An investigation of the effects of procalcitonin testing on antimicrobial prescribing in respiratory tract infections in an Irish university hospital setting: a feasibility study

BACKGROUND

Diagnostic uncertainty and a high prevalence of viral infections present unique challenges for antimicrobial prescribing for respiratory tract infections (RTIs). Procalcitonin (PCT) has been shown to support prescribing decisions and reduce antimicrobial use safely in patients with RTIs, but recent study results have been variable.

METHODS

We conducted a feasibility study of the introduction of PCT testing in patients admitted to hospital with a lower RTI to determine if PCT testing is an effective and worthwhile intervention to introduce to support the existing antimicrobial stewardship (AMS) programme and safely decrease antimicrobial prescribing in patients admitted with RTIs.

RESULTS

A total of 79 patients were randomized to the intervention PCT-guided treatment group and 40 patients to the standard care respiratory control group. The addition of PCT testing led to a significant decrease in duration of antimicrobial prescriptions (mean 6.8 versus 8.9 days, P = 0.012) and decreased length of hospital stay (median 7 versus 8 days, P = 0.009) between the PCT and respiratory control group. PCT did not demonstrate a significant reduction in antimicrobial consumption when measured as DDDs and days of therapy.

CONCLUSIONS

PCT testing had a positive effect on antimicrobial prescribing during this feasibility study. The successful implementation of PCT testing in a randomized controlled trial requires an ongoing comprehensive education programme, greater integration into the AMS programme and delivery of PCT results in a timely manner. This feasibility study has shown that a larger randomized controlled trial would be beneficial to further explore the positive aspects of these findings.

Retinal Vascular Caliber Association with Nonperfusion and Diabetic Retinopathy Severity Depends on Vascular Caliber Measurement Location

PURPOSE

To evaluate the association of retinal nonperfusion and diabetic retinopathy (DR) severity with location of vascular caliber measurement using ultrawide field (UWF) imaging.

DESIGN

Retrospective image review.

PARTICIPANTS

Adults with diabetes mellitus.

METHODS

All images from subjects with same-day UWF fluorescein angiography (FA) and color imaging were evaluated. Predominantly peripheral lesions (PPL) and DR severity were graded from UWF color images. Nonperfusion was quantified using UWF-FA in defined retinal regions [posterior pole (PP), mid-periphery (MP), far-periphery (FP)]. Retinal vessel calibers were measured at an optic disc centered inner and outer zone.

MAIN OUTCOME MEASURES

Nonperfusion index (NPI) in the PP, MP and FP. Mean arteriole and venule diameter in the inner and outer zones.

RESULTS

Two hundred eighty-five eyes of 193 patients (24.9% mild nonproliferative DR [NPDR], 22.8% moderate NPDR, 37.5% severe NPDR and 14.7% proliferative DR [PDR]) were reviewed. No significant associations between inner zone arteriolar diameter and retinal NPI overall or in any retinal region. In the outer zone, eyes with thinnest arteriolar calibers (quartile 1) were associated with a 1.7- to 2.4-fold nonperfusion increase across all retinal regions compared to the remaining eyes (P = 0.002 [PP] to 0.048 [FP]). In the outer zone, the percentage of eyes in the thinnest quartile of retinal arteriolar diameter increased with worsening DR severity (mild NPDR: 10% vs PDR: 31%, P = 0.007). This association was not observed when measured within the inner zone (P = 0.129). All venular caliber associations were not statistically significant when corrected for potentially confounding factors. Thinner outer zone retinal arteriolar caliber (quartile 1) was more common in eyes with PPL compared to eyes without PPL (34.1% vs 20.8%, P = 0.017) as were thicker outer venular calibers (quartile 4) (33% vs 21.3%, P = 0.036). Presence of PPL was associated with thinner outer zone arteriolar caliber (109.7 ± 26.5μm vs 123.0 ± 29.5μm, P = 0.001).

CONCLUSIONS

The association of vascular caliber with nonperfusion and DR severity differs based upon the retinal location at which vascular caliber is measured. Peripheral arterial narrowing is associated with increasing nonperfusion, worsening DR severity and presence of PPL. In contrast, inner zone retinal arteriolar caliber is not associated with these findings.

Fractal analysis of retinal vasculature in normal subjects on ultra-wide field fluorescein angiography

AIM

To evaluate the fractal feature of the retinal vasculature of normal eyes on a stereographic projected and montaged ultra-wide field (UWF) fluorescein angiography (FA).

