively. Steroid metabolism and cytochromes P450 are highly expressed in pyloric caeca and mid intestine while the distal intestine harbors genes related to vitamin and iron metabolism. The expression of genes for antigen presenting proteins and immunoglobulins shows a gradual increase towards the distal intestine.publishedVersio
High accuracy time transfer synchronization
In July 1994, the U.S. Naval Observatory (USNO) Time Service System Engineering Division conducted a field test to establish a baseline accuracy for two-way satellite time transfer synchronization. Three Hewlett-Packard model 5071 high performance cesium frequency standards were transported from the USNO in Washington, DC to Los Angeles, California in the USNO's mobile earth station. Two-Way Satellite Time Transfer links between the mobile earth station and the USNO were conducted each day of the trip, using the Naval Research Laboratory(NRL) designed spread spectrum modem, built by Allen Osborne Associates(AOA). A Motorola six channel GPS receiver was used to track the location and altitude of the mobile earth station and to provide coordinates for calculating Sagnac corrections for the two-way measurements, and relativistic corrections for the cesium clocks. This paper will discuss the trip, the measurement systems used and the results from the data collected. We will show the accuracy of using two-way satellite time transfer for synchronization and the performance of the three HP 5071 cesium clocks in an operational environment
Tilrettelegging for gravide arbeidstakere i ambulansetjenesten
KjĆønnsfordelingen i ambulansetjenesten er i endring. Andelen kvinner i fertil alder Ćøker, noe som sannsynligvis medfĆører en Ćøkende andel gravide arbeidstakere i ambulansetjenesten. PĆ„ generelt grunnlag stĆ„r gravide for en tredel av sykefravƦret for kvinner mellom 20 og 40 Ć„r i Norge, og bedre tilrettelegging kan bidra til Ć„ redusere fravƦret. Masteroppgaven ser pĆ„ stasjonslederes erfaring med tilrettelegging for gravide arbeidstakere og deres retur til arbeidsplassen i ambulansetjenesten.
Studien er avgrenset til stasjonsledere i ambulansetjenesten i Oslo universitetssykehus, og har som hensikt Ć„ kartlegge deres erfaringer. Studien har samlet inn kvalitative data ved Ć„ gjennomfĆøre seks semistrukturerte dybdeintervjuer. Resultatene drĆøftes og forstĆ„s i lys av organisasjonsteoretiske perspektiver, samt profesjon- og ledelsesteori.
Resultatene i studien ga innsikt i hvilke erfaringer og opplevelser stasjonsledere hadde i forbindelse med gjeldende styrende dokumenter, erfaringer med tilrettelegging, gjeldende praksis og oppfĆølging av gravide arbeidstakere og hvilke lĆøsninger stasjonslederne kan se for seg.
Studien viser at det er utfordrende Ć„ tilrettelegge for gravide arbeidstakere i ambulansetjenesten fordi det er fravƦr av styrende dokumenter med praktisk beskrivelse for hvordan lederne skal lĆøse utfordringer knyttet til tilrettelegging. FĆølgelig sĆøker stasjonsledere rĆ„d og erfaringer av hverandre, og ender opp med Ć„ lĆøse tilretteleggingsutfordringene pĆ„ ulike mĆ„ter. Det kan virke som 16-ukersskrivet, som er et informasjonsskriv til gravide og deres fastlege, har blitt en sedvane som stasjonslederne fĆølger som et styrende dokument. Studien viser at mangelen pĆ„ styrende dokumenter kan fĆøre til et handlingsrom med utydelige grenser for stasjonslederne, og skaper videre et krysspress mellom det begrensede handlingsrommet og den gravides behov for tilrettelegging. Videre har stasjonsledere en opplevelse av at gravide Ćønsker Ć„ vƦre i arbeid lenger, men da det ikke finnes tilretteleggings- eller omplasseringsmuligheter mĆ„ de ut av arbeid i uke 16. Dette kan fĆøre til at de gravide fĆøler seg unyttige og opplever et verdifall.The gender distribution in the ambulance service is changing. The proportion of women of childbearing age is increasing, which will likely result in a growing number of pregnant employees in the ambulance service. In Norway, pregnant women account for one-third of sick leave among women aged 20 to 40, and better accommodation can help reduce absence from work. This thesis examines ambulance station managers' experiences with accommodating pregnant employees and their return to the workplace after parental leave.
