The weatherloach,
Misgurnus anguillicaudatus, is a freshwater, facultative air-breathing fish that lives in streams and rice paddy fields, where it may experience drought and/or high environmental ...ammonia (HEA) conditions. The aim of this study was to determine what roles branchial Na
+/K
+-ATPase, H
+-ATPase, and Rhcg have in ammonia tolerance and how the weatherloach copes with ammonia loading conditions. The loach's high ammonia tolerance was confirmed as was evident from its high 96 h LC
50 value and high tissue tolerance to ammonia. The weatherloach does not appear to make use of Na
+/NH
4
+-ATPase facilitated transport to excrete ammonia when exposed to HEA or to high environmental pH since no changes in activity were observed. Using immunofluorescence microscopy, distinct populations of vacuolar (V)-type H
+-ATPase and Na
+/K
+-ATPase immunoreactive cells were identified in branchial epithelia, with apical and basolateral staining patterns, respectively. Rhesus C glycoprotein (Rhcg1), an ammonia transport protein, immunoreactivity was also found in a similar pattern as H
+-ATPase. Rhcg1 (Slc42a3) mRNA expression also increased significantly during aerial exposure, although not significantly under ammonia loading conditions. The colocalization of H
+-ATPase and Rhcg1 to the similar non-Na
+/K
+-ATPase immunoreactive cell type would support a role for H
+-ATPase in ammonia excretion via Rhcg by NH
4
+ trapping. The importance of gill boundary layer acidification in net ammonia excretion was confirmed in this fish; however, it was not associated with an increase in H
+-ATPase expression, since tissue activity and protein levels did not increase with high environmental pH and/or HEA. However the V-ATPase inhibitor, bafilomycin, did decrease net ammonia flux whereas other ion transport inhibitors (amiloride, SITS) had no effect. H
+-ATPase inhibition also resulted in a consequent elevation in plasma ammonia levels and a decrease in the net acid flux. In gill, aerial exposure was also associated with a significant increase in membrane fluidity (or increase in permeability) which would presumably enhance NH
3 permeation through the plasma membrane. Taken together, these results indicate the gill of the weatherloach is responsive to aerial conditions that would aid ammonia excretion.
A definitive understanding of the role of dietary lipids in determining cardioprotection (or cardiodetriment) has been elusive. Randomized trial findings have been variable and sex specificity of ...dietary interventions has not been determined. In this investigation the sex-selective cardiac functional effects of three diets enriched by omega-3 or omega-6 polyunsaturated fatty acids (PUFA) or enriched to an equivalent extent in saturated fatty acid components were examined in rats after an 8-wk treatment period. In females the myocardial membrane omega-6:omega-3 PUFA ratio was twofold higher than males in the omega-6 diet replacement group. In diets specified to be high in omega-3 PUFA or in saturated fat, this sex difference was not apparent. Isolated cardiomyocyte and heart Langendorff perfusion experiments were performed, and molecular measures of cell viability were assessed. Under basal conditions the contractile performance of omega-6 fed female cardiomyocytes and hearts was reduced compared with males. Omega-6 fed females exhibited impaired systolic resilience after ischemic insult. This response was associated with increased postischemia necrotic cell damage evaluated by coronary lactate dehydrogenase during reperfusion in omega-6 fed females. Cardiac and myocyte functional parameters were not different between omega-3 and saturated fat dietary groups and within these groups there were no discernible sex differences. Our data provide evidence at both the cardiac and cardiomyocyte levels that dietary saturated fatty acid intake replacement with an omega-6 (but not omega-3) enriched diet has selective adverse cardiac effect in females. This finding has potential relevance in relation to women, cardiac risk, and dietary management.
Osteomyelitis caused by Salmonella typhi is rare in patients with no haemoglobinopathies or other diseases causing immunosuppression. Brodie's abscess is a special variety of subacute or chronic ...osteomyelitis. An otherwise healthy woman who presented with forearm swelling for 6 months was diagnosed with a Brodie's abscess of the ulna caused by Salmonella typhi. Magnetic resonance imaging and a computed tomography-guided needle biopsy were performed. She was later found to be a Salmonella carrier. The Brodie's abscess was treated by surgical debridement and a course of antibiotics. The clinical, radiological, and management aspects of the disease are discussed.