METHODS

Prospective, observational, cross-sectional study. Totally 59 eyes of 31 normal subjects were imaged using the Optos 200Tx. Images obtained at different gaze angles stereographically projected and montaged. The early-phase UWF FA frames were processed to segment the retinal vasculature and the results were exported as binary masks. The fractal dimension (FD) was calculated using the box-counting method.

RESULTS

The global FD for the entire retina was 1.6±0.04, with no difference between males and females (1.59±0.04 vs 1.61±0.04, P=0.084) or between right and left eyes (1.6±0.04 vs 1.6±0.05, P=0.61). FD was non-uniformly distributed among four quadrants (P<0.001) and decreased as the distance from the fovea increased (P<0.001). A negative association was observed between FD and age (R=-0.37, P=0.006), and this relationship was observed in the posterior and mid-peripheral retina (P<0.05) but absent in far-periphery (P>0.05).

CONCLUSION

Fractal geometry is non-uniformly distributed across the retina in normal eyes and decreases from the fovea to the far-periphery. Subjects with an older age tend to have a smaller FD, however, the FD in the far-periphery does not appear to be influenced by age.

Symposium review: Multiple-trait single-step genomic evaluation for hoof health

Hoof lesions represent an important issue in modern dairy herds, with reported prevalence in different countries ranging from 40 to 70%. This high prevalence of hoof lesions has both economic and social consequences, resulting in increased labor expenses and decreasing animal production, longevity, reproduction, health, and welfare. Therefore, a key goal of dairy herds is to reduce the incidence of hoof lesions, which can be achieved both by improving management practices and through genetic selection. The Canadian dairy industry has recently released a hoof health sub-index. This national genetic evaluation program for hoof health was achieved by creating a centralized data collection system that routinely transfers data recorded by hoof trimmers into a coherent and sustainable national database. The 8 most prevalent lesions (digital dermatitis, interdigital dermatitis, interdigital hyperplasia, heel horn erosion, sole hemorrhage, sole ulcer, toe ulcer, and white line lesion) in Canada are analyzed with a multiple-trait model using a single-step genomic BLUP method. Estimated genomic breeding values for each lesion are combined into a sub-index according to their economic value and prevalence. In addition, data recorded within this system were used to create an interactive management report for dairy producers by Canadian DHI, including the prevalence of lesions on farm, their trends over time, and benchmarks with provincial and national averages.

Short communication: Time-dependent genetic parameters and single-step genome-wide association analyses for predicted milk fatty acid composition in Ayrshire and Jersey dairy cattle

Milk fat content and fatty acid (FA) composition have great economic value to the dairy industry as they are directly associated with taste and chemical-physical characteristics of milk and dairy products. In addition, consumers' choices are not only based on the nutritional aspects of food, but also on products known to promote better health. Milk FA composition is also related to the metabolic status and physiological stages of cows and thus can also be used as indicator for other novel traits of interest (e.g., metabolic diseases and methane yield). Genetic selection is a promising alternative to manipulate milk FA composition. In this study, we aimed to (1) estimate time-dependent genetic parameters for 5 milk FA groups (i.e., short-chain, medium-chain, long-chain, saturated, and unsaturated) predicted based on milk mid-infrared spectroscopy, for Canadian Ayrshire and Jersey breeds, and (2) conduct a time-dependent, single-step genome-wide association study to identify genomic regions, candidate genes, and metabolic pathways associated with milk FA. We analyzed 31,709 test-day records of 9,648 Ayrshire cows from 268 herds, and 34,341 records of 11,479 Jersey cows from 883 herds. The genomic database contained a total of 2,330 Ayrshire and 1,019 Jersey animals. The average daily heritability ranged from 0.18 (long-chain FA) to 0.34 (medium-chain FA) in Ayrshire, and from 0.25 (long-chain and unsaturated FA) to 0.52 (medium-chain and saturated FA) in Jersey. Important genomic regions were identified in Bos taurus autosomes BTA3, BTA5, BTA12, BTA13, BTA14, BTA16, BTA18, BTA20, and BTA21. The proportion of the variance explained by 20 adjacent SNP ranged from 0.71% (saturated FA) to 1.11% (long-chain FA) in Ayrshire, and from 0.70% (unsaturated FA) to 3.09% (medium-chain FA) in Jersey cattle. Important candidate genes and pathways were also identified, such as the PTK2 and TRAPPC9 genes, associated with milk fat percentage, and HMGCS, FGF10, and C6 genes, associated with fertility traits and immune response. Our findings on the genetic parameters and candidate genes contribute to a better understanding of the genetic architecture of milk FA composition in Ayrshire and Jersey dairy cattle.

