180 research outputs found

    Anthelmintic Treatment of Sheep and the Role of Parasites Refugia in a Local Context

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    Simple Summary The control of gastrointestinal parasites in sheep is often based on the integrated use of anthelmintics and pasture management. As problems with resistance to anthelmintics become more common, it is important to consider the timing of treatment. This is because one way to delay selection for anthelmintic resistance is to take into account that there are susceptible parasites in refugia that are not selected for treatment. In Sweden, stabled ewes are sometimes treated before being let out to pasture with their lambs in the spring. It is thought that this may increase selection for resistance. However, unlike in many other parts of the world, in Sweden, treatment is usually motivated by large numbers of worm eggs detected in faecal samples. In this review, we discuss whether the Swedish model is a risky strategy. In doing so, we consider the experience from several studies conducted in Sweden and abroad. We conclude that the evidence is inconclusive. Moreover, there are gaps in our knowledge, not least regarding the genetic background of resistance formation and how this is influenced by refugia. Further fundamental work is therefore needed on this topic. Gastrointestinal nematodes in grazing livestock are ubiquitous and can cause severe damage, leading to substantial losses in agricultural yields. It is undeniable that the integrated use of anthelmintics is often an essential component of successful intensive livestock management. However, anthelmintic resistance has been a major challenge for several decades, especially in pasture-based lamb production. Measures are therefore needed to reduce the risk and prevent further spread. In many countries with more extensive lamb production and pronounced resistance problems than in Sweden, the importance of keeping parasites in refugia is emphasised. To ensure that treatment is necessary, the Swedish model is based on deworming certain groups of ewes based on the parasitological results of a faecal examination and then releasing them with their lambs to safe pastures. This is intended to reduce the risk of infection, which ultimately reduces the number of subsequent treatments. Whether this preventive strategy in turn means an increased risk of resistance is debatable. In this review, we explain the importance of parasites in refugia and how they can help delay the development of resistance to anthelmintics. We also discuss how likely it is that our model contributes to an increase in resistance risk and whether there is reason to question whether it is a sustainable strategy in the long term

    SPECT image segmentation for estimation of tumour volume and activity concentration in 177Lu-DOTATATE radionuclide therapy

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    Background: Dosimetry in radionuclide therapy has the potential to allow for a treatment tailored to the individual patient. One therapeutic radiopharmaceutical where patient-specific dosimetry is feasible is 177Lu-DOTATATE, used for the treatment of neuroendocrine tumours. The emission of gamma photons by 177Lu allows for imaging with SPECT (single photon emission computed tomography). One important step for dosimetry using this imaging technique is the SPECT image segmentation, which needs to be robust and accurate for the estimated quantities to be reliable. This work investigates different methods for automatic tumour delineation in 177Lu-DOTATATE SPECT images. Three segmentation methods are considered: a fixed 42% threshold (FT), the Otsu method (OM) and a method based on Fourier surfaces (FS). Effects of including resolution compensation in the iterative SPECT image reconstruction are also studied. Evaluation is performed based on Monte Carlo-simulated SPECT images from 24 h and 336 h post injection (p.i.), for determination of the volume, activity concentration and dice similarity coefficient. In addition, patient data are used to investigate the correspondence of tumour volumes when delineated in SPECT or morphological CT or MR images. Patient data are also used to examine the sensitivity to the operator-dependent initialization. Results: For simulated images from 24 h p.i. reconstructed without resolution compensation, a volume and activity-concentration root-mean-square error below 15% is typically obtained for tumours above approximately 10 cm3 when using OM or FS, while FT performs considerably worse. When including resolution compensation, the tumour volume becomes underestimated and the activity concentration overestimated. The FS method appears to be robust to noise, as seen for the 336 h images. The differences between the tumour volumes estimated from the SPECT images and the volumes estimated from morphological images are generally larger than the discrepancies seen for the simulated data sets. Conclusions: Segmentation results are encouraging for future dosimetry of tumours with volumes above approximately 10 cm3. Using resolution compensation in the reconstruction may have a negative effect on volume estimation

    Expectant parents’ experiences of parental education within the antenatal health service

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    Being an expectant parent is a life changing event and it is something that most people will experience in their lifetime. Many people who are parents for the first time will participate in parenting education. Most of the previous studies associated with parenting education focus on subjects such as birth outcome and breastfeeding. The purpose of this study is to focus on the less investigated aspect of the parents’ experience of participating in parenting education with Maternal Healthcare Services (MVC). A qualitative, phenomenological, hermeneutical method was selected to be used to analyze our findings and we used the statements of twenty participants to accumulate enough material to develop it into twelve sub-themes and five themes. The results of this study show that these expectant parents had few or no expectations of the parenting education that they were going to participate in. Generally speaking the parents seemed to be satisfied with the program. They described their reasons for participating as a chance to get together with other people in similar circumstances and to share information and they found a midwife to be a trustworthy professional person to confirm the information that was available to them from other sources

    Biologically effective dose in fractionated molecular radiotherapy-application to treatment of neuroblastoma with (131)I-mIBG.

