3,168 research outputs found
Islet autoantibody profiles associated with higher diabetes risk in Lithuanian compared with English schoolchildren
Over a 15 year period, the incidence of type 1 diabetes has doubled in Lithuania, whilst increasing by a third in England, however England still has the higher incidence. Analysis of sera collected from non-diabetic schoolchildren from Lithuania and England more than 20 years ago showed a similar number of multiple autoantibody positive schoolchildren between the populations, but a higher prevalence of islet antigen-2 autoantibodies (IA-2A) in English schoolchildren. We aimed to use recently developed, more specific islet autoantibody tests, to characterise differences in humoral autoimmunity between these two general population cohorts in greater detail. Samples from 88 Lithuanian and 133 English schoolchildren previously found islet autoantibody positive were selected for measurement of additional islet autoantibodies by radioimmunoassay. Samples were tested for autoantibodies to zinc transporter 8 (ZnT8A), GAD(96-585), the protein tyrosine phosphatase region of islet antigen-2 (PTPA), and the related IA-2βA while autoantibodies to IA-2A were re-assayed using the current harmonized method. IA-2 related autoantibodies PTPA (0.13% vs. 0.45%, p=0.027) and IA-2βA (0% vs. 0.35%, p<0.001), but not IA-2A measured using the harmonized method, were less common in Lithuanian compared to English schoolchildren. Lithuanian schoolchildren who were islet autoantibody positive, were positive for fewer biochemical autoantibodies compared with English schoolchildren (p=0.043). Background rates of islet autoimmunity in childhood differ subtly between countries which have different incidences of type 1 diabetes. The optimal screening strategy (age and combination of markers) for detection of islet autoimmunity may vary between countries dependent on the pattern of autoantibodies found in the general population
Morning vaccination enhances antibody response over afternoon vaccination: A cluster-randomised trial
Objectives Older adults are less able to produce a protective antibody response to vaccinations. One factor that contributes to this is immune ageing. Here we examined whether diurnal variations in immune responses might extend to the antibody response to vaccination. Design We utilised a cluster-randomised trial design. Setting 24 General Practices (GPs) across the West Midlands, UK who were assigned to morning (9–11 am; 15 surgeries) or afternoon (3–5 pm; 9 surgeries) vaccination times for the annual UK influenza vaccination programme. Participants 276 adults (aged 65+ years and without a current infection or immune disorder or taking immunosuppressant medication). Interventions Participants were vaccinated in the morning or afternoon between 2011 and 2013. Main outcome measures The primary outcome was the change in antibody titres to the three vaccine influenza strains from pre-vaccination to one month post-vaccination. Secondary outcomes of serum cytokines and steroid hormone concentrations were analysed at baseline to identify relationships with antibody responses. Results The increase in antibody levels due to vaccination differed between morning and afternoon administration; mean difference (95% CI) for H1N1 A-strain, 293.3 (30.97–555.66) p = .03, B-strain, 15.89 (3.42–28.36) p = .01, but not H3N2 A-strain, 47.0 (−52.43 to 146.46) p = .35; those vaccinated in the morning had a greater antibody response. Cytokines and steroid hormones were not related to antibody responses. No adverse events were reported. Conclusions This simple manipulation in the timing of vaccine administration to favour morning vaccination may be beneficial for the influenza antibody response in older adults, with potential implications for vaccination strategies generally
A Cross-Cultural Comparison of Younger and Older Adults\u27 Simulated Highway Driving Performance Under Single and Dual Task Conditions
Driving is a complex psychomotor task that is often interrupted by secondary activities that divert attention away from the roadway. The risk of inattentive driving is known vary with age. The degree to which culture impacts these changes is less established. To study the impact of age and culture on drivers’ capacity to manage dual task demands, we developed a parallel driving simulation in the US and Korea. We assessed the performance of 135 drivers divided into two age groups, younger (20–29) and older (60-69). Both age and cultural group differences in basic highway driving performance measures were observed. However, the relative impact of the dual task demands on driving performance was largely consistent across cultures
Distribution of polymorphic forms at the porcine GH locus in a population of day-10 pig embryos
Abstract. The present study describes an analysis of genotype and allele distribution at the porcine GH locus among day-10 pig embryos. Embryos were collected post mortem from 6 crossbred (Danish Landrace × Yorkshire) sows inseminated with mixed Duroc semen and individually frozen for later analysis. After extraction, DNA was subjected to PCR amplification and restriction analysis with Msp I and Hae II enzymes. The genotype frequencies were: Msp I CD 0.17, DD 0.83; and Hae II AA 0.33, AB 0.58; and BB 0.09. The Msp I CC genotype was not found among analysed embryos. To our knowledge, this is the first report on the genotype and allele distribution at the GH locus among early pig embryos
Transdermal Blood Sampling for C-peptide Is a Minimally Invasive, Reliable Alternative to Venous Sampling in Children and Adults With Type 1 Diabetes
OBJECTIVE:C-peptide and islet autoantibodies are key type 1 diabetes biomarkers, typically requiring venous sampling, which limits their utility. We assessed transdermal capillary blood (TCB) collection as a practical alternative.RESEARCH DESIGN AND METHODS:Ninety-one individuals (71 with type 1 diabetes, 20 controls; individuals with type 1 diabetes: aged median 14.8 years [interquartile range (IQR) 9.1–17.1], diabetes duration 4.0 years [1.5–7.7]; controls: 42.2 years [38.0–52.1]) underwent contemporaneous venous and TCB sampling for measurement of plasma C-peptide. Participants with type 1 diabetes also provided venous serum and plasma, and TCB plasma for measurement of autoantibodies to glutamate decarboxylase, islet antigen-2, and zinc transporter 8. The ability of TCB plasma to detect significant endogenous insulin secretion (venous C-peptide ≥200 pmol/L) was compared along with agreement in levels, using Bland-Altman. Venous serum was compared with venous and TCB plasma for detection of autoantibodies, using established thresholds. Acceptability was assessed by age-appropriate questionnaire.RESULTS:Transdermal sampling took a mean of 2.35 min (SD 1.49). Median sample volume was 50 µL (IQR 40–50) with 3 of 91 (3.3%) failures, and 13 of 88 (14.7%) <35 µL. TCB C-peptide showed good agreement with venous plasma (mean venous ln[C-peptide] – TCB ln[C-peptide] = 0.008, 95% CI [−0.23, 0.29], with 100% [36 of 36] sensitivity/100% [50 of 50] specificity to detect venous C-peptide ≥200 pmol/L). Where venous serum in multiple autoantibody positive TCB plasma agreed in 22 of 32 (sensitivity 69%), comparative specificity was 35 of 36 (97%). TCB was preferred to venous sampling (type 1 diabetes: 63% vs. 7%; 30% undecided).CONCLUSIONS:Transdermal capillary testing for C-peptide is a sensitive, specific, and acceptable alternative to venous sampling; TCB sampling for islet autoantibodies needs further assessment
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