Obesity is South Africa's new HIV epidemic

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Biomechanical comparison of titanium alloy additively manufactured and conventionally manufactured plate-screw constructs

AIM

To biomechanically compare the bending stiffness, strength, and cyclic fatigue of titanium additively manufactured (AM) and conventionally manufactured (CM) limited contact plates (LCP) of equivalent dimensions using plate-screw constructs.

METHODS

Twenty-four 1.5/2.0-mm plate constructs (CM: n = 12; AM: n = 12) were placed under 4-point bending conditions. Data were collected during quasi-static single cycle to failure and cyclic fatigue testing until implants plastically deformed or failed. Bending stiffness, bending structural stiffness, and bending strength were determined from load-displacement curves. Fatigue life was determined as number of cycles to failure. Median test variables for each method were compared using the Wilcoxon rank sum test within each group. Fatigue data was also analysed by the Kaplan-Meier estimator of survival function.

RESULTS

There was no evidence for a difference in bending stiffness and bending structural stiffness between AM and CM constructs. However, AM constructs exhibited greater bending strength (median 3.07 (min 3.0, max 3.4) Nm) under quasi-static 4-point bending than the CM constructs (median 2.57 (min 2.5, max 2.6) Nm, p = 0.006). Number of cycles to failure under dynamic 4-point bending was higher for the CM constructs (median 164,272 (min 73,557, max 250,000) cycles) than the AM constructs (median 18,704 (min 14,427, max 33,228) cycles; p = 0.02). Survival analysis showed that 50% of AM plates failed by 18,842 cycles, while 50% CM plates failed by 78,543 cycles.

CONCLUSION AND CLINICAL RELEVANCE

Additively manufactured titanium implants, printed to replicate a conventional titanium orthopaedic plate, were more prone to failure in a shorter fatigue period despite being stronger in single cycle to failure. Patient-specific implants made using this process may be brittle and therefore not comparable to CM orthopaedic implants. Careful selection of their use on a case/patient-specific basis is recommended.

Importance of surgical assembly technique on the engagement of 12/14 modular tapers

Fretting-corrosion at the modular taper junction in total hip replacements (THR), leading to implant failure, has been identified as a clinical concern and has received increased interest in recent years. There are many parameters thought to affect the performance of the taper junction, with the assembly process being one of the few consistently identified to have a direct impact. Despite this, the assembly process used by surgeons during THR surgery differs from a suggested 'ideal' process. For example, taper junctions of cutting tools should be pushed together rather than impacted, while ensuring as much concentricity as possible between the male and female taper and loading axis. This study devised six simple assembly methodologies to investigate how surgical variations affect the success of the compressive fit achieved at the taper interface compared to a controlled assembly method, designed to represent a more 'ideal' scenario. Key findings from this study suggest that a more successful and repeatable engagement can be achieved by quasi-statically loading the male and female taper concentrically with the loading axis. This was shown by a greater disassembly to assembly force ratio of 0.626 ± 0.07 when assembled using the more 'ideal' process, compared to 0.480 ± 0.05 when using a method closer to that used by a surgeon intraoperatively. Findings from this study can be used to help inform new surgical instrumentation and an improved surgical assembly method.

Geometric Variations of Modular Head-Stem Taper Junctions of Total Hip Replacements

Taper degradation in Total Hip Replacements (THR) has been identified as a clinical concern, and the degradation occurring at these interfaces has received increased interest in recent years. Wear and corrosion products produced at the taper junction are associated with adverse local tissue responses, leading to early failure and revision surgery. Retrieval and in-vitro studies have found that variations in taper design affect degradation. However, there is a lack of consistent understanding within the literature of what makes a good taper interface. Previous studies assessed different design variations using their global parameters assuming a perfect cone such as: taper length, cone angle and diameters. This study assessed geometrical variations of as-manufactured head and stem tapers and any local deviations from their geometry. The purpose of this study was to provide a greater insight into possible engagement, a key performance influencing parameter predicted by Morse taper connection theory. This was achieved by taking measurements of twelve different commercially available male tapers and six female tapers using a coordinate measurement machine (CMM). The results suggested that engagement is specific to a particular head-stem couple. This is subject to both their micro-scale deviations, superimposed on their macro-scale differences. Differences in cone angles between female and male tapers from the same manufacturer was found to create a predominately proximal contact. However, distally mismatched couples are present in some metal-on-metal head-stem couples. On a local scale, different deviation patterns were observed from the geometry which appeared to be linked to the manufacturing process. Future work will look at using this measurement methodology to fully characterise an optimal modular taper junction for a THR prosthesis.

Kidney damage and associated risk factors in rural and urban sub-Saharan Africa (AWI-Gen): a cross-sectional population study

BACKGROUND

Rapid epidemiological health transitions occurring in vulnerable populations in Africa that have an existing burden of infectious and non-communicable diseases predict an increased risk and consequent prevalence of kidney disease. However, few studies have characterised the true burden of kidney damage and associated risk factors in Africans. We investigated the prevalence of markers for kidney damage and known risk factors in rural and urban settings in sub-Saharan Africa.

METHODS

In this cross-sectional population study (Africa Wits-International Network for the Demographic Evaluation of Populations and their Health Partnership for Genomic Studies [AWI-Gen]), we recruited unrelated adult participants aged 40-60 years from four rural community research sites (Nanoro, Burkina Faso; Navrongo, Ghana; Agincourt and Dikgale, South Africa), and two urban community research sites (Nairobi, Kenya; and Soweto, South Africa). Participants were identified and selected using random sampling frames already in use at each site. Participants completed a lifestyle and medical history questionnaire, had anthropometric and blood pressure measurements taken, and blood and urine samples were collected. Markers of kidney damage were defined as low estimated glomerular filtration rate (eGFR; <60 mL/min per 1·73 m²), presence of albuminuria (urine albumin creatinine ratio >3 mg/mmol); or chronic kidney disease (low eGFR or albuminuria, or both). We calculated age-adjusted prevalence of chronic kidney disease, low eGFR, and albuminuria by site and sex and used logistic regression models to assess risk factors of kidney damage.