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    In this work, the biologically effective dose (BED) is investigated for fractionated molecular radiotherapy (MRT). A formula for the Lea-Catcheside G-factor is derived which takes the possibility of combinations of sub-lethal damage due to radiation from different administrations of activity into account. In contrast to the previous formula, the new G-factor has an explicit dependence on the time interval between administrations. The BED of tumour and liver is analysed in MRT of neuroblastoma with (131)I-mIBG, following a common two-administration protocol with a mass-based activity prescription. A BED analysis is also made for modified schedules, when due to local regulations there is a maximum permitted activity for each administration. Modifications include both the simplistic approach of delivering this maximum permitted activity in each of the two administrations, and also the introduction of additional administrations while maintaining the protocol-prescribed total activity. For the cases studied with additional (i.e. more than two) administrations, BED of tumour and liver decreases at most 12% and 29%, respectively. The decrease in BED of the tumour is however modest compared to the two-administration schedule using the maximum permitted activity, where the decrease compared to the original schedule is 47%

    Vitamin D and stress urinary incontinence in pregnancy: a cross-sectional study

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    Objective To assess the association between levels of vitamin D and urinary incontinence (UI) in pregnancy. Design A cross‐sectional study. Secondary analysis of a randomised controlled trial. Setting Two university hospitals in Norway. Population A total of 851 healthy, pregnant women >18 years in gestational weeks 18–22 with a singleton live fetus. Methods Data on UI were collected from a questionnaire at inclusion and serum analysis of 25‐hydroxy vitamin D (25(OH)D) was performed. Univariable and multivariable logistic regression analyses were applied to study associations between exposure and outcomes. Main outcome measures Prevalence of self‐reported UI, stress (SUI) and urge (UUI) or mixed UI. Results In total, 230/851 (27%) of the participants were vitamin D insufficient (25(OH)D <50 nmol/l) and 42% reported to have any UI. Women with 25(OH)D <50 nmol/l were more likely to report any UI (P = 0.03) and SUI (P < 0.01) compared with women with 25(OH)D ≄50 nmol/l. In a univariable logistic regression analysis, serum levels of 25(OH)D <50 nmol/l was associated with increased risk of any UI (odds ratio [OR] 1.5 with 95% CI 1.0–2.1), SUI only (OR 1.7, 95% CI 1.2–2.4), but not mixed UI or UUI only (OR 0.8, 95% CI 0.5–1.5). In a multivariable logistic regression model, serum levels of 25(OH)D <50 nmol/l were associated with a higher risk of experiencing SUI only (OR 1.5, 95% CI 1.1–2.2). Conclusions Serum 25(OH)D <50 nmol/l was associated with increased risk of any UI, and SUI in particular.publishedVersio

    The LEADING Guideline:Reporting Standards for Expert Panel, Best-Estimate Diagnosis, and Longitudinal Expert All Data (LEAD) Studies.

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    Accurate assessments of symptoms and diagnoses are essential for health research and clinical practice but face many challenges. The absence of a single error-free measure is currently addressed by assessment methods involving experts reviewing several sources of information to achieve a more accurate or best-estimate assessment. Three bodies of work spanning medicine, psychiatry, and psychology propose similar assessment methods: The Expert Panel, the Best-Estimate Diagnosis, and the Longitudinal Expert All Data (LEAD). However, the quality of such best-estimate assessments is typically very difficult to evaluate due to poor reporting of the assessment methods and when it is reported, the reporting quality varies substantially. Here we tackle this gap by developing reporting guidelines for such studies, using a four-stage approach: 1) drafting reporting standards accompanied by rationales and empirical evidence, which were further developed with a patient organization for depression, 2) incorporating expert feedback through a two-round Delphi procedure, 3) refining the guideline based on an expert consensus meeting, and 4) testing the guideline by i) having two researchers test it and ii) using it to examine the extent previously published articles report the standards. The last step also demonstrates the need for the guideline: 18 to 58% (Mean = 33%) of the standards were not reported across fifteen randomly selected studies. The LEADING guideline comprises 20 reporting standards related to four groups: The Longitudinal design; the Appropriate data; the Evaluation - experts, materials, and procedures; and the Validity group. We hope that the LEADING guideline will be useful in assisting researchers in planning, reporting, and evaluating research aiming to achieve best-estimate assessments. Open data (Delphi surveys 1 and 2), code (analyses), and material (surveys): https://osf.io/fkv4b

    Analysis of spatial variability in hyperspectral imagery of the uterine cervix in vivo

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    The use of fluorescence and reflectance spectroscopy in the analysis of cervical histopathology is a growing field of research. The majority of this research is performed with point-like probes. Typically, clinicians select probe sites visually, collecting a handful of spectral samples. An exception to this methodology is the Hyperspectral Diagnostic Imaging (HSDIÂź) instrument developed by Science and Technology International. This non-invasive device collects contiguous hyperspectral images across the entire cervical portio. The high spatial and spectral resolution of the HSDI instruments make them uniquely well suited for addressing the issues of coupled spatial and spectral variability of tissues in vivo. Analysis of HSDI data indicates that tissue spectra vary from point to point, even within histopathologically homogeneous regions. This spectral variability exhibits both random and patterned components, implying that point monitoring may be susceptible to significant sources of noise and clutter inherent in the tissue. We have analyzed HSDI images from clinical CIN (cervical intraepithelial neoplasia) patients to quantify the spatial variability of fluorescence and reflectance spectra. This analysis shows the spatial structure of images to be fractal in nature, in both intensity and spectrum. These fractal tissue textures will limit the performance of any point-monitoring technology
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