Local and systemic immune responses in mice to intranasal delivery of peptides representing bovine respiratory syncytial virus epitopes encapsulated in poly (dl-lactide-co-glycolide) microparticles

The potential of a microparticulate vaccine delivery system in eliciting a specific mucosal antibody response in the respiratory tract of mice was evaluated. Two vaccine candidate peptides representing epitopes from the G attachment and F fusion antigens from bovine respiratory syncytial virus (BRSV) were encapsulated into poly(dl- lactide co-glycolide) biodegradable microparticles. The encapsulation process did not denature the entrapped peptides as verified by detection of peptide-specific antibodies in mucosal secretions by ELISA using peptide as antigen. Following intranasal immunisation, the encapsulated peptides induced stronger upper and lower respiratory tract specific-IgA responses, respectively, than the soluble peptide forms. Moreover, a strong peptide-specific cell-mediated immune response was measured in splenocytes in vitro from the mice inoculated with the encapsulated peptides compared to their soluble form alone indicating that migration of primed T cells had taken place from the site of mucosal stimulation in the upper respiratory tract to the spleen. These results act as a foundation for vaccine efficacy studies in large animal BRSV challenge models.

Antigen-specific IgA and IgG responses in calves inoculated intranasally with ovalbumin encapsulated in poly(DL-lactide-co-glycolide) microspheres

The immunogenicity of proteins encapsulated in poly(DL-lactide-co-glycolide) (PLG) microspheres has not been investigated to any extent in large animal models. In this study, IgG and IgA responses to ovalbumin (OVA), encapsulated in microspheres was investigated following intranasal inoculation into calves. Scanning electron microscopy and flow cytometric analysis demonstrated a uniform microsphere population with a diameter of <2.5 micrometers. Ovalbumin was released steadily from particles stored in PBS almost in a linear fashion, and after 4 weeks many particles showed cracks and fissures in their surface structure. Following intranasal inoculation of calves with different doses of encapsulated antigen, mean levels of ovalbumin-specific IgA were observed to increase steadily but significant differences in IgA levels (from the pre-inoculation level) were only observed following a second intranasal inoculation. With 0.5 and 1.0mg doses of antigen, ovalbumin-specific IgG was also detected in serum. Ovalbumin-specific IgA persisted in nasal secretions for a considerable period of time and were still detectable in four out of seven animals, 6 months after inoculation.

"...and they won land among the Picts by friendly treaty or the sword": How a re-examination of early historical sources and an analysis of early medieval settlement in north Co. Antrim confirms the validity of traditional accounts of Dál Riatic migration to Scotland from Ulster

Much recent scholarship has been critical of the concept of a Dál Riatic migration to, or colonisation of, Argyll. Scepticism of the accuracy of the early medieval accounts of this population movement, arguing that these are late amendments to early sources, coupled with an apparent lack of archaeological evidence for such a migration have led to its rejection. It is argued here, however, that this rejection has been based on too narrow a reading of historical sources and that there are several early accounts which, while differing in detail, agree on one point of substance, that the origin of Scottish Dál Riata lies in Ireland. Also, the use of archaeological evidence to suggest no migration to Argyll by the Dál Riata is flawed, misunderstanding the nature of early migrations and how they might be archaeologically identified, and it's proposed that there is actually quite a lot of evidence for migration to Argyll by the Dál Riata, in the form of settlement and artefactural evidence, but that it is to be found in Ireland through the mechanism of counterstream migration, rather than in Scotland.

Immunogenetic responses in calves to intranasal delivery of bovine respiratory syncytial virus (BRSV) epitopes encapsulated in poly (DL-lactide-co-glycolide) microparticles

Bovine respiratory syncytial virus (BRSV) is the principal aetiological agent of the bovine respiratory disease complex. A BRSV subunit vaccine candidate consisting of two synthetic peptides representing putative protective epitopes on BRSV surface glycoproteins in soluble form or encapsulated in poly(lactide-co-glycolide) (PLG) microparticles were prepared. Calves (10 weeks old) with diminishing levels of BRSV-specific maternal antibody were intranasally administered a single dose of the different peptide formulations. Peptide-specific local immune responses (nasal secretion IgA), but not systemic humoral (serum IgG) or cellular responses (serum IFN-γ), were generated by all forms of peptide. There was a significant reduction in occurrence of respiratory disease in the animals inoculated with all peptide formulations compared to animals given PBS alone. Furthermore no adverse effects were observed in any of the animals post vaccination. These results suggest that intranasal immunisation with the peptide subunit vaccine does induce an as yet unidentified protective immune response.

