Prevalence of chronic pain or analgesic use in children and young people and its long-term impact on substance misuse, mental illness, and prescription opioid use: a retrospective longitudinal cohort study

Background

Epidemiological studies suggest chronic and recurrent pain affects around a quarter of children, while 8% report intense and frequent pain. The long-term implications of chronic pain in childhood are uncertain. Using electronic health records (EHRs) we used both disease codes and medicines prescription records to investigate the scale of chronic pain and long-term analgesic use in children and young people (CYP), and if chronic pain and/or use of analgesic medicines at an early age is associated with substance misuse, use of prescription opioids, and poor mental health in adulthood.

Methods

We conducted a cohort study using data from IQVIA Medical Research Data UK. We identified individuals aged 2-24 with exposure to either a diagnostic code indicating chronic pain (diagnosis-exposed), repeat prescription for medicines commonly used to treat pain (prescription-exposed), or both. Follow-up began at 25, and the unexposed population acted as comparators. We calculated hazard ratios (HR) for mental health and substance misuse outcomes, and rate ratios (RR) for opioid prescriptions in adulthood. Additionally, we investigated which diagnoses, if any, were over-represented in the prescription-exposed subgroup.

Findings

The cohort constituted 853,625 individuals; 146,431 had one or more of the exposures of interest (diagnosis-exposed = 115,101, prescription-exposed = 20,298, both-exposed = 11,032), leaving 707,194 as comparators. Median age at index exposure was 18.7 years (IQR 14.7-22.3). On average during follow-up, the pooled exposed group had, respectively, a 31% and 17% higher risk of adverse mental health and substance misuse outcomes (adjusted HR [95% CI] of 1.31 [1.29-1.32] and 1.17 [1.11-1.24]). Exposed individuals also received prescription opioids at double the rate of unexposed individuals on average during follow-up (adjusted RR 2.01 [95% CI 1.95-2.10]). Outcomes varied between exposure subgroups, with prescription- and both-exposure tending to have worse outcomes. Unlike these two subgroups, in the diagnosis-exposed subgroup we did not detect a greater risk of substance misuse.

Interpretation

Chronic pain in CYP is associated with increased prescription opioid use and adverse mental health outcomes in adulthood, as is repeat prescription for analgesic medicines, but only the latter is also associated with substance misuse in adulthood. It is essential to avoid the harms of under-treating pain in CYP while giving due consideration to the risks posed by analgesic medicines. Early recognition of chronic pain in CYP and utilising non-pharmacological management options may help minimise overprescribing, and long-term reliance on dependence-forming-drugs.

Funding

AL is an NIHR funded academic clinical fellow, and was supported by funding from UCLH Charities while carrying out this work. RS and DS are part of the Advanced Pain Discovery Platform and were supported by a UKRI and Versus Arthritis grant (MR/W002566/1) as part of the Consortium Against Pain Inequality. AW was supported by the Wellcome Trust (220558/Z/20/Z).

TIE1 and TEK signalling, intraocular pressure, and primary open-angle glaucoma: a Mendelian randomization study

BACKGROUND

In primary open-angle glaucoma (POAG), lowering intraocular pressure (IOP) is the only proven way of slowing vision loss. Schlemm's canal (SC) is a hybrid vascular and lymphatic vessel that mediates aqueous humour drainage from the anterior ocular chamber. Animal studies support the importance of SC endothelial angiopoietin-TEK signalling, and more recently TIE1 signalling, in maintaining normal IOP. However, human genetic support for a causal role of TIE1 and TEK signalling in lowering IOP is currently lacking.

METHODS

GWAS summary statistics were obtained for plasma soluble TIE1 (sTIE1) protein levels (N = 35,559), soluble TEK (sTEK) protein levels (N = 35,559), IOP (N = 139,555) and POAG (Ncases = 16,677, Ncontrols = 199,580). Mendelian randomization (MR) was performed to estimate the association of genetically proxied TIE1 and TEK protein levels with IOP and POAG liability. Where significant MR estimates were obtained, genetic colocalization was performed to assess the probability of a shared causal variant (PPshared) versus distinct (PPdistinct) causal variants underlying TIE1/TEK signalling and the outcome. Publicly available single-nucleus RNA-sequencing data were leveraged to investigate differential expression of TIE1 and TEK in the human ocular anterior segment.

RESULTS

Increased genetically proxied TIE1 signalling and TEK signalling associated with a reduction in IOP (- 0.21 mmHg per SD increase in sTIE1, 95% CI = - 0.09 to - 0.33 mmHg, P = 6.57 × 10-4, and - 0.14 mmHg per SD decrease in sTEK, 95% CI = - 0.03 to - 0.25 mmHg, P = 0.011), but not with POAG liability. Colocalization analysis found that the probability of a shared causal variant was greater for TIE1 and IOP than for TEK and IOP (PPshared/(PPdistinct + PPshared) = 0.98 for TIE1 and 0.30 for TEK). In the anterior segment, TIE1 and TEK were preferentially expressed in SC, lymphatic, and vascular endothelium.

CONCLUSIONS

This study provides novel human genetic support for a causal role of both TIE1 and TEK signalling in regulating IOP. Here, combined evidence from cis-MR and colocalization analyses provide stronger support for TIE1 than TEK as a potential IOP-lowering therapeutic target.

The Association of Physical Activity with Glaucoma and Related Traits in the UK Biobank

PURPOSE

To examine the association of physical activity (PA) with glaucoma and related traits, to assess whether genetic predisposition to glaucoma modified these associations, and to probe causal relationships using Mendelian randomization (MR).

DESIGN

Cross-sectional observational and gene-environment interaction analyses in the UK Biobank. Two-sample MR experiments using summary statistics from large genetic consortia.

PARTICIPANTS

UK Biobank participants with data on self-reported or accelerometer-derived PA and intraocular pressure (IOP; n = 94 206 and n = 27 777, respectively), macular inner retinal OCT measurements (n = 36 274 and n = 9991, respectively), and glaucoma status (n = 86 803 and n = 23 556, respectively).

METHODS

We evaluated multivariable-adjusted associations of self-reported (International Physical Activity Questionnaire) and accelerometer-derived PA with IOP and macular inner retinal OCT parameters using linear regression and with glaucoma status using logistic regression. For all outcomes, we examined gene-PA interactions using a polygenic risk score (PRS) that combined the effects of 2673 genetic variants associated with glaucoma.

MAIN OUTCOME MEASURES

Intraocular pressure, macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and glaucoma status.

RESULTS

In multivariable-adjusted regression models, we found no association of PA level or time spent in PA with glaucoma status. Higher overall levels and greater time spent in higher levels of both self-reported and accelerometer-derived PA were associated positively with thicker mGCIPL (P < 0.001 for trend for each). Compared with the lowest quartile of PA, participants in the highest quartiles of accelerometer-derived moderate- and vigorous-intensity PA showed a thicker mGCIPL by +0.57 μm (P < 0.001) and +0.42 μm (P = 0.005). No association was found with mRNFL thickness. High overall level of self-reported PA was associated with a modestly higher IOP of +0.08 mmHg (P = 0.01), but this was not replicated in the accelerometry data. No associations were modified by a glaucoma PRS, and MR analyses did not support a causal relationship between PA and any glaucoma-related outcome.

