Immunohistochemical study of experimental malignant catarrhal fever in rabbits

Malignant catarrhal fever (MCF) is an often-fatal lymphoproliferative disease of a variety of ungulates that occurs worldwide. It is caused by either of the highly related but distinct gammaherpesviruses alcelaphine herpesvirus-1 (AlHV-1, wildebeest reservoir) or ovine herpesvirus-2 (OvHV-2, sheep reservoir). MCF in rabbits is an excellent model as it closely resembles the disease in susceptible ungulates that include cattle, deer and bison. In this study, newly available and previously characterized monoclonal antibodies specific for rabbit leucocyte differentiation molecules were used to perform a detailed immunohistochemical examination of both AlHV-1 MCF and OvHV-2 MCF in rabbits. Differences in the MCF caused by the two viruses included: less tissue necrosis and more lymphoid cell accumulations in AlHV-1 MCF compared with OvHV-2 MCF, and in particular marked tissue necrosis in the mesenteric lymph node, appendix and liver of OvHV-2-infected animals when compared with either other tissues in OvHV-2 MCF or AlHV-1 MCF lesions in any tissue. In both AlHV-1 MCF and OvHV-2 MCF, lymphoid cell accumulations in lymphoid and non-lymphoid tissues consisted mainly of T-cells with a corresponding absence of B-cells. CD8(+) T-cells accounted for a proportion of these in the non-lymphoid tissues, but there was evidence for the accumulation of an unidentified T-cell subset/subsets as well. This study extends our understanding of the mechanisms of immuno-pathogenesis of MCF.

Investigation of the role of ENPP1 and TNAP genes in chondrocalcinosis

OBJECTIVES

Extracellular inorganic pyrophosphate (ePPi) inhibits certain forms of pathological mineralization while promoting others. Three molecules involved in ePPi regulation are important candidates for the development of calcium pyrophosphate dihydrate chondrocalcinosis (CPPD CC). These include ANKH, ectonucleotide pyrophosphatase (ENPP1) and TNAP. We have previously showed that genetic variation in ANKH is a cause of autosomal dominant familial CC and also some sporadic cases of CPPD CC. We now investigate the possible role of ENPP1 and TNAP in CPPD CC.

METHODS

Exons, untranslated regions (UTR) and exon-intron boundaries of ENPP1 and TNAP were sequenced using ABI Big Dye chemistry on automated sequencers. Sixteen variants were identified (3 in ENPP1 and 13 in TNAP) and were subsequently genotyped in 128 sporadic Caucasian CPPD CC patients and 600 healthy controls using a combination of polymerase chain reaction/restriction fragment-length polymorphism analysis or using Taqman. Allele and genotype frequencies were compared between cases and controls using the chi(2) test. Linkage disequilibrium, haplotype and the single nucleotide polymorphism-specific analyses were also performed. This study had 80% power to detect an odds ratio of 2.2 or more at these loci.

RESULTS

No difference was observed in the allele or genotype frequencies between patients and controls at either ENPP1 or TNAP.

CONCLUSIONS

Polymorphisms of ENPP1 and TNAP are not major determinants of susceptibility to CC in the population studied. Further studies of the aetiology of sporadic CPPD CC are required to determine its causes.

Very high dose inhaled corticosteroids: panacea or poison?

Perspective on the paper by Paton et al (see page 808)

Genetic diversity within and between European pig breeds using microsatellite markers

An important prerequisite for a conservation programme is a comprehensive description of genetic diversity. The aim of this study was to use anonymous genetic markers to assess the between- and the within-population components of genetic diversity for European pig breeds at the scale of the whole continent using microsatellites. Fifty-eight European pig breeds and lines were analysed including local breeds, national varieties of international breeds and commercial lines. A sample of the Chinese Meishan breed was also included. Eleven additional breeds from a previous project were added for some analyses. Approximately 50 individuals per breed were genotyped for a maximum of 50 microsatellite loci. Substantial within-breed variability was observed, with the average expected heterozygosity and observed number of alleles per locus being 0.56 [range 0.43-0.68] and 4.5 respectively. Genotypic frequencies departed from Hardy-Weinberg expectations (P < 0.01) in 15 European populations, with an excess of homozygotes in 12 of them. The European breeds were on average genetically very distinct, with a Wright F(ST) index value of 0.21. The Neighbour-Joining tree drawn from the Reynolds distances among the breeds showed that the national varieties of major breeds and the commercial lines were mostly clustered around their breeds of reference (Duroc, Hampshire, Landrace, Large White and Piétrain). In contrast, local breeds, with the exception of the Iberian breeds, exhibited a star-like topology. The results are discussed in the light of various forces, which may have driven the recent evolution of European pig breeds. This study has consequences for the interpretation of biodiversity results and will be of importance for future conservation programmes.

