The tracheal system of the Common Wasp (Vespula vulgaris) - A micro-CT study.

X-ray micro-CT has been used to study the tracheal system of Pre and Post hibernation Queen wasps (Vespula vulgaris) and their workers. We have compared our findings in wasps with Snodgrass's description of the tracheal system of the honeybee as characterised by anatomical dissection. Our images, whilst broadly similar, identify the tracheal system as being considerably more complex than previously suggested. One of the 30 wasps imaged had a markedly different, previously undescribed tracheal system. Since completing this study, a large micro-CT study from the American Museum of Natural History (AMNH) has been published. This used different software (Slicer) and analysed 16bit digital data. We have compared our methods with that described in the AMNH publication, adopted their suggested nomenclature and have made recommendations for future studies.

Visualising fat reserves in an insect: A method using X-ray micro-computerised tomography of the Common Wasp (Vespula vulgaris).

The Common Wasp, Vespula vulgaris (Hymenoptera: Vespidae), has an annual nest cycle with new colonies initiated by over-wintered queens. Survival of adult queen wasps through winter dormancy is enabled through the deposition of substantial quantities of triglycerides in fat bodies. Worker (and male) wasps lack these fat reserves. By comparing micro-CT scans of workers, pre-hibernation queens and post-hibernation queens, we demonstrate that it is possible to semi-quantitatively measure fat reserves using arbitrary X-ray attenuation ranges. Venom in the venom gland of the queen wasps, has a significantly lower X-ray attenuation value than the triglyceride-rich fat bodies. This may be due to its content of low molecular weight volatile pheromones in addition to its other known constituents. We also demonstrate the utility of micro-CT for visualising a range of physiological and anatomical features of insects. This non-destructive method for measuring fat reserves can be used on appropriately preserved or freshly collected insect specimens.

Patient chosen gap payments in primary care: Predictions of patient acceptability, uptake and willingness to pay from a discrete choice experiment.

Compulsory co-payments limit access and may compromise quality in primary care. Patient Chosen Gap Payments (PCGPs) allow patients to specify a (voluntary) out-of-pocket contribution, creating an incentive for patient-centred care without the need for complex outcomes-based funding formulae. It is not yet known if widespread use of PCGP services is consistent with consumer preferences. We conducted a discrete choice experiment (DCE) in a sample of the adult Australian general population (n = 1457) during April 2019 to simulate patient choice between alternative primary care services and describe preferences for PCGP services. Participants also completed a supplementary valuation task in which participants reported their intended PCGP contribution for PCGP services. Finally, we conducted policy-simulations to predict market shares when PCGP clinics operate alongside the two existing models of primary care funding in Australia. Results suggest that patients prefer shorter wait time, longer consults, lower compulsory copayments, services with higher patient satisfaction ratings, choice of doctor and $0 suggested voluntary contribution for PCGP services. Policy-simulations suggest that high-quality PCGP services could obtain market share of up to 39% and voluntary contributions of up to $25.36 per service (95%CI: $10.24, $40.47), potentially adding $1.48 billion AUD in revenues and funding for primary care at no cost to government. Low-quality PCGP services are unlikely to capture significant market share and PCGP contributions were lowest for low-quality PCGP services ($12.12, 95%CI: $2.09, $26.34). Further field testing is recommended where (i) patients make consequential choices (e.g. real payments for simulated services), and (ii) dynamic effects on quality of care and utilisation can be observed; particularly in vulnerable populations. We conclude that PCGP services aligned with patient preferences could capture significant market share and substantially increase revenue to general practice.

Recently listed Stockholm convention POPs: Analytical methodology, occurrence in food and dietary exposure.