CONCLUSIONS

Higher overall PA level and greater time spent in moderate and vigorous PA were not associated with glaucoma status but were associated with thicker mGCIPL. Associations with IOP were modest and inconsistent. Despite the well-documented acute reduction in IOP after PA, we found no evidence that high levels of habitual PA are associated with glaucoma status or IOP in the general population.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Deep Ocular Phenotyping Across Primary Open-Angle Glaucoma Genetic Burden

Importance

Better understanding of primary open-angle glaucoma (POAG) genetics could enable timely screening and promote individualized disease risk prognostication.

Objective

To evaluate phenotypic features across genetic burden for POAG.

Design, Setting, and Participants

This was a cross-sectional, population-based study conducted from 2006 to 2010. Included participants were individuals from the UK Biobank aged 40 to 69 years. Individuals with non-POAG forms of glaucoma were excluded from the analysis. Data were statistically analyzed from October 2022 to January 2023.

Main Outcomes and Measures

POAG prevalence based on structural coding, self-reports, and glaucoma-related traits.

Results

Among 407 667 participants (mean [SD] age, 56.3 [8.1] years; 219 183 majority sex [53.8%]) were 14 171 POAG cases. Area under receiver operating characteristic curve for POAG detection was 0.748 in a model including polygenic risk score (PRS), age, sex, and ancestry. POAG prevalence in the highest decile of PRS was 7.4% (3005 of 40 644) vs 1.3% (544 of 40 795) in lowest decile (P < .001). A 1-SD increase in PRS was associated with 1.74 times higher odds of POAG (95% CI, 1.71-1.77), a 0.61-mm Hg increase in corneal-compensated intraocular pressure (IOP; 95% CI, 0.59-0.64), a -0.09-mm Hg decrease in corneal hysteresis (95% CI, -0.10 to -0.08), a 0.08-mm Hg increase in corneal resistance factor (95% CI, 0.06-0.09), and a -0.08-diopter decrease in spherical equivalent (95% CI, -0.11 to -0.07; P < .001 for all). A 1-SD increase in PRS was associated with a thinning of the macula-region retinal nerve fiber layer (mRNFL) of 0.14 μm and macular ganglion cell complex (GCC) of 0.26 μm (P < .001 for both). In the subset of individuals with fundus photographs, a 1-SD increase in PRS was associated with 1.42 times higher odds of suspicious optic disc features (95% CI, 1.19-1.69) and a 0.013 increase in cup-disc ratio (CDR; 95% CI, 0.012-0.014; P < .001 for both). A total of 22 of 5193 fundus photographs (0.4%) in decile 10 had disc hemorrhages, and 27 of 5257 (0.5%) had suspicious optic disc features compared with 9 of 5158 (0.2%) and 10 of 5219 (0.2%), respectively, in decile 1 (P < .001 for both). CDR in decile 10 was 0.46 compared with 0.41 in decile 1 (P < .001).

Conclusion and Relevance

Results suggest that PRS identified a group of individuals at substantially higher risk for POAG. Higher genetic risk was associated with more advanced disease, namely higher CDR and corneal-compensated IOP, thinner mRNFL, and thinner GCC. Associations with POAG PRS and corneal hysteresis and greater prevalence of disc hemorrhages were identified. These results suggest that genetic risk is an increasingly important parameter for risk stratification to consider in clinical practice.

Evaluation of retinal nerve fibre layer thickness as a possible measure of diabetic retinal neurodegeneration in the EPIC-Norfolk Eye Study

BACKGROUND/AIMS

Markers to clinically evaluate structural changes from diabetic retinal neurodegeneration (DRN) have not yet been established. To study the potential role of peripapillary retinal nerve fibre layer (pRNFL) thickness as a marker for DRN, we evaluated the relationship between diabetes, as well as glycaemic control irrespective of diabetes status and pRNFL thickness.

METHODS

Leveraging data from a population-based cohort, we used general linear mixed models (GLMMs) with a random intercept for patient and eye to assess the association between pRNFL thickness (measured using GDx) and demographic, systemic and ocular parameters after adjusting for typical scan score. GLMMs were also used to determine: (1) the relationship between: (A) glycated haemoglobin (HbA1c) irrespective of diabetes diagnosis and pRNFL thickness, (B) diabetes and pRNFL thickness and (2) which quadrants of pRNFL may be affected in participants with diabetes and in relation to HbA1c.

RESULTS

7076 participants were included. After controlling for covariates, inferior pRNFL thickness was 0.94 µm lower (95% CI -1.28 µm to -0.60 µm), superior pRNFL thickness was 0.83 µm lower (95% CI -1.17 µm to -0.49 µm) and temporal pRNFL thickness was 1.33 µm higher (95% CI 0.99 µm to 1.67 µm) per unit increase in HbA1c. Nasal pRNFL thickness was not significantly associated with HbA1c (p=0.23). Similar trends were noted when diabetes was used as the predictor.

CONCLUSION

Superior and inferior pRNFL was significantly thinner among those with higher HbA1c levels and/or diabetes, representing areas of the pRNFL that may be most affected by diabetes.

Comorbidities of Keloid and Hypertrophic Scars Among Participants in UK Biobank

Importance

Keloids and hypertrophic scars (excessive scarring) are relatively understudied disfiguring chronic skin conditions with high treatment resistance.

Objective

To evaluate established comorbidities of excessive scarring in European individuals, with comparisons across ethnic groups, and to identify novel comorbidities via a phenome-wide association study (PheWAS).

Design, Setting, and Participants

This multicenter cross-sectional population-based cohort study used UK Biobank (UKB) data and fitted logistic regression models for testing associations between excessive scarring and a variety of outcomes, including previously studied comorbidities and 1518 systematically defined disease categories. Additional modeling was performed within subgroups of participants defined by self-reported ethnicity (as defined in UK Biobank). Of 502 701 UKB participants, analyses were restricted to 230078 individuals with linked primary care records.

Exposures

Keloid or hypertrophic scar diagnoses.

Main Outcomes and Measures

Previously studied disease associations (hypertension, uterine leiomyoma, vitamin D deficiency, atopic eczema) and phenotypes defined in the PheWAS Catalog.

Results

Of the 972 people with excessive scarring, there was a higher proportion of female participants compared with the 229 106 controls (65% vs 55%) and a lower proportion of White ethnicity (86% vs 95%); mean (SD) age of the total cohort was 64 (8) years. Associations were identified with hypertension and atopic eczema in models accounting for age, sex, and ethnicity, and the association with atopic eczema (odds ratio [OR], 1.68; 95% CI, 1.36-2.07; P < .001) remained statistically significant after accounting for additional potential confounders. Fully adjusted analyses within ethnic groups revealed associations with hypertension in Black participants (OR, 2.05; 95% CI, 1.13-3.72; P = .02) and with vitamin D deficiency in Asian participants (OR, 2.24; 95% CI, 1.26-3.97; P = .006). The association with uterine leiomyoma was borderline significant in Black women (OR, 1.93; 95% CI, 1.00-3.71; P = .05), whereas the association with atopic eczema was significant in White participants (OR, 1.68; 95% CI, 1.34-2.12; P < .001) and showed a similar trend in Asian (OR, 2.17; 95% CI, 1.01-4.67; P = .048) and Black participants (OR, 1.89; 95% CI, 0.83-4.28; P = .13). The PheWAS identified 110 significant associations across disease systems; of the nondermatological, musculoskeletal disease and pain symptoms were prominent.

