Bone mineral density optimisation in adults with perinatally acquired HIV infection in routine care

We report on BMD and factors associated with reductions in BMD for all adults with perinatally acquired HIV who attended a London clinic between May 2014 and October 2016. We observed a high prevalence of reductions in BMD and a higher than expected prevalence of factors associated with adverse bone health, namely vitamin D deficiency

New synchronization method for <i>Plasmodium falciparum</i>

&lt;b&gt;Background&lt;/b&gt;: Plasmodium falciparum is usually asynchronous during in vitro culture. Although various synchronization methods are available, they are not able to narrow the range of ages of parasites. A newly developed method is described that allows synchronization of parasites to produce cultures with an age range as low as 30 minutes. &lt;b&gt;Methods&lt;/b&gt;: Trophozoites and schizonts are enriched using Plasmion. The enriched late stage parasites are immobilized as a monolayer onto plastic Petri dishes using concanavalin A. Uninfected erythrocytes are placed onto the monolayer for a limited time period, during which time schizonts on the monolayer rupture and the released merozoites invade the fresh erythrocytes. The overlay is then taken off into a culture flask, resulting in a highly synchronized population of parasites. &lt;b&gt;Results&lt;/b&gt;: Plasmion treatment results in a 10- to 13-fold enrichment of late stage parasites. The monolayer method results in highly synchronized cultures of parasites where invasion has occurred within a very limited time window, which can be as low as 30 minutes. The method is simple, requiring no specialized equipment and relatively cheap reagents. &lt;b&gt;Conclusions&lt;/b&gt;: The new method for parasite synchronization results in highly synchronized populations of parasites, which will be useful for studies of the parasite asexual cell cycle

Plasmodium falciparum:Rosettes do not protect merozoites from invasion-inhibitory antibodies

Rosetting is a parasite adhesion phenotype associated with severe malaria in African children. Why parasites form rosettes is unknown, although enhanced invasion or immune evasion have been suggested as possible functions. Previous work showed that rosetting does not enhance parasite invasion under standard in vitro conditions. We hypothesised that rosetting might promote invasion in the presence of host invasion-inhibitory antibodies, by allowing merozoites direct entry into the erythrocytes in the rosette and so minimising exposure to plasma antibodies. We therefore investigated whether rosetting influences invasion in the presence of invasion-inhibitory antibodies to MSP-1. We found no difference in invasion rates between isogenic rosetting and non-rosetting lines from two parasite strains, R29 and TM284, in the presence of MSP-1 antibodies (P=0.62 and P=0.63, Student's t test, TM284 and R29, respectively). These results do not support the hypothesis that rosettes protect merozoites from inhibitory antibodies during invasion. The biological function of rosetting remains unknown

Inflammatory bowel disease in the United Kingdom: Epidemiological trends in primary care and associations with contraception

Background: The epidemiology of inflammatory bowel disease (IBD) in the UK is poorly described. Primary care contraceptive prescribing data published by the NHS are not linked to individual patients. Studies have linked contraceptive pills to the development of IBD. However, there is a paucity of literature on how contraceptive formulation and duration of therapy affect IBD risk. Aims: To describe changes in the incidence and prevalence of IBD in the UK from 2000-2018. To describe non-barrier contraceptive prescribing patterns in primary care over the same period. To investigate the associations between exposure to contraception and development of IBD. Methods: Three epidemiological studies using IQVIATM Medical Research Data; a cohort study examining temporal trends in IBD incidence and prevalence, a repeated cross-sectional study exploring trends in contraceptive prescribing, a nested case-control study investigating the associations between a range of contraceptives and development of IBD. Results: Overall, the incidence of IBD is falling, but prevalence continues to rise. Some of the highest recorded incidence and prevalence rates globally were observed, with a 94% rise in incidence in adolescents since the year 2000. Over the same period, combined hormonal contraception prescribing has halved whereas progestogen-only pill prescribing has more than doubled. Methods of contraception prescribed by GPs are influenced by social deprivation. Withdrawal of a pay-for-performance incentive may have adversely affected adolescent long-acting reversible contraception uptake. Results suggest that oestrogen-containing contraception is associated with development of IBD whereas progestogen-only methods have minimal to no effect. Conclusion: This thesis provides evidence relating to a wide range of temporal trends in the epidemiology of IBD and patterns of contraceptive prescribing in the UK. Although previous associations between oral contraceptive pills and IBD have been made, this thesis provides the first epidemiological evidence that oestrogen-containing contraceptives, but not progestogen-only methods, are associated with development of IBD

