A kV-MV approach to CBCT metal artifact reduction using multi-layer MV-CBCT

Objective. To demonstrate that complete cone beam CT (CBCT) scans from both MV-energy and kV-energy LINAC sources can reduce metal artifacts in radiotherapy guidance, while maintaining standard-of-care x-ray doses levels.Approach. MV-CBCT and kV-CBCT scans are acquired at half normal dose. The impact of lowered dose on MV-CBCT data quality is mitigated by the use of a 4-layer MV-imager prototype and reduced LINAC energy settings (2.5 MV) to improve photon capture. Additionally, the MV-CBCT is used to determine the 3D position and pose of metal implants, which in turn is used to guide model-based poly-energetic correction and interleaving of the kV-CBCT and MV-CBCT data. Certain edge-preserving regularization steps incorporated into the model-based correction algorithm further reduce MV data noise.Main results. The method was tested in digital phantoms and a real pelvis phantom with large 2.5″ spherical inserts, emulating hip replacements of different materials. The proposed method demonstrated an appealing compromise between the high contrast of kV-CBCT and low artifact content of MV-CBCT. Contrast-to-noise improved 3-fold compared to MV-CBCT with a clinical 1-layer architecture at matched dose (37 mGy) and edge blur levels. Visual delineation of the bladder and prostate improved noteably over kV- or MV-CBCT alone.Significance. The proposed method demonstrates that a full MV-CBCT scan can be combined with kV-CBCT to reduce metal artifacts without resorting to complicated beam collimation strategies to limit the MV-CBCT dose contribution. Additionally, significant improvements in CNR can be achieved as compared to metal artifact reduction through current clinical MV-CBCT practices.

Randomised clinical trial: Efficacy and safety of on-demand vonoprazan versus placebo for non-erosive reflux disease

BACKGROUND

Non-erosive reflux disease (NERD) symptoms are often episodic, making on-demand treatment an attractive treatment approach.

AIMS

We compared the efficacy and safety of on-demand vonoprazan versus placebo in patients with NERD.

METHODS

Patients with NERD, defined as heartburn for ≥6 months and for ≥4/7 consecutive days with normal endoscopy, received once-daily vonoprazan 20 mg during a 4-week run-in period. Patients without heartburn during the last 7 days and with ≥80% study drug and diary compliance were randomised 1:1:1:1 to vonoprazan 10, 20, 40 mg or placebo on-demand for 6 weeks. The primary endpoint was the percentage of evaluable heartburn episodes completely relieved within 3 h of on-demand dosing and sustained for 24 h.

RESULTS

Of 458 patients in the run-in period, 207 entered the on-demand period. In the vonoprazan 10 mg group, 56.0% (201/359) of evaluable heartburn episodes met the criteria for complete and sustained relief; 60.6% (198/327) in the 20 mg group; and 70.0% (226/323) in the 40 mg group, compared with 27.3% (101/370) in the placebo group (p < 0.0001 versus placebo for each vonoprazan group). By 1 h post-dose, vonoprazan was associated with complete relief of significantly more heartburn episodes compared with placebo. No serious treatment-emergent adverse events were reported.

CONCLUSION

On-demand vonoprazan may be a potential alternative to continued daily acid suppression therapy for the relief of episodic heartburn in patients with NERD.

CLINICALTRIALS

gov: NCT04799158.

Changes in the Abundances of Cervical and Rectal Mycobiota during Chemoradiotherapy in Cervical Cancer

PURPOSE/OBJECTIVE(S)

Globally, cervical cancer is the fourth most frequent cancer in women. The local and gut microbiomes of cervical cancer patients primarily consist of bacteria, viruses, and fungi. Bacterial composition has been previously associated with response to chemoradiotherapy (CRT) and patient outcome. Recently, our group has demonstrated that the HPV virome dynamically shifts during treatment and was associated with treatment response. Although connections between fungi and cervicovaginal health have been established, little is known about the fungal microbiome during treatment of cervical cancer. In this study, we sought to explore changes in fungal distribution throughout CRT for a cohort of cervical cancer patients.

MATERIALS/METHODS

This study includes 57 patients diagnosed with cervical cancer at a single institution with samples collected throughout CRT timepoints: baseline, week 1, week 3, and week 5. 170 swab specimens were included in this analysis: 138 cervical swabs from 56 patients and 32 rectal swabs from 9 patients. Whole genome sequencing data was obtained from the swabs using the Illumina HiSeqX platform (2 × 150bp). Fungal reads were log transformed to reduce variability and skewness and normalized to the total library size resulting in log normalized fungal reads per million (RPM). Bacterial reads were normalized with the same methodology. Timepoint analysis was performed using Wilcoxon signed rank tests or Friedman tests (with Dunn's multiple comparisons test) when comparing two or more time points, respectively.