Conclusions and Relevance

This cross-sectional study validated comorbidities of excessive scarring in UKB with comprehensive coverage of health outcomes. It also documented additional phenome-wide associations that will serve as a reference for future studies to investigate common underlying pathophysiologic mechanisms.

Associations Between HbA1c Across the Normal Range, Diagnosed, and Undiagnosed Diabetes and Retinal Layer Thickness in UK Biobank Cohort

Purpose

The purpose of this study was to investigate the association between glycated hemoglobin (HbA1c) levels and retinal sub-layer thicknesses in people with and without diabetes.

Methods

We included 41,453 UK Biobank participants aged 40 to 69 years old. Diabetes status was defined by self-report of diagnosis or use of insulin. Participants were categorized into groups: (1) those with HbA1c <48 mmol/mol were subdivided into quintiles according to normal range of HbA1c; (2) those previously diagnosed with diabetes with no evidence of diabetic retinopathy; and (3) undiagnosed diabetes: >48 mmol/mol. Total macular and retinal sub-layer thicknesses were derived from spectral-domain optical coherence tomography (SD-OCT) images. Multivariable linear regression was used to evaluate the associations between diabetes status and retinal layer thickness.

Results

Compared with participants in the second quintile of the normal HbA1c range, those in the fifth quintile had a thinner photoreceptor layer thickness (-0.33 µm, P = 0.006). Participants with diagnosed diabetes had a thinner macular retinal nerve fiber layer (mRNFL; -0.58 µm, P < 0.001), photoreceptor layer thickness (-0.94 µm, P < 0.001), and total macular thickness (-1.61 µm, P < 0.001), whereas undiagnosed diabetes participants had a reduced photoreceptor layer thickness (-1.22 µm, P = 0.009) and total macular thickness (-2.26 µm, P = 0.005). Compared to participants without diabetes, those with diabetes had a thinner mRNFL (-0.50 µm, P < 0.001), photoreceptor layer thickness (-0.77 µm, P < 0.001), and total macular thickness (-1.36 µm, P < 0.001).

Conclusions

Participants with higher HbA1c in the normal range had marginally thinner photoreceptor thickness, whereas those with diabetes (including undiagnosed diabetes) had meaningfully thinner retinal sublayer and total macular thickness.

Translational Relevance

We showed that early retinal neurodegeneration occurs in people whose HbA1c levels are below the current diabetes diagnostic threshold; this might impact the management of pre-diabetes individuals.

The Association between Serum Lipids and Intraocular Pressure in 2 Large United Kingdom Cohorts

PURPOSE

Serum lipids are modifiable, routinely collected blood test features associated with cardiovascular health. We examined the association of commonly collected serum lipid measures (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides) with intraocular pressure (IOP).

DESIGN

Cross-sectional study in the UK Biobank and European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohorts.

PARTICIPANTS

We included 94 323 participants from the UK Biobank (mean age, 57 years) and 6230 participants from the EPIC-Norfolk (mean age, 68 years) cohorts with data on TC, HDL-C, LDL-C, and triglycerides collected between 2006 and 2009.

METHODS

Multivariate linear regression adjusting for demographic, lifestyle, anthropometric, medical, and ophthalmic covariables was used to examine the associations of serum lipids with corneal-compensated IOP (IOPcc).

MAIN OUTCOME MEASURES

Corneal-compensated IOP.

RESULTS

Higher levels of TC, HDL-C, and LDL-C were associated independently with higher IOPcc in both cohorts after adjustment for key demographic, medical, and lifestyle factors. For each 1-standard deviation increase in TC, HDL-C, and LDL-C, IOPcc was higher by 0.09 mmHg (95% confidence interval [CI], 0.06-0.11 mmHg; P < 0.001), 0.11 mmHg (95% CI, 0.08-0.13 mmHg; P < 0.001), and 0.07 mmHg (95% CI, 0.05-0.09 mmHg; P < 0.001), respectively, in the UK Biobank cohort. In the EPIC-Norfolk cohort, each 1-standard deviation increase in TC, HDL-C, and LDL-C was associated with a higher IOPcc by 0.19 mmHg (95% CI, 0.07-0.31 mmHg; P = 0.001), 0.14 mmHg (95% CI, 0.03-0.25 mmHg; P = 0.016), and 0.17 mmHg (95% CI, 0.06-0.29 mmHg; P = 0.003). An inverse association between triglyceride levels and IOP in the UK Biobank (-0.05 mmHg; 95% CI, -0.08 to -0.03; P < 0.001) was not replicated in the EPIC-Norfolk cohort (P = 0.30).

CONCLUSIONS

Our findings suggest that serum TC, HDL-C, and LDL-C are associated positively with IOP in 2 United Kingdom cohorts and that triglyceride levels may be associated negatively. Future research is required to assess whether these associations are causal in nature.

393 Communication in Catheter Care: A Closed Loop Audit of Catheter Documentation in Emergency Presentations to a Tertiary Urology Centre

Aim

Estimates suggest that 20% of patients admitted to hospital undergo catheterisation, some of whom will end up discharged with catheters. Clear documentation assists in communication between hospital and community teams. The EAUN has identified key areas for documentation including use of care plans. We audited compliance with documentation pre- and post-intervention in a tertiary urology department

Method

Emergency patients presenting to urology were identified over a 3-week period pre-intervention and 3-weeks post-intervention. Clinical notes were audited for documentation of catheterisation. Domains assessed included indication, type/size of catheter, catheter balloon volume, residual volume, urinalysis, and plan. Use of care plans was also audited. Intervention involved development and deployment of a poster as well as discussion with staff.

Results

In total 274 patients were identified. 47 catheters were inserted pre-intervention, with variable compliance in documentation throughout the domains with similar pattern of compliance noted in the post-intervention group (n=42). Compliance was highest in size of catheter and indication for insertion, with urinalysis the most frequently missed domain (14.9% pre-intervention, 9.5% post-intervention). The only area with significant improvement was documentation of balloon volume (p=0.0019). Use of the care plan showed some minor improvement but was generally poor.

Conclusion

Use of visual cues did not result in approvement in documentation. Discussion with the teams suggested awareness of the domains and care plan however, they didn't necessarily think of them at time of documentation. As such a text prompt for the electronic notes is now in development and further audit to assess impact pending.

Estimating excess visual loss from neovascular age-related macular degeneration in the UK during the COVID-19 pandemic: a retrospective clinical audit and simulation model

OBJECTIVES

To report the reduction in new neovascular age-related macular degeneration (nAMD) referrals during the COVID-19 pandemic and estimate the impact of delayed treatment on visual outcomes at 1 year.

DESIGN

Retrospective clinical audit and simulation model.

SETTING

Multiple UK National Health Service (NHS) ophthalmology centres.