FINDINGS

Between August, 2013, and August, 2016, we recruited 10 702 participants, of whom 8110 were analysable. 4120 (50·8%) of analysable participants were male, with a mean age of 49·9 years (SD 5·8). Age-standardised population prevalence was 2·4% (95% CI 2·1-2·8) for low eGFR, 9·2% (8·4-10·0) for albuminuria, and 10·7% (9·9-11·7) for chronic kidney disease, with higher prevalences in South African sites than in west African sites (14·0% [11·9-16·4] in Agincourt vs 6·6% [5·5-7·9] in Nanoro). Women had a higher prevalence of chronic kidney disease (12·0% [10·8-13·2] vs 9·5% [8·3-10·8]) and low eGFR (3·0% [2·6-3·6] vs 1·7% [1·3-2·3]) than did men, with no sex-specific differences for albuminuria (9·9% [8·8-11·0] vs 8·4% [7·3-9·7]). Risk factors for kidney damage were older age (relative risk 1·04, 95% CI 1·03-1·05; p<0·0001), hypertension (1·97, 1·68-2·30; p<0·0001), diabetes (2·22, 1·76-2·78; p<0·0001), and HIV (1·65, 1·36-1·99; p<0·0001); whereas male sex was protective (0·85, 0·73-0·98; p=0·02).

INTERPRETATION

Regional differences in prevalence and risks of chronic kidney disease in sub-Saharan Africa relate in part to varying stages of sociodemographic and epidemiological health transitions across the area. Public health policy should focus on integrated strategies for screening, prevention, and risk factor management in the broader non-communicable disease and infectious diseases framework.

FUNDING

National Human Genome Research Institute, Office of the Director, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institute of Environmental Health Sciences, the Office of AIDS Research, and National Institute of Diabetes and Digestive and Kidney Diseases, all of the National Institutes of Health, and the South African Department of Science and Technology.

83 A Deficit Accumulation Frailty Index Predicts Mortality in Older South Africans: Findings from the HAALSI Study

Introduction

Few studies have investigated frailty in older people in sub-Saharan Africa, yet such information is vital to prepare responses to rapid population ageing. We aimed to derive and test a cumulative deficit frailty index in a population of older people from rural South Africa.

Methods

We analysed data from the Health and Ageing in Africa: Longitudinal Studies of an INDEPTH Community (HAALSI) study, which enrolled participants aged 40 years and older nested within the Agincourt Health and Demographic Survey Site, South Africa. We created a 32-variable cumulative deficit frailty index using questionnaire (illnesses, symptoms and activities of daily living), physical performance and physiological indices, and blood test results. Each variable was dichotomised to 1 (deficit) or 0 (no deficit). The frailty index for each individual was calculated as the mean of all frailty variables. Frailty categories were defined using cut-offs from the UK electronic frailty index: 0-0.12 (non-frail), &gt;0.12-0.24 (mild frailty), &gt;0.24-0.36 (moderate frailty) and &gt;0.36 (severe frailty). Cox proportional hazards models, both unadjusted and adjusted for age and sex, were fitted to test the association between frailty status and all-cause mortality.

Results

We analysed data from 3989 participants, mean age 61 years (SD 13); 2175 (54.5%) were female. The mean follow-up period was 17 months; 1464 (36.7%) were non-frail, 2059 (51.6%) had mild frailty, 402 (10.1%) had moderate frailty and 64 (1.6%) had severe frailty. A total of 135 (3.4%) died. Adjusted Cox models showed worse frailty category was associated with higher risk of death compared with non-frail individuals: hazard ratios 1.94 (95% CI 1.23, 3.07) for mild frailty, 3.25 (95% CI 1.86, 5.68) for moderate frailty, and 5.50 (95% CI 2.44, 12.40) for severe frailty.

Conclusions

Frailty measured by a cumulative deficits index is common and predicts mortality in a rural population of older South Africans.

Endocrine morbidity in midline brain defects: Differences between septo-optic dysplasia and related disorders

BACKGROUND

Septo-optic dysplasia (SOD) is a heterogeneous congenital condition. The aim of this study was to investigate the clinical phenotypes of a large cohort of children with SOD, Multiple Pituitary Hormone Deficiency (MPHD) and Optic Nerve Hypoplasia (ONH), with a focus on endocrine testing.

METHODS

Retrospective single-centre longitudinal study of children with SOD (n:171), MPHD (n:53) and ONH (n:35). SOD+ and SOD- indicate patients with or without hypopituitarism, respectively.

FINDINGS

All deficits were more frequent and occurred earlier in MPHD than SOD+ [Hazard Ratios (HR): 0·63(0·45,0·89) for GH, 0·48(0·34,0·69) for TSH, 0·55(0·38,0·80) for ACTH, 0·28(0·11,0·68) for gonadotropins], except Diabetes Insipidus (DI) [HR: 2·27(0·88,5·9)]. Severe hypothalamo-pituitary (H-P) abnormalities were more frequent in MPHD [80·0% vs 41·6%, p<0·0001 for Ectopic Posterior Pituitary (EPP)]. Stalk and PP abnormalities were associated with more severe endocrine phenotypes and placed a subgroup of SOD+ at risk of developing deficits earlier. SOD and ONH shared heterogeneous phenotypes ranging from pubertal delay to precocity and from leanness to extreme obesity, whilst MPHD had GnD and obesity only. Mortality was recorded in 4·2% (6/144) SOD and 3·2% (1/31) ONH, and only in patients with multisystem phenotypes.

INTERPRETATION

More than a single disease, SOD represents a spectrum of malformative conditions involving different brain structures and characterised by a dynamic and sequential nature of endocrine. In contrast, MPHD displays a more homogeneous phenotype of (mainly) anterior pituitary early-onset failure. Stalk and PP abnormalities place a subgroup of SOD+ at a higher risk of early-onset deficits. Additionally, there are striking differences between the SOD and MPHD cohorts in terms of pubertal progression. The shared phenotypes between ONH and SOD could be partly explained by common hypothalamic dysfunction. The differences between the cohorts are important as they may aid in planning management and preventing morbidity by dictating earlier interventions.

FUNDING

M.C., M.G., and N.I. were supported by the European Society of Paediatric Endocrinology (ESPE) through ESPE Clinical Fellowships.

Strong dose response after immunotherapy with PQ grass using conjunctival provocation testing

Background

Pollinex Quattro Grass (PQ Grass) is an effective, well-tolerated, short pre-seasonal subcutaneous immunotherapy to treat seasonal allergic rhinoconjunctivitis (SAR) due to grass pollen. In this Phase II study, 4 cumulative doses of PQ Grass and placebo were evaluated to determine its optimal cumulative dose.

Methods

Patients with grass pollen-induced SAR were randomised to either a cumulative dose of PQ Grass (5100, 14400, 27600 and 35600 SU) or placebo, administered as 6 weekly subcutaneous injections over 31-41 days (EudraCT number 2017-000333-31). Standardized conjunctival provocation tests (CPT) using grass pollen allergen extract were performed at screening, baseline and post-treatment to determine the total symptom score (TSS) assessed approximately 4 weeks after dosing. Three models were pre-defined (Emax, logistic, and linear in log-dose model) to evaluate a dose response relationship.