Once and Again: Intergenerational Transmission of Parenting

Introduction

Animal and human studies suggest that individual differences in maternal parenting behaviour are transmitted from one generation to the next.

Objective

This study aimed to examine potential psychosocial mechanisms underlying an intergenerational transmission of conceptualization of parenting, including affect, cognition, and parental support.

Methods

In a subsample of 201 first-time mothers participating in the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project, we assessed maternal childhood rearing experiences, using the Parental Bonding Instrument and the Childhood Trauma Questionnaire. At 6 months postpartum, mothers completed questionnaires on parenting stress, symptoms of depression, internalization of maternal care regulation and current relationship with mother and father.

Results

We found significant direct associations of maltreatment and rearing by the grandmother with parenting stress at 6 months. These associations were mediated through distinct psychosocial pathways: the association of maltreatment on higher parenting stress was fully mediated through more maternal symptoms of depression (z = 2.297; P = 022). The association between sub-optimal rearing provided by the mother and higher parenting stress was mediated through lower internalization of maternal care regulation (z = -2.155; P = 031) and to a lesser degree through more symptoms of depression (z = -1.842; P = 065). Finally, higher quality rearing by the grandfather was indirectly related to lower parenting stress through positive current relationship with the father (z = -2.617; P = 009).

Conclusions

There are distinct pathways by which early experiences manifest in parenting stress. By understanding the structure of dysregulated parenting, clinicians will have practical information to specifically target maternal motivation, social supports, and depressed mood to disrupt maladaptive parenting cognitions and practices.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Disparity of microaneurysm count between ultrawide field colour imaging and ultrawide field fluorescein angiography in eyes with diabetic retinopathy

AIMS

To compare microaneurysm (MA) counts using ultrawide field colour images (UWF-CI) and ultrawide field fluorescein angiography (UWF-FA).

METHODS

Retrospective study including patients with type 1 or 2 diabetes mellitus receiving UWF-FA and UWF-CI within 2 weeks. MAs were manually counted in individual Early Treatment Diabetic Retinopathy Study (ETDRS) and extended UWF zones. Fields with MAs ≥20 determined diabetic retinopathy (DR) severity (0 fields=mild, 1-3=moderate, ≥4=severe). UWF-FA and UWF-CI agreement was determined and UWF-CI DR severity sensitivity analysis adjusting for UWF-FA MA counts performed.

RESULTS

In 193 patients (288 eyes), 2.4% had no DR, 29.9% mild non-proliferative DR (NPDR), 32.6% moderate (NPDR), 22.9% severe NPDR and 12.2% proliferative DR. UWF-FA MA counts were 3.5-fold higher (p<0.001) than UWF-CI counts overall, 3.2x-fold higher in ETDRS fields (p<0.001) and 5.3-fold higher in extended ETDRS fields (p<0.001) and higher in type 1 versus type 2 diabetes (p<0.001). In eyes with NPDR on UWF-CI (n=246), UWF-FA images had 1.6x-3.5x more fields with ≥20 MAs (p<0.001). Fair agreement existed between imaging modalities (k=0.221-0.416). In ETDRS fields, DR severity agreement increased from k=0.346 to 0.600 when dividing UWF-FA counts by a factor of 3, followed by rapid decline in agreement thereafter. Total UWF area agreement increased from k=0.317 to 0.565 with an adjustment factor of either 4 or 5.

CONCLUSIONS

UWF-FA detects threefold to fivefold more MAs than UWF-CI and identifies 1.6-3.5-fold more fields affecting DR severity. Differences exist at all DR severity levels, thus limiting direct comparison between the modalities. However, correcting UWF-FA MA counts substantially improves DR severity agreement between the modalities.

Association between hypertension and retinal vascular features in ultra-widefield fundus imaging

Objective

Changes to the retinal vasculature are known to be associated with hypertension independently of traditional risk factors. We investigated whether measurements of retinal vascular calibre from ultra-widefield fundus imaging were associated with hypertensive status.

Methods

We retrospectively collected and semiautomatically measured ultra-widefield retinal fundus images from a subset of participants enrolled in an ongoing population study of ageing, categorised as normotensive or hypertensive according to thresholds on systolic/diastolic blood pressure (140/90 mm Hg) measured in a clinical setting. Vascular calibre in the peripheral retina was measured to calculate the nasal–annular arteriole:venule ratio (NA-AVR), a novel combined parameter.