PARTICIPANTS

Data on the reduction in new nAMD referrals were obtained from four NHS Trusts comparing April 2020 with April 2019. To estimate the potential impact on 1-year visual outcomes, a stratified bootstrap simulation model was developed drawing on an electronic medical records dataset of 20 825 nAMD eyes from 27 NHS Trusts.

MAIN OUTCOME MEASURES

Simulated mean visual acuity and proportions of eyes with vision ≤6/60, ≤6/24 and ≥6/12 at 1 year under four hypothetical scenarios: 0-month, 3-month, 6-month and 9-month treatment delays. Estimated additional number of eyes with vision ≤6/60 at 1 year nationally.

RESULTS

The number of nAMD referrals dropped on average by 72% (range 65%-87%). Simulated 1-year visual outcomes for 1000 nAMD eyes with a 3-month treatment delay suggested an increase in the proportion of eyes with vision ≤6/60 from 15.5% (13.2%-17.9%) to 23.3% (20.7%-25.9%), and a decrease in the proportion of eyes with vision ≥6/12 (driving vision) from 35.1% (32.1%-38.1%) to 26.4% (23.8%-29.2%). Outcomes worsened incrementally with longer modelled delays. Assuming nAMD referrals are reduced to this level for 1 month nationally, these simulated results suggest an additional 186-365 eyes with vision ≤6/60 at 1 year.

CONCLUSIONS

We report a large decrease in nAMD referrals during the COVID-19 lockdown and provide an important public health message regarding the risk of delayed treatment. As a conservative estimate, a treatment delay of 3 months could lead to a >50% relative increase in the number of eyes with vision ≤6/60 and 25% relative decrease in the number of eyes with driving vision at 1 year.

Association of Smoking, Alcohol Consumption, Blood Pressure, Body Mass Index, and Glycemic Risk Factors With Age-Related Macular Degeneration: A Mendelian Randomization Study

IMPORTANCE

Advanced age-related macular degeneration (AMD) is a leading cause of blindness in Western countries. Causal, modifiable risk factors need to be identified to develop preventive measures for advanced AMD.

OBJECTIVE

To assess whether smoking, alcohol consumption, blood pressure, body mass index, and glycemic traits are associated with increased risk of advanced AMD.

DESIGN, SETTING, PARTICIPANTS

This study used 2-sample mendelian randomization. Genetic instruments composed of variants associated with risk factors at genome-wide significance (P < 5 × 10-8) were obtained from published genome-wide association studies. Summary-level statistics for these instruments were obtained for advanced AMD from the International AMD Genomics Consortium 2016 data set, which consisted of 16 144 individuals with AMD and 17 832 control individuals. Data were analyzed from July 2020 to September 2021.

EXPOSURES

Smoking initiation, smoking cessation, lifetime smoking, age at smoking initiation, alcoholic drinks per week, body mass index, systolic and diastolic blood pressure, type 2 diabetes, glycated hemoglobin, fasting glucose, and fasting insulin.

MAIN OUTCOMES AND MEASURES

Advanced AMD and its subtypes, geographic atrophy (GA), and neovascular AMD.

RESULTS

A 1-SD increase in logodds of genetically predicted smoking initiation was associated with higher risk of advanced AMD (odds ratio [OR], 1.26; 95% CI, 1.13-1.40; P < .001), while a 1-SD increase in logodds of genetically predicted smoking cessation (former vs current smoking) was associated with lower risk of advanced AMD (OR, 0.66; 95% CI, 0.50-0.87; P = .003). Genetically predicted increased lifetime smoking was associated with increased risk of advanced AMD (OR per 1-SD increase in lifetime smoking behavior, 1.32; 95% CI, 1.09-1.59; P = .004). Genetically predicted alcohol consumption was associated with higher risk of GA (OR per 1-SD increase of log-transformed alcoholic drinks per week, 2.70; 95% CI, 1.48-4.94; P = .001). There was insufficient evidence to suggest that genetically predicted blood pressure, body mass index, and glycemic traits were associated with advanced AMD.

CONCLUSIONS AND RELEVANCE

This study provides genetic evidence that increased alcohol intake may be a causal risk factor for GA. As there are currently no known treatments for GA, this finding has important public health implications. These results also support previous observational studies associating smoking behavior with risk of advanced AMD, thus reinforcing existing public health messages regarding the risk of blindness associated with smoking.

Evolving Treatment Patterns and Outcomes of Neovascular Age-Related Macular Degeneration Over a Decade

PURPOSE

Management of neovascular age-related macular degeneration (nAMD) has evolved over the last decade with several treatment regimens and medications. This study describes the treatment patterns and visual outcomes over 10 years in a large cohort of patients.

DESIGN

Retrospective analysis of electronic health records from 27 National Health Service secondary care healthcare providers in the UK.

PARTICIPANTS

Treatment-naïve patients receiving at least 3 intravitreal anti-vascular endothelial growth factor (VEGF) injections for nAMD in their first 6 months of follow-up were included. Patients with missing data for age or gender and those aged less than 55 years were excluded.

METHODS

Eyes with at least 3 years of follow-up were grouped by years of treatment initiation, and 3-year outcomes were compared between the groups. Data were generated during routine clinical care between September 2008 and December 2018.

MAIN OUTCOME MEASURES

Visual acuity (VA), number of injections, and number of visits.

RESULTS

A total of 15 810 eyes of 13 705 patients receiving 195 104 injections were included. Visual acuity improved from baseline during the first year, but decreased thereafter, resulting in loss of visual gains. This trend remained consistent throughout the past decade. Although an increasing proportion of eyes remained in the driving standard, this was driven by better presenting VA over the decade. The number of injections decreased substantially between the first and subsequent years, from a mean of 6.25 in year 1 to 3 in year 2 and 2.5 in year 3, without improvement over the decade. In a multivariable regression analysis, final VA improved by 0.24 letters for each year since 2008, and younger age and baseline VA were significantly associated with VA at 3 years.

CONCLUSIONS

Our findings show that despite improvement in functional VA over the years, primarily driven by improving baseline VA, patients continue to lose vision after the first year of treatment, with only marginal change over the past decade. The data suggest these results may be related to suboptimal treatment patterns, which have not improved over the years. Rethinking treatment strategies may be warranted, possibly on a national level or through the introduction of longer-acting therapies.

Alcohol Consumption and Incident Cataract Surgery in Two Large UK Cohorts

Purpose

To examine the association of alcohol consumption and type of alcoholic beverage with incident cataract surgery in 2 large cohorts.

Design

Longitudinal, observational study.

Participants

We included 469 387 participants of UK Biobank with a mean age of 56 years and 23 162 participants of European Prospective Investigation of Cancer (EPIC)-Norfolk with a mean age of 59 years.

Methods

Self-reported alcohol consumption at baseline was ascertained by a touchscreen questionnaire in UK Biobank and a food-frequency questionnaire in EPIC-Norfolk. Cases were defined as participants undergoing cataract surgery in either eye as ascertained via data linkage to National Health Service procedure statistics. We excluded participants with cataract surgery up to 1 year after the baseline assessment visit or those with self-reported cataract at baseline. Cox proportional hazards models were used to examine the associations of alcohol consumption with incident cataract surgery, adjusted for age, sex, ethnicity, Townsend deprivation index, body mass index (BMI), smoking, and diabetes status.