Results

In total, 95.5% of the 447 randomized patients received all 6 injections. A highly statistically significant (p < 0.0001), monotonic dose response was observed for all three pre-specified models. All treatment groups showed a statistically significant decrease from baseline in TSS compared to placebo, with the largest decrease observed after 27600 SU (p < 0.0001). The full course of 6 injections was completed by 95.5% of patients. Treatment-emergent adverse events were similar across PQ Grass groups, and mostly mild and transient in nature.

Conclusions

PQ Grass demonstrated a strong curvilinear dose response in TSS following CPT without compromising its safety profile.

Investigating the relationship between multimorbidity and dental attendance: a cross-sectional study of UK adults

Introduction

Regular dental attendance is related to better oral health. However, long-standing health conditions (LSHCs) may be related to dental attendance and this relationship may vary by socioeconomic status.

Method

Data were collected from wave two (2013–2015) of the Yorkshire Health Study (n= 7,654). Data included dental attendance, LSHC, age, gender, education-level, smoking, body mass index, and area-level deprivation. Logistic regression (attend or not) was used to analyse associations with LSHC and multimorbidity.

Results

Overall, 63.1% (n = 4,826) of individuals attended the dentist. Of these, 37.8% (n =2894) had no LSHC, 26.0% (n = 1987) had one LSHC and 36.4% (n = 2784) had two or more LSHC. The presence of a singular LSHC was not associated with dental attendance(OR = 0.91 [0.81, 1.04]), however, those with two or more LSHCs were more likely to attend the dentist (OR = 0.81 [95% CI 0.72, 0.92]). Interactions between individual-level education, as a marker of socioeconomic status, and LSHC revealed few associations with dental attendance.

Conclusion

Multimorbidity was associated with dental attendance such that those with multimorbidity were more likely to attend. These important findings highlight the increasing challenge of multimorbidity for global healthcare systems.

MON-604 Reference Ranges for Thyroid Stimulating Hormone and Free Thyroxine in an Older Rural South African Population

Background: Despite recognition that TSH and free T4 (fT4) ranges are population-specific, little data exist on these ranges in sub-Saharan African (SSA) populations. Evaluation of thyroid function is therefore based on reference ranges that may not be representative, potentially resulting in misdiagnosis. We hypothesized that population-specific reference ranges for TSH and fT4 in an older, rural South African population would differ from those cited by the assay manufacturer. Methods: 1498 people, 40-80 years, were randomly selected from the population-based Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) cohort in Mpumalanga province in rural South Africa, an iodine-sufficient country. 3^rd generation TSH, fT4 and antithyroperoxidase antibodies (antiTPO Ab) were measured using chemiluminescent immunoassays. A disease-free population without self-reported thyroid disease was identified (n=1466). Non-pregnant, HIV-negative individuals with antiTPO Ab <35 IU/ml were then selected, with further exclusion of those with overt hypo/hyperthyroidism (TSH>4μIU/ml & fT4<0.89 ng/dl or TSH<0.4 μIU/ml & fT4>1.76 ng/dl) and with potential subclinical dysfunction (normal fT4 with TSH<0.1 μIU/ml or >10 μIU/ml) to form a reference population (n=681). Median, 2.5^th and 97.5^th percentile values of TSH and fT4 were determined for the overall reference population and for subgroups defined by age and sex. Population-specific ranges were used to classify the disease-free population. Results: Median age of the reference population was 61 years, with 51.5% males. Median TSH was 1.27 μIU/ml and median fT4 was 1.04 ng/dl. Population-specific TSH range was 0.43-3.86 μIU/ml (manufacturer 0.4-4.0 μIU/ml). There were no significant differences in age (p=0.061) or gender distribution (p=0.696), but those aged 70-80 had an upper reference limit of 5.03 μIU/ml. fT4 range was 0.70-1.47 ng/dl (manufacturer 0.89-1.76 ng/dl), with distribution of fT4 differing by sex (p=0.025) and age (p<0.001). 3.3% of the disease-free population had overt or subclinical hypothyroidism and 3.1 % had overt or subclinical hyperthyroidism. Conclusion: In one of the first population-based studies of TSH and fT4 reference ranges in SSA, we demonstrate that, in those <70, the upper limit of TSH and ranges for fT4 in a rural South African population are lower than manufacturer-specified values, mimicking findings in African-American (AA) populations, though in contrast to AAs, the lower limit of TSH in our population was higher than the manufacturer value. Hypothyroidism may therefore be underdiagnosed when TSH alone is used to screen for thyroid dysfunction. Further work is needed to define normal ranges in specific South African populations, such as pregnant women, who may be more vulnerable to the effects of thyroid dysfunction. Funding: FIC/NIH; NIA/NIH, NHGRI/NIH, OD/NIH

Hypertension and diabetes control along the HIV care cascade in rural South Africa

INTRODUCTION

Participation in antiretroviral therapy (ART) programmes has been associated with greater utilization of care for hypertension and diabetes in rural South Africa. The objective of this study was to assess whether people living with HIV on ART with comorbid hypertension or diabetes also have improved chronic disease management indicators.

METHODS

The Health and Aging in Africa: a longitudinal study of an INDEPTH Community in South Africa (HAALSI) is a cohort of 5059 adults >40 years old. Enrollment took place between November 2014 and November 2015. The study collected population-based data on demographics, healthcare utilization, height, weight, blood pressure (BP) and blood glucose as well as HIV infection, HIV-1 RNA viral load (VL) and ART exposure. We used regression models to determine whether HIV care cascade stage (HIV-negative, HIV+ /No ART, ART/Detected HIV VL, and ART/Undetectable VL) was associated with diagnosis or treatment of hypertension or diabetes, and systolic blood pressure and glucose among those with diagnosed hypertension or diabetes. ART use was measured from drug level testing on dried blood spots.

RESULTS AND DISCUSSION

Compared to people without HIV, ART/Undetectable VL was associated with greater awareness of hypertension diagnosis (adjusted risk ratio (aRR) 1.18, 95% CI: 1.09 to 1.28) and treatment of hypertension (aRR 1.24, 95% CI: 1.10 to 1.41) among those who met hypertension diagnostic criteria. HIV care cascade stage was not significantly associated with awareness of diagnosis or treatment of diabetes. Among those with diagnosed hypertension or diabetes, ART/Undetectable VL was associated with lower mean systolic blood pressure (5.98 mm Hg, 95% CI: 9.65 to 2.32) and lower mean glucose (3.77 mmol/L, 95% CI: 6.85 to 0.69), compared to being HIV-negative.

CONCLUSIONS

Participants on ART with an undetectable VL had lower systolic blood pressure and blood glucose than the HIV-negative participants. HIV treatment programmes may provide a platform for health systems strengthening for cardiometabolic disease.