The study is limited to station managers in the ambulance service at Oslo University Hospital and aims to document their experiences. The study collected qualitative data by conducting six semi-structured in-depth interviews. The results are discussed and interpreted with respect to theoretical organizational perspectives, as well as profession and leadership theory.
The result of the study provides insight into the experiences and views of station managers regarding existing governing documents, experiences with accommodation, current practices, and follow-up of pregnant employees, as well as possible solutions for the future.
The study shows that accommodating pregnant employees in the ambulance service is challenging due to the absence of governing documents with practical descriptions of how leaders should resolve difficulties related to accommodation. Consequently, station managers seek advice from each other, resulting in different solutions for accommodating pregnant employees. The 16-week letter, which is an informational letter to pregnant women and their doctor, seems to have become common practice and used by station managers as a governing document. The study reveals that the lack of governing documents can create a discretionary space with unclear boundaries for station managers, leading to a conflict between said space and the pregnant employee's need for accommodation. Furthermore, station managers observe that pregnant women want to remain at work beyond week 16, but without accommodation or reassignment options they are forced to leave. This can make pregnant employees feel useless and experience a loss of professional value
Baltic Salmon, Salmo salar, from Swedish River Lule Ćlv Is More Resistant to Furunculosis Compared to Rainbow Trout
BACKGROUND: Furunculosis, caused by Aeromonas salmonicida, continues to be a major health problem for the growing salmonid aquaculture. Despite effective vaccination programs regular outbreaks occur at the fish farms calling for repeated antibiotic treatment. We hypothesized that a difference in natural susceptibility to this disease might exist between Baltic salmon and the widely used rainbow trout. STUDY DESIGN: A cohabitation challenge model was applied to investigate the relative susceptibility to infection with A. salmonicida in rainbow trout and Baltic salmon. The course of infection was monitored daily over a 30-day period post challenge and the results were summarized in mortality curves. RESULTS: A. salmonicida was recovered from mortalities during the entire test period. At day 30 the survival was 6.2% and 34.0% for rainbow trout and Baltic salmon, respectively. Significant differences in susceptibility to A. salmonicida were demonstrated between the two salmonids and hazard ratio estimation between rainbow trout and Baltic salmon showed a 3.36 higher risk of dying from the infection in the former. CONCLUSION: The finding that Baltic salmon carries a high level of natural resistance to furunculosis might raise new possibilities for salmonid aquaculture in terms of minimizing disease outbreaks and the use of antibiotics
Glandular Odontogenic Cyst: Report of Two Cases and Review of Literature
Glandular odontogenic cyst (GOC) is an uncommon jaw bone cyst of odontogenic origin described in 1987 by Gardner et al. It is a cyst having an unpredictable and potentially aggressive behaviour. It also has the propensity to grow to a large size and tendency to recur with only 111 cases having been reported thus far. The first case occurred in a 42-year-old female and presented as a localized swelling extending from 19 to 29 regions. There was a history of traumatic injury at the site. There was evidence of bicortical expansion and radiographs revealed a multilocular radiolucency. The second case occurred in a 21-year-old male, as a large swelling in the mandible and radiograph revealed radiolucency in the region. On histopathological examination, these lesions were diagnosed as GOC. It was concluded that, two cases submitted by us correlate with the existing literature that GOCās affect more commonly in the middle age group, having predilection for mandible and that trauma could be a precipitating factor for its occurrence. The increased recurrence rates can be due to its intrinsic biological behavior, multilocularity of the cyst, and incomplete removal of the lining following conservative treatment
An Enriched European Eel Transcriptome Sheds Light upon Host-Pathogen Interactions with Vibrio vulnificus