RESULTS

All swab samples contained reads mapped to fungi. Of the 3.70 × 109 total reads across all sequenced samples, 19.2% did not map specifically to the human genome: 91.8% of these non-human reads could not be mapped to an individual microbial genome. Of the remaining 8.2% of non-human reads that mapped to a specific microbial genome (1.6% of total), 97.4% were classified as bacterial (1.5% of total), 0.71% as virus (0.011% of total), and 0.44% as fungal (0.0069% of total). Comparison of fungal RPM in the cervical and rectal microbiome revealed a significant decrease during treatment from baseline to week 5 (cervical, P = 0.0002; rectal, P = 0.0273). Distribution of bacterial reads exhibited similar trends as decreases were observed between baseline and week 5 for both cervical (P = 0.0116) and rectal (P = 0.0195) samples. Fungi to bacteria distribution ratios in the rectal microbiome revealed significant differences when comparing across all timepoints (P = 0.0041), baseline vs. week 1 (P = 0.0028), baseline vs. week 3 (P = 0.0389), and baseline vs. week 5 (P = 0.0113) with all three later timepoints higher relative to baseline.

CONCLUSION

The distributions of cervical and gut fungal reads and their relationship to the bacteriome shift during CRT. Further investigation into characterizing fungi and their relationship with other microbiota will be valuable to understanding its potential associations with cervical cancer and treatment response.

Association of Bacterial Composition and Diversity in the Cervical Tumor Microbiome with HPV Genotype in a Large, International Patient Cohort

PURPOSE/OBJECTIVE(S)

Tumor bacterial composition is strongly associated with response to cancer therapy, and is impacted by environment, including geography. Human papillomavirus (HPV) genotypic diversity composition and load are dynamic during pelvic radiation (RT) and correlate with differential responses to RT in cervical cancer patients. In this multi-institutional, collaborative study, we aimed to explore associations between bacterial composition, HPV serotypes, and geographical distribution in an international patient population.

MATERIALS/METHODS

Cervical swabs were collected from 287 patients diagnosed with cervical cancer/ dysplasia in four locations: Houston, USA (TX; N = 94), Ethiopia (ETH; N = 85), Puerto Rico (PR; N = 71), and Botswana (BOT; N = 37). Swabs were collected prior to treatment and were subjected to 16S V4 rRNA gene sequencing and HPV genotyping. We compared HPV types and geography via Chi-squared test. We analyzed bacterial composition, alpha diversity (ANOVA), and beta diversity (principal coordinates analysis [PCoA] with PERMANOVA) for HPV type and geography. We used Linear Discriminant Effect Size (LEfSe) analysis to distinguish taxa associated with HPV types.

RESULTS

Overall, the global bacterial composition for patients with cancer or dysplasia did not significantly vary by location. However, the proportion of patients with each HPV type varied by location (p<0.01); HPV16 was most frequent in TX (54%), BOT (70%) and ETH (61%), while HPV18 was most frequent in PR (62%). The proportion of patients with HPV low-risk/negative tumors was highest in ETH (25%) compared to other sites (2% - 14%). Patients with HPV 16 had significantly higher bacterial alpha diversity across locations (all p<0.01). The bacterial composition also differed by HPV type across locations (p = 0.01). On LEfSe, bacterial genera enriched in HPV 16 samples were Bacteroides, Clostridium, and Prevotella. Non-HPV16 tumors were enriched in species of Lactobacillus and Gardnerella and HPV 18 and high-risk type tumors were enriched in Escherichia.

CONCLUSION

In thislarge, international cohort of cervical cancer and dysplasia patients, bacterial composition was more closely associated with cervical HPV genotype than with geography. This finding has implications for the development of biomarkers and interventions aimed at improving chemotherapy and radiation response through manipulation of the microbiome.

Iatrogenic and spontaneous preterm birth in England: a population-based cohort study

OBJECTIVE

To describe the rates of and risk factors associated with iatrogenic and spontaneous preterm birth and the variation in rates between hospitals.

DESIGN

Cohort study using electronic health records.

SETTING

English National Health Service.

POPULATION

Singleton births between 1^st April 2015 and 31^st March 2017.

METHODS

Multivariable Poisson regression models were used to estimate adjusted risk ratios (adjRR) to measure association with maternal demographic and clinical risk factors.

MAIN OUTCOME MEASURES

Preterm births (<37 weeks gestation) were defined as iatrogenic or spontaneous according to mode of onset of labour.

RESULTS

6.1% of births were preterm and of these, 52.8% were iatrogenic. The proportion of preterm births that were iatrogenic increased after 32 weeks. Both sub-groups are associated with previous preterm birth, extremes of maternal age, socioeconomic deprivation and smoking. Iatrogenic preterm birth was associated with higher BMI (adjRR BMI >40 1.59 (1.50, 1.69)), and previous caesarean (adjRR 1.88 (1.83, 1.95)). Spontaneous preterm birth was less common in women with a higher BMI (adjRR BMI>40 0.77 (0.70, 0.84)) and in women with a previous caesarean (adjRR 0.87 (0.83, 0.90)). More variation between NHS hospital trusts was observed in rates of iatrogenic, compared to spontaneous, preterm births.