In recent years, the Stockholm Convention has listed an additional set of persistent organic pollutants (POPs) for elimination or restricted use/release. Data on the occurrence of these contaminants in food is scarce. Validated analytical methodology was developed to investigate the occurrence of hexachlorobutadiene (HCBD), pentachlorobenzene (PCBz), hexachlorobenzene (HCB) pentachlorophenol (PCP) and polychlorinated naphthalenes (PCNs) in 120 retail foods and 19 total diet study samples. The foods covered the range of commonly consumed dietary items including dairy products, eggs (hen and other species), poultry, meat, fish, vegetables, etc. HCBD showed a low frequency of detection, whereas PCBz, HCB and PCNs occurred in most samples (ranges: <0.01 to 0.19 µg/kg; <0.01 to 3.16 µg/kg and 0.1 to 166 ng ΣPCNs/kg respectively). PCP (<0.01 to 1.9 µg/kg) was detected more frequently in meat products, offal and eggs. Fish, shellfish, eggs from all species, animal fats, meat, offal and meat products showed higher contamination levels, which is normal when investigating lipophilic POPs. These levels of occurrence are similar to more recently reported literature levels but perhaps lower, relative to historic data. This is not unexpected, given the restrictions/limitations on these chemicals within the UK and Western Europe. The estimated human exposure to population groups through dietary intake is correspondingly low and based on current toxicological knowledge, the levels in the examined samples do not suggest a cause for health concern. The data also provide a current baseline for HCBD, PCBz and PCP, and update existing data for PCN and HCB occurrence in foods.

Cairo consensus on the IVF laboratory environment and air quality: report of an expert meeting.

This proceedings report presents the outcomes from an international Expert Meeting to establish a consensus on the recommended technical and operational requirements for air quality within modern assisted reproduction technology (ART) laboratories. Topics considered included design and construction of the facility, as well as its heating, ventilation and air conditioning system; control of particulates, micro-organisms (bacteria, fungi and viruses) and volatile organic compounds (VOCs) within critical areas; safe cleaning practices; operational practices to optimize air quality while minimizing physicochemical risks to gametes and embryos (temperature control versus air flow); and appropriate infection-control practices that minimize exposure to VOC. More than 50 consensus points were established under the general headings of assessing site suitability, basic design criteria for new construction, and laboratory commissioning and ongoing VOC management. These consensus points should be considered as aspirational benchmarks for existing ART laboratories, and as guidelines for the construction of new ART laboratories.

Occurrence and spatial distribution of chemical contaminants in edible fish species collected from UK and proximate marine waters.

The occurrence of a range of regulated and emerging organic environmental contaminants was investigated in 182 samples of edible marine fish sampled mainly from UK marine regions, but extending northerly to the coast of Norway and south to the Algarve. These species (sprats, mackerel, turbot, halibut, herring, grey mullet, sea bass, grey mullet, sardines, etc.) are among those considered to be at the highest risk of contamination with regulated contaminants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins), and polychlorinated biphenyls (PCBs), but the occurrence of polybrominated diphenylethers (PBDEs) and polybrominated biphenyls (PBBs) was also investigated. Sub-sets of samples (50-75) were also analysed for emerging contaminants: polychlorinated naphthalenes (PCNs), polybrominated and mixed halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls (PBDD/Fs, PXDD/Fs and PXBs) and perfluoroalkyl substances (PFAS). Contaminant occurrence varied with species and location, but all measured contaminants were detected, with sprats, sea bass, sardines, mackerel, and herring showing higher tissue concentrations. The concentrations of the different contaminants in the various samples were mapped utilising the GPS coordinate data of the capture locations to visualise spatial distribution levels. In terms of catch location, fish sampled from the coasts of southern Britain, north-western France and the Irish Sea appeared to contain proportionately higher levels of some contaminants - e.g. samples from the Irish Sea tended to show higher PCN concentrations, whereas higher levels of PCBs were observed in some fish sampled off the coasts of northern France. Similarly, samples of mullet from the southeast coast of UK showed much higher concentrations of BDE-99 than the other regions. In terms of occurrence trends, PCDD/F and PCB concentrations show a modest decline over the last decade but where limited background data is available for emerging contaminants, there is no evidence of downward trends.