Risk factors for UK Plasmodium falciparum cases

Background An increasing proportion of malaria cases diagnosed in UK residents with a history of travel to malaria endemic areas are due to Plasmodium falciparum. Methods In order to identify travellers at most risk of acquiring malaria a proportional hazards model was used to estimate the risk of acquiring malaria stratified by purpose of travel and age whilst adjusting for entomological inoculation rate (EIR) and duration of stay in endemic countries. Results Travellers visiting friends and relatives and business travellers were found to have significantly higher hazard of acquiring malaria (adjusted hazard ratio (HR) relative to that of holiday makers 7.4, 95% CI 6.4–8.5, p < 0. 0001 and HR 3.4, 95% CI 2.9-3.8, p < 0. 0001, respectively). All age-groups were at lower risk than children aged 0–15 years. Conclusions These estimates of the increased risk for business travellers and those visiting friends and relatives should be used to inform programmes to improve awareness of the risks of malaria when travelling

Multidrug resistant pulmonary tuberculosis treatment regimens and patient outcomes: an individual patient data meta-analysis of 9,153 patients.

Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB

Time trends in contraceptive prescribing in UK primary care 2000–2018: a repeated cross-sectional study

BACKGROUND: Over the last 20 years, new contraceptive methods became available and incentives to increase contraceptive uptake were introduced. We aimed to describe temporal trends in non-barrier contraceptive prescribing in UK primary care for the period 2000-2018. METHODS: A repeated cross-sectional study using patient data from the IQVIA Medical Research Data (IMRD) database. The proportion (95% CI) of women prescribed non-barrier contraception per year was captured. RESULTS: A total of 2 705 638 women aged 15-49 years were included. Between 2000 and 2018, the proportion of women prescribed combined hormonal contraception (CHC) fell from 26.2% (26.0%-26.3%) to 14.3% (14.2%-14.3%). Prescriptions for progestogen-only pills (POPs) and long-acting reversible contraception (LARC) rose from 4.3% (4.3%-4.4%) to 10.8% (10.7%-10.9%) and 4.2% (4.1%-4.2%) to 6.5% (6.5%-6.6%), respectively. Comparing 2018 data for most deprived versus least deprived areas, women from the most deprived areas were more likely to be prescribed LARC (7.7% (7.5%-7.9%) vs 5.6% (5.4%-5.8%)) while women from the least deprived areas were more likely to be prescribed contraceptive pills (20.8% (21.1%-21.5%) vs 26.2% (26.5%-26.9%)). In 2009, LARC prescriptions increased irrespective of age and social deprivation in line with a pay-for-performance incentive. However, following the incentive's withdrawal in 2014, LARC prescriptions for adolescents aged 15-19 years fell from 6.8% (6.6%-7.0%) in 2013 to 5.6% (5.4%-5.8%) in 2018. CONCLUSIONS: CHC prescribing fell by 46% while POP prescribing more than doubled. The type of contraception prescribed was influenced by social deprivation. Withdrawal of a pay-for-performance incentive may have adversely affected adolescent LARC uptake, highlighting the need for further intervention to target this at-risk group

Bone mineral density optimisation in adults with perinatally acquired HIV infection in routine care.

We report on BMD and factors associated with reductions in BMD for all adults with perinatally acquired HIV who attended a London clinic between May 2014 and October 2016. We observed a high prevalence of reductions in BMD and a higher than expected prevalence of factors associated with adverse bone health, namely vitamin D deficiency

Hematological profile of East African Short-Horn Zebu calves: From birth to 51 weeks of age

This paper is the first attempt to accurately describe the hematological parameters for any African breed of cattle, by capturing the changes in these parameters over the first 12 months of an animal’s life using a population based sample of calves reared under field conditions and natural disease challenge. Using a longitudinal study design, a stratified clustered random sample of newborn calves was recruited into the Infectious Diseases of East African Livestock (IDEAL) study and monitored at 5-weekly intervals until 51 weeks of age. The blood cell analysis performed at each visit included: packed cell volume; red cell count; red cell distribution width; mean corpuscular volume; mean corpuscular hemoglobin concentration; hemoglobin concentration; white cell count; absolute lymphocyte, eosinophil, monocyte, and neutrophil counts; platelet count; mean platelet volume; and total serum protein. The most significant age-related change in the red cell parameters was a rise in red cell count and hemoglobin concentration during the neonatal period. This is in contrast to what is reported for other ruminants, including European cattle breeds where the neonatal period is marked by a fall in the red cell parameters. There is a need to establish breed specific reference ranges for blood parameters for indigenous cattle breeds. The possible role of the postnatal rise in the red cell parameters in the adaptability to environmental constraints and innate disease resistance warrants further research into the dynamics of blood cell parameters of these breed