The dynamics of granular flow from a silo with two symmetric openings

The dynamics of granular flow in a rectangular silo with two symmetrically placed exit openings is investigated using particle image velocimetry (PIV), flow rate measurements and discrete element modelling (DEM). The flow of mustard seeds in a Perspex silo is recorded using a high-speed camera and the resulting image frames are analysed using PIV to obtain velocity, velocity divergence and shear rate plots. A change in flow structure is observed as the distance L between the two openings is varied. The mass flow rate is shown to be at a maximum at zero opening separation, decreasing as L is increased; it then reaches a minimum before rising to an equilibrium rate close to two times that of an isolated (non-interacting) opening. The flow rate experiment is repeated using amaranth and screened sand and similar behaviour is observed. Although this result is in contrast with some recent DEM and physical experiments in silo systems, this effect has been reported in an analogous system: the evacuation of pedestrians from a room through two doors. Our experimental results are replicated using DEM and we show that inter-particle friction controls the flow rate behaviour and explains the discrepancies in the literature results.

Cross-sectional relationship between haemoglobin concentration and measures of physical and cognitive function in an older rural South African population

Background

Age cohort differences in haemoglobin concentrations and associations with physical and cognitive performance among populations of lower income and middle-income countries have not previously been described. We examined the association between these factors among older men and women in rural South Africa.

Methods

We analysed cross-sectional data from a population-based study of rural South African men and women aged 40 and over (n=4499), with data drawn from questionnaire responses, a cognitive battery, objective physical function tests and blood tests. Anaemia was defined as a haemoglobin concentration <12 g/dL for women and <13 g/dL for men. We related haemoglobin concentrations to each of age, grip strength, walk speed and a latent cognitive function z-score for men and women separately. We used unadjusted correlations and linear models to adjust for comorbidities and inflammation.

Results

In total, 1042 (43.0%) women and 833 (40.1%) men were anaemic. Haemoglobin concentrations were inversely correlated with age for men but not for women; in adjusted analyses, haemoglobin was 0.3 g/dL lower per decade older for men (95% CI 0.2 to 0.4 g/dL). In adjusted analyses, haemoglobin concentration was independently associated with grip strength in women (B=0.391, 95% CI 0.177 to 0.605), but this did not reach significance in men (B=0.266, 95% CI −0.019 to 0.552); no associations were observed between haemoglobin levels and walk speed or cognitive score.

Conclusions

Anaemia was prevalent in this study population of middle-aged and older, rural South African adults, but in contrast to high-income countries, it was not associated with poor physical or cognitive function. Our findings need to be replicated in other populations.

Genomic and environmental risk factors for cardiometabolic diseases in Africa: methods used for Phase 1 of the AWI-Gen population cross-sectional study

There is an alarming tide of cardiovascular and metabolic disease (CMD) sweeping across Africa. This may be a result of an increasingly urbanized lifestyle characterized by the growing consumption of processed and calorie-dense food, combined with physical inactivity and more sedentary behaviour. While the link between lifestyle and public health has been extensively studied in Caucasian and African American populations, few studies have been conducted in Africa. This paper describes the detailed methods for Phase 1 of the AWI-Gen study that were used to capture phenotype data and assess the associated risk factors and end points for CMD in persons over the age of 40 years in sub-Saharan Africa (SSA). We developed a population-based cross-sectional study of disease burden and phenotype in Africans, across six centres in SSA. These centres are in West Africa (Nanoro, Burkina Faso, and Navrongo, Ghana), in East Africa (Nairobi, Kenya) and in South Africa (Agincourt, Dikgale and Soweto). A total of 10,702 individuals between the ages of 40 and 60 years were recruited into the study across the six centres, plus an additional 1021 participants over the age of 60 years from the Agincourt centre. We collected socio-demographic, anthropometric, medical history, diet, physical activity, fat distribution and alcohol/tobacco consumption data from participants. Blood samples were collected for disease-related biomarker assays, and genomic DNA extraction for genome-wide association studies. Urine samples were collected to assess kidney function. The study provides base-line data for the development of a series of cohorts with a second wave of data collection in Phase 2 of the study. These data will provide valuable insights into the genetic and environmental influences on CMD on the African continent.

Effect of Intravenous Administration of Cobalt Chloride to Horses on Clinical and Hemodynamic Variables

Background

Cobalt chloride (CoCl₂) is administered to racehorses to enhance performance. The purpose of this study was to evaluate the clinical, cardiovascular, and endocrine effects of parenterally administered CoCl₂.

Objectives

To describe the effects of weekly intravenous doses of CoCl₂ on Standardbred horses.

Animals

Five, healthy Standardbred mares.

Methods

Prospective, randomized, experimental dose‐escalation pilot. Five Standardbred mares were assigned to receive 1 of 5 doses of CoCl₂ (4, 2, 1, 0.5, or 0.25 mg/kg) weekly IV for 5 weeks. Physical examination, blood pressure, cardiac output, and electrocardiography (ECG) were evaluated for 4 hours after administration of the first and fifth doses. Blood and urine samples were collected for evaluation of cobalt concentration, CBC and clinical chemistry, and hormone concentrations.

Results

All mares displayed pawing, nostril flaring, muscle tremors, and straining after CoCl₂ infusion. Mares receiving 4, 2, or 1 mg/kg doses developed tachycardia after dosing (HR 60–126 bpm). Ventricular tachycardia was noted for 10 minutes after administration of the 4 mg/kg dose. Increases in systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) occurred after administration of all doses (4, 2, 1, 0.5, and 0.25 mg/kg). Profound hypertension was observed after the 4 mg/kg dose (SAP/DAP, MAP [mmHg] = 291–300/163–213, 218–279). Hemodynamics normalized by 1–2 hours after administration. ACTH and cortisol concentrations increased within 30 minutes of administration of all CoCl₂ doses, and cardiac troponin I concentration increased after administration of the 4 and 2 mg/kg doses.

Conclusions and Clinical Importance

The degree of hypertension and arrhythmia observed after IV CoCl₂ administration raises animal welfare and human safety concerns.

Prevalence and correlates of frailty in an older rural African population: findings from the HAALSI cohort study

Background

Frailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort.

Methods

We analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1–2) and frail participants (score 3+).

Results

Five thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail).

Conclusions

Phenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death.

Electronic supplementary material

The online version of this article (10.1186/s12877-017-0694-y) contains supplementary material, which is available to authorized users.

A Randomized Control Trial Investigating the Effect of Presurgical Orthopedics on Feeding in Infants with Cleft Lip and/or Palate

Objective:

To investigate the controversial assertion that presurgical orthopedics (PSO) facilitate feeding in infants with cleft lip and palate.