Main Outcome Measures

Incident cataract surgery.

Results

There were 19 011 (mean cohort follow-up of 95 months) and 4573 (mean cohort follow-up of 193 months) incident cases of cataract surgery in UK Biobank and EPIC-Norfolk, respectively. Compared with nondrinkers, drinkers were less likely to undergo cataract surgery in UK Biobank (hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.85–0.93) and EPIC-Norfolk (HR, 0.90; 95% CI, 0.84–0.97) after adjusting for covariables. Among alcohol consumers, greater alcohol consumption was associated with a reduced risk of undergoing cataract surgery in EPIC-Norfolk (P < 0.001), whereas a U-shaped association was observed in the UK Biobank. Compared with nondrinkers, subgroup analysis by type of alcohol beverage showed the strongest protective association with wine consumption; the risk of incident cataract surgery was 23% and 14% lower among those in the highest category of wine consumption in EPIC-Norfolk and UK Biobank, respectively.

Conclusions

Our findings suggest a lower risk of undergoing cataract surgery with low to moderate alcohol consumption. The association was particularly apparent with wine consumption. We cannot exclude the possibility of residual confounding, and further studies are required to determine whether this association is causal in nature.

Association of ambient air pollution with age-related macular degeneration and retinal thickness in UK Biobank

AIM

To examine the associations of air pollution with both self-reported age-related macular degeneration (AMD), and in vivo measures of retinal sublayer thicknesses.

METHODS

We included 115 954 UK Biobank participants aged 40-69 years old in this cross-sectional study. Ambient air pollution measures included particulate matter, nitrogen dioxide (NO₂) and nitrogen oxides (NO_x). Participants with self-reported ocular conditions, high refractive error (< -6 or > +6 diopters) and poor spectral-domain optical coherence tomography (SD-OCT) image were excluded. Self-reported AMD was used to identify overt disease. SD-OCT imaging derived photoreceptor sublayer thickness and retinal pigment epithelium (RPE) layer thickness were used as structural biomarkers of AMD for 52 602 participants. We examined the associations of ambient air pollution with self-reported AMD and both photoreceptor sublayers and RPE layer thicknesses.

RESULTS

After adjusting for covariates, people who were exposed to higher fine ambient particulate matter with an aerodynamic diameter <2.5 µm (PM_2.5, per IQR increase) had higher odds of self-reported AMD (OR=1.08, p=0.036), thinner photoreceptor synaptic region (β=-0.16 µm, p=2.0 × 10^-5), thicker photoreceptor inner segment layer (β=0.04 µm, p=0.001) and thinner RPE (β=-0.13 µm, p=0.002). Higher levels of PM_2.5 absorbance and NO₂ were associated with thicker photoreceptor inner and outer segment layers, and a thinner RPE layer. Higher levels of PM₁₀ (PM with an aerodynamic diameter <10 µm) was associated with thicker photoreceptor outer segment and thinner RPE, while higher exposure to NO_x was associated with thinner photoreceptor synaptic region.

CONCLUSION

Greater exposure to PM_2.5 was associated with self-reported AMD, while PM_2.5, PM_2.5 absorbance, PM₁₀, NO₂ and NO_x were all associated with differences in retinal layer thickness.

Visual and autorefraction outcomes following toric intraocular lens insertion without calculation of posterior corneal astigmatism in the UK National Health Service

OBJECTIVE

To ascertain visual and refractive outcomes following toric intraocular lens (IOL) implantation in the UK National Health Service (NHS) without posterior corneal astigmatism calculation, with multiple surgeons of different grades, pooled input and output pathways and autorefraction as the refractive outcome measure.

METHODS

Preoperative and 1-month post-operative data were analysed retrospectively in 114 eyes (95 patients) receiving a toric IOL between 2014 and 2016 at Imperial College NHS Trust. Preoperative keratometric astigmatism was ≥2 dioptres (D).

RESULTS

Mean preoperative best-corrected visual acuity (BCVA) was 0.50 logMAR (±0.46), improving to a mean uncorrected VA (UCVA) of 0.35 logMAR (±0.36) postoperatively (p < 0.001) with 65% of eyes attaining a UCVA ≤ 0.30 logMAR. Excluding 33 eyes with pre-existing visual comorbidities and one targeting monovision, mean post-operative UCVA was 0.24 logMAR (±0.29) (p < 0.001), and 85% had UCVA ≤ 0.30 logMAR, 62% UCVA ≤ 0.20 logMAR. Mean refractive astigmatism improved from 3.04 D (±1.46) to 1.36 D (±1.13) (p < 0.001). In total, 52% of eyes had post-operative refractive astigmatism ≤1.00 D. The Alpins correction index was 1.05 (±0.22), indicating a tendency to overcorrect. Toric IOL misalignment was noted in two eyes, and two cases of posterior capsule rupture were converted to a non-toric IOL.

CONCLUSIONS

Visual outcomes of toric IOL implantation in our pooled pathway are comparable to single-surgeon case series where posterior corneal astigmatism has not been accounted for. However, with 1-month post-operative autorefraction, only 52% of eyes had ≤1 D refractive astigmatism, which is lower than previously published series, but may be standard for 1-month autorefraction outcomes.

Genetics and genetic testing for age-related macular degeneration

Considerable advances have been made in our understanding of age-related macular degeneration (AMD) genetics over the past decade. The genetic associations discovered to date are estimated to account for approximately half of AMD heritability, and functional studies of these variants have revealed new insights into disease pathogenesis, leading to the development of potential novel therapies. There is furthermore growing interest in genetic testing for predicting an individual's risk of AMD and offering personalised preventive or therapeutic treatments. We review the progress made so far in AMD genetics and discuss the possible applications for genetic testing.

Bilateral cataract surgery with intraocular lens implant in a captive western lowland gorilla

We report a case of bilateral cataract surgery performed in a 21-year-old western lowland gorilla. Phacoemulsification with intraocular lens insertion was performed using standard human surgical equipment. Visual function significantly improved. She subsequently mated and gave birth. Ultimately, cataract surgery enabled the birth of a baby gorilla.

Problems and solutions in delivering global surgery in the 21st century

BACKGROUND

Surgery has had low priority in global health planning, so the delivery of surgical care in low- and middle-income countries is often poorly resourced. A recent Lancet Commission on Global Surgery has highlighted the need for change.

METHODS

A consensus view of the problems and solutions was identified by individual surgeons from high-income countries, familiar with surgical care in remote and poorer environments, based on recent publications related to global surgery.

RESULTS

The major issues identified were: the perceived unimportance of surgery, shortage of personnel, lack of appropriate training and failure to establish surgical standards, failure to appreciate local needs and poor coordination of service delivery.

CONCLUSION

Surgery deserves a higher priority in global health resource allocation. Lessons learned from participation in humanitarian crises should be considered in surgical developments.

A rare penetrant TIMP3 mutation confers relatively late onset choroidal neovascularisation which can mimic age-related macular degeneration

PURPOSE

To perform a genotype-phenotype correlation for three patients heterozygous for a missense mutation in the tissue inhibitor of metalloproteinase 3 (TIMP3) gene.