CONCLUSIONS

Just over half of all preterm births resulted from iatrogenic intervention. Iatrogenic births have overlapping but different patterns of maternal demographic and clinical risk factors to spontaneous preterm births. Iatrogenic and spontaneous sub-groups should therefore be measured and monitored separately, as well as in aggregate, to facilitate different prevention strategies. This is feasible using routinely acquired hospital data.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The redistributive power of cash transfers vs VAT exemptions: A multi-country study

Like high-income countries, low- and middle-income countries (LMICs) offer reduced rates and exemptions on particular goods and services in their value-added tax (VAT) systems. These policies are often motivated by distributional concerns and target items thought to take up a larger share of the budgets of poorer households. This paper explores the effectiveness of such policies in six LMICs. We estimate their impact on tax revenues, inequality and poverty, and compare these effects to existing cash transfer schemes and a hypothetical Universal Transfer (UT) funded by broadening the VAT base. To do so, we use tax-benefit microsimulation models incorporating input-output tables, allowing us to estimate the impact of exemptions on consumer prices due to VAT embedded in supply chains. We show that although preferential VAT rates reduce poverty, they are not well targeted towards poor households overall. Existing cash transfer schemes are better targeted but generally have limited coverage. A UT funded by a broader VAT base would create large net gains for the poorest households, reducing inequality and most measures of extreme poverty in each of the countries studied. Our results suggest that the widespread practice of providing special VAT treatment to certain goods and services is an expensive way of reaching poor households. In principle, expanding the VAT base and social protection schemes in tandem has the potential to both raise tax revenues and reduce poverty. Such reforms therefore warrant consideration for LMICs as they pursue Domestic Revenue Mobilisation and broader development objectives.

124 The Microsurgical Learning Curve: Can We Make the First Steps Faster and Safer; A Cadaveric Study with A Novel Principle of Learning

Aim

Learning anew surgical technique can be a daunting experience for both the teacher and learner. Raising free flaps is a complex process, and our aim is to find out whether using Hi-fidelity simulation on cadavers can make the learning faster and safer.

Method

We used fresh frozen cadavers according to our local protocols. In the first stage of the study, we used 4 upper limbs in the first instance using different dye techniques. We use these in an international course and obtain feedback from the trainees.

Results

To a novel learner, we found that using a bright green dye was the important factor in making the first steps of learning easier and faster. This is perhaps due to the confounding information when raising the flap. We found that it made understanding the concept of free flap raising much faster when clarified with colour. It also made anticipating the steps easier when identifying the perforators. To an experienced trainee/consultant: We found teaching the concept of perforators easier, the ease of finding the perforators would raise confidence of the novel trainees. They will be able to conceptualize the principles of flap raising much faster. They believed it would also make them quicker at anticipating steps of the procedure.

Conclusions

Learning is an incredible process that we still have to better control and understand. Using simple tricks such as colour changes can make initial learning faster, which means cheaper and safer

Associations between ethnicity and admission to intensive care among women giving birth: a cohort study

OBJECTIVE

To determine the association between ethnic group and likelihood of admission to intensive care in pregnancy and the postnatal period.

DESIGN

Cohort study.

SETTING

Maternity and intensive care units in England and Wales.

POPULATION OR SAMPLE

A total of 631 851 women who had a record of a registerable birth between 1 April 2015 and 31 March 2016 in a database used for national audit.

METHODS

Logistic regression analyses of linked maternity and intensive care records, with multiple imputation to account for missing data.

MAIN OUTCOME MEASURES

Admission to intensive care in pregnancy or postnatal period to 6 weeks after birth.

RESULTS

In all, 2.24 per 1000 maternities were associated with intensive care admission. Black women were more than twice as likely as women from other ethnic groups to be admitted (odds ratio [OR] 2.21, 95% CI 1.82-2.68). This association was only partially explained by demographic, lifestyle, pregnancy and birth factors (adjusted OR 1.69, 95% CI 1.37-2.09). A higher proportion of intensive care admissions in Black women were for obstetric haemorrhage than in women from other ethnic groups.

CONCLUSIONS

Black women have an increased risk of intensive care admission that cannot be explained by demographic, health, lifestyle, pregnancy and birth factors. Clinical and policy intervention should focus on the early identification and management of severe illness, particularly obstetric haemorrhage, in Black women, in order to reduce inequalities in intensive care admission.

TWEETABLE ABSTRACT

Black women are almost twice as likely as White women to be admitted to intensive care during pregnancy and the postpartum period; this risk remains after accounting for demographic, health, lifestyle, pregnancy and birth factors.

Abbreviated on-treatment CBCT using roughness penalized mono-energization of kV-MV data and a multi-layer MV imager

Simultaneous acquisition of cone beam CT (CBCT) projections using both the kV and MV imagers of an image guided radiotherapy system reduces set-up scan times-a benefit to lung cancer radiation oncology patients-but increases noise in the 3D reconstruction. In this article, we present a kV-MV scan time reduction technique that uses two noise-reducing measures to achieve superior performance. The first is a high-DQE multi-layer MV imager prototype. The second is a beam hardening correction algorithm which combines poly-energetic modeling with edge-preserving, regularized smoothing of the projections. Performance was tested in real acquisitions of the Catphan 604 and a thorax phantom. Percent noise was quantified from voxel values in a soft tissue volume of interest (VOI) while edge blur was quantified from a VOI straddling a boundary between air and soft material. Comparisons in noise/resolution performance trade-off were made between our proposed approach, a dose-equivalent kV-only scan, and a kV-MV reconstruction technique previously published by Yinet al(2005Med. Phys.329). The proposed technique demonstrated lower noise as a function of spatial resolution than the baseline kV-MV method, notably a 50% noise reduction at typical edge blur levels. Our proposed method also exhibited fainter non-uniformity artifacts and in some cases superior contrast. Overall, we find that the combination of a multi-layer MV imager, acquiring at a LINAC source energy of 2.5 MV, and a denoised beam hardening correction algorithm enables noise, resolution, and dose performance comparable to standard kV-imager only set-up CBCT, but with nearly half the gantry rotation time.