Design:

Randomized control trial of 34 infants with nonsyndromic complete unilateral cleft lip and palate and 16 with cleft of the soft and at least two thirds of the hard palate. Allocation to receive presurgical orthopedics or not used minimization for parity and gender. Other aspects of care were standardized.

Setting:

The North Thames Regional Cleft Centre.

Main Outcome Measures:

Measurements were made at 3 months of age (presurgery) and at 12 months of age (postsurgery). Primary outcomes were anthropometry and oral motor skills. Objective measures of sucking also were collected at 3 months using the Great Ormond Street Measure of Infant Feeding. Twenty-one infants also had videofluoroscopic assessment.

Results:

At 1 year, all infants had normal oral motor skills and no clear pattern of anthropometric differences emerged. For both cleft groups, infants randomized to presurgical orthopedics were, on average, shorter. The presurgical orthopedics infants were, on average, lighter in the unilateral cleft and lip palate group, but heavier in the isolated cleft palate group. Infants with complete unilateral cleft and lip palate randomized to presurgical orthopedics had lower average body mass index (mean difference PSO-No PSO: −0.45 (95% confidence interval [−1.78, 0.88]), this trend was reversed among infants with isolated cleft palates (mean difference PSO-No PSO: 1.98 [−0.95, 4.91]). None of the differences were statistically significant at either age.

Conclusions:

Presurgical orthopedics did not improve feeding efficiency or general body growth within the first year in either group of infants.

Disparities in Management of Cardiovascular Disease in Rural South Africa: Data From the HAALSI Study (Health and Aging in Africa: Longitudinal Studies of International Network for the Demographic Evaluation of Populations and Their Health Communities)

BACKGROUND

Optimal secondary prevention is critical for the reduction of repeated cardiovascular events, and the control of cardiovascular risk factors in this context is essential. Data on secondary prevention of cardiovascular disease (CVD) in sub-Saharan Africa are needed to inform intervention strategies with a particular focus on local disparities. The aim of this study was to assess CVD management in a rural community in northeast South Africa.

METHODS AND RESULTS

We recruited adults aged ≥40 years residing in the Agincourt subdistrict of Mpumalanga province. Data collection included socioeconomic and clinical data, anthropometric measures, blood pressure, human immunodeficiency virus status, and point-of-care glucose and lipid levels. CVD was defined as self-report of myocardial infarction and stroke or angina diagnosed by Rose Criteria. A linear regression model was built to identify variables independently associated with the number of cardiovascular risk factors controlled. Of 5059 subjects, 592 (11.7%) met CVD diagnostic criteria. Angina was reported in 77.0% of these subjects, stroke in 25.2%, and myocardial infarction in 3.7%. Percent controlled of the 5 individual risk factors assessed were as follows: tobacco 92.9%; blood pressure 51.2%; body mass index 33.8%; low-density lipoprotein 31.4%; and waist-to-hip ratio 29.7%. Only 4.4% had all 5 risk factors controlled and 42.4% had ≥3 risk factors controlled. Male sex (β coefficient=0.44; 95% confidence interval, 0.25-0.63; P<0.001), absence of physical disability (β coefficient=0.40; 95% confidence interval, 0.16-0.65; P=0.001), and socioeconomic status (β coefficient=0.10; 95% confidence interval, 0.01-0.19; P=0.035) were directly associated with the number of risk factors controlled.

CONCLUSIONS

Currently, CVD is not being optimally managed in this rural area of South Africa. There are significant disparities in control of CVD risk factors by sex, socioeconomic status, and level of disability. Efforts to improve secondary prevention in this population should be focused on females, subjects from lower socioeconomic status, and those with physical disabilities.

Awareness, treatment, and control of dyslipidemia in rural South Africa: The HAALSI (Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa) study

Dyslipidemia is a primary driver for chronic cardiovascular conditions and there is no comprehensive literature about its management in South Africa. The objective of this study was to assess the prevalence, awareness, treatment, and control of dyslipidemia in rural South Africa and how they are impacted by different behaviors and non-modifiable factors. To fulfill this objective we recruited for this cohort study adults aged ≥40 years residing in the Agincourt sub-district of Mpumalanga Province. Data collection included socioeconomic and clinical data, anthropometric measures, blood pressure (BP), HIV-status, point-of-care glucose and lipid levels. Framingham CVD Risk Score was ascribed to patients based upon categories for 10 year cardiovascular risk of low (<3%), moderate (≥3% and <15%), high (≥15% and <30%), and very high (≥30%).LDL cholesterol control by risk category was defined according to South African Guidelines. Multivariable logistic regression models were built to identify factors that were significantly associated with dyslipidemia and awareness of dyslipidemia From 5,059 respondents a total of 4247 subjects (83.9%) had their cholesterol levels measured and were included in our analysis. Overall, 67.3% (2860) of these met criteria for dyslipidemia, only 30 (1.05%) were aware of their condition, and only 21 subjects (0.73%) were on treatment. The majority have abnormalities in triglycerides (59.3%). As cardiovascular risk increased the rates of lipid control according to LDL level dropped. Multivariate logistic regression analyses showed that being overweight was predictive of dyslipidemia (OR 1.76; 95%CI 1.51–2.05, p<0.001) and dyslipidemia awareness (OR 2.58; 95%CI 1.19–5.58; p = 0.017). In conclusion, the very low awareness and treatment of dyslipidemia in this cohort indicate a greater need for systematic screening and education within the population and demonstrate that there are multiple opportunities to allay this burden.

Leveraging the ART Advantage: diabetes and hypertension along the HIV care cascade in rural South Africa

Background

Participation in antiretroviral therapy (ART) programs has been associated with greater utilization of care for diabetes and hypertension in rural South Africa. However, there is limited data about whether this apparent “ART advantage” translates into improved chronic disease management indicators.

Methods

The Health and Aging in Africa: a Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) is a cohort of 5,059 adults >40 in Agincourt. The study collects data on demographics, healthcare utilization, height, weight, blood pressure (BP), and blood glucose. HIV infection, HIV-1 RNA viral load (VL) and ART drug levels are tested via dried blood spots. We defined hypertension (HTN) based on measured BP or self-report of diagnosis by a healthcare provider or use of antihypertensive medication and diabetes (DM) by measured glucose or self-report of diagnosis by a healthcare provider or the use of DM medications. Our primary predictor of interest was stage along the HIV care cascade (HIV-, HIV+ not on ART, ART with a detectable VL, and with a suppressed VL). We compared the proportion in each sub-group who were aware of and treated for their hypertension or diabetes diagnosis, and fit adjusted linear regression models to estimate differences in systolic BP and glucose among those with diagnosed HTN or DM.