Influenza surveillance systems provide important and timely information to health service providers on trends in the circulation of influenza virus and other upper respiratory tract infections. ...Online dissemination of surveillance data is useful for risk communication to health care professionals, the media and the general public. We reviewed national influenza surveillance websites from around the world to describe the main features of surveillance data dissemination.
We searched for national influenza surveillance websites for every country and reviewed the resulting sites where available during the period from November 2008 through February 2009. Literature about influenza surveillance was searched at MEDLINE for relevant hyperlinks to related websites. Non-English websites were translated into English using human translators or Google language tools.
A total of 70 national influenza surveillance websites were identified. The percentage of developing countries with surveillance websites was lower than that of developed countries (22% versus 57% respectively). Most of the websites (74%) were in English or provided an English version. The most common surveillance methods included influenza-like illness consultation rates in primary care settings (89%) and laboratory surveillance (44%). Most websites (70%) provided data within a static report format and 66% of the websites provided data with at least weekly resolution.
Appropriate dissemination of surveillance data is important to maximize the utility of collected data. There may be room for improvement in the style and content of the dissemination of influenza data to health care professionals and the general public.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Eosinophils are principal effector cells of inflammation in allergic asthma, characterized by their accumulation and infiltration at inflammatory sites mediated by the chemokine eotaxin and ...their interaction with adhesion molecules expressed on bronchial epithelial cells. We investigated the modulation of nuclear factor‐κB (NF‐κB) and the mitogen‐activated protein kinase (MAPK) pathway on the in vitro release of chemokines including regulated upon activation normal T cell expressed and secreted (RANTES), monokine induced by interferon‐γ (MIG), monocyte chemoattractant protein‐1 (MCP‐1), interleukin (IL)‐8, and interferon‐inducible protein‐10 (IP‐10) upon the interaction of human bronchial epithelial BEAS‐2B cells and eosinophils. Gene expression of chemokines was evaluated by RT‐PCR and the induction amount of chemokines quantified by cytometric bead array. NF‐κB and p38 MAPK activities were assessed by electrophoretic mobility shift assay and Western blot, respectively. The interaction of eosinophils and BEAS‐2B cells was found to up‐regulate the gene expression of the chemokines IL‐8, MCP‐1, MIG, RANTES and IP‐10 expression in BEAS‐2B cells, and to significantly elevate the release of the aforementioned chemokines except RANTES in a coculture of BEAS‐2B cells and eosinophils. IκB‐α phosphorylation inhibitor, BAY 11–7082, and p38 MAPK inhibitor, SB 203580 could decrease the release of IL‐8, IP‐10 and MCP‐1 in the coculture. Together, the above results show that the induction of the release of chemokines in a coculture of epithelial cells and eosinophils are regulated by p38 MAPK and NF‐κB activities of BEAS‐2B cells, at least partly, through intercellular contact. Our findings therefore shed light on the future development of more effective agents for allergic and inflammatory diseases.
Polymesoda expansa spends a considerable portion of its life exposed to air in mangrove swamps where salinity fluctuates greatly. Thus, the aim of this study was to evaluate the effects of aerial ...exposure (transfer from 10 per thousand brackish water directly to air) or salinity changes (transfer from 10 per thousand brackish water directly to 30 per thousand seawater) on nitrogen metabolism in P. expansa. We concluded that P. expansa is non-ureogenic because carbamoyl phosphate (CPS) III activity was undetectable in the adductor muscle, foot muscle, hepatopancreas and mantle when exposed to brackish water (control), seawater or air for 17 days. It is ammonotelic as it excretes nitrogenous wastes mainly as ammonia in brackish water or seawater. After transfer to seawater for 17 days, the contents of total free amino acids (TFAA) in the adductor muscle, foot muscle, hepatopancreas and mantle increased significantly. This could be related to an increase in protein degradation because exposure to seawater led to a greater rate of ammonia excretion on days 15 and 17, despite unchanged tissue ammonia contents. Alanine was the major free amino acid (FAA) in P. expansa. The contribution of alanine to the TFAA pool in various tissues increased from 43-48% in brackish water to 62-73% in seawater. In contrast, in clams exposed to air for 17 days there were no changes in alanine content in any of the tissues studied. Thus, the functional role of alanine in P. expansa is mainly connected with intracellular osmoregulation. Although 8.5-16.1% of the TFAA pool of P. expansa was attributable to glutamine, the glutamine contents in the adductor muscle, foot muscle, hepatopancreas and mantle were unaffected by 17 days of exposure to seawater. However, after exposure to air for 17 days, there were significant increases in ammonia content in all these tissues in P. expansa, accompanied by significant increases in glutamine content (2.9-, 2.5-, 4.5- and 3.4-fold, respectively). Simultaneously, there were significant increases in glutamine synthetase activities in the adductor muscle (1.56-fold) and hepatopancreas (3.8-fold). This is the first report on the accumulation of glutamine associated with an upregulation of glutamine synthetase in a bivalve species in response to aerial exposure, and these results reveal that the evolution of glutamine synthesis as a means for detoxification of ammonia first occurred among invertebrates.