Waterbirth: a national retrospective cohort study of factors associated with its use among women in England

Background

Waterbirth is widely available in English maternity settings for women who are not at increased risk of complications during labour. Immersion in water during labour is associated with a number of maternal benefits. However for birth in water the situation is less clear, with conclusive evidence on safety lacking and little known about the characteristics of women who give birth in water.

This retrospective cohort study uses electronic data routinely collected in the course of maternity care in England in 2015–16 to describe the proportion of births recorded as having occurred in water, the characteristics of women who experienced waterbirth and the odds of key maternal and neonatal complications associated with giving birth in water.

Methods

Data were obtained from three population level electronic datasets linked together for the purposes of a national audit of maternity care. The study cohort included women who had no risk factors requiring them to give birth in an obstetric unit according to national guidelines. Multivariate logistic regression models were used to examine maternal (postpartum haemorrhage of 1500mls or more, obstetric anal sphincter injury (OASI)) and neonatal (Apgar score less than 7, neonatal unit admission) outcomes associated with waterbirth.

Results

46,088 low and intermediate risk singleton term spontaneous vaginal births in 35 NHS Trusts in England were included in the analysis cohort. Of these 6264 (13.6%) were recorded as having occurred in water. Waterbirth was more likely in older women up to the age of 40 (adjusted odds ratio (adjOR) for age group 35–39 1.27, 95% confidence interval (1.15,1.41)) and less common in women under 25 (adjOR 18–24 0.76 (0.70, 0.82)), those of higher parity (parity ≥3 adjOR 0.56 (0.47,0.66)) or who were obese (BMI 30–34.9 adjOR 0.77 (0.70,0.85)). Waterbirth was also less likely in black (adjOR 0.42 (0.36, 0.51)) and Asian (adjOR 0.26 (0.23,0.30)) women and in those from areas of increased socioeconomic deprivation (most affluent versus least affluent areas adjOR 0.47 (0.43, 0.52)).

There was no association between delivery in water and low Apgar score (adjOR 0.95 (0.66,1.36)) or incidence of OASI (adjOR 1.00 (0.86,1.16)). There was an association between waterbirth and reduced incidence of postpartum haemorrhage (adjOR 0.68 (0.51,0.90)) and neonatal unit admission (adjOR 0.65 (0.53,0.78)).

Conclusions

In this large observational cohort study, there was no association between waterbirth and specific adverse outcomes for either the mother or the baby. There was evidence that white women from higher socioeconomic backgrounds were more likely to be recorded as giving birth in water. Maternity services should focus on ensuring equitable access to waterbirth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03724-6.

Automated MV markerless tumor tracking for VMAT

Tumor tracking during radiotherapy treatment can improve dose accuracy, conformity and sparing of healthy tissue. Many methods have been introduced to tackle this challenge utilizing multiple imaging modalities, including a template matching based approach using the megavoltage (MV) on-board portal imager demonstrated on 3D conformal treatments. However, the complexity of treatments is evolving with the introduction of VMAT and IMRT, and successful motion management is becoming more important due to a trend towards hypofractionation. We have developed a markerless lung tumor tracking algorithm, utilizing the electronic portal imager (EPID) of the treatment machine. The algorithm has been specifically adapted to track during complex treatment deliveries with gantry and MLC motion. The core of the algorithm is an adaptive template matching method that relies on template stability metrics and local relative orientations to perform multiple feature tracking simultaneously. Only a single image is required to initialize the algorithm and features are automatically added, modified or removed in response to the input images. This algorithm was evaluated against images collected during VMAT arcs of a dynamic thorax phantom. Dynamic phantom images were collected during radiation delivery for multiple lung SBRT breathing traces and an example patient data set. The tracking error was 1.34 mm for the phantom data and 0.68 mm for the patient data. A multi-region, markerless tracking algorithm has been developed, capable of tracking multiple features simultaneously without requiring any other a priori information. This novel approach delivers robust target localization during complex treatment delivery. The reported tracking error is similar to previous reports for 3D conformal treatments.

High water vs. ad libitum water intake for autosomal dominant polycystic kidney disease: a randomized controlled feasibility trial

BACKGROUND

Vasopressin stimulates cyst growth in autosomal dominant polycystic kidney disease (ADPKD) and is a key therapeutic target. Evaluation of high water intake as an alternative to pharmacological vasopressin blockade is supported by patients. However feasibility, safety and adherence-promoting strategies required to deliver this remain unknown.

AIMS

Assess the feasibility of a definitive randomized high water intake trial in ADPKD.