Infectious diseases are one of the principal bottlenecks for the European eel recovery. The aim of this study was to develop a new molecular tool to be used in host-pathogen interaction experiments in the eel. To this end, we first stimulated adult eels with different pathogen-associated molecular patterns (PAMPs), extracted RNA from the immune-related tissues and sequenced the transcriptome. We obtained more than 2 x 10(6) reads that were assembled and annotated into 45,067 new descriptions with a notable representation of novel transcripts related with pathogen recognition, signal transduction and the immune response. Then, we designed a DNA-microarray that was used to analyze the early immune response against Vibrio vulnificus, a septicemic pathogen that uses the gills as the portal of entry into the blood, as well as the role of the main toxin of this species (RtxA13) on this early interaction. The gill transcriptomic profiles obtained after bath infecting eels with the wild type strain or with a mutant deficient in rtxA13 were analyzed and compared. Results demonstrate that eels react rapidly and locally against the pathogen and that this immune-response is rtxA13-dependent as transcripts related with cell destruction were highly up-regulated only in the gills from eels infected with the wild-type strain. Furthermore, significant differences in the immune response against the wild type and the mutant strain also suggest that host survival after V. vulnificus infection could depend on an efficient local phagocytic activity. Finally, we also found evidence of the presence of an interbranchial lymphoid tissue in European eel gills although further experiments will be necessary to identify such tissue
Nitrosylation of Myoglobin and Nitrosation of Cysteine by Nitrite in a Model System Simulating Meat Curing
Demand is growing for meat products cured without the addition of sodium nitrite. Instead of the direct addition of nitrite to meat in formulation, nitrite is supplied by bacterial reduction of natural nitrate often added as vegetable juice/powder. However, the rate of nitrite formation in this process is relatively slow, and the total ingoing nitrite is typically less than in conventional curing processes. The objective of this study was to determine the impact of the rate of addition of nitrite and the amount of nitrite added on nitrosylation/nitrosation reactions in a model meat curing system. Myoglobin was preferentially nitrosylated as no decrease in sulfhydryl groups was found until maximum nitrosylmyoglobin color was achieved. The cysteineāmyoglobin model retained more sulfhydryl groups than the cysteine-only model (p \u3c 0.05). The rate of nitrite addition did not alter nitrosylation/nitrosation reactions (p \u3e 0.05). These data suggest that the amount of nitrite but not the rate of addition impacts the nitrosylation/nitrosation reactions this syste
Characterisation and expression analysis of the Atlantic halibut (Hippoglossus hippoglossus L.) cytokines: IL-1Ī², IL-6, IL-11, IL-12Ī² and IFNĪ³
Genes encoding the five Atlantic halibut (Hippoglossus hippoglossus L.) cytokines; interleukin (IL)-1Ī², IL-6, IL-11b, IL-12Ī²c, and interferon (IFN) Ī³, were cloned and characterised at a molecular level. The genomic organisation of the halibut cytokine genes was similar to that seen in mammals and/or other fish species. Several mRNA instability motifs were found within the 3ā²-untranslated region (UTR) of all cytokine cDNA sequences. The putative cytokine protein sequences showed a low sequence identity with the corresponding homologues in mammals, avian and other fish species. Nevertheless, important structural features were presumably conserved such as the presence, or absence in the case of IL-1Ī², of a signal peptide, secondary structure and family signature motifs. The relative expression pattern of the cytokine genes was analyzed in several halibut organs, revealing a constitutive expression in both lymphoid and non-lymphoid organs. Interestingly, the gills showed a relatively high expression of IL-1Ī², IL-12Ī²c and IFNĪ³. The real time RT-PCR data also showed that the mRNA level of IL-1Ī², IL-6, IL-12Ī²c and IFNĪ³ was high in the thymus, while IL-11b was relatively highly expressed in the posterior kidney and posterior gut. Moreover, the halibut brain showed a relatively high level of IL-6 transcripts. Anterior kidney leucocytes in vitro stimulated with imiquimod showed a significant increase in mRNA level of the five halibut cytokine genes. The sequence and characterisation data presented here will be useful for further investigation of both innate and adaptive immune responses in halibut, and be helpful in the design of vaccines for the control of various infectious diseases
Regulation of pH During Amelogenesis
During amelogenesis, extracellular matrix proteins interact with growing hydroxyapatite crystals to create one of the most architecturally complex biological tissues. The process of enamel formation is a unique biomineralizing system characterized first by an increase in crystallite length during the secretory phase of amelogenesis, followed by a vast increase in crystallite width and thickness in the later maturation phase when organic complexes are enzymatically removed. Crystal growth is modulated by changes in the pH of the enamel microenvironment that is critical for proper enamel biomineralization. Whereas the genetic bases for most abnormal enamel phenotypes (amelogenesis imperfecta) are generally associated with mutations to enamel matrix specific genes, mutations to genes involved in pH regulation may result in severely affected enamel structure, highlighting the importance of pH regulation for normal enamel development. This review summarizes the intra- and extracellular mechanisms employed by the enamel-forming cells, ameloblasts, to maintain pH homeostasis and, also, discusses the enamel phenotypes associated with disruptions to genes involved in pH regulation
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