A dynamic relationship between mucosal T helper type 17 and regulatory T-cell populations in nasopharynx evolves with age and associates with the clearance of pneumococcal carriage in humans

Pneumococcal carriage is common in young children, which may account for the high incidence of disease in this age group. Host factors determining the clearance of carriage in humans remain unclear. We aimed to study the relationships between T helper type 17 (Th17) and Foxp3(+) regulatory T (Treg) cells in nasopharynx-associated lymphoid tissue (NALT) and carriage in children and adults. Frequencies of Th17 and Treg cells in NALT were analysed by flow cytometry in association with age and pneumococcal carriage status. Cytokine responses following pneumococcal stimulation were analysed by cytometric beads array. The frequencies of Th17 and Treg cells in NALT were inversely correlated (R -0.60). Whereas Treg cell frequency decreased with age (R -0.63), both Th17 and the Th17: Treg ratio increased with age (R 0.62 and R 0.64, respectively). Also, the Th17: Treg ratio was higher in carriage-negative than in carriage-positive children (p <0.01). Pneumococcal stimulation of tonsillar cells increased both Th17 and Treg cell numbers, but the Th17: Treg ratio and pattern of cytokine responses differed between carriage-negative and carriage-positive children. The former showed markedly higher Th17: Treg and interleukin-17A: interleukin-10 ratios than in the latter (p <0.01). Pneumococcal stimulation also induces Th17, although the capacity of this Th17 differentiation from naive T cells of young children was low, but increased with age. We demonstrated a dynamic relationship between Th17 and Treg cells in human nasopharynx that evolves with age. The balance between Th17 and Treg cells in NALT appears to be a major host factor closely associated with the clearance of Streptococcus pneumoniae from the nasopharynx

Dried blood spots as a source of anti-malarial antibodies for epidemiological studies

BACKGROUND: Blood spots collected onto filter paper are an established and convenient source of antibodies for serological diagnosis and epidemiological surveys. Although recommendations for the storage and analysis of small molecule analytes in blood spots exist, there are no published systematic studies of the stability of antibodies under different storage conditions. METHODS: Blood spots, on filter paper or glass fibre mats and containing malaria-endemic plasma, were desiccated and stored at various temperatures for different times. Eluates of these spots were assayed for antibodies against two Plasmodium falciparum antigens, MSP-119 and MSP2, and calculated titres used to fit an exponential (first order kinetic) decay model. The first order rate constants (k) for each spot storage temperature were used to fit an Arrhenius equation, in order to estimate the thermal and temporal stability of antibodies in dried blood spots. The utility of blood spots for serological assays was confirmed by comparing antibodies eluted from blood spots with the equivalent plasma values in a series of samples from North Eastern Tanzania and by using blood spot-derived antibodies to estimate malaria transmission intensity in this site and for two localities in Uganda. RESULTS: Antibodies in spots on filter paper and glass fibre paper had similar stabilities but blood was more easily absorbed onto filter papers than glass fibre, spots were more regular and spot size was more closely correlated with blood volume for filter paper spots. Desiccated spots could be stored at or below 4 degrees C for extended periods, but were stable for only very limited periods at ambient temperature. When desiccated, recoveries of antibodies that are predominantly of IgG1 or IgG3 subclasses were similar. Recoveries of antibodies from paired samples of serum and of blood spots from Tanzania which had been suitably stored showed similar recoveries of antibodies, but spots which had been stored for extended periods at ambient humidity and temperature showed severe loss of recoveries. Estimates of malaria transmission intensity obtained from serum and from blood spots were similar, and values obtained using blood spots agreed well with entomologically determined values. CONCLUSION: This study has demonstrated the suitability of filter paper blood spots paper for collection of serum antibodies, and provided clear guidelines for the treatment and storage of filter papers which emphasize the importance of desiccation and minimisation of time spent at ambient temperatures. A recommended protocol for collecting, storing and assaying blood spots is provided