Results

Left and right eyes were analysed from 440 participants (aged 50–59 years, mean age of 54.6±2.9 years, 247, 56.1% women), including 151 (34.3%) categorised as hypertensive. Arterioles were thinner and the NA-AVR was smaller in people with hypertension. The area under the receiver operating characteristic curve of NA-AVR for hypertensive status was 0.73 (95% CI 0.68 to 0.78) using measurements from left eyes, while for right eyes, it was 0.64 (95% CI 0.59 to 0.70), representing evidence of a statistically significant difference between the eyes (p=0.020).

Conclusions

Semiautomated measurements of NA-AVR in ultra-widefield fundus imaging were associated with hypertension. With further development, this may help screen people attending routine eye health check-ups for high blood pressure. These individuals may then follow a care pathway for suspected hypertension. Our results showed differences between left and right eyes, highlighting the importance of investigating both eyes of a patient.

Does Cellular Metabolism from Primary Fibroblasts and Oxidative Stress in Blood Differ between Mammals and Birds? The (Lack-thereof) Scaling of Oxidative Stress

As part of mitonuclear communication, retrograde and anterograde signaling helps maintain homeostasis under basal conditions. Basal conditions, however, vary across phylogeny. At the cell-level, some mitonuclear retrograde responses can be quantified by measuring the constitutive components of oxidative stress, the balance between reactive oxygen species (ROS) and antioxidants. ROS are metabolic by-products produced by the mitochondria that can damage macromolecules by structurally altering proteins and inducing mutations in DNA, among other processes. To combat accumulating damage, organisms have evolved endogenous antioxidants and can consume exogenous antioxidants to sequester ROS before they cause cellular damage. ROS are also considered to be regulated through a retrograde signaling cascade from the mitochondria to the nucleus. These cellular pathways may have implications at the whole-animal level as well. For example, birds have higher basal metabolic rates, higher blood glucose concentration, and longer lifespans than similar sized mammals, however, the literature is divergent on whether oxidative stress is higher in birds compared with mammals. Herein, we collected literature values for whole-animal metabolism of birds and mammals. Then, we collected cellular metabolic rate data from primary fibroblast cells isolated from birds and mammals and we collected blood from a phylogenetically diverse group of birds and mammals housed at zoos and measured several parameters of oxidative stress. Additionally, we reviewed the literature on basal-level oxidative stress parameters between mammals and birds. We found that mass-specific metabolic rates were higher in birds compared with mammals. Our laboratory results suggest that cellular basal metabolism, total antioxidant capacity, circulating lipid damage, and catalase activity were significantly lower in birds compared with mammals. We found no body-size correlation on cellular metabolism or oxidative stress. We also found that most oxidative stress parameters significantly correlate with increasing age in mammals, but not in birds; and that correlations with reported maximum lifespans show different results compared with correlations with known aged birds. Our literature review revealed that basal levels of oxidative stress measurements for birds were rare, which made it difficult to draw conclusions.

Lipoedema – myths and facts, Part 5

The four previous articles in this series addressed the myths and facts surrounding lipoedema. We have shown that there is no scientific evidence at all for the key statements made about lipoedema – which are published time and time again. The main result of this “misunderstanding” of lipoedema is a therapeutic concept that misses the mark. The patient’s real problems are overlooked.

The national and especially the international response to the series, which can be read in both German and English, has been immense and has exceeded all our expectations. The numerous reactions to our articles make it clear that in other countries, too, the fallacies regarding lipoedema have led to an increasing discrepancy between the experience of healthcare workers and the perspective of patients and self-help groups, based on misinformation mostly generated by the medical profession.

Parts 1 to 4 in this series of articles on the myths surrounding lipoedema have made it clear that we have to radically change the view of lipoedema that has been held for decades. Changing our perspective means getting away from the idea of “oedema in lipoedema” – and hence away from the dogma that decongestion is absolutely necessary – and towards the actual problems faced by our patients with lipoedema. Such a paradigm shift in a disease that has been described in the same way for decades cannot be left to individuals but must be put on a much broader footing. For this reason, the lead author of this series of articles invited renowned lipoedema experts from various European countries to discussions on the subject. Experts from seven different countries took part in the two European Lipoedema Forums, with the goal of establishing a consensus. The consensus reflects the experts’ shared view on the disease, having scrutinized the available literature, and having taken into account the many years of clinical practice with this particular patient group. Appropriate to the clinical complexity of lipoedema, participants from different specialties provided an interdisciplinary approach. Nearly all of the participants in the European Lipoedema Forum had already published work on lipoedema, had been involved in drawing up their national lipoedema guidelines, or were on the executive board of their respective specialty society.