METHODS

In this prospective open-label randomized trial, adult ADPKD patients with eGFR ≥ 20 ml/min/1.73 m2 were randomized to prescribed high water (HW) intake targeting urine osmolality (UOsm) ≤270 mOsm/kg, or ad libitum (AW) intake (UOsm >300 mOsm/kg). Self-management strategies including home-monitoring of urine-specific gravity (USG) were employed to promote adherence.

RESULTS

We enrolled 42 participants, baseline median eGFR (HW 68.4 [interquartile range (IQR) 35.9-107.2] vs. AW 75.8 [IQR 59.0-111.0 ml/min/1.73 m2, P = 0.22) and UOsm (HW 353 [IQR 190-438] vs. AW 350 [IQR 240-452] mOsm/kg, P = 0.71) were similar between groups. After 8 weeks, 67% in the HW vs. 24% in AW group achieved UOsm ≤270 mOsm/kg, P = 0.001. HW group achieved lower UOsm (194 [IQR 190-438] vs. 379 [IQR 235-503] mOsm/kg, P = 0.01) and higher urine volumes (3155 [IQR 2270-4295] vs. 1920 [IQR 1670-2960] ml/day, P = 0.02). Two cases of hyponatraemia occurred in HW group. No acute GFR effects were detected. In total 79% (519/672) of USG were submitted and 90% (468/519) were within target. Overall, 17% withdrew during the study.

CONCLUSION

DRINK demonstrated successful recruitment and adherence leading to separation between treatment arms in primary outcomes. These findings suggest a definitive trial assessing the impact of high water on kidney disease progression in ADPKD is feasible.

Evaluating the use of whole genome sequencing for the investigation of a large mumps outbreak in Ontario, Canada

In 2017 Ontario experienced the largest mumps outbreak in the province in 8 years, at a time when multiple outbreaks were occurring across North America. Of 259 reported cases, 143 occurred in Toronto, primarily among young adults. Routine genotyping of the small hydrophobic gene indicated that the outbreak was due to mumps virus genotype G. We performed a retrospective study of whole genome sequencing of 26 mumps virus isolates from early in the outbreak, using a tiling amplicon method. Results indicated that two of the cases were genetically divergent, with the remaining 24 cases belonging to two major clades and one minor clade. Phylogeographic analysis confirmed circulation of virus from each clade between Toronto and other regions in Ontario. Comparison with other genotype G strains from North America suggested that the presence of co-circulating major clades may have been due to separate importation events from outbreaks in the United States. A transmission network analysis performed with the software program TransPhylo was compared with previously collected epidemiological data. The transmission tree correlated with known epidemiological links between nine patients and identified new potential clusters with no known epidemiological links.

An experimental evaluation of the benefits and costs of providing fertility information to adolescents and emerging adults

STUDY QUESTION

Does the provision of fertility (compared to control) information affect fertility-related knowledge, perceived threat of infertility, anxiety, physical stress and fertility plans in adolescents and emerging adults?

SUMMARY ANSWER

The provision of fertility information was associated with increased fertility knowledge (emerging adults) and greater infertility threat (adolescents and emerging adults).

WHAT IS KNOWN ALREADY

According to fertility education research, adolescents and emerging adults know less than they should know about fertility topics. Fertility knowledge can be improved through the provision of information in older adults.

STUDY DESIGN, SIZE, DURATION

Experimental design. Secondary and university students completed pre-information questionnaires, were randomly assigned via computer to an experimental group, read either fertility (FertiEduc group) or healthy pregnancy information (Control group), and completed post-information questionnaires. Data were collected in group sessions via an online portal.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible participants were aged 16–18 (adolescents) or 21–24 years (emerging adults), childless, not currently pregnant (for men, partner not pregnant) or trying to conceive, presumed fertile and intending to have a child in the future. Of the 255 invited, 208 (n = 93 adolescents, n = 115 emerging adults) participated. The FertiEduc group received ‘A Guide to Fertility’, four online pages of information about fertility topics (e.g. ‘When are men and women most fertile?’) and the Control group received four online pages from the National Health Service (NHS) pregnancy booklet ‘Baby Bump and Beyond’. Participants completed a questionnaire (fertility knowledge, perceived threat of infertility, anxiety, physical stress and fertility plans, moderators) prior to and after the provision of information. Mixed factorial analysis of variance was used to examine the effects of information provision and hierarchical multiple regression to assess potential moderators of knowledge.

MAIN RESULTS AND THE ROLE OF CHANCE

The FertiEduc and Control groups were equivalent on age, gender, disability, relationship status and orientation at baseline. Results showed that fertility information significantly increased fertility knowledge for emerging adults only (P < 0.001) and threat of infertility for emerging adults and adolescents (P = 0.05). The moderators were not significant. Participation in the study was associated with an increase in feelings of anxiety but a decrease in physical stress reactions. Adolescents had more optimal fertility plans compared to emerging adults due to being younger.

LIMITATIONS, REASONS FOR CAUTION

This was an experimental study on a self-selected sample of men and women from selected educational institutions and only short term effects of information were studied.

WIDER IMPLICATIONS OF THE FINDINGS

Provision of fertility information can have benefits (increased fertility knowledge) but also costs (increase potential threat of infertility). Adolescents find fertility information positive but do not learn from it. Fertility education should be tailored according to age groups and created to minimise negative effects. Longitudinal examination of the effects of fertility information in multi-centre studies is warranted and should include measures of perceived threat of infertility.