SPARC 2019 Fake news & home truths : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2019 SPARC conference. This year we not only celebrate the work of our PGRs but also our first ever Doctoral School Best Supervisor awards, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 90 presenters, the conference truly showcases a vibrant, innovative and collaborative PGR community at Salford. These abstracts provide a taster of the inspiring, relevant and impactful research in progress, and provide delegates with a reference point for networking and initiating critical debate. Find an abstract that interests you, and say “Hello” to the author. Who knows what might result from your conversation? With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research needs interdisciplinary collaboration. This is recognised and rewarded by all major research funders. Engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers. Even better, our free ice cream van means that you can have those conversations while enjoying a refreshing ice lolly

Can environmental or occupational hazards alter the sex ratio at birth? A systematic review

More than 100 studies have examined whether environmental or occupational exposures of parents affect the sex ratio of their offspring at birth. For this review, we searched Medline and Web of Science using the terms ‘sex ratio at birth’ and ‘sex ratio and exposure’ for all dates, and reviewed bibliographies of relevant studies to find additional articles. This review focuses on exposures that have been the subject of at least four studies including polychlorinated biphenyls (PCBs), dioxins, pesticides, lead and other metals, radiation, boron, and g-forces. For paternal exposures, only dioxins and PCBs were consistently associated with sex ratios higher or lower than the expected 1.06. Dioxins were associated with a decreased proportion of male births, whereas PCBs were associated with an increased proportion of male births. There was limited evidence for a decrease in the proportion of male births after paternal exposure to DBCP, lead, methylmercury, non-ionizing radiation, ionizing radiation treatment for childhood cancer, boron, or g-forces. Few studies have found higher or lower sex ratios associated with maternal exposures. Studies in humans and animals have found a reduction in the number of male births associated with lower male fertility, but the mechanism by which environmental hazards might change the sex ratio has not yet been established

Role of magnetic resonance planimetry and magnetic resonance parkinsonism index in discriminating Parkinson&rsquo;s disease and progressive supranuclear palsy: a retrospective study based on 1.5 and 3 T MRI

Waseem Mehmood Nizamani,1 Fatima Mubarak,1 Muhammad Danish Barakzai,1 Muhammad Saad Ahmed2 1Department of Radiology, Aga Khan University Hospital, Karachi, Pakistan, 2Department of Radiology, Ziauddin University Hospital, Karachi, Pakistan Objective: The objective of the study was to assess magnetic resonance (MR) planimetric measurements and MR parkinsonism index (MRPI) in differentiating progressive supranuclear palsy (PSP) from Parkinson&rsquo;s disease (PD) using 1.5 and 3 T MRI scanner. Subjects and methods: After ethical approval was obtained, analysis of 34 consecutive patients with PSP, 34 patients with PD and 34 healthy controls (HCs) was performed. HCs were age-matched adults without any history of neurodegenerative disease or movement disorders. Retrospective data from the past 10 years (from January 2006 to December 2015) were obtained from the Hospital Information Management System, and informed consent was obtained from all participants. The measurements of pons area&ndash;midbrain area ratio (P/M) and MCP width&ndash;superior cerebellar peduncle (SCP) width ratio (MCP/SCP) were used, and MRPI was calculated by the formula ([P/M]&times;[MCP/SCP]). Results: Midbrain area and SCP width in patients with PSP (19 males, 15 females; mean age =66.7 years) were significantly (P&lt;0.001) smaller than in patients with PD (20 males, 14 females; mean age =66.7 years) and control participants (17 males, 17 females; mean age =66.1 years). P/M and MCP/SCP were significantly higher in patients with PSP than in patients with PD and control participants. All measurements showed some overlap of values between patients with PSP and patients from PD group and control participants. MRPI value was significantly higher in patients with PSP (mean 21.00) than in patients with PD (mean 9.50; P&lt;0.001) and control participants (mean 9.6; P&lt;0.001), without any overlap of values among groups. No correlation was found between the duration of disease, PSP rating scale, PSP staging system and MRPI in this study. No patient with PSP received a misdiagnosis when the index was used (sensitivity and specificity, 100%). Conclusion: MRPI should be made an essential part of all MRI brain reporting whenever differentiation between PD and PSP is sought for. Keywords: cognitive dysfunction, movement disorders, progressive supranuclear palsy, Parkinsonism Index&nbsp