Genetic diversity in European pigs utilizing amplified fragment length polymorphism markers

The use of DNA markers to evaluate genetic diversity is an important component of the management of animal genetic resources. The Food and Agriculture Organisation of the United Nations (FAO) has published a list of recommended microsatellite markers for such studies; however, other markers are potential alternatives. This paper describes results obtained with a set of amplified fragment length polymorphism (AFLP) markers as part of a genetic diversity study of European pig breeds that also utilized microsatellite markers. Data from 148 AFLP markers genotyped across samples from 58 European and one Chinese breed were analysed. The results were compared with previous analyses of data from 50 microsatellite markers genotyped on the same animals. The AFLP markers had an average within-breed heterozygosity of 0.124 but there was wide variation, with individual markers being monomorphic in 3-98% of the populations. The biallelic and dominant nature of AFLP markers creates a challenge for their use in genetic diversity studies as each individual marker contains limited information and AFLPs only provide indirect estimates of the allelic frequencies that are needed to estimate genetic distances. Nonetheless, AFLP marker-based characterization of genetic distances was consistent with expectations based on breed and regional distributions and produced a similar pattern to that obtained with microsatellites. Thus, data from AFLP markers can be combined with microsatellite data for measuring genetic diversity.

Characteristics of sudden death in hemodialysis patients

Hemodialysis (HD) is an intermittent procedure during which large fluid and electrolyte shifts occur. We hypothesized that sudden death occurrences in HD patients are related to the timing of HD, and that they occur more frequently in the 12 h period starting with dialysis and in the 12 h period at the end of the dialysis-free weekend interval. In a retrospective study, 228 patient deaths were screened to determine if they met the criteria for sudden death. Information was obtained from clinic charts, dialysis center records, and interview of witnesses of the death event. There were 80 HD patients who met the criteria for sudden death. A bimodal distribution of death occurrences was present, with a 1.7-fold increased death risk occurring in the 12 h period starting with the dialysis procedure and a threefold increased risk of death in the 12 h before HD at the end of the weekend interval (P=0.011). Patients with sudden death had a high prevalence of congestive heart failure and coronary artery disease. Only 40% of patients experiencing sudden death were receiving beta-blockers, and the prior monthly serum potassium value was less than 4 mEq/l in 25%. Sudden death is temporally related to the HD procedure. Every other day HD could be beneficial in preventing sudden death. Careful attention to the usage of beta-blockers and to the maintenance of normal serum potassium values is indicated in HD patients at risk for sudden death.

From psychiatric ward to the streets and shelters

The issue of discharge from hospital ward to the streets is seldom explored in the literature, but all too commonly experienced by individuals experiencing psychiatric disorders. The Community University Research Alliance on Housing and Mental Health sought to determine how frequently people were discharged from psychiatric wards to shelters or the street in London, Ontario, Canada. A number of data sources were accessed to determine instances of discharges to shelters or the street. Data were analysed to determine the number of moves occurring between hospital and shelter or no fixed address. All datasets revealed the problem of discharge to shelters or the street occurred regularly. All data sources used have the difficulty of likely underestimating the extent of the problem. This type of discharge occurred at least 194 times in 2002 in London, Ontario, Canada. Policies that contribute to this problem include income-support policies, the reduction in psychiatric hospital beds and the lack of community supports. Without recognition, this problem is at risk of remaining invisible with no further improvements to the situation.

The childhood asthma epidemic

A case of delayed rather than mistaken diagnosis

A randomized, controlled trial of a new vascular catheter flush solution (minocycline-EDTA) in temporary hemodialysis access

BACKGROUND AND OBJECTIVE

We previously demonstrated that minocycline-EDTA was efficacious at preventing catheter-related bloodstream infections (BSIs) in three patients with recurrent infections. This study compared heparin with minocycline-EDTA as flush solutions used among dialysis patients with central venous catheters, a high-risk group for catheter-related BSI.