METHODS

Retrospective, observational case series. The medical records and photographs were reviewed for three patients diagnosed at the time with neovascular age-related macular degeneration (AMD). All were later found to carry a predicted C113G mutation in the TIMP3 gene, other known mutations in which are associated with Sorsby's fundus dystrophy.

RESULTS

All three patients developed drusen and bilateral choroidal neovascularisation with subsequent disciform scarring and atrophy. Visual acuity rapidly deteriorated to <6/60 in both eyes. The age of onset varied from 56 to 64 years and the interval to contralateral eye involvement varied from 4 to 6 years. Two of the three patients had a family history of AMD. All three patients were heterozygous for the C113G nucleotide change, resulting in a Ser38Cys change at the N terminus of the TIMP3 protein.

CONCLUSION

This case series suggests the C113G TIMP3 variant may represent a novel highly penetrant mutation causing choroidal neovascularisation of relatively late onset for Sorsby's fundus dystrophy, mimicking early onset AMD.

Age-Related Macular Degeneration: A Disease of Systemic or Local Complement Dysregulation?

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in developed countries. The role of complement in the development of AMD is now well-established. While some studies show evidence of complement dysregulation within the eye, others have demonstrated elevated systemic complement activation in association with AMD. It is unclear which one is the primary driver of disease. This has important implications for designing novel complement-based AMD therapies. We present a summary of the current literature and suggest that intraocular rather than systemic modulation of complement may prove more effective.

Mifamurtide in metastatic and recurrent osteosarcoma: a patient access study with pharmacokinetic, pharmacodynamic, and safety assessments

PURPOSE

This non-randomized, patient-access protocol, assessed both safety and efficacy outcomes following liposomal muramyl-tripeptide-phosphatidylethanolamine (L-MTP-PE; mifamurtide) in patients with high-risk, recurrent and/or metastatic osteosarcoma.

METHODS

Patients received mifamurtide 2 mg/m(2) intravenously twice-weekly ×12 weeks, then weekly ×24 weeks with and without chemotherapy. Serum concentration-time profiles were collected. Adverse events within 24 hours of drug administration were classified as infusion-related adverse events (IRAE); other AEs and overall survival (OS) were assessed.

RESULTS

The study began therapy in January 2008; the last patient completed therapy in October 2012. Two hundred five patients were enrolled; median age was 16.0 years and 146/205 (71%) had active disease. Mifamurtide serum concentrations declined rapidly in the first 30 minutes post-infusion, then in a log-linear manner 2-6 hours post-dose; t1/2 was 2 hours. There were no readily apparent relationships between age and BSA-normalized clearance, half-life, or pharmacodynamic effects, supporting the dose of 2 mg/m(2) mifamurtide across the age range. Patients reported 3,679 IRAE after 7,482 mifamurtide infusions. These were very rarely grade 3 or 4 and most commonly included chills + fever or headache + fatigue symptom clusters. One- and 2-year OS was 71.7% and 45.9%. Patients with initial metastatic disease or progression approximated by within 9 months of diagnosis (N = 40) had similar 2-year OS (39.9%) as the entire cohort (45.9%)

CONCLUSIONS

Mifamurtide had a manageable safety profile; PK/PD of mifamurtide in this patient access study was consistent with prior studies. Two-year OS was 45.9%. A randomized clinical trial would be required to definitively determine impact on patient outcomes.

Nutrient and light limitation of periphyton in the River Thames: implications for catchment management

Soluble reactive phosphorus (SRP) concentrations in the River Thames, south east England, have significantly decreased from an annual maximum of 2100 μg l(-1) in 1997 to 344 in 2010, primarily due to the introduction of phosphorus (P) removal at sewage treatment works within the catchment. However, despite this improvement in water quality, phytoplankton biomass in the River Thames has greatly increased in recent years, with peak chlorophyll concentrations increasing from 87 μg l(-1) in the period 1997 to 2002, to 328 μg l(-1) in 2009. A series of within-river flume mesocosm experiments were performed to determine the effect of changing nutrient concentrations and light levels on periphyton biomass accrual. Nutrient enrichment experiments showed that phosphorus, nitrogen and silicon were not limiting or co-limiting periphyton growth in the Thames at the time of the experiment (August-September 2010). Decreasing ambient SRP concentration from 225 μg l(-1) to 173 μg l(-1) had no effect on periphyton biomass accrual rate or diatom assemblage. Phosphorus limitation became apparent at 83 μg SRP l(-1), at which point a 25% reduction in periphyton biomass was observed. Diatom assemblage significantly changed when the SRP concentration was reduced to 30 μg l(-1). Such stringent phosphorus targets are costly and difficult to achieve for the River Thames, due to the high population density and intensive agriculture within the Thames basin. Reducing light levels by shading reduced the periphyton accrual rate by 50%. Providing shading along the River Thames by planting riparian tree cover could be an effective measure to reduce the risk of excessive algal growth. If the ecology of the Thames is to reach the WFD's "good ecological status", then both SRP concentration reductions (probably to below 100 μg l(-1)) and increased shading will be required.

Acute promyelocytic leukaemia presenting as postpartum haemorrhage

Acute leukaemia is encountered rarely in obstetric practice, occurring once in every 100,000 pregnancies. Such cases are usually diagnosed in the second and third trimesters. We describe a patient who developed a postpartum haemorrhage (PPH) as the presenting feature of acute promyelocytic leukaemia, which, to the best of our knowledge, has not been reported previously.

Phosphorus uptake into algal biofilms in a lowland chalk river

This paper examines the growth and uptake of phosphorus into algal biofilms in the River Kennet, a lowland chalk (Cretaceous-age) stream in southern England. Algal biofilms were grown on artificial plastic substrates (templates) placed (i) on the riverbed and (ii) within the mid-water column. Experiments were set up to examine differences in growth rates of newly colonising biofilms compared with biofilms left to accumulate for periods of up to 6 months. Rates of algal biofilm production were measured by the chlorophyll a concentration that had accumulated per cm2 over the number of days that the biofilm template had been immersed in the river water. An algal biofilm bloom occurred in early spring, prior to peak suspended chlorophyll a concentrations within the water column. Biofilm samples collected in February and March had the highest chlorophyll a and total phosphorus concentrations. The biofilm bloom corresponded with increased solar radiation and declining river flow conditions. Periodic increases in soluble reactive phosphorus concentrations in the overlying river water did not correspond with any significant increase in biofilm production. These results suggest that light, rather than phosphorus is a key factor for biofilm growth in the River Kennet. Higher rates of chlorophyll a development in mid-water column biofilms may be linked to greater light exposure; however, maximum total-P concentrations were similar for both bed and water column biofilms. Newly colonising biofilms exhibited higher chlorophyll a and total-P concentrations than biofilms left to accumulate over longer terms, suggesting that fresh substrate availability promotes high rates of biofilm growth. Both 'condensed and organic' P (stored in biomass) and 'inorganic' (mineral) P fractions within the biofilms were present in varying proportions, although the early spring biofilm bloom resulted in maximum proportions and absolute concentrations of 'condensed and organic' P. Calcite was the only crystalline mineral detected within the biofilms. Ratios of Ca:inorganic P are largely consistent with the presence of CaCO3-P co-precipitates, although one very low value suggested that there may also be additional sources of inorganic P, possibly P adsorbed to clays or organics within the biofilm. However, poor linkages between CaCO3 and inorganic P concentrations suggest that, although the inorganic P fraction within the biofilm may be derived largely from CaCO3-P co-precipitation, the subsequent processes controlling overall CaCO3 and inorganic P concentrations in the biofilm are complex.