In this fifth and final part of our series on lipoedema, we will summarise the relevant findings of this consensus, emphasising the treatment of lipoedema as we now recommend it. As the next step, the actual consensus paper “European Best Practice of Lipoedema” will be issued as an international publication.

Instead of looking at the treatment of oedema, the consensus paper will focus on treatment of the soft tissue pain, as well as the psychological vulnerability of patients with lipoedema. The relationship between pain perception and the patient’s mental health is recognised and dealt with specifically. The consensus also addresses the problem of self-acceptance, and this plays a prominent role in the new therapeutic concept. The treatment of obesity provides a further pillar of treatment. Obesity is recognised as being the most common comorbid condition by far and an important trigger of lipoedema. Bariatric surgery should therefore also be considered for patients with lipoedema who are morbidly obese. The expert group upgraded the importance of compression therapy and appropriate physical activity, as the demonstrated anti-inflammatory effects directly improve the patients’ symptoms. Patients will be provided with tools for personalised self-management in order to sustain sucessful treatment. Should conservative therapy fail to improve the symptoms, liposuction may be considered in strictly defined circumstances.

The change in the view of lipoedema that we describe here brings the patients’ actual symptoms to the forefront. This approach allows us to focus on more comprehensive treatment that is not only more effective but also more sustainable than focusing on the removal of non-existent oedema.

Relationship Between Retinal Fractal Dimension and Nonperfusion in Diabetic Retinopathy on Ultrawide-Field Fluorescein Angiography

PURPOSE

To correlate fractal dimension (FD) of the retinal vasculature with the extent of retinal nonperfusion area in diabetic retinopathy (DR) on ultrawide-field fluorescein angiography (FA).

DESIGN

Cross-sectional study.

METHODS

Baseline Optos 200Tx ultrawide-field FA images of 80 eyes with DR from the DAVE (NCT01552408) and RECOVERY (NCT02863354) studies were stereographically projected at the Doheny Image Reading Center. The retinal vasculature was extracted from an early-phase FA frame by exploiting the elongated nature of the vessels and then skeletonized for calculation of FD using a box-counting method. The nonperfusion area was delineated by 2 independent, reading center-certified graders who were masked to the study groups and who were using a standardized protocol and then computed in millimeters squared.

RESULTS

While no difference in FD was observed for the entire retina in DR compared with normal control subjects, a significantly smaller FD was found in the far-periphery of the DR eyes (P < .001). FD for the entire retina was negatively associated with global nonperfusion area (R = -0.44; P < .001), and this relationship was also present within the 3 concentric retinal zones (posterior: R = -0.31, P = .016; midperiphery: R = -0.35, P = .007; and far periphery: R = -0.31, P = .015).

CONCLUSIONS

Peripheral FD on ultrawide-field FA is reduced in DR eyes compared with normal eyes and is correlated with severity of retinal nonperfusion. FD can be calculated automatically without the need for correction of peripheral distortion, and therefore it may prove to be a useful surrogate biomarker when precise quantification of nonperfusion is not feasible.

Distribution of Nonperfusion and Neovascularization on Ultrawide-Field Fluorescein Angiography in Proliferative Diabetic Retinopathy (RECOVERY Study): Report 1

PURPOSE

To explore the distribution of nonperfusion area (NPA) on ultrawide-field fluorescein angiography (UWF FA) in proliferative diabetic retinopathy (PDR) and its relationship with the presence of neovascularization of the optic disc (NVD) and distribution of neovascularization elsewhere (NVE).

DESIGN

Prospective, observational case series.

METHODS

Baseline Optos 200Tx UWF FA images of 38 eyes with treatment-naïve early-stage PDR from the RECOVERY (NCT02863354) study were stereographically projected at the Doheny Image Reading Center. Two independent/masked certified graders manually delineated the NPA and the total visible retinal area (TRA). NPA and TRA were then computed in square millimeters using the manufacturer software. Ischemic index (ISI) was calculated by dividing NPA by TRA. NPA and ISI were correlated with the presence and distribution of neovascularization in the corresponding zones.

RESULTS

Eyes with NVD appeared to have more severe global NPA than those without (P = .026). Although the ISI appeared to increase with increasing distance from the foveal center (P < .001), NVE was more likely to be located in the posterior pole than the midperiphery or far-periphery (P < .001). Presence of NVE in the posterior polar retina appeared to demonstrate more severe ischemia in the posterior pole and midperiphery than those without (P < .05), but interestingly, was not correlated with the severity of overall global ischemia or of ischemia in the far-periphery alone (P > .05).

