Potential of hydrogel-forming and dissolving microneedles for use in paediatric populations

Development of formulations and drug delivery strategies for paediatric use is challenging, partially due to the age ranges within this population, resulting in varying requirements to achieve optimised patient outcomes. Although the oral route of drug delivery remains the preferred option, there are problematic issues, such as difficulty swallowing and palatability of medicines specific to this population. The parenteral route is not well accepted by children due to needle-related fear and pain. Accordingly, a plethora of alternative routes of drug administration have been investigated. Microneedles (MN) breach the stratum corneum (SC), the outermost layer of skin, increasing the number of drug substances amenable to transdermal delivery. This strategy involves the use of micron-sized needles to painlessly, and without drawing blood, create transient aqueous conduits in the SC. In this study, polymeric dissolving MN and hydrogel-forming MN were fabricated incorporating two model drugs commonly used in paediatric patients (caffeine and lidocaine hydrochloride). The potential efficacy of these MN for paediatric dosing was investigated via in vitro and in vivo studies. Views pertaining to MN technology were sought amongst school children in Northern Ireland, members of the UK general public and UK-based paediatricians, to determine perceived benefits, acceptance, barriers and concerns for adoption of this technology. In this study, polymeric MN were shown to substantially enhance skin permeability of the model therapeutic molecules in vitro and in vivo. In particular, hydrogel-forming MN led to a 6.1-fold increase in caffeine delivery whilst lidocaine HCl delivery was increased by 3.3-fold using dissolving MN in vitro. Application of caffeine-loaded MN led to a caffeine plasma concentration of 23.87μg/mL in rats at 24h. This research also highlighted a strong consensus regarding MN technology amongst schoolchildren, paediatricians and the general public, regarding potential use of MN in the paediatric population. Overall, 93.6% of general public respondents and 85.9% of paediatricians regarded the use of MN as a positive approach.

Molecular mechanisms of virulence of Burkholderia cepacia complex bacteria: Survival in Phagocytic Cells

Burkholderia cepacia complex (Bcc) species are a group of Gram-negative opportunistic pathogens that chronically infect the airways of cystic fibrosis patients, but they can also infect patients with various types of immunosuppressive disorders. Bcc members are multidrug resistant bacteria that have the ability to persist in the infected host and also elicit robust inflammatory responses. Studies using macrophages, neutrophils and dendritic cells, combined with dramatic advances in the ability to genetically manipulate these microorganisms have contributed to increase our understanding of the molecular mechanisms of virulence in these pathogens and the molecular details of the cell host responses triggering inflammation. This chapter reviews our understanding of the pathogenic mechanisms used by Bcc to establish an intracellular niche in phagocytic cells and modulate host cell responses that ultimately end up in cell death and a proinflammatory response.

Prevalence of the factor VR506Q mutation in two Irish control populations:use of a novel nested polymerase chain reaction approach

The prevalence of factor V (FV) Leiden among normal populations has primarily been determined using blood donors. This control group is carefully selected and therefore may not accurately reflect the true prevalence within the population. We assessed the prevalence of FV Leiden within the Irish population using Guthrie card samples randomly selected from all newborns. We compared this result with the prevalence of FV Leiden within blood donors. A novel nested polymerase chain reaction (PCR) method for FV Leiden was developed for analysis of the Guthrie card samples. There was no significant difference between the allele frequency within the Guthrie card samples and blood donors (2.07% vs. 2.35%, P = 0.66)

Prevalence of the prothrombin G20210A mutation in the Irish populations:use of a novel polymerase chain reaction approach

The prothrombin G20210A polymorphism is associated with a threefold-increased risk of venous thrombosis. There is considerable variation in the reported prevalence of this polymorphism within normal populations, ranging from 0 to 6.5%. The prevalence within the Irish population has not been determined. A restriction fragment length polymorphism (RFLP)-based assay is commonly used for the detection of the prothrombin 20210A allele. This assay does not include a control restriction digest fragment and, consequently, failure of the enzyme activity or lack of addition of enzyme to the sample cannot be distinguished from wild-type prothrombin. We developed a RFLP-based assay, which incorporates an invariant digest site, resulting in the generation of a control digest fragment. Furthermore, we developed a nested polymerase chain reaction (PCR) method for the amplification and digestion of poor-quality or low-concentration DNA. In the Irish population studied, five of 385 (1.29%) were heterozygous and one patient was homozygous for the prothrombin 20210A polymorphism. This is the first reported data on an Irish or Celtic population and suggests that the allele frequency is similar to Anglo-Saxon populations. The nested PCR method successfully amplified and digested 100/100 (100%) of the archived samples; none of these samples could be analyzed by the standard single-round PCR method. In conclusion, nested PCR should be considered in the analysis of archived samples. Single-round PCR is appropriate for recently collected samples; however, an invariant control digest site should be incorporated in RFLP-based assays to validate the integrity of the digestion enzyme and limit the risk of false-negative results.