Do routine antibiotics after loop diathermy excision reduce morbidity?

OBJECTIVE

To evaluate whether routinely giving an antibiotic after loop diathermy excision of the cervical transformation zone reduced post-operative vaginal loss.

DESIGN

Prospective, randomised, double-blind placebo controlled parallel study.

PARTICIPANTS

Five hundred women undergoing loop diathermy excision in a colposcopy clinic.

INTERVENTION

Administration of either ofloxacin 400 mg (2x200 mg) once daily for 5 days or an identical placebo.

MAIN OUTCOME MEASURE

Vaginal loss, assessed using a pictorial chart.

RESULTS

No significant difference in post-operative vaginal loss was found.

CONCLUSION

Routine antibiotic prophylaxis after loop diathermy excision is not justified.

Hepatic kinetics and magnetic resonance imaging of gadolinium-EOB-DTPA in dogs

RATIONALE AND OBJECTIVES

To measure the hepatic uptake and biliary elimination kinetics of gadolinium (Gd)-EOB-DTPA in dogs.

METHOD

Two groups of four beagles each were anesthetized and given an intravenous bolus of 25 mumol/kg or 250 mumol/kg of Gd-EOB-DTPA. Blood, hepatic bile, and urine were collected over 140 minutes, and liver samples were obtained immediately after the dogs were killed. Conventional T1-weighted spin echo sequences of the liver were performed on a 1.5-Tesla (T) magnetic resonance imager during sampling. A ninth beagle received a bolus of 25 mumol/kg followed 140 minutes later with a bolus of 250 mumol/kg of Gd-EOB-DTPA. Wedge liver biopsies were obtained for Gd estimation at various times after dosing, and Gd concentration was measured by inductively coupled plasma atomic emission spectroscopy.

RESULTS

The plasma concentration of Gd-EOB-DTPA decreased in a biexponential manner with half-lives of approximately 4 minutes and 60 minutes for the distribution and elimination phase independent of the dose given. Gadolinium bile concentration reached peak values between 80 and 140 minutes: 6.3 +/- 1.6 mmol/L for the low dose (LD) and 11.6 +/- mmol/L for the high dose (HD). Bile Gd output was 62.0 +/- 8.8 (LD) and 78.3 +/- 30.2 (HD) nmol/minute-kg 50 to 80 minutes after injection. Gadolinium-EOB-DTPA was excreted by the biliary route to 24.8 +/- 2.6 (LD) and 3.6 +/- 1.2 (HD) percent of the dose within 140 minutes. Liver Gd concentration was 0.43 +/- 0.14 (LD) and 4.3 +/- 0.5 (HD) mmol/kg liver tissue at the conclusion of the studies. Calculated concentrations in the hepatocyte were 60 (LD) and 15 (HD) times higher than in plasma at 25 minutes after dosing. Whereas the low dose exhibited excellent contrast enhancement for the whole period, the high dose displayed a biphasic signal enhancement with a decreasing signal caused by the too-high hepatic gadolinium accumulation.

CONCLUSIONS

Transport of the Gd-EOB-DTPA into the hepatocyte exceeded elimination from hepatocyte to bile. The high dose defined a biliary transport maximum for Gd-EOB-DTPA of 78.3 +/- 30.2 nmol/minute-kg. The liver accumulation results from fast transport into the hepatocyte and rate-limited slower transport from hepatocyte to bile. The accumulation occurs against a strong concentration gradient, suggesting energy-dependent active transport into the hepatocyte.

Theta class glutathione S-transferase GSTT1 genotypes and susceptibility to cervical neoplasia: interactions with GSTM1, CYP2D6 and smoking

The factors that determine progression of cervical intra-epithelial neoplasia (CIN) to squamous cell carcinoma (SCC) are unknown. Cigarette smoking is a risk factor, suggesting polymorphism at loci that encode carcinogen-metabolizing enzymes such as glutathione S-transferase (GSTT1, GSTM1) and cytochrome P450 (CYP2D6) may determine susceptibility to these cancers. We have studied the frequency of the null genotype at the theta class GSTT1 locus in women with low-grade CIN, high-grade CIN and SCC. The control group comprised women with normal cervical pathology suffering menorrhagia. We found the frequency of GSTT1 null in the control and case groups was not significantly different, though frequency distributions of combinations of the genotype with smoking in mutually exclusive groups in the high-grade CIN group and the other case groups were significantly different. Interactive effects of GSTT1 null with the GSTM1 null and CYP2D6 EM genotypes, and cigarette smoking were also studied by comparing the multinomial frequency distributions of these factors over mutually exclusive categories. These showed no significant differences between the controls and SCC or low-grade CIN. Frequency distributions in high-grade CIN, however, were significantly different to the controls, and both SCC and low-grade CIN; frequency distributions of GSTT1 null with smoking and CYP2D6 EM, individually and in combination, were significantly different. However, inspection of our data does not indicate that GSTT1 null is a major factor mediating risk. Thus, comparison of chi 2 values for the differences between frequency distributions in high-grade CIN and other groups shows that values for combinations of GSTT1 null with other factors are lower than those for equivalent combinations with smoking and CYP2D6 EM. Interestingly, the combination GSTT1 null/GSTM1 null did not appear to influence susceptibility to CIN or SCC.

A comparative study of the safety and efficacy of dysprosium-165 hydroxide macro-aggregate and yttrium-90 silicate colloid in radiation synovectomy--a multicentre double blind clinical trial. Australian Dysprosium Trial Group

The aim of our study was to compare the safety and efficacy of a new preparation, Dysprosium-165 Hydroxide Macroaggregate (165Dy) with Yttrium-90 Silicate (90Y) for radiation synovectomy of the knee in patients with RA and OA. A multicentre double blind clinical trial with subjects randomized to receive 165Dy or 90Y was undertaken in Sydney, Melbourne and Perth. Seventy knees of 59 patients were studied, using as clinical end point measurements, pain in the knee on walking, pain in the knee at rest and stiffness in the knee after rest. Cytogenetic damage, knee retention and extra-articular spread of the radionuclide to regional lymph nodes, liver, urine and blood were evaluated. There was no significant difference in clinical response in the two treatment groups for either RA or OA. Chromosomal changes occurred with equal frequency and the knee retention and extra-articular leakage of radiocolloids to regional lymph nodes and liver were comparable in the two groups. For radiation synovectomy of the knee, 165Dy is at least as safe and as effective as 90Y and has the advantage of a short half-life (2.334 h) and hence requires a shorter period of post-injection immobilization and hospitalization.