Results

Rates of HTN and DM were higher in HIV- than those with a suppressed VL (HTN: 68.4% v. 46.4%, DM: 12.9% vs.. 8.8%, respectively). However, the suppressed VL group had higher crude rates of awareness of HTN diagnosis and treated HTN as compared with the HIV- group (Aware: 69.9% vs.. 65.2%, p = 0.118; Treated: 50.2% vs.. 46.4%, p = 0.002). There were no significant differences in awareness or treatment rates for DM. In adjusted linear regression models among those with diagnosed HTN or DM, having a suppressed VL was associated with lower mean systolic BP (-5.94mm Hg, 95% CI: -9.68 – -2.20) and lower mean glucose (-3.74 mmol/L, 95% CI: -5.95 – -0.58), compared with being HIV-. This effect was preserved in models restricted to overweight and obese participants.

Conclusion

The HIV care delivery platform in South Africa appears to offer a vehicle for healthcare delivery for other chronic conditions. Future studies are needed to assess causality of these relationships, and to determine optimal methods of integrating chronic disease with HIV management.

Disclosures

All authors: No reported disclosures.

Evidence for enzootic circulation of Rift Valley fever virus among livestock in Cameroon

Rift Valley fever virus (RVFV) is an arthropod-borne pathogen, causing serious epidemics in Africa and the Arabian Peninsula. In Cameroon serological data indicate the presence of RVFV, but active circulation of RVFV, causing clinical infections has not been proven yet. For this purpose we carried out a serological and molecular study on a total of 1953 randomly selected serum samples of small ruminants and cattle, which were collected in years 2013 and 2014 in Cameroon. In a first step, sera were screened serologically using a variety of assay formats to reveal RVFV specific antibodies. At the second stage, seropositive specimen were assessed for acute RVFV infections via IgM-specific ELISA and quantitative real-time RT-PCR. Our data show a significant difference in the antibody prevalence in cattle (13.5% [95% confidence interval: 11.4-15.7]) and small ruminants (3.4% [95% confidence interval: 2.3-4.7]), with indications for annual fluctuations and significant regional differences of seropositivity. One small ruminant and three bovines were eventually found to be positive in IgM ELISA and indications for viremia were found in one bovine by RVFV genome detection using quantitative real-time RT-PCR. The results of this study therefore corroborate the presence of acute RVFV-infection and its circulation in Cameroon.

Regional and Sex Differences in the Prevalence and Awareness of Hypertension: An H3Africa AWI-Gen Study Across 6 Sites in Sub-Saharan Africa

BACKGROUND

There is a high prevalence of hypertension and related cardiovascular diseases in sub-Saharan Africa, yet few large studies exploring hypertension in Africa are available. The actual burden of disease is poorly understood and awareness and treatment to control it is often suboptimal.

OBJECTIVES

The study sought to report the prevalence of measured hypertension and to assess awareness and control of blood pressure among older adults in rural and urban settings in 6 sites located in West, East, and Southern Africa. In addition, we examined regional, sex, and age differences related to hypertension.

METHODS

A population-based cross-sectional study was performed at 6 sites in 4 African countries: Burkina Faso (Nanoro), Ghana (Navrongo), Kenya (Nairobi), and South Africa (Agincourt, Dikgale, Soweto). Blood pressure measurements were taken using standardized procedures on 10,696 adults 40 to 60 years of age. Hypertension was defined as systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg or taking antihypertensive medication.

RESULTS

The mean prevalence of hypertension ranged from 15.1% in Nanoro to 54.1% in Soweto. All 3 of the South African sites had a mean prevalence of hypertension of over 40.0%, significantly higher than in Nairobi (25.6%) and Navrongo (24.5%). Prevalence increased with age in both sexes and at all sites. A significantly higher prevalence of hypertension was observed in women in Agincourt, Dikgale, and Nairobi, whereas in Nanoro this trend was reversed. Within the hypertensive group the average proportion of participants who were aware of their blood pressure status was only 39.4% for men and 53.8% for women, and varied widely across sites.

CONCLUSIONS

Our study demonstrates that the prevalence of hypertension and the level of disease awareness differ not only between but also within sub-Saharan African countries. Each nation must tailor their regional hypertension awareness and screening programs to match the characteristics of their local populations.

Cardiometabolic risk in a population of older adults with multiple co-morbidities in rural south africa: the HAALSI (Health and Aging in Africa: longitudinal studies of INDEPTH communities) study

BACKGROUND

A consequence of the widespread uptake of anti-retroviral therapy (ART) is that the older South African population will experience an increase in life expectancy, increasing their risk for cardiometabolic diseases (CMD), and its risk factors. The long-term interactions between HIV infection, treatment, and CMD remain to be elucidated in the African population. The HAALSI cohort was established to investigate the impact of these interactions on CMD morbidity and mortality among middle-aged and older adults.

METHODS

We recruited randomly selected adults aged 40 or older residing in the rural Agincourt sub-district in Mpumalanga Province. In-person interviews were conducted to collect baseline household and socioeconomic data, self-reported health, anthropometric measures, blood pressure, high-sensitivity C-reactive protein (hsCRP), HbA1c, HIV-status, and point-of-care glucose and lipid levels.

RESULTS

Five thousand fifty nine persons (46.4% male) were enrolled with a mean age of 61.7 ± 13.06 years. Waist-to-hip ratio was high for men and women (0.92 ± 0.08 vs. 0.89 ± 0.08), with 70% of women and 44% of men being overweight or obese. Blood pressure was similar for men and women with a combined hypertension prevalence of 58.4% and statistically significant increases were observed with increasing age. High total cholesterol prevalence in women was twice that observed for men (8.5 vs. 4.1%). The prevalence of self-reported CMD conditions was higher among women, except for myocardial infarction, and women had a statistically significantly higher prevalence of angina (10.82 vs. 6.97%) using Rose Criteria. The HIV- persons were significantly more likely to have hypertension, diabetes, or be overweight or obese than HIV+ persons. Approximately 56% of the cohort had at least 2 measured or self-reported clinical co-morbidities, with HIV+ persons having a consistently lower prevalence of co-morbidities compared to those without HIV. Absolute 10-year risk cardiovascular risk scores ranged from 7.7-9.7% for women and from 12.5-15.3% for men, depending on the risk score equations used.

CONCLUSIONS

This cohort has high CMD risk based on both traditional risk factors and novel markers like hsCRP. Longitudinal follow-up of the cohort will allow us to determine the long-term impact of increased lifespan in a population with both high HIV infection and CMD risk.