Epoxy dispensing is a popular way to perform microchip encapsulation for chip-on-board (COB) packages. However, the determination of the proper process parameters setting for a satisfactory ...encapsulation quality is difficult due to the complex behaviour of the encapsulant during the dispensing process and the inherent fuzziness of epoxy dispensing systems. Sometimes, the observed values from the process may be irregular. In conventional regression models, deviations between the observed values and the estimated values are supposed to have a probability distribution. However, when data is scattered, the obtained regression model has too wide of a possibility range. These deviations in processes such as epoxy dispensing can be regarded as system fuzziness that can be dealt with satisfactorily using a fuzzy regression method. In this paper, the fuzzy linear regression concept with fuzzy intervals and its application to the process modelling of epoxy dispensing for microchip encapsulation are described. Two fuzzy regression models, expressing the correlation between various process parameters and the two quality characteristics, respectively, were developed. Validation experiments were performed to demonstrate the effectiveness of the method for process modelling.
An analytical model is developed to predict the modal characteristics of thin-walled circular cylindrical laminated shells with free ends. The shell is orthotropic and has mid-plane symmetry. By ...using Love's first-approximation shell theory, a strain energy functional containing both bending and stretching effects is formulated. The shell vibration mode shapes are then modelled by utilizing characteristic beam functions in the Rayleigh-Ritz variational procedure and the accuracy of the model is verified by test data. With the developed model, in extensional Rayleigh and Love modes can be identified having frequencies close to each other. The contributions to the strain energy due to various elastic properties are also investigated. Results show that the circumferential modulus provides a major portion of the flexural energy of the vibrating structure while the longitudinal and in-plane shear moduli contribute mostly to the stretching energy. It is also observed that reducing the shell thickness would result in a substantial increase in the ratio of the energies associated with the longitudinal and shear moduli, respectively. By rearranging the lamination stacking sequence, shells can be made to be more resilient to bending or twisting with only minor alterations in natural frequencies.
The swamp eel, Monopterus albus, is an air-breathing teleost which typically lives in freshwater but can also be found in estuaries, where it has to deal with ambient salinity fluctuations. Unlike ...other teleosts, its gills are highly degenerate. Hence, it may have uncommon osmoregulatory adaptations, but no information is available on its osmoregulatory capacity and mechanisms at present. In this study M. albus was exposed to a 5 day progressive increase in salinity from freshwater (1 per thousand) to brackish water (25 per thousand) and subsequently kept in 25 per thousand water for a total of 4 days. The results indicate that M. albus switched from hyperosmotic hyperionic regulation in freshwater to a combination of osmoconforming and hypoosmotic hypoionic regulation in 25 per thousand water. Exposure to 25 per thousand water resulted in relatively large increases in plasma osmolality, Na(+) and Cl(-). Consequently, fish exposed to 25 per thousand water had to undergo cell volume regulation through accumulation of organic osmolytes and inorganic ions. Increases in tissue free amino acid content were apparently the result of increased protein degradation, decreased amino acid catabolism, and increased synthesis of certain non-essential amino acids. Here we report for the first time that glutamine is the major organic osmolyte in M. albus. Glutamine content increased to a phenomenal level of > 12 micromol g(-1) and > 30 micromol g(-1) in the muscle and liver, respectively, of fish exposed to 25 per thousand water. There were significant increases in glutamine synthetase (GS) activity in muscle and liver of these fish. In addition, exposure to 25 per thousand water for 4 days led to significant increases in GS protein abundance in both muscle and liver, indicating that increases in the expression of GS mRNA could have occurred.
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