Bromine content and brominated flame retardants in food and animal feed from the UK.

Current occurrence data for polybrominated diphenyl ethers (PBDE) and hexa-bromocyclododecane (HBCD) measured in most commonly consumed foods (n = 156) and animal feeds (n = 51) sampled in the UK, demonstrates an ongoing ubiquity of these contaminants in human and animal diets. PBDE concentrations for the sum of 17 measured congeners ranged from 0.02 ng/g to 8.91 ng/g whole weight for food, and 0.11 ng/g to 9.63 ng/g whole weight for animal feeds. The highest concentration ranges, and mean values were detected in fish, processed foods and fish feeds. HBCD diastereomers (alpha-HBCD was the most commonly detected) generally occurred at lower concentrations (from <0.01 ng/g to 10.1 ng/g for food and <0.01 ng/g to 0.66 ng/g for animal feed) and less frequently than PBDEs, but tetrabromobisphenol A which was also measured, was rarely detected. The total bromine content of the samples was also determined in an attempt to use a mass balance approach to investigate some of these samples for the occurrence of novel and emerging BFRs. Although the approach was further refined by measuring organic bromine content, the concentrations of bromine were too high (in most cases by orders of magnitude) to allow use of the approach. A selected sub-set of samples was screened by GC-MS, for the presence of novel/emerging brominated flame retardants (PBT, TBX, PBEB, DBHCTD, HCTBPH and OBTMPI) but these were not detected at the higher limits of detection that result from full scan (GC-MS) screening. This data will contribute to the EU wide risk assessment on these contaminants.

The cost-effectiveness of shopping to a predetermined grocery list to reduce overweight and obesity.

BACKGROUND: Pre-commitment strategies can encourage participants to commit to a healthy food plan and have been suggested as a potential strategy for weight loss. However, it is unclear whether such strategies are cost-effective. OBJECTIVE: To analyse whether pre-commitment interventions that facilitate healthier diets are a cost-effective approach to tackle obesity. METHODS: Effectiveness evidence was obtained from a systematic review of the literature. For interventions demonstrating a clinically significant change in weight, a Markov model was employed to simulate the long-term health and economic consequences. The review supported modelling just one intervention: grocery shopping to a predetermined list combined with standard behavioural therapy (SBT). SBT alone and do nothing were used as comparators. The target population was overweight or obese adult women. A lifetime horizon for health effects (expressed as quality-adjusted life years (QALYs)) and costs from the perspective of the UK health sector were used to calculate incremental cost-effectiveness ratios (ICERs). RESULTS: In the base case analysis, the pre-commitment strategy of shopping to a list was found to be more effective and cost saving when compared against SBT, and cost-effective when compared against 'do nothing' (ICER=£166 per QALY gained). A sensitivity analysis indicated that shopping to a list remained dominant or cost-effective under various scenarios. CONCLUSION: Our findings suggest grocery shopping to a predetermined list combined with SBT is a cost-effective means for reducing obesity and its related health conditions.

Proposal of guidelines for the appraisal of SEMen QUAlity studies (SEMQUA).