STUDY FUNDING/COMPETING INTEREST(S)

Cardiff University funded this research. All authors have no conflicts of interest to declare.

Biofidelic finite element models for accurately classifying hip fracture in a retrospective clinical study of elderly women from the AGES Reykjavik cohort

Clinical retrospective studies have only reported limited improvements in hip fracture classification accuracy using finite element (FE) models compared to conventional areal bone mineral density (aBMD) measurements. A possible explanation is that state-of-the-art quasi-static models do not estimate patient-specific loads. A novel FE modeling technique was developed to improve the biofidelity of simulated impact loading from sideways falling. This included surrogate models of the pelvis, lower extremities, and soft tissue that were morphed based on subject anthropometrics. Hip fracture prediction models based on aBMD and FE measurements were compared in a retrospective study of 254 elderly female subjects from the AGES-Reykjavik study. Subject fragility ratio (FR) was defined as the ratio between the ultimate forces of paired biofidelic models, one with linear elastic and the other with non-linear stress-strain relationships in the proximal femur. The expected end-point value (EEV) was defined as the FR weighted by the probability of one sideways fall over five years, based on self-reported fall frequency at baseline. The change in maximum volumetric strain (ΔMVS) on the surface of the femoral neck was calculated between time of ultimate femur force and 90% post-ultimate force in order to assess the extent of tensile tissue damage present in non-linear models. After age-adjusted logistic regression, the area under the receiver-operator curve (AUC) was highest for ΔMVS (0.72), followed by FR (0.71), aBMD (0.70), and EEV (0.67), however the differences between FEA and aBMD based prediction models were not deemed statistically significant. When subjects with no history of falling were excluded from the analysis, thus artificially assuming that falls were known a priori with no uncertainty, a statistically significant difference in AUC was detected between ΔMVS (0.85), and aBMD (0.74). Multivariable linear regression suggested that the variance in maximum elastic femur force was best explained by femoral head radius, pelvis width, and soft tissue thickness (R² = 0.79; RMSE = 0.46 kN; p < 0.005). Weighting the hip fracture prediction models based on self-reported fall frequency did not improve the models' sensitivity, however excluding non-fallers lead to significant differences between aBMD and FE based models. These findings suggest that an accurate assessment of fall probability is necessary for accurately identifying individuals predisposed to hip fracture.

The Use of Lung Ultrasound in Acute Medicine

POCUS (Point of Care Ultrasound) refers to ultrasound performed by clinicians as part of their initial patient evaluation, often with the aim of answering a specific question as opposed to being a comprehensive assessment. Such ultrasound is noninvasive, involves no radiation and can be rapidly performed at the bedside. It is also widely practiced in emergency and intensive care medicine leading to earlier and more accurate diagnoses for a wide range of presentations such as shock, renal failure and dyspnoea.

104 Teratospermia in tigers: Evidence for declining sperm quality over time

Ejaculate traits in male tigers (Panthera tigris) were studied in the 1980s, but little work has been done on male tigers since then and the reproductive status of the current zoo population is not known. In order to characterise ejaculate traits in male tigers, semen was collected by electroejaculation (90 to 100 stimulations, 3 to 7V), subjected to a standard semen analysis (volume and pH and sperm concentration, motility, and morphology), and cryopreserved. To date, semen has been collected from 24 males (n=16 Amur tigers, Panthera tigris altaica, 10.3±1.1 y; n=7 Sumatran tigers, Panthera tigris sumatrae, 9.4±1.3 y; n=1 Malayan tiger, Panthera tigris jacksoni, 6 y), maintained at 18 USA institutions. Ejaculates (4.7±0.6 mL; pH=8.4±0.1) contained 240.3±54.9×106 spermatozoa, which yielded 357 straws of cryopreserved spermatozoa that were used to establish a Tiger Genome Resource Bank. The majority of the spermatozoa were motile (69.2±4.6%), but the proportion of spermatozoa exhibiting normal morphology was very low (18.7±3.3%) and similar between both Amur (20.0±4.8%) and Sumatran (16.3±5.2%) males, with the majority of abnormalities affecting the midpiece (retained cytoplasmic droplets, bent midpieces, or both). Previous studies of male tigers that utilised comparable anaesthesia regimens and collection techniques recovered similar quantities of semen (5 to 10mL), but the proportions of normal spermatozoa in those studies (&gt;65%) were very high (Wildt et al. 1988 Biol. Reprod. 38, 245; Byers et al. 1990 J. Reprod. Fert. 90, 119). Proportions of normal spermatozoa in the current study more closely resemble those reported for the teratospermic (&lt;40% normal spermatozoa) clouded leopard (Neofelis nebulosa, 18.5% normal spermatozoa, Pukazhenthi et al. 2006 Theriogenology 66, 1790) and cheetah (Acinonyx jubatus, 18.4% normal spermatozoa, Crosier et al. 2007 Reprod. Fertil. Dev. 19, 370), as well as the South China tiger (Panthera tigris amoyensis, 27% normal spermatozoa). The number of spermatozoa per ejaculate was also decreased in Amur tigers (190.1±67.7×106) compared to Sumatran tigers in the current study (362.9±99.5×106) and earlier studies of other Amur tigers (&gt;500×106). The reasons for this apparent decline in sperm quality are unclear, but reduced proportions of normal spermatozoa have been associated with reduced heterozygosity in small, isolated populations of felids (Florida panthers, South China tigers) or species that have been through a genetic bottleneck (cheetahs). Semen collections and evaluations will continue in order to determine if trends for compromised sperm quality are representative of the current SSP population(s) or an artifact of our reduced sample size. Additional studies investigating possible environmental, genetic, or nutritional influences on sperm morphology are also warranted. This work is supported by grants from Association of Zoo and Aquarium’s Conservation Grants Fund and Point Defiance Zoo and Aquarium’s Dr. Holly Reed Conservation Fund.

