An experimental means of transmitting pancreas disease in Atlantic salmon Salmo salar L. fry in freshwater

A challenge model for pancreas disease in Atlantic salmon, Salmo salar L. fry, was developed comparing two salmonid alphavirus (SAV) subtypes: SAV1 and SAV5. Viral doses of 3 × 10(5) TCID50  mL(-1) for SAV1 and 3 × 10(4) for SAV5 were tested in triplicate tanks, each containing 450 salmon fry. Cumulative mortalities of 1.2% were recorded. Titres of virus recovered from the mortalities ranged from 10(2) to 10(7) TCID50  mL(-1) . Fry were sampled at 3, 5 and 7.5 weeks post-challenge. Sampling after 3 weeks revealed a high prevalence of infection in the absence of clinical signs, and infectious virus was recovered from 80% and 43% of sampled fry infected with SAV1 and SAV5, respectively. After 5 weeks pancreas, heart and red skeletal muscle lesions were generally observed, whilst degeneration in white skeletal muscle was observed only in fish infected with SAV1. In situ hybridisation confirmed the presence of viral genome in infected pancreas, heart and muscle. After 7.5 weeks, infectious virus (both isolates) was recovered from 13.3% of the fish sampled, with a viral titre of 10(2) TCID50  mL(-1) . Clearly, salmon fry are susceptible to SAV infection and pancreas disease.

Studies on the effect of temperature and pH on the inactivation of fish viral and bacterial pathogens

Disposal of fish by-products in the European Community must comply with Regulation (EC) No 1069/2009 which categorizes animal by-products according to risk, and specifies methods of disposal of by-products according to that risk. There is provision under the regulation for composting or ensiling to be used for by-products from aquatic animals. Biosecurity considerations require knowledge of the parameters of time and temperature, or time and pH, required to inactivate any fish pathogens that may be present. To provide those data, we undertook laboratory studies on the inactivation of a number of fish pathogenic viruses and bacteria at 60 °C, pH 4.0 and pH 12.0 as a preliminary to conducting subsequent trials with the most resistant viruses and bacteria in fish tissues. The most resistant bacterium to 60 °C, pH 4.0 as well as pH 12.0 was Lactococcus garvieae. Its concentration was reduced to the level of sensitivity of the test after 24-48 h exposure to 60 °C, but it survived for at least 7 days at pH 4.0 and 14 days at pH 12.0. The most resistant virus to 60 °C was infectious pancreatic necrosis virus, and to pH 12.0 was infectious salmon anaemia virus. The majority of the viruses tested survived exposure to pH 4.0 for up to 28 days. The results suggest that the process of acid ensiling alone is not an effective method for the inactivation of many viral and bacterial pathogens, and fish by-products would need further treatment by a method approved under the regulation following ensiling, whereas alkaline or heat treatment are likely to provide an increased degree of biosecurity for on-farm processing of mortalities.

Studies on the inactivation of selected viral and bacterial fish pathogens at high pH for waste disposal purposes

This study investigated the use of alkaline hydrolysis at ambient temperature for inactivation of selected fish pathogens in fish tissues under conditions approximating those that are likely to be found in the aquaculture industry. Infectious salmon anaemia virus (ISAV) and Lactococcus garvieae have been determined in a previous study to be the most resistant virus and bacteria to pH 12 from a wide range of viruses and bacteria tested. They were spiked at high titres into fish extracts that were then treated with 1 m sodium hydroxide (NaOH). Viable L. garvieae was not detected in the treated fish extract after 1 h, and ISAV was not detected after 24-h exposure. Field mortalities of Atlantic salmon, Salmo salar L., caused by infectious pancreatic necrosis virus were treated by alkaline hydrolysis at ambient temperature. The macerated fish mortalities contained a high titre of virus (3.38 × 10⁸ TCID₅₀ g⁻¹) that was reduced to approximately 2.2 × 10³ TCID₅₀ g⁻¹ after 24-h exposure to NaOH, and virus was not detected after exposure for 48 h. The results suggest that alkaline hydrolysis at ambient temperature has potential as a biosecure treatment method for fish by-products containing fish pathogens.