STUDY QUESTION: Is there a need for a specific guide addressing studies of seminal quality? SUMMARY ANSWER: The proposed guidelines for the appraisal of SEMinal QUAlity studies (SEMQUA) reflect the need for improvement in methodology and research on semen quality. WHAT IS KNOWN ALREADY: From an examination of other instruments used to assess the quality of diagnostic studies, there was no guideline on studies of seminal quality. STUDY DESIGN, SIZE AND DURATION: Through systematic bibliographic search, potential items were identified and grouped into four blocks: participants, analytical methods, statistical methods and results. PARTICIPANTS/MATERIALS, SETTING AND METHODS: Our findings were presented to a panel of experts who were asked to identify opportunities for improvement. Then, a checklist was designed containing the questions generated by the items that summarize the essential points that need to be considered for the successful outcome of a SEMQUA. MAIN RESULTS AND THE ROLE OF CHANCE: Eighteen items were identified, from which 19 questions, grouped into four blocks, were generated to constitute the final checklist. An explanation for the inclusion of each item was provided and some examples found in the bibliographic search were cited. LIMITATIONS AND REASONS FOR CAUTION: We consider that not all items are equally applicable to all study designs, and so the hypothetical results are not comparable. For that reason, a score would not be fair to critically appraise a study. This checklist is presented as an instrument for appraising SEMQUAs and therefore remains open to constructive criticism. It will be further developed in the future, in parallel with the continuing evolution of SEMQUAs. WIDER IMPLICATIONS OF THE FINDINGS: The final configuration of the SEMQUA is in the form of a checklist, and includes the items generally considered to be essential for the proper development of a SEMQUA. The final checklist produced has various areas of application; for example, it would be useful for designing and constructing a SEMQUA, for reviewing a paper on the question, for educational purposes or as an instrument for appraising the quality of research articles in this field. STUDY FUNDING/COMPETING INTEREST(S): None.

ESHRE special interest group for andrology basic semen analysis course: a continued focus on accuracy, quality, efficiency and clinical relevance.

ESHRE has been running courses for basic semen analysis since 1994 and course material has been updated regularly in response to new findings and publications. Following publication of the 5th edition of the WHO laboratory manual, entitled WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO5), the Subcommittee for training of the ESHRE Special Interest Group for Andrology evaluated potential amendments to its course. In respect of the updated ESHRE course, there are eight particular areas of discourse that are reviewed (i) maintaining the four-class differential motility count allowing distinction between rapid and slow progressive sperm for assisted reproduction technology. (ii) Maintaining the four-category assessment for sperm morphology with calculation of the teratozoospermic index. (iii) Continuing to advocate the use of three categories of results: 'normal', 'borderline' and 'abnormal' with respect to the clinical interpretation of the data. (iv) Presenting clear and unequivocal methods for performing assessments e.g. morphology. (v) Correcting the inconsistencies in WHO5, some of which are actually erroneous. (vi) Reducing the requirements for substantial extra work for what are unestablished improvements in accuracy and/or precision in the final results. (vii) Presentation of logical methods of sperm preparation. (viii) Discussion of the suddenly changed limits between fertile and subfertile men.

Dietary intake estimate for perfluorooctanesulphonic acid (PFOS) and other perfluorocompounds (PFCs) in UK retail foods following determination using standard addition LC-MS/MS.

The analysis of 252 food samples (UK-produced and imported) purchased from a variety of retail outlets in the UK was undertaken for the presence of perfluorooctanesulphonic acid (PFOS), perfluorooctanoic acid (PFOA) and nine other perfluorocompounds (PFCs). A limit of quantification (LOQ) of 1 microg/kg was achieved for all target analytes, in all samples. Standard addition was used for quantification of PFC levels. All 11 of the targeted PFCs were detected in 75 individual food items. In 70% of the samples, including all meat other than offal, none of the analytes were present above the LOD. The highest levels found were 59 microg/kg perfluorooctanesulphonic acid (PFOS) and 63 microg/kg total PFCs (SigmaPFCs) in an eel sample, and 40 microg/kg PFOS (62 microg/kg SigmaPFCs) in a whitebait sample. The highest level in an offal sample was 10 microg/kg, in a wild roe deer liver. There were six samples with SigmaPFCs >15 microg/kg (fish, shellfish, crustaceans), a further seven samples with SigmaPFCs ranging 11-15 microg/kg (including a liver), nine with SigmaPFCs ranging 6-10 microg/kg (fish and livers), 31 with SigmaPFCs in the range 2-5 microg/kg (including kidneys, popcorn and processed peas) and a further 22 with SigmaPFCs close to the LOD of 1 microg/kg (including eggs and potatoes). These concentrations indicate that UK consumers are being exposed to a low level of PFC contamination from food. The estimated upper bound dietary intake of 10 ng/kg bodyweight (bw)/day of PFOS for average adult consumers is well below the 0.15 microg (150 ng)/kg bw tolerable daily intake (TDI) set by the European Food Safety Authority. The lower bound adult dietary intake estimate of 1 ng/kg bw/day is similar to estimates undertaken and reported in countries such as Canada, Germany and Spain.