Body weight lower limits of fetal postmortem MRI at 1.5 T

OBJECTIVE

To evaluate the diagnostic yield of postmortem magnetic resonance imaging (PM-MRI) compared with conventional autopsy in fetuses of early gestational age and low body weight.

METHODS

Fetuses of < 31 weeks' gestation that underwent 1.5-T PM-MRI and conventional autopsy were included. The findings of PM-MRI and conventional autopsy were reported blinded to each other. The reports of conventional autopsy and PM-MRI for each organ system (cardiovascular, neurological, abdominal, non-cardiac thoracic and musculoskeletal) were classified as either diagnostic or non-diagnostic. The likelihood of a non-diagnostic examination by PM-MRI was calculated according to fetal gestational age and body weight.

RESULTS

Full datasets were examined of 204 fetuses, with mean gestational age of 20.95 ± 3.82 weeks (range, 12.0-30.7 weeks) and body-weight range of 15.9-1872 g. Body weight was the most significant predictor of diagnostic yield of PM-MRI. There was 95% confidence that 90% of fetuses will show diagnostic images by PM-MRI for all five organ systems when fetal body weight is ≥ 535 g, but < 50% of fetuses will have all five systems diagnostic on PM-MRI when body weight is < 122 g.

CONCLUSION

PM-MRI is highly likely to provide adequate diagnostic images for fetuses with a body weight > 500 g. Below this weight, the diagnostic yield of standard 1.5-T PM-MRI decreases significantly. These data should help inform parents and clinicians on the suitability of performing PM-MRI in fetuses with low body weight. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Procalcitonin levels predict infectious complications and response to treatment in patients undergoing cytoreductive surgery for peritoneal malignancy

BACKGROUND

Cytoreductive-surgery for peritoneal-malignancy (PM) involves extensive intra-abdominal surgery and a massive post-operative systemic-inflammatory-response (SIRS). It is often challenging to differentiate SIRS that are solely surgery-associated from those of post-operative infections. White-Cell-Counts (WCC) and C-Reactive-Protein (CRP) are routinely used as markers for infection, but are non-specific and their elevation is often delayed in PM cases. Other markers need to be evaluated to assist early identification/prediction of post-operative infections.

METHODOLOGY

Prospective evaluation of serum procalcitonin (PCT), CRP and WCC in 50 patients pre-operatively (Day0), and on post-operative days (POD) 1, 3 & 6, following cytoreductive-surgery with or without splenectomy.

RESULTS

Day0 PCT, CRP and WCC values were within normal limits, but increasing physiologically in post-operative period without infection, with noticeable higher PCT in splenectomized patients. In our cohort post-operative infections were diagnosed in 14 patients, often within 48 h. There was a trend for faster rise in serum PCT on POD1 compared to CRP and WCC, and faster PCT decline following appropriate therapy on POD3 and POD6 when infected cases were clinically resolving while WCC and CRP continued to rise, particularly in non-spelenectomised patients. The AUC on POD1 was significantly higher for PCT (0.689) vs. WCC (0.476) and CRP (0.477) (p = 0.04). Sensitivity, specificity, positive-predictive-value and negative-predictive-values for PCT ranged between (57%-100%), (22%-74%), (33%-47%) & (81%-100%), for CRP (28%-78%), (5.5%-86%), (18%-44.4%) & (40%-75.5%) and for WCC (14%-26.5%), (65.5-80.5%), (22%-25%), (67%-70%) respectively.

CONCLUSION

PCT, like WCC and CRP, needs to be interpreted with extreme cautions in the context of infections post-cytoreductive-surgery and should only be used in association with other clinical and investigational findings.

Cardiovascular status after Kawasaki disease in the UK

OBJECTIVE

Kawasaki disease (KD) is an acute vasculitis that causes coronary artery aneurysms (CAA) in young children. Previous studies have emphasised poor long-term outcomes for those with severe CAA. Little is known about the fate of those without CAA or patients with regressed CAA. We aimed to study long-term cardiovascular status after KD by examining the relationship between coronary artery (CA) status, endothelial injury, systemic inflammatory markers, cardiovascular risk factors (CRF), pulse-wave velocity (PWV) and carotid intima media thickness (cIMT) after KD.

METHODS

Circulating endothelial cells (CECs), endothelial microparticles (EMPs), soluble cell-adhesion molecules cytokines, CRF, PWV and cIMT were compared between patients with KD and healthy controls (HC). CA status of the patients with KD was classified as CAA present (CAA+) or absent (CAA-) according to their worst-ever CA status. Data are median (range).

RESULTS

Ninety-two KD subjects were studied, aged 11.9 years (4.3-32.2), 8.3 years (1.0-30.7) from KD diagnosis. 54 (59%) were CAA-, and 38 (41%) were CAA+. There were 51 demographically similar HC. Patients with KD had higher CECs than HC (p=0.00003), most evident in the CAA+ group (p=0.00009), but also higher in the CAA- group than HC (p=0.0010). Patients with persistent CAA had the highest CECs, but even those with regressed CAA had higher CECs than HC (p=0.011). CD105 EMPs were also higher in the KD group versus HC (p=0.04), particularly in the CAA+ group (p=0.02), with similar findings for soluble vascular cell adhesion molecule 1 and soluble intercellular adhesion molecule 1. There was no difference in PWV, cIMT, CRF or in markers of systemic inflammation in the patients with KD (CAA+ or CAA-) compared with HC.

CONCLUSIONS

Markers of endothelial injury persist for years after KD, including in a subset of patients without CAA.

Diagnostic accuracy and limitations of post-mortem MRI for neurological abnormalities in fetuses and children

AIM

To compare the diagnostic accuracy of non-invasive cerebral post-mortem magnetic resonance imaging (PMMRI) specifically for cerebral and neurological abnormalities in a series of fetuses and children, compared to conventional autopsy.

MATERIALS AND METHODS

Institutional ethics approval and parental consent was obtained. Pre-autopsy cerebral PMMRI was performed in a sequential prospective cohort (n = 400) of fetuses (n = 277; 185 ≤ 24 weeks and 92 > 24 weeks gestation) and children <16 years (n = 123) of age. PMMRI and conventional autopsy findings were reported blinded and independently of each other.

RESULTS

Cerebral PMMRI had sensitivities and specificities (95% confidence interval) of 88.4% (75.5 to 94.9), and 95.2% (92.1 to 97.1), respectively, for cerebral malformations; 100% (83.9 to 100), and 99.1% (97.2 to 99.7) for major intracranial bleeds; and 87.5% (80.1 to 92.4) and 74.1% (68 to 79.4) for overall brain pathology. Formal neuropathological examination was non-diagnostic due to maceration/autolysis in 43/277 (16%) fetuses; of these, cerebral PMMRI imaging provided clinically important information in 23 (53%). The sensitivity of PMMRI for detecting significant ante-mortem ischaemic injury was only 68% (48.4 to 82.8) overall.