Viral load of various tissues of rainbow trout challenged with viral haemorrhagic septicaemia virus at various stages of disease

Market-sized rainbow trout Oncorhynchus mykiss were challenged by waterborne exposure to viral haemorrhagic septicaemia virus (VHSV isolate of genogroup Ia). Fish were sampled at 4 stages of infection (before onset of clinical signs, clinically affected fish, mortalities and survivors) and the viral load determined in (1) internal organs, (2) muscle tissue and (3) brain and gill tissue. Virus levels were determined by virus titration and real-time RT-PCR. VHSV was detected by either method in the majority of fish before onset of clinical signs and in the survivor group as well as in all fish in the clinically affected fish and mortality groups. Mean virus amounts per mg of tissue determined by virus titration (TCID50) or real-time RT-PCR (copy number) were > 10(4) in preclinical fish, > 10(3.8) in clinically affected fish, > 10(3.9) in mortalities and > 10(1.2) in survivors. Virus levels tended to be highest in the internal organs of subclinical and clinically affected fish and in brain and gill tissue of survivors. The results demonstrate that significant levels of VHSV can be found in tissues of rainbow trout that may be marketed for human consumption, which may have relevance for the biosecurity of VHS-free areas.

Risks associated with commodity trade: transmission of viral haemorrhagic septicaemia virus (VHSV) to rainbow trout fry from VHSV-carrying tissue-homogenates

Movements of commodity fish present a potential risk of transferring pathogens. Within a study to estimate the risk from imported rainbow trout Oncorhynchus mykiss carcases, fry were exposed to tissue homogenates from market size rainbow trout infected experimentally with viral haemorrhagic septicaemia (VHS) by waterborne exposure to VHS virus (VHSV, isolate of genotype Ia). Tissues were collected from fish that showed clinical signs and from recent mortalities. Homogenates of (i) internal organs, (ii) brain/gills and (iii) muscle tissue were prepared and added to tanks holding the fry. Virus transmission occurred from all tissues tested, causing high mortality of the fry. The results underline the potential risk of introduction of VHSV through the trade of fish products.

Osteoporosis in people with intellectual disabilities: a review and a brief study of risk factors for osteoporosis in a community sample of people with intellectual disabilities

BACKGROUND

The population of people with intellectual disabilities (ID) is increasing and their health needs impact on primary and secondary healthcare specialities. One important aspect of their physical health is bone health as people with ID have increased risk factors associated with osteoporosis. It has been identified that this population has an increased prevalence of low bone mineral density (BMD), osteoporosis and osteopenia. The main contributory factors for low BMD are age, use of antiepileptics, immobility and diagnosis of Down's syndrome.

METHODS

A literature search of electronic databases was undertaken. Studies that included people with ID were reviewed for the prevalence of osteoporosis and osteopenia. A cross-sectional survey was conducted in a community sample (n = 149) to screen for risk factors for osteoporosis.

RESULTS

The majority of studies identified increased prevalence of osteoporosis and osteopenia with associated low BMD. In most studies individuals with ID presented with more than two risk factors. In our survey, we identified an increased prevalence of risk factors associated with osteoporosis, namely use of antiepileptics (64%), immobility (23%), history of falls (20%) and fractures (11%). We found that 54% of our sample fulfilled the criteria for screening. Of those who went on to have scans, 55% had osteoporosis and 33% had osteopenia.

CONCLUSION

We conclude that we should be screening for the risk factors associated with low BMD in adults with ID. If these are present further investigations should take place and those found to have osteoporosis and osteopenia should have treatment at an early stage to prevent morbidity and improve their quality of life.

Antibody response of two populations of common carp, Cyprinus carpio L., exposed to koi herpesvirus

Common carp, Cyprinus carpio L., exposed to koi herpesvirus (KHV) may become persistently infected and populations containing such virus-infected individuals may transmit the virus to other fish when co-habited. Detection of virus-infected fish in a population is thus critical to surveillance and control programmes for KHV. A study was therefore designed to detect anti-KHV serum antibodies, with an enzyme-linked immunosorbent assay, in common carp following experimental exposures to KHV under varying environmental conditions. The study determined that a proportion of fish within a population experimentally exposed to KHV (at least 10-25%) develop high antibody titres (1/1600 or greater) to the virus, and this immunological response was detectable for several months (observed at the termination of the experiments at 65, 46 and 27 weeks post-exposure). Furthermore, this response was detected in one population of fish that did not succumb to a high level of mortality when maintained at water temperatures that were non-permissive for KHV. Elevating the water temperatures to permissive conditions for KHV resulted in recurrence of disease despite the presence of anti-virus antibodies, suggesting that serum antibodies alone are not protective under the conditions of our trials.