Occurrence of dioxins (PCDDs, PCDFs) and polychlorinated biphenyls (PCBs) in wild, farmed and processed fish, and shellfish.

Forty-eight composite samples of the most commonly consumed fish and shellfish species were prepared from up to 60 individual subsamples of each species and analysed for chlorinated dioxins (PCDD/Fs) and polychlorinated biphenyls (PCBs). These included 24 species of fresh wild fish, seven of farmed fish, seven of fresh shellfish, and ten processed fish and shellfish products. The ISO 17025-accredited analytical methodology used is consistent with the requirements given in European Commission Directive 2002/69/EC. Concentrations ranged from 0.03 ng kg(-1) PCDD/F plus PCB World Health Organization-toxic equivalent quantity (WHO-TEQ) for a sample of surimi, to approximately 6 ng kg(-1) for wild pilchards/sardines. The corresponding range for the ΣICES-6 PCBs was 0.04 µ g kg(-1) to approximately 47 µ g kg(-1). None of the samples showed concentrations above the European Union maximum permitted limits. Averaged PCDD/F and PCB concentrations for the two groups of farmed and wild fish show that there is little difference between the two categories, although individual species may show variations depending on factors such as the sampling location.

Risk management in IVF.

Patient safety incidents occur in approximately 10% of hospital admissions in the UK. Although robust data are not available, assisted conception is unlikely to be any less prone to adverse incidents; indeed there have been several high-profile cases which have drawn attention to this problem. Recently established national reporting systems for adverse events are collecting data which will inform trends in patient safety. Because of the nature of the work undertaken in assisted conception, there is the potential to affect not only future generations but also many patients simultaneously because of storage of biological material. It is therefore important to implement strategies to reduce the likelihood of patient safety incidents. Established methodologies exist for the reactive (root cause analysis) and the proactive assessment of risk (failure mode effects analysis). Furthermore, establishing the detail of a process and its context through process mapping is an important prerequisite for understanding its risk. The knowledge gained through these enquiries enables the implementation of an effective risk management programme which this chapter examines in detail.

Is there a real risk of transmitting variant Creutzfeldt-Jakob disease by donor sperm insemination?

Although >99% of cases of Creutzfeldt-Jakob disease (CJD) are caused by spontaneous or inherited mutations in the prion protein, 'variant' CJD (vCJD) arose from dietary exposure to meat products infected with the bovine spongiform encephalopathy prion. While European and Canadian sperm donor candidates are rejected for significant CJD risk factors, American sperm donors are managed like blood donors (excluding all men who spent > or =3 months in the UK during 1980-1996 or > or =5 years in Europe since 1980), even though no evidence exists for sexual transmission of prion disease. This study surveyed international experts on either prions/prion disease or donor sperm/cryobanking as to the risk of vCJD transmission via semen/donor spermatozoa (45/104 replied). Consensus expert opinion was that the risk of transmission was <1:10,000,000, even for UK men, hence ultra-conservative risk avoidance would have minimal impact on public safety. Defining 'high vCJD risk' should be based on knowledge rather than fear, and due caution founded upon quantifying real risks rather than avoiding theoretical risks. Women seeking treatment using donor spermatozoa should be allowed to judge the negligible risk of vCJD infection in comparison with acceptable everyday risks, and given the choice of accepting spermatozoa from donors screened according to European-style criteria.