CONCLUSIONS

PMMRI is an accurate investigational technique for identifying significant neuropathology in fetuses and children, and may provide important information even in cases where autolysis prevents formal neuropathological examination; however, PMMRI is less sensitive at detecting hypoxic-ischaemic brain injury, and may not detect rarer disorders not encountered in this study.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Randomised clinical trial: relief of upper gastrointestinal symptoms by an acid pocket-targeting alginate-antacid (Gaviscon Double Action) - a double-blind, placebo-controlled, pilot study in gastro-oesophageal reflux disease

BACKGROUND

The alginate-antacid, Gaviscon Double Action (Gaviscon DA; Reckitt Benckiser, Slough, UK) suppresses reflux after meals by creating a gel-like barrier that caps and displaces the acid pocket distal to the oesophago-gastric junction. The effect of Gaviscon DA on reflux and dyspepsia symptoms has not yet been demonstrated with a modern trial design.

AIM

A pilot study to assess the efficacy and safety of Gaviscon DA compared with matched placebo for decreasing upper gastrointestinal symptoms in symptomatic gastro-oesophageal reflux disease (GERD) patients.

METHODS

A randomised, double-blind, parallel group study was performed in 110 patients with symptoms of GERD. Patients received Gaviscon DA or placebo tablets for 7 consecutive days. The primary endpoint compared the change in overall Reflux Disease Questionnaire (RDQ) symptom score (combined heartburn/regurgitation/dyspepsia). Secondary endpoints assessed individual dimensions, GERD dimension (heartburn and regurgitation) and overall treatment evaluation (OTE).

RESULTS

There was a greater decrease in overall RDQ symptom score in the Gaviscon DA group compared with the placebo group (Least Squares Mean difference -0.55; P = 0.0033), and for each of the dimensions independently. Patients in the Gaviscon DA group evaluated their overall treatment response higher than patients in the placebo group [mean (standard deviation) OTE 4.1 (2.44) vs. 1.9 (3.34); P = 0.0005]. No differences in the incidence of adverse events were observed between treatment groups.

CONCLUSIONS

Gaviscon DA decreases reflux and dyspeptic symptoms in GERD patients compared with matched placebo and has a favourable benefit-risk balance. Larger scale clinical investigations of medications targeting the acid pocket are warranted. (EudraCT, 2012-002188-84).

Public health costs for tuberculosis suspects in Wake County, North Carolina, United States

SETTING

As the incidence of tuberculosis (TB) declines in high-income countries, resources to control TB are also declining. A portion of these resources are utilized for the evaluation and treatment of persons initially suspected of, but who do not actually have, TB (TB suspects).

OBJECTIVE

To describe the cost of TB suspects to public health departments, and determine whether part of this cost can be averted using improved diagnostic tools.

DESIGN

We evaluated resource utilization for all TB suspects as well as a random sample of TB cases managed at the Wake County public health clinic during 2008-2010. The proportion of total health department costs attributable to TB suspects was estimated. A sensitivity analysis assessed the potential impact of a rapid, accurate diagnostic test to avert suspect-associated costs.

RESULTS

Of 135 patients evaluated for TB, 36 (27%) were suspects, accounting for 14% (US5,885) of the total estimated costs for managing all patients. A perfect diagnostic test with a 3-day turnaround would have averted US27,975 (53%) of the costs attributable to suspects.

CONCLUSION

A substantial proportion of public health resources is utilized to manage persons whose final diagnosis is not TB. Efficient implementation of novel rapid tests could avert substantial public health costs.

Community-acquired, healthcare-associated and hospital-acquired bloodstream infection definitions in children: a systematic review demonstrating inconsistent criteria

BACKGROUND

Historically, bacterial infections were categorized as either community-acquired (CA) or hospital-acquired (HA). However, the CA/HA dichotomy no longer adequately reflects patterns of emerging healthcare-associated (HCA) infections in complex patients managed between hospital and the community. Studies trying to define this evolving epidemiology often excluded children.

AIM

To identify what criteria have been used to distinguish between CA, HCA and HA bloodstream infections (BSIs) in children, and the proportional distribution of CA, HCA and HA among total BSIs and by organism.

METHODS

We systematically reviewed published literature from PubMed, UK Department of Health and US Centers for Disease Control and Prevention websites.

FINDINGS

Results from 23 studies and the websites highlighted the use of inconsistent criteria. There were 13 and 15 criteria variations for CA and HA BSI respectively, although a 48h cut-off for cultures sampled post admission was most commonly reported. Five studies used variable clinical criteria to define HCA. The mean proportion of paediatric CA BSI in nine studies was 50%. Only four BSI organisms from five studies were predominantly CA (Streptococcus pneumoniae, Salmonella spp.) or HA (coagulase-negative staphylococci, Enterococcus spp.), whereas Pseudomonas spp., Klebsiella spp. and Enterobacter spp. did not clearly fit into either category.

CONCLUSIONS

Our study reveals inconsistent use of criteria, and a lack of evidence upon which to base them, to distinguish between CA, HCA and HA BSI in children. Criteria for CA, HCA and HA BSI need to be developed using population-based studies that consider patients' clinical characteristics, recent healthcare exposure as well as isolated organism species.

Normal ascent of the conus medullaris: a post-mortem foetal MRI study

OBJECTIVES

The position of the conus medullaris is considered abnormal if it ends below lumbar vertebrae three (L3) at birth. We used magnetic resonance imaging (MRI) to measure the position of the conus in post-mortem foetuses, to investigate the timing of normal ascent.

METHODS

The position of the conus in 84 post-mortem foetuses (mean gestation 26.3 weeks; range 14-41 weeks) was identified using 3D MRI datasets. A numerical scale was used for vertebral levels, from 1 (S2) to 15 (T12).

RESULTS

There was significant ascent of the conus medullaris with increasing gestation. At 20 weeks gestation, an estimated 84.2% (95% confidence interval (CI): 72.9, 93.2%) of foetuses have a conus position of L4/5 or higher, but only 22.8% (95% CI 11.7, 34.9%) at L3 or higher. By 26 weeks, an estimated 50.7% (95% CI 34.1, 67.5) will have reached L3, and 94.8% (95% CI 87.0, 98.5%) reach L3 by 40 weeks.

CONCLUSION

There is regular ascent of the conus throughout foetal life. Although growth for each individual foetus may be non-linear, most foetuses have a conus level within the normal adult range by 33 weeks gestation.