METHODS

Patients were enrolled within 72 hours of catheter insertion and randomized to receive heparin or minocycline-EDTA as a flush after each dialysis session. Each syringe containing flush solution was wrapped in orange plastic to conceal the type of solution it contained. Patients were observed for evidence of infection and catheter thrombosis. After catheters were removed, cultures were performed to determine whether microbial colonization had occurred.

RESULTS

During a 14-month period, 60 patients were enrolled (30 in each group). The two groups had similar demographics and underlying diseases. Catheter survival at 90 days was 83% for the minocycline-EDTA group versus 66% for the heparin group (P = .07). Significant catheter colonization, a surrogate measure of catheter-related infection, was significantly more frequent in the heparin group (9 of 14 vs 1 of 11; P = .005). There was only one catheter-related bacteremia and it occurred in the heparin group.

CONCLUSIONS

When compared with heparin, minocycline-EDTA had a better 90-day catheter survival (P = .07) and a decreased rate of catheter colonization. This pilot study warrants a larger prospective, randomized trial.

Changes in cardiovascular calcification after parathyroidectomy in patients with ESRD

BACKGROUND

The effect of parathyroidectomy on vascular calcification in patients with end-stage renal disease has been a subject of interest for many years, although studies in this area have not been definitive. The purpose of this investigation is to determine changes in vascular calcification after subtotal parathyroidectomy by using fast-gated helical computed axial tomographic imaging to measure coronary and carotid artery calcification.

METHODS

Computed tomographic imaging was performed at baseline and in follow-up on 10 patients who had undergone subtotal parathyroidectomy and 10 reference patients who had not undergone parathyroidectomy.

RESULTS

Patients who underwent subtotal parathyroidectomy had a mean change in coronary calcification of -92.3 +/- 469/y, and reference patients had a mean change of +479 +/- 630/y (P = 0.03). The 2 parathyroidectomy patients with the highest baseline scores had significant declines in both coronary and carotid calcification.

CONCLUSION

In this study, subtotal parathyroidectomy is associated with a significant decrease in vascular calcification in 2 of 10 dialysis patients with high coronary artery calcium scores and stabilization in 7 of 10 patients with low baseline scores.

Amplification of surface temperature trends and variability in the tropical atmosphere

The month-to-month variability of tropical temperatures is larger in the troposphere than at Earth's surface. This amplification behavior is similar in a range of observations and climate model simulations and is consistent with basic theory. On multidecadal time scales, tropospheric amplification of surface warming is a robust feature of model simulations, but it occurs in only one observational data set. Other observations show weak, or even negative, amplification. These results suggest either that different physical mechanisms control amplification processes on monthly and decadal time scales, and models fail to capture such behavior; or (more plausibly) that residual errors in several observational data sets used here affect their representation of long-term trends.

Deprivation, smoking, and quality of life in asthma

AIMS

To explore associations of deprivation and smoking, with prevalence of asthma, wheeze, and quality of life.

METHODS

Survey, using International Study of Asthma and Allergies in Childhood (ISAAC) methodology, of children aged 13-14 years attending Scottish schools previously surveyed in 1995.

RESULTS

4665/5247 (89%) pupils completed questionnaires. 3656/4665 (78.4%) had missed school for any reason in the last 12 months, 587 (12.6%) because of asthma or wheeze. Compared to children with 1-3 wheeze attacks per year, those with >12 attacks in the last year were more likely to have missed school, twice as likely to have missed physical education in the last month, to report interference with home activities, or to have visited accident and emergency departments, and three times more likely to have been hospitalised. Deprivation was not independently associated with self-reported asthma or wheeze, but was associated with school absence, either for any reason or specifically for asthma or wheeze, but not with use of services such as accident and emergency visits, doctor visits, or hospital admissions. Active smoking was associated with wheezy symptoms, and active and passive smoking with use of medical services. These associations were independent of wheeze severity, treatment taken, and other associated atopic conditions. Smoking also had an impact on school absence and home and school activities.

CONCLUSIONS

Deprivation does not affect the prevalence of asthma or wheeze. Exposure to cigarette smoke was associated with the increased use of services. Deprivation and smoking have independent adverse effects on the quality of life in subjects with asthma or wheeze.

Childhood asthma in the Highlands of Scotland--morbidity and school absence

BACKGROUND

The prevalence of childhood asthma in Scotland is one of the highest in the world. The morbidity secondary to allergic diseases is significant in terms of costs to the nation and effects on the family including the child.

AIMS

The aims of this study were to describe the prevalence of asthma, eczema and hay fever in the Highlands of Scotland and in the Shetland Isles and to examine factors in relation to quality of life and social deprivation.