Whole Genome Sequencing Reveals Local Transmission Patterns of Mycobacterium bovis in Sympatric Cattle and Badger Populations

Whole genome sequencing (WGS) technology holds great promise as a tool for the forensic epidemiology of bacterial pathogens. It is likely to be particularly useful for studying the transmission dynamics of an observed epidemic involving a largely unsampled 'reservoir' host, as for bovine tuberculosis (bTB) in British and Irish cattle and badgers. BTB is caused by Mycobacterium bovis, a member of the M. tuberculosis complex that also includes the aetiological agent for human TB. In this study, we identified a spatio-temporally linked group of 26 cattle and 4 badgers infected with the same Variable Number Tandem Repeat (VNTR) type of M. bovis. Single-nucleotide polymorphisms (SNPs) between sequences identified differences that were consistent with bacterial lineages being persistent on or near farms for several years, despite multiple clear whole herd tests in the interim. Comparing WGS data to mathematical models showed good correlations between genetic divergence and spatial distance, but poor correspondence to the network of cattle movements or within-herd contacts. Badger isolates showed between zero and four SNP differences from the nearest cattle isolate, providing evidence for recent transmissions between the two hosts. This is the first direct genetic evidence of M. bovis persistence on farms over multiple outbreaks with a continued, ongoing interaction with local badgers. However, despite unprecedented resolution, directionality of transmission cannot be inferred at this stage. Despite the often notoriously long timescales between time of infection and time of sampling for TB, our results suggest that WGS data alone can provide insights into TB epidemiology even where detailed contact data are not available, and that more extensive sampling and analysis will allow for quantification of the extent and direction of transmission between cattle and badgers. © 2012 Biek et al.

Traumatic brain injury and co-occurring problems in prison populations: a systematic review.

Background: A growing body of epidemiological research suggests high rates of traumatic brain injury (TBI) in prisoners. The aim of this review is to systematically explore the literature surrounding the rates of TBI and their co-occurrences in a prison population.
Methods: Six electronic databases were systematically searched for articles published between 1980 and 2014. Studies were screened for inclusion based on predetermined criteria by two researchers who independently performed data extraction. Study quality was appraised based on a modified quality assessment tool.
Results: Twenty six studies were included in this review. Quality assessment ranged from 20% (poor) to 80% (good) with an overall average of 60%. Twenty four papers included TBI prevalence rates, which ranged from 5.69%-88%. Seventeen studies explored co-occurring factors including rates of aggression (n=7), substance abuse (n=9), anxiety and depression (n=5), neurocognitive deficits (n=4), and psychiatric conditions (n=3).
Conclusions: The high degree of variation in TBI rates may be attributed to the inconsistent way in which TBI was measured with only seven studies using valid and reliable screening tools. Additionally, gaps in the literature surrounding personality outcomes in prisoners with TBI, female prisoners with TBI, and qualitative outcomes were found.

Incentives and rewards: what do adult populations truly want? Insights from the physical activity loyalty (PAL) scheme

Background
Trials depend on good recruitment and retention, but efforts to improve these have had varying success. This may be due to inadequate understanding of what participants would value in return for taking part. An opportunity arose in one trial to investigate the incentives that might help recruit and retain participants to another.

Aim
To determine what adults value as an incentive for involvement in a trial.

Methods
In the PAL Scheme, employees used a ‘loyalty card’ to monitor their physical activity over 12 weeks. The incentive group (n=199) collected points and received rewards for physical activity (1 minute = 1 point, max: 30 pts/day). A comparator group (n=207) self-monitored their physical activity only. Points could be redeemed as retail vouchers. 17 different incentives were available, from 75 pts (£2.50, a sandwich) to 1800 pts (£60, 1 month gym membership).

Results
148 of the 199 intervention participants used their card at least once, earning a mean of 374 pts. 121 earned sufficient to collect a reward and 76 redeemed points for vouchers but only 48 exchanged the vouchers for rewards. The most popular reward was not that of highest monetary value: two cinema tickets (300 pts, £10).

Conclusions
The value that participants place on a reward might be more important than its monetary value. Some might appreciate receiving the voucher, without spending it. In choosing incentives to boost trial participation, it may help to allow people to choose from a variety of rewards, rather than reimbursing in money.