SrTiO3(001)(2x1) reconstructions: First-principles calculations of surface energy and atomic structure compared with scanning tunneling microscopy images

(1x1) and (2x1) reconstructions of the (001) SrTiO3 surface were studied using the first-principles full-potential linear muffin-tin orbital method. Surface energies were calculated as a function of TiO2 chemical potential, oxygen partial pressure and temperature. The (1x1) unreconstructed surfaces were found to be energetically stable for many of the conditions considered. Under conditions of very low oxygen partial pressure the (2x1) Ti2O3 reconstruction [Martin R. Castell, Surf. Sci. 505, 1 (2002)] is stable. The question as to why STM images of the (1x1) surfaces have not been obtained was addressed by calculating charge densities for each surface. These suggest that the (2x1) reconstructions would be easier to image than the (1x1) surfaces. The possibility that the presence of oxygen vacancies would destabilise the (1x1) surfaces was also investigated. If the (1x1) surfaces are unstable then there exists the further possibility that the (2x1) DL-TiO2 reconstruction [Natasha Erdman Nature (London) 419, 55 (2002)] is stable in a TiO2-rich environment and for p(O2)>10(-18) atm.

Level of renal function and serum erythropoietin levels independently predict anaemia post-renal transplantation

Background. Post-renal transplant anaemia is a potentially reversible cardiovascular risk factor. Graft function, immunosuppressive agents and inhibition of the renin-angiotensin system have been implicated in its aetiology. The evaluation of erythropoietin (EPO) levels may contribute to understanding the relative contributions of these factors. Methods. Two-hundred and seven renal transplant recipients attending the Belfast City Hospital were studied. Clinical and laboratory data were extracted from the medical records and laboratory systems. Results. Of the 207 patients (126 male), 47 (22.7%) were found to be anaemic (males, haemoglobin (Hb) <12 g/dl, females Hb <11g/dl). The anaemic group had a significantly higher mean serum creatinine level (162.8 µmol/l vs 131.0 µmol/l, P <0.001) and lower mean estimated glomerular filtration rate (eGFR) (41.5 ml/min vs 54.9 ml/min, P <0.001) than the non-anaemic group. Individual immunosuppressive regimens were comparable between those with and those without anaemia. Angiotensin converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) administration was not more prevalent in those with anaemia compared with those without (36.2 vs 38.8, P = 0.88). There was a significant inverse correlation between Hb levels and serum EPO levels (R = -0.29, P <0.001), but not between EPO levels and eGFR (R = 0.02, P = 0.74). Higher EPO levels were predictive of anaemia, independent of eGFR in multivariate analysis. Conclusion. Anaemia is common in post-renal transplant patients. The levels of renal function and serum EPO and not immunosuppressive regimens or ACE-I/ARB use, are strong and independent predictors of anaemia. © The Author [2007]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Characterisation of antibodies to chloramphenicol, produced in different species by enzyme-linked immunosorbent assay and biosensor technologies

Six polyclonal antisera to chloramphenicol (CAP) were successfully raised in camels, donkeys and goats. As a comparison of sensitivity, IC50 values ranged from 0.3 ng mL(-1) to 5.5 ng mL(-1) by enzyme-linked immunosorbent assay (ELISA) and from 0.7 ng mL(-1) to 1.7 ng mL(-1) by biosensor assay. The introduction of bovine milk extract improved the sensitivity of four of the antisera by ELISA and two by biosensor assay; a reduction in sensitivity of the remaining antisera ranged by a factor of 1.1-2.6. Porcine kidney extract reduced the sensitivity of all the antisera by a factor ranging from 1.1 to 7 by ELISA and a factor of 1.5 to 4 by biosensor. A low cross-reactivity with thiamphenicol (TAP) and florfenicol (FF) was displayed by antiserurn G2 (1.2% and 18%, respectively) when a homologous ELISA assay format was employed. No cross-reactivity was displayed by any of the antisera when a homologous biosensor assay format was employed. Switching to a heterologous ELISA format prompted three of the antisera to display more significant cross-reactivity with TAP and FF (53% and 82%, respectively, using Dl). The heterologous biosensor assay also increased the cross-reactivity of D1 for TAP and FF (56% and 129%, respectively) and of one other antiserum (Gl) to a lesser degree. However, unlike the ELISA, the heterologous biosensor assay produced a substantial reduction in sensitivity (by a factor of 6 for D1). (C) 2007 Elsevier B.V. All rights reserved.