CONCLUSIONS

Whereas the presence of NVD was associated with the severity of global ischemia, the distribution of NVE did not appear to be influenced by the distribution of ischemia.

Nonlinear optical memory effect

Light propagating through random media produces characteristic speckle patterns, directly related to the large multitude of scattering events. These complex dynamics remarkably display robustness to perturbation of the incoming light parameters, maintaining correlation in the scattered wavefront. This behavior is known as the optical memory effect. Here we unveil the properties of the nonlinear optical memory effect, which occurs when an optothermal nonlinearity perturbs the random material. The effect is characterized through a series of pump and probe experiments in silica aerogel, in the visible range. This additional degree of freedom further generalizes the memory effect, opening the road to applications based on the nonlinear response of random media.

A systematic approach to map the adolescent human papillomavirus vaccine decision and identify intervention strategies to address vaccine hesitancy

OBJECTIVES

Unsubstantiated safety concerns with human papillomavirus (HPV) vaccines continue to linger. This study sought to identify factors that influence the adolescent HPV vaccine decision and systematically identify intervention functions and strategies likely to be effective in reducing vaccine hesitancy.

STUDY DESIGN

This is a qualitative focus group study.

METHODS

Focus groups were conducted with female adolescents (aged 14-16 years) in Cork and Kerry. During focus groups, the trained facilitator used a semistructured, Theoretical Domains Framework (TDF)-based topic guide to prompt discussion. Transcripts were thematically analysed using the TDF and Behaviour Change Wheel. Behaviour Change Technique Taxonomy version 1 was used to suggest intervention functions and strategies for addressing HPV vaccine hesitancy.

RESULTS

A total of 50 adolescents (96% vaccinated), participated in 10 focus groups. The key themes were presented by means of the relevant TDF domains. Seven domains were selected as the most relevant: knowledge, social influences, beliefs about capabilities, optimism, beliefs about consequences, emotion and environmental context and resources. Five intervention functions were identified, education, persuasion, enablement, modelling and environmental restructuring, and linked to 11 relevant Behaviour Change Technique (BCTs). Potential intervention strategies were developed.

CONCLUSIONS

This study provided a detailed insight into behavioural factors influencing the vaccine decision-making process. It was identified that awareness and knowledge about HPV and its health sequelae was low. Lack of information is a well-recognised determinant of vaccine hesitancy. Therefore, education was recommended as a key area to address in future intervention studies.

Comparison of Subjective Assessment and Precise Quantitative Assessment of Lesion Distribution in Diabetic Retinopathy

Importance

Predominantly peripheral disease in eyes with nonproliferative diabetic retinopathy (DR) is suggested as a potential strong risk factor for progression to proliferative disease. However, the reliability and optimal method for the assessment of lesion distribution are still uncertain.

Objective

To compare agreement between subjective assessment and precise quantification of lesion burden in ultrawidefield (UWF) images of eyes with DR.

Design, Setting, and Participants

This multisite cross-sectional study examines UWF pseudocolor images acquired from DR screening clinic patients from December 20, 2014, through August 1, 2014. Of 104 cases, 161 eyes with DR were included. Data analysis was conducted from June 1, 2016, through December 1, 2016 at the Doheny Image Reading Center.

Main Outcomes and Measures

Distribution of DR lesions in eyes was assessed subjectively and quantitatively, and eyes were classified as having predominantly central lesions (PCLs) or predominantly peripheral lesions (PPLs). The frequency and surface area (SA) of each lesion type were quantified. Intergrader and subjective vs quantitative classification were compared for level of agreement. Several methods of determining PPL distribution were also compared.

Results

On subjective frequency-based evaluation by graders, 133 eyes were classified as having PCL, and 28 eyes as having PPL. On exact quantification of lesion SA, 121 eyes were classified as PCL, and 40 eyes as having PPL. On SA-based quantification, 134 eyes were classified as having PCL, and 27 eyes as having PPL. There was a significant difference between qualitative and quantitative classification of DR lesion distribution for both frequency-based (mean difference [SD]: PCL, 6 [2]; PPL, 13 [6]; P < .001) and SA-based (mean difference [SD]: PCL, 6 [1]; PPL, 20 [7]; P < .001) methods. Both intergrader reproducibility and subjective vs quantitative agreement were higher with frequency-based classification.

Conclusions and Relevance

Subjective assessment of PPL DR lesions on UWF images differed in some cases from precise quantitative assessments, particularly when considering the area of lesions. These findings highlight the benefit of objective quantitative approaches to DR assessment, which may facilitate the development of a more precise DR scoring system.