Application of the pMHC Array to Characterise Tumour Antigen Specific T Cell Populations in Leukaemia Patients at Disease Diagnosis

Immunotherapy treatments for cancer are becoming increasingly successful, however to further improve our understanding of the T-cell recognition involved in effective responses and to encourage moves towards the development of personalised treatments for leukaemia immunotherapy, precise antigenic targets in individual patients have been identified. Cellular arrays using peptide-MHC (pMHC) tetramers allow the simultaneous detection of different antigen specific T-cell populations naturally circulating in patients and normal donors. We have developed the pMHC array to detect CD8+ T-cell populations in leukaemia patients that recognise epitopes within viral antigens (cytomegalovirus (CMV) and influenza (Flu)) and leukaemia antigens (including Per Arnt Sim domain 1 (PASD1), MelanA, Wilms' Tumour (WT1) and tyrosinase). We show that the pMHC array is at least as sensitive as flow cytometry and has the potential to rapidly identify more than 40 specific T-cell populations in a small sample of T-cells (0.8-1.4 x 106). Fourteen of the twenty-six acute myeloid leukaemia (AML) patients analysed had T cells that recognised tumour antigen epitopes, and eight of these recognised PASD1 epitopes. Other tumour epitopes recognised were MelanA (n = 3), tyrosinase (n = 3) and WT1126-134 (n = 1). One of the seven acute lymphocytic leukaemia (ALL) patients analysed had T cells that recognised the MUC1950-958 epitope. In the future the pMHC array may be used provide point of care T-cell analyses, predict patient response to conventional therapy and direct personalised immunotherapy for patients.

Outlier SNP markers reveal fine-scale genetic structuring across European hake populations (Merluccius merluccius)

Shallow population structure is generally reported for most marine fish and explained as a consequence of high dispersal, connectivity and large population size. Targeted gene analyses and more recently genome-wide studies have challenged such view, suggesting that adaptive divergence might occur even when neutral markers provide genetic homogeneity across populations. Here, 381 SNPs located in transcribed regions were used to assess large- and fine-scale population structure in the European hake (Merluccius merluccius), a widely distributed demersal species of high priority for the European fishery. Analysis of 850 individuals from 19 locations across the entire distribution range showed evidence for several outlier loci, with significantly higher resolving power. While 299 putatively neutral SNPs confirmed the genetic break between basins (F(CT) = 0.016) and weak differentiation within basins, outlier loci revealed a dramatic divergence between Atlantic and Mediterranean populations (F(CT) range 0.275-0.705) and fine-scale significant population structure. Outlier loci separated North Sea and Northern Portugal populations from all other Atlantic samples and revealed a strong differentiation among Western, Central and Eastern Mediterranean geographical samples. Significant correlation of allele frequencies at outlier loci with seawater surface temperature and salinity supported the hypothesis that populations might be adapted to local conditions. Such evidence highlights the importance of integrating information from neutral and adaptive evolutionary patterns towards a better assessment of genetic diversity. Accordingly, the generated outlier SNP data could be used for tackling illegal practices in hake fishing and commercialization as well as to develop explicit spatial models for defining management units and stock boundaries.

The dynamics of murid gammaherpesvirus 4 within wild, sympatric populations of bank voles and wood mice

Murid gammaherpesvirus 4 (MuHV-4) is widely used as a small animal model for understanding gammaherpesvirus infections in man. However, there have been no epidemiological studies of the virus in wild populations of small mammals. As MuHV-4 both infects cells associated with the respiratory and immune systems and attempts to evade immune control via various molecular mechanisms, infection may reduce immunocompetence with potentially serious fitness consequences for individuals. Here we report a longitudinal study of antibody to MuHV-4 in a mixed assemblage of bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus) in the UK. The study was conducted between April 2001 and March 2004. Seroprevalence was higher in wood mice than bank voles, supporting earlier work that suggested wood mice were the major host even though the virus was originally isolated from a bank vole. Analyses of both the probability of having antibodies and the probability of initial seroconversion indicated no clear seasonal pattern or relationship with host density. Instead, infection risk was most closely associated with individual characteristics, with heavier males having the highest risk. This may reflect individual variation in susceptibility, potentially related to variability in the ability to mount an effective immune response.

ANRIL Variants and Aggressive Periodontitis in European and African Populations

Introduction: The chromosome 9p21 locus has been identified as a marker of coronary artery disease. In this locus studies have focused on variations in the ANRIL gene that has also been identified as a strong candidate for association with aggressive periodontitis (AgP).
Objective: To investigate possible associations between gene variants of ANRIL and AgP in European and African populations.
Methods: European AgP cases (n= 213) and age-matched periodontally healthy controls (n= 81) were recruited from centres in the United Kingdom (Belfast, Glasgow, Newcastle and London). African AgP cases (n= 95) and controls (n= 105) were recruited in Khartoum, Sudan. Five single nucleotide polymorphisms (SNPs) in ANRIL were genotyped using Sequenom and analysed using Haploview with permutation testing to correct for multiple candidates. Odds ratios (OR) and 95% confidence intervals (95%CI) were calculated.
Results: In the European subjects there was a significant association between rs518394 (p=0.0013; OR = 1.81, 95%CI 1.26-2.61) and rs1333049 (p=0.0028; OR = 1.75, 95%CI 1.21-2.52) and AgP. These associations remained significant after permutation testing. In addition there was an association between rs 1360590 (p=0.035) and AgP in females. In the African subjects there was a significant association between only one SNP rs1537415 and AgP (p=0.036; OR = 1.59, 95%CI 1.04-2.43), however, this was not significant following permutation testing. There were no significant associations with rs3217992 in either population.
Conclusions: SNP variants in the ANRIL locus were shown to be significantly associated with AgP in a European population and for the first time in an African population confirming this as the best replicated locus for aggressive periodontitis.