Through-thickness control of polymer bioresorption via electron beam irradiation

Predicable and controlled degradation is not only central to the accurate delivery of bioactive agents and drugs, it also plays a vital role in key aspects of bone tissue engineering. The work addressed in this paper investigates the utilisation of e-beam irradiation in order to achieve a controlled (surface) degradation profile. This study focuses on the modification of commercially and clinically relevant materials, namely poly(L-lactic acid) (PLLA), poly(L-lactide-hydroxyapatite) (PLLA-HA), poly(L-lactide-glycolide) co-polymer (PLG) and poly(L-lactide-DL-lactide) co-polymer (PLDL). Samples were subjected to irradiation treatments using a 0.5 MeV electron beam with delivered surface doses of 150 and 500 kGy. In addition, an acrylic attenuation shield was used for selected samples to control the penetration of the e-beam. E-beam irradiation induced chain scission in all polymers, as characterized by reduced molecular weights and glass transition temperatures (T-g). Irradiation not only produced changes in the physical properties of the polymers but also had associated effects on surface erosion of the materials during hydrolytic degradation. Moreover, the extent to which both mechanical and hydrolytic degradation was observed is synonymous with the estimated penetration of the beam (as controlled by the employment of an attenuation shield). (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Contractile and vasorelaxant effects of hydrogen sulfide and its biosynthesis in the human internal mammary artery

This study aimed to test these hypotheses: cystathionine gamma-lyase (CSE) is expressed in a human artery, it generates hydrogen sulfide (H2S), and H2S relaxes a human artery. H2S is produced endogenously in rat arteries from cysteine by CSE. Endogenously produced H2S dilates rat resistance arteries. Although CSE is expressed in rat arteries, its presence in human blood vessels has not been described. In this study, we showed that both CSE mRNA, determined by reverse transcription-polymerase chain reaction, and CSE protein, determined by Western blotting, apparently occur in the human internal mammary artery (internal thoracic artery). Artery homogenates converted cysteine to H2S, and the H2S production was inhibited by DL-propargylglycine, an inhibitor of CSE. We also showed that H2S relaxes phenylephrine-precontracted human internal mammary artery at higher concentrations but produces contraction at low concentrations. The latter contractions are stronger in acetylcholine-prerelaxed arteries, suggesting inhibition of nitric oxide action. The relaxation is partially blocked by glibenclamide, an inhibitor of K-ATP channels. The present results indicate that CSE protein is expressed in human arteries, that human arteries synthesize H2S, and that higher concentrations of H2S relax human arteries, in part by opening K-ATP channels. Low concentrations of H2S contract the human internal mammary artery, possibly by reacting with nitric oxide to form an inactive nitrosothiol. The possibility that CSE, and the H2S it generates, together play a physiological role in regulating the diameter of arteries in humans, as has been demonstrated in rats, should be considered.

Analysis of pharmacists attitudes toward a distance learning initiative on health screening

A questionnaire was developed to investigate pharmacists' attitudes to distance learning (DL) as a vehicle for continuing education (CE). It was included in each of a two part DL course on Health Screening. Part One was mailed to all community pharmacists in England (16,400) and returns were received from 1487. The questionnaire in Part Two was returned by 436 pharmacists. Attitude statements were scored using a five-point Likert scale. The mean response to all attitude statements was positive. Participants were significantly more satisfied than non-participants with DL in general and the DL course studied (P less than or equal to 0.05). Over 80 percent of respondents completing the course found DL to be enjoyable and more suitable than other CE methods. More females and less males than expected (based on registration statistics) requested (P less than or equal to 0.001) and completed the course (P less than or equal to 0.001). Pharmacists of all ages participated, although those recently qualified showed greater interest.

Telephone survey evaluation of the educational impact of a distance learning course

The educational impact of a distance learning (DL) course entitled ''Health Screening for Health Promotion, was investigated using a telephone questionnaire survey. An introduction to the DL course was distributed to all community pharmacists in England (16,400); the main body of the course, on which pharmacists were examined, was distributed free of charge to all pharmacists who requested it (1,485). Pharmacists participating in the survey (868) were organized by random selection into groups and stratified according to age, sex and postcode. A matched control group was randomly drawn from those pharmacists who had not participated in the course. The DL course improved pharmacists' knowledge about health screening/health promotion issues (e.g., mean score of 66 percent achieved by a group who had completed the course; 51 percent achieved by the control group; P<0.001). Factors influencing score achieved included sex and year of registration. Males performed better than females (P<0.008) while performance decreased with number of years on the register (P<0.001).