Radiological differences between HIV-positive and HIV-negative children with cholesteatoma

INTRODUCTION

HIV-positive children are possibly more prone to developing cholesteatoma. Chronic inflammation of the middle ear cleft may be more common in patients with HIV and this may predispose HIV-positive children to developing cholesteatoma. There are no studies that describe the radiological morphology of the middle ear cleft in HIV-positive compared to HIV-negative children with cholesteatoma.

OBJECTIVES

Compare the radiological differences of the middle ear cleft in HIV-positive and HIV-negative children with cholesteatoma.

METHODS

A retrospective, cross-sectional, observational analytical review of patients with cholesteatoma at our institute over a 6 year period.

RESULTS

Forty patients were included in the study, 11 of whom had bilateral cholesteatoma and therefore 51 ears were eligible for our evaluation. HIV-positive patients had smaller (p=0.02) mastoid air cell systems (MACS). Forty percent of HIV-positive patients had sclerotic mastoids, whereas the rate was 3% in HIV-negative ears (p<0.02). Eighty-two percent of the HIV-positive patients had bilateral cholesteatoma compared to 7% of the control group (p<0.02). There was no difference between the 2 groups with regards to opacification of the middle ear cleft, bony erosion of middle ear structures, Eustachian tube obstruction or soft tissue occlusion of the post-nasal space.

CONCLUSION

HIV-positive paediatric patients with cholesteatoma are more likely to have smaller, sclerotic mastoids compared to HIV-negative patients. They are significantly more likely to have bilateral cholesteatoma. This may have implications in terms of surveillance of HIV-positive children, as well as, an approach to management, recurrence and follow-up. HIV infection should be flagged as a risk factor for developing cholesteatoma.

Administration of a live attenuated Salmonella vaccine using an inactivated oil-emulsion vaccine as a vehicle for commercial chicken flocks

Since the finding that inoculating an aroA- deletion live Salmonella Typhimurium vaccine parenterally provides improved and longer-lasting protection against Salmonella colonisation of the laying-hen intestine, this administration route has been adopted by the industry. To make this method practicable and economical, mixing the live bacterial vaccine with an inactivated viral vaccine has become popular. In vitro and in vivo studies were performed designed to assess the effect on the survival of the live salmonellae and the ability to stimulate serum antibody when mixed into oil-emulsion vaccines, compared with more traditional diluents. A rapid decline in viable salmonellae was observed when mixing with an inactivated Riemerella/Pasteurella bacterin. Mixing with an inactivated viral vaccine produced a less severe and more gradual decline in viable salmonellae over time; however, there was a surprising resuscitation of the bacteria 60 min after mixing. Serum antibody 14 days after inoculation of vaccine diluted in a universal diluent rose significantly, compared with sham vaccinated birds. Birds receiving the vaccine diluted in an inactivated vaccine at the time of preparation did not show a significant serological response; however, when given 60 min post-preparation, serum antibody was significantly increased. There appeared to be a correlation of the magnitude of serum antibody produced with the number of viable salmonellae inoculated. The use of the live vaccine incorporated into an inactivated vaccine may give variable results and needs assessment before adoption.

Author response

We share your understanding that fluid responsiveness is NOT equivalent to hypovolaemia, and that it also does not equate to fluid administration being of benefit. We offer our apologies should our article have suggested otherwise. Indeed, this is one of the key reasons why we advocate fluid administration against measurable goals, such as stroke volume, as well as blood pressure and pulse.

Assessment of Fluid responsiveness in the Acute Medical Patient and the Role of Echocardiography

Both hyper and hypovolaemia have been associated with poor outcomes. Assessment of fluid responsiveness is challenging in the acute medical patient, due to time constraints, limited evidence and quite often the lack of accurate assessment tools on the Acute Medicine Unit (AMU). This article explains how focused echo assessment is quick and easy to use for this purpose on the acute medical take and highlights key principles to bear in mind when assessing for hypovolaemia and whether to administer fluid therapy. The increasing familiarity with focused echo such as Focused Intensive Care Echocardiography (FICE) and Point Of Care Ultrasound (POCUS) makes extension of these skill sets to assess for fluid responsiveness a relatively straightforward next step for acute physicians.