Microbiological Profile of Aggressive Periodontitis in a Sudanese Population

Background: Several bacterial species have been identified as being associated with aggressive periodontitis (AgP) notably Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg). There are limited data on bacterial associations with AgP in African populations. Objective: To investigate possible associations between specific bacteria and AgP in a Sudanese population. Methods: Subgingival plaque samples were collected from 93 (20 male, 73 female) Sudanese patients diagnosed with AgP and from 72 (23 male, 48 female) periodontally healthy Sudanese controls. Quantitative PCR was used to identify Aa, Pg, Treponema denticola (Td) and Fusobacterium nucleatum (Fn). The prevalence of these bacterial species was compared using Chi-square analysis. Odds ratios (OR) were calculated using standard methods. Results: The cases with AgP were well matched in age with the controls: 24.8 (SD 5.1) compared with 23.5 (SD 3.7) years, p=0.07. There was a significantly higher prevalence of Pg in AgP (73%) than in the controls (33%), p<0.0001. The OR for Pg to be associated with AgP was 5.44 (95% confidence intervals 2.78-10.64). In 26 (38%) of the AgP cases positive for Pg there were low levels of this bacterium (<100 copies). Both Td and Fn were identified in virtually all (>95%) the plaque samples studied from both AgP and controls. Aa was the least frequently identified species and was present in only 28% of AgP and 18% of controls, p=0.14. The OR for Aa to be associated with AgP was slightly increased at 1.76 (95% CI 0.83-3.74), however, this was not significant (p=0.14). Conclusion: In the Sudanese subjects studied Pg but not Aa was associated with AgP. There were very low levels of Pg in many of the plaque samples from AgP.

Neuropeptides display antimicrobial activity against cariogenic and endodontic bacteria

Introduction: Many neuropeptides are similar in size, amino acid composition and charge to antimicrobial peptides. It is therefore possible that the nervous system employs neuropeptides as antimicrobial agents by delivering them rapidly and precisely to innervated sites such as the dental pulp. Objectives: The aim of this study was to determine whether the neuropeptides substance P (SP), neurokinin A (NKA), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP), which we have previously shown to be present in dental pulp, displayed antimicrobial activity against the cariogenic bacterium Streptococcus mutans and the endodontic bacterium Enterococcus faecalis. Methods: Neuropeptides were purchased from Bachem and utilised in antibacterial assays using a previously described ultra sensitive radial diffusion method. Results: Antimicrobial activity was identified as clear zones around neuropeptide-containing wells. NPY was found to exhibit antimicrobial against both Streptococcus mutans and Enterococcus faecalis. SP and VIP were shown to exhibit antimicrobial activity against Streptococcus mutans only. The neuropeptides NKA and CGRP did not show antimicrobial activity against either micro-organism. Conclusion: This study is the first to describe an antimicrobial role for neuropeptides in pulp biology. The antimicrobial actions of neuropeptides contribute a novel aspect to pulpal defence against cariogenic and endodontic bacteria worthy of further investigation.

Biometry and primary angle-closure glaucoma among Chinese, white, and black populations

PURPOSE: Primary angle-closure glaucoma (PACG) is more prevalent among Chinese than whites. The authors tested the hypothesis that Chinese have shallower anterior chambers than do whites, a factor that may be related to PACG prevalence. METHODS: The authors compared anterior chamber depth, axial length, radius of corneal curvature, and refractive error among 531 Chinese, 170 whites, and 188 blacks older than 40 years of age using the same model of instruments and identical technique. RESULTS: Mean anterior chamber depth and axial length did not differ significantly for the three groups. Whites had a significantly higher prevalence of hyperopia > 2 diopters than did Chinese. Radius of corneal curvature was significantly smaller among Chinese than whites or blacks. CONCLUSIONS: These results suggest that Chinese do not differ on a population basis from other ethnic groups in many of the biometric risk factors known to be of importance for PACG. It will be necessary to identify other ocular biometric parameters to explain the excess burden of PACG among Chinese, which may improve the effectiveness of screening for this disease in all populations.