A nonsynonymous LNK polymorphism associated with idiopathic erythrocytosis

Anemia is a symptom associated with cognitive dysfunction and is diagnosed if the hemoglobin level of a blood sample is too low. The clinical impact of chronically low hemoglobin level may be insuf?cient
brain oxygenation, which may result in a decline in cognitive functioning. Previous studies have provided evidence of decrements in cognitive functioning associated with anemia across various disease processes, but few have investigated the association between cognitive dysfunction and hemoglobin level in patients with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS). As this population is inherently anemic, studying these patients allowed for an exploration of cognitive changes at mild, moderate, and severe levels of anemia. This investigation explored cutoff points for hemoglobin at which cognitive decline may occur. Findings showed decrements in cognitive functioning occurring at hemoglobin levels of 10 g/dL or below. Performance on measures of word retrieval, attention, and ?ne motor function was most affected which suggests fronto-temporal lobe dysfunction. Results provided evidence as to a hemoglobin cutoff point below which cognitive function may be affected in patients with AML and MDS. This cutoff value may provide a clinical marker at which cognitive testing and therapeutic interventions could be utilized to improve patients’ cognitive function, level of fatigue and overall quality of life.

Transfusion in the management of patients with megaloblastic anaemia

Transfusion has been associated with significant morbidity and mortality in megaloblastic anaemia (MA). This retrospective study was undertaken to examine the usefulness of transfusion in the management of MA. Fifty-two patients with MA were identified. Of the 20 transfused patients 13 were treated with diuretics and six with potassium supplements. The mean haemoglobin (Hb) of the transfused group was 6.5 g/dl (range 4.8-10.4 g/dl), and of the 32 non-transfused patients 10.5 g/dl (range 5.6-17.0 g/dl). The Hb and packed cell volume (PCV) were significantly lower in the transfused group. Only two of 32 non-transfused group were given potassium supplements. In this small group of patients with MA, transfusion appeared to be safe and no complications of transfusion were identified. However, advice was not being followed. We would suggest that, although transfusion has a minor role in the management of MA, consideration must be given to the general hazards of transfusion.

The potential of electron beam radiation for simultaneous surface modification and bioresorption control of PLLA

Bioresorbable polymers have been widely investigated as materials exhibiting significant potential for successful application in the fields of tissue engineering and drug delivery. Further to the ability to control degradation, surface engineering of polymers has been highlighted as a key method central to their development. Previous work has demonstrated the ability of electron beam (e-beam) technology to control the degradation profiles and bioresorption of a number of commercially relevant bioresorbable polymers (poly-l-lactic acid (PLLA), Llactide/DL-lactide co-polymer (PLDL) and poly(lactic-co-glycolic acid (PLGA)). This work investigates the further potential of ebeam technology to impart added biofunctionality through the manipulation of polymer (PLLA) surface properties. PLLA samples were subjected to e-beam treatments in air, with varying beam energies and doses. Surface characterization was then performed using contact angle analysis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy. Results demonstrated a significant increase in surface wettability post e-beam treatment. In correlation with this, XPS data showed the introduction of oxygen-containing functional groups to the surface of PLLA. Raman spectroscopy indicated chain scission in the near surface region of PLLA (as predicted). However, e-beam effects on surface properties were not shown to be dependent on beam energy or dose. E-beam irradiation did not seem to affect the surface roughness of PLLA as a direct consequence of the treatment.

Study of aflatoxin exposure in a Brazilian population using an aflatoxin - albumin biomarker

The evaluation of exposure to aflatoxins (AF) by measurement of the level of contamination in food is hampered due to the heterogeneous distribution of AF in food. Therefore, an alternative is to estimate the exposure using specific biological markers (biomarkers) based on an understanding of the metabolism of the compound. For AF, these include aflatoxin-N-7-guanine in the urine, or AFB(1)-albumin (AF-alb) in the blood. This study assessed the level of exposure to AF in Brazilian individuals using a biomarker approach, i.e. the AF-alb adducts. Blood samples were collected from urban residents (n=50; aged 18-52) in June 1999, at the Blood Center of Antonio Carlos de Camargo Hospital, Sao Paulo, Brazil. AF-alb adduct levels were determined, by ELISA following serum albumin extraction and digestion. AF-alb adducts were detected in 31/50 (62%) samples [range 0-57.3 pg AFB(1)-lys adducts/mg of blood albumin (pg/mg)]. The mean level of positives was 14.9 pg/mg and males had the two highest levels measured (57.1 and 57.3 pg/mg). There was no correlation with age or profession. This is the first study of Brazilian, or indeed South American, individuals that has determined exposure to AF at the individual level using a biomarker approach. These levels are similar to those observed in the Philippines. These data warrant further investigation of both the sources and consequences of exposure to this potent toxin in Brazil.