Hepatic kinetics and magnetic resonance imaging of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dogs

This complex study was designed to measure the transport and excretion characteristics of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dog's livers following bolus and infusion. Simultaneous T1 magnetic resonance imaging was performed to measure maximum signal enhancement. Anaesthetized dogs had cannulation of the common bile duct and urinary bladder for collections and cannulation of the femoral artery and vein for monitoring, blood sampling and infusion. Gd-EOB-DTPA was administered by bolus (range 12.5-200 mumol/kg) and infusion (range 0.4-6.4 mumol/min per kg). An hepatic transport maximum 0.09-0.15 mumol/min/kg was achieved with a blood concentration of 0.03-0.06 mumol/mL. Marked hepatic affinity for Gd-EOB-DTPA was demonstrated with measurements of liver concentration. Maximum T1 signal enhancement was achieved with blood Gd-EOB-DTPA concentration of 0.02-0.03 mumol/mL and a liver concentration of 1-2 mumol/g. The transport maximum for Gd-EOB-DTPA in the dog was similar to that for ipodate and iodipamide and effective imaging was achieved with sub-maximal doses. The maximum signal enhancement at blood concentrations less than required for maximum transport suggest a wide latitude for effective clinical imaging.

A randomised prospective study comparing the new vacuum extractor policy with forceps delivery

OBJECTIVE

To compare assisted vaginal delivery by forceps with delivery by vacuum extractor, where a new vacuum extractor policy was employed which dictated the cup to be used in specific situations.

DESIGN

Multicentre randomised controlled trial.

SETTING

Four district general hospitals in the West Midlands.

SUBJECTS

Six hundred-seven women requiring assisted vaginal delivery, of whom 296 were allocated to vacuum extractor delivery and 311 to forceps.

MAIN OUTCOME MEASURES

Delivery success rate, maternal perineal and vaginal injuries, maternal anaesthetic requirements, neonatal scalp and facial injuries.

RESULTS

Of the vacuum extractor group, 85% were delivered by the allocated instrument compared to 90% in the forceps group (odds ratio (OR) 0.64; 95% confidence intervals (CI) 0.4-1.04). However, more women in the vacuum extractor group were delivered vaginally (98%) than in the forceps group (96%). There were significantly fewer women with anal sphincter damage or upper vaginal extensions in the vacuum extractor group (11% vs 17%, OR 0.6; 95% CI, 0.38-0.97). There were significantly fewer women in the vacuum extractor group requiring epidural or spinal anaesthetics (25.4% vs 32.7%, OR 0.69; 95% CI 0.49-0.99) or general anaesthetics (1% vs 4%, OR 0.17; 95% CI 0.04-0.76). Although there were significantly more babies in the vacuum extractor group with cephalhaematomata (9% vs 3%, OR 3.3; 95% CI 1.4-7.4) there were fewer babies in the vacuum extractor group with other facial injuries. There were three babies in the forceps group with unexplained neonatal convulsions.

CONCLUSIONS

Assisted vaginal delivery using the new vacuum extractor policy is associated with significantly less maternal trauma than with forceps. Further studies are required to assess neonatal morbidity adequately.

Mapping the spread of epidural phenol in cancer pain patients by radionuclide admixture and epidural scintigraphy

This study used a radionuclide imaging technique to map the spread and density contours of phenol in glycerin injected into the epidural space of cancer patients. Correlations were made between phenol injectate volume, sequence of injection, position of patient, and resultant epidural spread and analgesic outcome. Fifteen patients with cancer pain (average age of 61 years) were treated with serial epidural phenol in glycerin injections. Phenol in glycerin is miscible with [99mTc]sulfur colloid. An assumption was made that the admixture injected epidurally was inseparable prior to absorption and the spread was recorded by continuous gamma camera observations with computer collection for 30 min postinjection. The spread of injectate volumes of 2, 3, and 4 ml were compared and further correlations made between observed spread and sequence of injections (first to fifth in series within each patient) and position of patient. Small volumes of phenol may spread extensively in the epidural space (3 ml spreads a mean 13.6 segments) with wide variation among patients. Initial phenol injections spread further than subsequent injections. Maximum spread is achieved by 15 min postinjection and epidural distribution is mostly uniform, independent of patient position. Good analgesia was obtained in 14 patients (93%). Epidural neurolysis using serial injections of small volumes of phenol in glycerin is an effective, safe technique for cancer pain relief. Injectate volumes larger than 3 ml may be unnecessary and potentially dangerous.

Presumptive invasive Chrysosporium infection in a bone marrow transplant recipient

Chrysosporium species caused an invasive infection in an 18-year-old patient following allogeneic sibling bone marrow transplant for T lineage acute lymphoblastic leukemia. This infection began as a facial swelling and extended into the central nervous system. Fungal disease spread rapidly despite antifungal agents. An autopsy showed fungal involvement of brain, lungs, liver and kidneys.

Loss of surface coat by Strongyloides ratti infective larvae during skin penetration: evidence using larvae radiolabelled with 67gallium

The optimal conditions for labelling infective larvae of Strongyloides ratti with 67gallium citrate were determined. Radiolabelled larvae were injected s.c. into normal and previously infected rats. The distribution of radioactivity in these animals was compared with that in rats infected subcutaneously with a similar dose of free 67Ga by using a gamma camera linked to a computer system. Whereas free 67Ga was distributed throughout the body and excreted via the hepatobiliary system, the bulk of radioactivity in rats injected with radiolabelled larvae remained at the injection sites. Direct microscopical examination of these sites, however, revealed only minimal numbers of worms. When rats were infected percutaneously with radiolabelled larvae, it was found that most radioactivity remained at the surface, despite penetration of worms. When infective larvae were exposed to CO2 in vitro and examined carefully by light microscopy, loss of an outer coat was observed. It was concluded that infective larvae lose an outer coat on skin penetration.

A sensitive human thyroglobulin RIA to define clearly the presence or absence of functioning thyroid tissue

This paper describes a practical procedure to establish a sensitive radioimmunoassay for the measurement of human thyroglobulin (HTg) in serum. The assay enables a clear distinction to be made between levels of HTg indicating the presence or absence of functioning thyroid tissue. It compares the use of HTg serum levels with the conventional I-131 scintigram as a marker for recurrent thyroid cancer. In addition, a simple and sensitive radioimmunologic assay is described for the determination of serum antithyroglobulin autoantibodies, the presence of which may give falsely elevated HTg levels.

Ontogeny of macrophage resistance to mouse hepatitis in vivo and in vitro

Adult or weanling C(3)H mice were found to be genetically resistant to a strain of mouse hepatitis virus. Infant C(3)H mice, however, developed infection and died from mouse hepatitis virus when minimal infectious doses of virus were given to them. There was a delay in the time of death compared to that of the genetically susceptible strain, and the virus recovered from these mice had increased pathogenicity for C(3)H mice. The ontogeny of resistance to hepatitis in the C(3)H mice thus progresses from delayed susceptibility to complete resistance as the age of the host increases. It is reflected in increased resistance of macrophages derived in vitro from liver cultures of infant mice of different ages. This increase in resistance with age was reduced by maintaining the cultures for a longer period of time before inoculation, or by increasing the number of explants in a given culture. Resistant cells were uniformly furnished by mice age 16 days, or more. It is concluded that a process of maturation of resistance of the cells takes place after the mice are born, but that this does not continue under in vitro conditions, and that it may be modified by the environment of the cells.