Phylogenetic analysis of spring virema of carp virus reveals distinct subgroups with common origins for recent isolates in North America and the UK

Genetic relationships between 35 spring viremia of carp virus (SVCV) genogroup Ia isolates were determined based on the nucleotide sequences of the phosphoprotein (P) gene and glycoprotein (G) genes. Phylogenetic analysis based on P gene sequences revealed 2 distinct subgroups within SVCV genogroup Ia, designated SVCV Iai and Iaii, and suggests at least 2 independent introductions of the virus into the USA in 2002. Combined P- and G-sequence data support the emergence of SVCV in Illinois, USA, and in Lake Ontario, Canada, from the initial outbreak in Wisconsin, USA, and demonstrate a close genetic link to viruses isolated during routine import checks on fish brought into the UK from Asia. The data also showed a genetic link between SVCV isolations made in Missouri and Washington, USA, in 2004 and the earlier isolation made in North Carolina, USA, in 2002. However, based on the close relationship to a 2004 UK isolate, the data suggest than the Washington isolate represents a third introduction into the US from a common source, rather than a reemergence from the 2002 isolate. There was strong phylogenetic support for an Asian origin for 9 of 16 UK viruses isolated either from imported fish, or shown to have been in direct contact with fish imported from Asia. In one case, there was 100% nucleotide identity in the G-gene with a virus isolated in China.

Reactivation of koi herpesvirus infections in common carp Cyprinus carpio

Two co-habitation studies with common carp were conducted to determine whether latent infections of koi herpesvirus (KHV) exist. Fish were exposed to KHV using 2 different temperature profiles, which induced low and high initial mortality. Subsequently, certain groups of fish were co-habited with naive fish while others were not. Koi herpesvirus was reactivated in fish from 3 of the 5 experimental tanks. Reactivation of the virus occurred regardless of the initial mortality associated with the virus or whether fish were co-habited with naive fish. The reactivation of the virus in our experiments occurred several months after the initial exposure to KHV and appeared to be temperature dependent.

Biocompatibility of Laser-deposited Hydroxyapatite Coatings on Titanium and Polymer Implant Materials

We have investigated the biocompatibility of calcium phosphate coatings deposited by pulsed laser ablation from hydroxyapatite (HA) targets onto polyethylene and Teflon substrates. It was found that the cell density, attachment, and morphology of primary rat calvaria osteoblasts were influenced by both the original polymer and by the nature of the apatite coatings. HA coatings on Teflon were found to have higher biocompatibility in terms of cell adhesion and spreading. In vivo studies of bone response to coatings deposited by KrF excimer and CO2 lasers on commercial Ti6A14V alloy implants show that both deposition techniques suppress fibrous tissue formation and promote osteogenesis. © 1998 Society of Photo-Optical Instrumentation Engineers.

NHE-1 is the sodium-hydrogen exchanger isoform present in erythroid cells

Erythrocyte sodium hydrogen exchanger (NHE) represents one of a limited number of sodium entry pathway in erythrocytes. At least five NHE isoforms have been identified, differing in tissue specificity, regulatory characteristics, and pharmacological sensitivities. Although physiological characteristics of erythrocyte NHE suggest that the widely expressed NHE-1 isoform may be present, evidence is not conclusive and does not exclude the existence of other isoforms. In this study, Northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analyses were used to test for five NHE isoforms in erythroid cells. Blood from patients with sickle cell disease was depleted of white blood cells (WBC) by passage through leukocyte filters and cellulose column. RT-PCR performed on WBC depleted reticulocyte RNA using a NHE-1 primer set yielded product a of expected size, the sequence of which was identical to the published human NHE-1 sequence. Northern blot analysis of the reticulocyte RNA using a 1.6 kb probe revealed a message of approximately 5.0 kb in size. RT-PCR analysis of rat kidney RNA using primers specific for NHE isoforms -2, -3, -4 and rat brain RNA using primer specific for NHE-5 isoform yielded products of expected size, whereas WBC depleted RNA under identical conditions yielded no products. These results identify the erythroid isoform of the sodium hydrogen exchanger as NHE-1.