METHOD

A total population survey of 12 year old children using a parent completed questionnaire.

RESULTS

86.3% (2658/3080) returned questionnaires. Of the 2549 questionnaires analysed, 476 (18.7%) reported asthma ever, 362 (14.2%) wheeze in last 12 months, 508 (19.9%) reported hay fever ever and 555 (21.8%) reported eczema ever. Of the children reporting asthma or wheeze, 35.4% (229/647) had missed school because of asthma or wheeze, 38.0% (246/647) had missed physical education. 62.5% (354/566) of subjects with wheeze ever reported sleep disturbance. Deprivation measured by DEPCAT scores was associated with maternal smoking and bronchitis in the child but not with allergic diseases.

CONCLUSION

Compared with previous studies, the prevalence of asthma was unchanged but eczema has increased in Highland adolescents. Allergic disease has a significant impact on school attendance and physical activity. Deprivation was associated with maternal smoking and bronchitis in the child but not with allergic diseases. The impact of allergic diseases in rural areas may be different from urban areas.

Association of CCR5Delta32 with reduced risk of childhood but not adult asthma

BACKGROUND

A number of potential candidate genes have been implicated in the pathogenesis of asthma. A 32 base pair deletion in the CCR5 gene renders this chemokine receptor non-functioning and has been shown to be associated with a reduced prevalence of asthma in childhood. The mechanism may be related to impairment of pathogen entry into cells and modified host inflammatory response. We sought to determine the influence of the CCR5Delta32 mutation on asthma and allergy in the transition from childhood to adulthood.

METHODS

627 individuals first studied as part of a whole population schoolchildren cohort in 1989 when aged 8-12 years were followed up 10 years later for respiratory and allergy symptoms and laboratory markers of atopy. CCR5Delta32 status was also characterised and the association with childhood and adulthood symptoms determined.

RESULTS

The follow up sample was representative of the original cohort except for a slightly greater prevalence of symptomatic individuals. As children, none who were homozygous for the CCR5Delta32 mutation had a current physician's diagnosis of asthma. In multivariate analysis and controlling for known confounders, the protective effect of carrying the allele in childhood was highly significant (OR 0.31, 95% CI 0.14 to 0.72, p=0.006). There was no protective association with "current asthma" as classified in adulthood within the same population. Subjective or laboratory markers of atopy in childhood or adulthood were not associated with the CCR5Delta32 mutation. Methacholine bronchial hyperresponsiveness in adulthood was also unrelated to gene carrier status.

CONCLUSIONS

In a population with a high allelic frequency for the CCR5Delta32 mutation, a significant protection against childhood asthma is evident which is independent of atopy. This protection is lost in the transition between childhood and early adulthood. The contribution of different genetic candidates to the expression of asthma may change with advancing maturity and confound the interpretation of association and linkage studies unless age is taken into account.

Inhaled corticosteroids and adrenal insufficiency

Inhaled steroids are safe at normal doses, but beware very high doses, especially of fluticasone

An application of the United Kingdom Working Party diagnostic criteria for atopic dermatitis in Scottish infants

The United Kingdom Working Party diagnostic criteria for atopic dermatitis have been characterized in infants and children; however, the need for visual confirmation of flexural dermatitis by a trained investigator limits their use in large epidemiologic studies. We have administered the complete United Kingdom Working Party criteria in a postal questionnaire format to the mothers of year old infants and determined the concordance between mothers' and trained investigator's reports of visual flexural dermatitis. Based on mothers' responses to the questionnaire, 59 infants with atopic dermatitis and 59 controls were identified. In subsequent home interviews conducted by a trained investigator, the United Kingdom criteria questions were repeated and sites of current visible dermatitis were identified by mothers and the investigator as per United Kingdom Working Party protocol. Agreement between the mothers' postal and home interview responses was high: kappa= 0.75-0.94 for individual criteria; kappa= 0.93 for diagnosed atopic dermatitis. Agreement between the mothers' and investigator's observations of visible flexural dermatitis was high for all sites: kappa= 0.88-1.0. The results demonstrate that mothers are able to apply the United Kingdom criteria and accurately report visible flexural dermatitis in their year old infants. The postal application of the United Kingdom Working Party's diagnostic criteria for atopic dermatitis in year old infants appears to be a practical, reliable, epidemiologic tool in the investigation of atopic dermatitis with results comparable with formal application of the criteria by a trained investigator.