Genome-wide association analysis for β-hydroxybutyrate concentration in Milk in Holstein dairy cattle

BACKGROUND

Ketosis in dairy cattle has been shown to cause a high morbidity in the farm and substantial financial losses to dairy farmers. Ketosis symptoms, however, are difficult to identify, therefore, the amount of ketone bodies (mainly β-hydroxybutyric acid, BHB) is used as an indicator of subclinical ketosis in cows. It has also been shown that milk BHB concentrations have a strong correlation with ketosis in dairy cattle. Mid-infrared spectroscopy (MIR) has recently became a fast, cheap and high-throughput method for analyzing milk components. The aim of this study was to perform a genome-wide association study (GWAS) on the MIR-predicted milk BHB to identify genomic regions, genes and pathways potentially affecting subclinical ketosis in North American Holstein dairy cattle.

RESULTS

Several significant regions were identified associated with MIR-predicted milk BHB concentrations (indicator of subclinical ketosis) in the first lactation (SCK1) and second and later lactations (SCK2) in Holstein dairy cows. The strongest association was located on BTA6 for SCK1 and BTA14 on SCK2. Several SNPs on BTA6 were identified in regions and variants reported previously to be associated with susceptibility to ketosis and clinical mastitis in Jersey and Holstein dairy cattle, respectively. One highly significant SNP on BTA14 was found within the DGAT1 gene with known functions on fat metabolism and inflammatory response in dairy cattle. A region on BTA6 and three SNPs on BTA20 were found to overlap between SCK1 and SCK2. However, a novel region on BTA20 (55-63 Mb) for SCK2 was also identified, which was not reported in previous association studies. Enrichment analysis of the list of candidate genes within the identified regions for MIR-predicted milk BHB concentrations yielded molecular functions and biological processes that may be involved in the inflammatory response and lipid metabolism in dairy cattle.

CONCLUSIONS

The results of this study confirmed several SNPs and genes identified in previous studies as associated with ketosis susceptibility and immune response, and also found a novel region that can be used for further analysis to identify causal variations and key regulatory genes that affect clinical/ subclinical ketosis.

Phenotypic investigation of fine milk components in bovine milk and their prediction using mid-infrared spectroscopy

This study aimed to examine the phenotypic variation observed in fine milk components, the use of mid-infrared (MIR) spectroscopy to predict these components, and the correlations with other milk production traits. A total of 4116 milk samples were collected from 414 dairy cows from 44 Canadian herds. Overall 3117 samples were analyzed for casein micelle size, 986 and 937 for total and soluble calcium, respectively, and 2054 for lactoferrin. Individual milk MIR spectra were obtained. Linear mixed models with repeated records were used to test the effects of herd nested within breed, breed, days in milk class, parity, and season on milk components. Lactoferrin content in milk increased with stage of lactation and parity number. Prediction equations were developed by partial least squares regression to predict each milk component using MIR spectroscopy, with the greatest coefficient of determination achieved for lactoferrin (0.55). Pearson correlation coefficients for lactoferrin with somatic cell score and protein percentage were 0.49% and 0.40%, respectively. The estimated correlation increased to 0.53% for predicted lactoferrin and protein percentage. The examined fine milk components exhibited variation, but low accuracies for their MIR prediction may limit the utility of this technology for their phenotyping.

Automated detection of age-related macular degeneration in color fundus photography: a systematic review

The rising prevalence of age-related eye diseases, particularly age-related macular degeneration, places an ever-increasing burden on health care providers. As new treatments emerge, it is necessary to develop methods for reliably assessing patients' disease status and stratifying risk of progression. The presence of drusen in the retina represents a key early feature in which size, number, and morphology are thought to correlate significantly with the risk of progression to sight-threatening age-related macular degeneration. Manual labeling of drusen on color fundus photographs by a human is labor intensive and is where automatic computerized detection would appreciably aid patient care. We review and evaluate current artificial intelligence methods and developments for the automated detection of drusen in the context of age-related macular degeneration.