Cholesterol domains in biological membranes

Membrane cholesterol is distributed asymmetrically both within the cell or within cellular membranes. Elaboration of intracellular cholesterol trafficking, targeting and intramembrane distribution has been spurred by both molecular and structural approaches. The expression of recombinant sterol carrier proteins in L-cell fibroblasts has been especially useful in demonstrating for the first time that such proteins actually elicit intracellular and intraplasma membrane redistribution of sterol. Additional advances in the use of native fluorescent sterols allowed resolution of transbilayer and lateral cholesterol domains in plasma membranes from cultured fibroblasts, brain synaptosomes and erythrocytes. In all three cell surface membranes, cholesterol is enriched in the inner, cytofacial leaflet. Up to three different cholesterol domains have been identified in the lateral plane of the plasma membrane: a fast exchanging domain comprising less than 10% of cholesterol, a slowly exchanging domain comprising about 30% of cholesterol, and a very slowly or non-exchangeable sterol domain comprising 50-60% of plasma membrane cholesterol. Factors modulating plasma membrane cholesterol domains include polyunsaturated fatty acids, expression of intracellular sterol carrier proteins, drugs such as ethanol, and several membrane pathologies (systemic lupus erythematosus, sickle cell anaemia and aging). Disturbances in plasma membrane cholesterol domains alter transbilayer fluidity gradients in plasma membranes. Such changes are associated with decreased Ca(2+)-ATPase and Na+, K(+)-ATPase activity. Thus, the size, dynamics and distribution of cholesterol domains within membranes not only regulate cholesterol efflux/influx but also modulate plasma membrane protein functions and receptor-effector coupled systems.

Transmembrane distribution of sterol in the human erythrocyte

The transbilayer cholesterol distribution of human erythrocytes was examined by two independent techniques, quenching of dehydroergosterol fluorescence and fluorescence photobleaching of NBD-cholesterol. Dehydroergosterol in conjunction with leaflet selective quenching showed that, at equilibrium, 75% of the sterol was localized to the inner leaflet of resealed erythrocyte ghosts. NBD-cholesterol and fluorescence photobleaching displayed two diffusion values in both resealed ghosts and intact erythrocytes. The fractional contribution of the fast and slow diffusion constants of NBD-labelled cholesterol represent its inner and outer leaflet distribution. At room temperature the plasma membrane inner leaflet of erythrocyte ghosts as well as intact erythrocytes cells contained 78% of the plasma membrane sterol. The erythrocyte membrane transbilayer distribution of sterol was independent of temperature. In conclusion, dehydroergosterol and NBD-cholesterol data are consistent with an enrichment of cholesterol in the inner leaflet of the human erythrocyte.

Nurses as image emissaries: are role conflicts impinging on a potential asset for an internal marketing strategy?

This article addresses role conflict and image problems nurses have with role partners. If these problems were corrected, nurses could be valuable assets in a "team selling" effort to help hospitals build their images. This research integrates sales management concepts and cites literature alluding to sales management research on identical problems.

Reward preferences of nurses: a marketing concept viewpoint

A survey of 500 nurses in a midwestern urban area was conducted to determine their preferences for intrinsic and extrinsic rewards in their jobs. This study indicates that in light of the expectancy/valence principle of motivation, hospitals and other employers of nursing services that individualize reward offerings should be in a much better position to recruit, and retain, nurses.

Planning and budgeting in the crippled children's sector through goal programming

This article describes how the goal programming methodology was applied to a state level Crippled Children's Program. The various organizational goals are incorporated into the programming model to indicate the trade-offs associated with the resource allocation process. Alternative allocations are presented in terms of a "what if" approach to programming.