Dioxins and polychlorinated biphenyls (PCBs) in fish oil dietary supplements: occurrence and human exposure in the UK.

Commercially available fish oil supplements sourced from retail outlets in the UK, as well as by mail order, were surveyed in 2000-02 for dioxin (PCDD/Fs) and polychlorinated biphenyl (PCB) content. Sampled products were representative of market share. The WHO-TEQ values for these products ranged from 0.18 to 8.4 ng kg-1 for SigmaPCDD/F and from 1.1 to 41 ng kg-1 for Sigma dioxin-like PCBs. The results suggest a downward trend in the levels of dioxins in fish oil supplements over the last decade, since levels for similar products ranged from 0.3 to 10 ng kg-1 for SigmaPCDD/F WHO-TEQ in 1996. Levels of ICES (International Council for the Exploration of the Seas) 7 PCBs in the current study ranged from 8.3 to 267 microg kg-1. Subsequent to this survey, European Union legislation has been introduced that includes a maximum limit of 2 ng kg-1 WHO-TEQ for dioxins in fish oil products for human consumption. Twelve of the 33 products reported here would have exceeded this limit. Negotiations are in progress to incorporate dioxin-like PCBs into the European Union regulations. When manufacturer-recommended doses were applied to the observed levels, the estimated upper bound human exposure to dioxins and dioxin-like PCBs from dietary intake of these products ranged from 0.02 to 7.1 pg WHO-TEQ kg-1 body weight day-1 for adults and from 0.02 to 10 pg WHO-TEQ kg-1 body weight day-1 for schoolchildren. This level rises to 1.8-8.9 pg WHO-TEQ kg-1 body weight day-1 for adults and 1.4-14 pg WHO-TEQ kg-1 body weight day-1 for schoolchildren when combined with the average exposure from the whole diet in 1997. Again, subsequent to this survey, the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) revised the UK tolerable daily intake (TDI) for mixtures of dioxins and dioxin-like PCBs from 10 to 2 pg WHO-TEQ kg-1 body weight day-1. This is in line with the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg-1 body weight set by the Scientific Committee on Food (SCF).

Current and future concepts and practices in human sperm cryobanking.

This article focuses on a range of issues that are of current concern to those working in human sperm cryobanking and considers them within a general framework of risk analysis and management, taking into account the available evidence and perceptions of 'best practice' from both the medical and legal perspectives. In particular, issues arising from concerns over the risk of cross-contamination between samples during storage immersed in liquid nitrogen have been analysed in detail. Even though such an occurrence has never been reported for spermatozoa or embryos, and the risk is generally accepted to be vanishingly small, it does represent a finite risk and all reasonable measures should be taken to reduce the chance of its occurring. It is concluded that all methods used to collect, cryopreserve, store, thaw and use cryobanked human spermatozoa must address the risk of contamination from any source throughout the entire process. To assist workers in this area, a series of recommendations as to current best practice are made, based upon conclusions from risk analyses using currently available information.

ESHRE basic semen analysis courses 1995-1999: immediate beneficial effects of standardized training.

BACKGROUND: Many reports have shown problems with the high variability in results of semen analyses. The Special Interest Group in Andrology (SIGA) of the European Society of Human Reproduction and Embryology (ESHRE) implemented a standardized training course which has been run in different regions of the world on more than 20 occasions since 1994. The aim of the present analysis was to investigate to what extent training resulted in any immediate effects on the variability of assessments made by different observers. METHODS: The variability in participants' results from the beginning to the end of each course was analysed in eight courses given between 1995 and 1999. RESULTS: For assessments of sperm concentration, motility, vitality and morphology, substantial improvement was seen over the duration of the course. CONCLUSIONS: A comprehensive, structured training course does lead to substantial reductions in inter-observer variability in semen analysis. This supports our contention that providing a thorough theoretical background and repeated practical training, combined with daily feedback of results, is highly effective in raising the technical skills of laboratory personnel performing semen analysis.