Symposium review: The choice and collection of new relevant phenotypes for fertility selection

In dairy production, high fertility contributes to herd profitability by achieving greater production and maintaining short calving intervals. Improved management practices and genetic selection have contributed to reversing negative trends in dairy cow fertility, but further progress is still required. Phenotypes included in current genetic evaluations are largely interval and binary traits calculated from insemination and calving date records. Several indicator traits such as calving, health, variation in body condition score, and longevity traits also apply to genetic improvement of fertility. Several fertility traits are included in the selection indices of many countries, but for improved selection, the development of novel phenotypes that more closely describe the physiology of reproduction and limit management bias could be more effective. Progesterone-based phenotypes can be determined from milk samples to describe the heritable interval from calving to corpus luteum activity, as well as additional measures of cow cyclicity. A fundamental component of artificial insemination practices is the observation of estrus. Novel phenotypes collected on estrous activity could be used to select for cows clearly displaying heat, as those cows are more likely to be inseminated at the right time and therefore have greater fertility performance. On-farm technologies, including in-line milk testing and activity monitors, may allow for phenotyping novel traits on large numbers of animals. Additionally, selection for improved fertility using traditional traits could benefit from refined and accurate recording and implementation of parameters such as pregnancy confirmation and reproductive management strategy, to differentiate embryonic or fetal loss, and to ensure selection for reproductive capability without producer intervention. Opportunities exist to achieve genetic improvement of reproductive efficiency in cattle using novel phenotypes, which is required for long-term sustainability of the dairy cattle population and industry.

A landscape of the heritability of Fourier-transform infrared spectral wavelengths of milk samples by parity and lactation stage in Holstein cows

Fourier-transform near- and mid-infrared (FTIR) milk spectral data are routinely collected in many countries worldwide. Establishing an optimal strategy to use spectral data in genetic evaluations requires knowledge of the heritabilities of individual FTIR wavelength absorbances. Previous FTIR heritability estimates have been based on relatively small sample sizes and have not considered the possibility that heritability may vary across parities and stages of the lactation. We used data from ∼370,000 test-day records of Canadian Holstein cows to produce a landscape of the heritability of FTIR spectra, 1,060 wavelengths in the near- and mid-infrared spectrum (5,011-925 cm^-1), by parity and month of the lactation (mo 1 to 3 and mo 1 to 6, respectively). The 2 regions of the spectrum associated with absorption of electromagnetic energy by water molecules were estimated to have very high phenotypic variances, very low heritabilities, and very low proportion of variance explained by herd-year-season (HYS) subclasses. The near- or short-wavelength infrared (SWIR: 5,066-3,672 cm^-1) region was also characterized by low heritability estimates, whereas the estimated proportion of the variance explained by HYS was high. The mid-wavelength infrared region (MWIR: 3,000-2,500 cm^-1) and the transition between mid and long-wavelength infrared region (MWIR-LWIR: 1,500-925 cm^-1) harbor several waves characterized by moderately high (≥0.4) heritabilities. Most of the high-heritability regions contained wavelengths that are reported to be associated with important milk metabolites and components. Interestingly, these 2 same regions tended to show more variability in heritabilities between parity and lactation stage. Second parity showed heritability patterns that were distinctly different from those of the first and third parities, whereas the first 2 mo of the lactation had clearly distinct heritability patterns compared with mo 3 to 6.

Abstract P400: Screening for Hypertension Using Retinal Vascular Calibre in Ultra-Widefield Fundus Imaging

Fundus images from the left eyes of 440 subjects aged 50-59 years enrolled in the Northern Ireland Cohort of Longitudinal Ageing were analyzed. Subjects were categorized as normotensive or hypertensive, according to thresholds on systolic/diastolic blood pressure measurement (140/90 mm Hg) averaged over two sitting measurements in a clinical setting. A fully automatic system to analyze each image used conventional and deep neural network machine learning techniques to locate retinal landmarks and detect, classify and measure retinal vessels. From this data, a measure of the arteriolar-venular ratio (AVR) in the peripheral retina was calculated. Semi-automatic analysis was also performed. Results are presented in Table 1. Subjects had mean age of 54.6 ± 2.9 years; 56.1% (247 of 440) females, with 34.3% (151 of 440) subjects categorized as hypertensive. Narrower arterioles and smaller AVR were observed in subjects with hypertension. This was also observed in fully-automated analysis, however 4% (17 of 440) subjects failed to be processed by the system. In fully-automated analysis the area under a receiver operator characteristic curve of AVR for hypertensive status was 0.69 (95% CI, 0.63 to 0.74).

Table 1 - Results for semi-automated and automated analysis of retinal vessel parameters. *p<0.005

Automated measurement of AVR in ultra-widefield fundus imaging was associated with hypertension. With further development, such as evaluation against diagnosis of hypertension obtained from ambulatory blood pressure monitoring clinics, this system could become a test for undiagnosed hypertension in people attending routine eye health check-ups.