Use of a Granulocyte Immunofluorescence Assay Designed for Humans for Detection of Antineutrophil Cytoplasmic Antibodies in Dogs with Chronic Enteropathies

BACKGROUND

Perinuclear antineutrophil cytoplasmic antibodies (pANCA) previously have been shown to be serum markers in dogs with chronic enteropathies, with dogs that have food-responsive disease (FRD) having higher frequencies of seropositivity than dogs with steroid-responsive disease (SRD). The indirect immunofluorescence (IIF) assay used in previous publications is time-consuming to perform, with low interobserver agreement.

HYPOTHESIS/OBJECTIVES

We hypothesized that a commercially available granulocyte IIF assay designed for humans could be used to detect perinuclear antineutrophil cytoplasmic antibodies in dogs.

ANIMALS

Forty-four dogs with FRD, 20 dogs with SRD, 20 control dogs, and 38 soft-coated wheaten terrier (SCWT) or SCWT-cross dogs.

METHODS

A granulocyte assay designed for humans was used to detect pANCA, cANCA, and antinuclear antibodies (ANA), as well as antibodies against proteinase-3 protein (PR-3) and myeloperoxidase protein (MPO) in archived serum samples.

RESULTS

Sensitivity of the granulocyte assay to predict FRD in dogs was 0.61 (95% confidence interval (CI), 0.45, 0.75), and specificity was 1.00 (95% CI, 0.91, 1.00). A significant association was identified between positive pANCA or cANCA result and diagnosis of FRD (P < 0.0001). Agreement between the two assays to detect ANCA in the same serum samples from SCWT with protein-losing enteropathy/protein-losing nephropathy (PLE/PLN) was substantial (kappa, 0.77; 95% CI, 0.53, 1.00). Eight ANCA-positive cases were positive for MPO or PR-3 antibodies.

CONCLUSIONS AND CLINICAL IMPORTANCE

The granulocyte immunofluorescence assay used in our pilot study was easy and quick to perform. Agreement with the previously published method was good.

The heterogeneous impact of a successful tobacco control campaign: a case study of Mauritius

BACKGROUND

Mauritius has one of the highest smoking prevalences in Africa, contributing to its high burden of non-communicable diseases. Mauritius implemented a series of tobacco control measures from 2009 to 2012, including tobacco tax increases. There is evidence that these policies reduced tobacco consumption, but it is not clear what impact they had across different socioeconomic groups.

METHOD

The impact of tobacco control measures on different income groups was analysed by contrasting household tobacco expenditures reported in 2006-2007 and 2012 household expenditure surveys. We employed the seemingly unrelated regression model to assess the impact of tobacco use on other household expenditures and calculated Gini coefficients to assess tobacco expenditure inequality.

RESULTS

From 2006 to 2012, excise taxes and retail cigarette prices increased by 40.6% and 15.3% in real terms, respectively. These increases were accompanied by numerous non-price tobacco control measures. The share of tobacco-consuming households declined from 35.7% to 29.3%, with the largest relative drop among low-income households. The Gini coefficient of household tobacco expenditures increased by 10.4% due to decreased spending by low-income households. Low-income households demonstrated the largest fall in their tobacco budget shares, and the impact of tobacco consumption on poverty decreased by 26.2%. Households that continued purchasing tobacco reduced their expenditures on transportation, communication, health, and education.

CONCLUSIONS

These results suggest that tobacco control policies, including sizeable tax increases, were progressive in their impact. We conclude that tobacco use increases poverty and inequality, but stronger tobacco control policies can mitigate the impact of tobacco use on impoverishment.

Effect of Cranberry Extract on the Frequency of Bacteriuria in Dogs with Acute Thoracolumbar Disk Herniation: A Randomized Controlled Clinical Trial

Background

Dogs with spinal cord injury are at increased risk of developing bacteriuria due to increased residual urine volume. Cranberry extract inhibits binding of E. coli to uroepithelial cells, potentially reducing risk of bacteriuria.

Hypothesis

Cranberry extract reduces risk of bacteriuria in dogs after acute TL‐IVDH.

Animals

Client‐owned dogs with acute onset TL‐IVDH causing nonambulatory status.

Methods

Randomized, placebo‐controlled, blinded, prospective clinical trial. Dogs with acute TL‐IVDH were recruited 48 hours postoperatively and randomized to receive cranberry extract or placebo in a masked fashion. Urine cultures and neurological examinations were performed 2, 4, and 6 weeks postoperatively. The number of dogs with bacteriuria (all bacterial species) and bacteriuria (E. coli) were primary and secondary outcome measures and were evaluated using chi‐squared test. Urine antiadhesion activity (AAA) was measured in a subset (N = 47) and examined in a secondary analysis evaluating additional risk factors for bacteriuria.

Results

Bacteriuria was detected 17 times in 94 dogs (6 placebo, 11 cranberry, P = .12). There were 7 E. coli. positive cultures (1 placebo, 6 cranberry, P = .09). Dogs in both groups had positive urine AAA (14/21: placebo, 16/26: cranberry), and dogs with urine AAA had significantly fewer E. coli positive cultures (n = 1) than dogs without it (n = 4) (P = .047).

Conclusions and Clinical Importance

This clinical trial did not show a benefit of oral cranberry extract but had low power. Cranberry extract supplementation did not impact urine AAA, but a possible association between urine AAA and lower risk of E. coli bacteriuria was identified. Other doses could be investigated.