Dysregulated placental expression of kynurenine pathway enzymes is associated with inflammation and depression in pregnancy

BACKGROUND

Perinatal depression (including antenatal-, postnatal-, and depression that spans both timepoints) is a prevalent disorder with high morbidity that affects both mother and child. Even though the full biological blueprints of perinatal depression remain incomplete, multiple studies indicate that, at least for antenatal depression, the disorder has an inflammatory component likely linked to a dysregulation of the enzymatic kynurenine pathway. The production of neuroactive metabolites in this pathway, including quinolinic acid (QUIN), is upregulated in the placenta due to the multiple immunological roles of the metabolites during pregnancy. Since neuroactive metabolites produced by the pathway also may affect mood by directly affecting glutamate neurotransmission, we sought to investigate whether the placental expression of kynurenine pathway enzymes controlling QUIN production was associated with both peripheral inflammation and depressive symptoms during pregnancy.

METHODS

68 placentas obtained at birth were analyzed using qPCR to determine the expression of kynurenine pathway enzymes. Cytokines and metabolites were quantified in plasma using high-sensitivity electroluminescence and ultra-performance liquid chromatography, respectively. Maternal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS) throughout pregnancy and the post-partum. Associations between these factors were assessed using robust linear regression with ranked enzymes.

RESULTS

Low placental quinolinate phosphoribosyl transferase (QPRT), the enzyme responsible for degrading QUIN, was associated with higher IL-6 and higher QUIN/kynurenic acid ratios at the 3rd trimester. Moreover, women with severe depressive symptoms in the 3rd trimester had significantly lower placental expression of both QPRT and 2-amino-3-carboxymuconate-6-semialdehyde decarboxylase (ACMSD); impaired activity of these two enzymes leads to QUIN accumulation.

CONCLUSION

Overall, our data support that a compromised placental environment, featuring low expression of critical kynurenine pathway enzymes is associated with increased levels of plasma cytokines and the dysregulated kynurenine metabolite pattern observed in depressed women during pregnancy.

Stitching Locally Fitted T-Splines for Fast Fitting of Large-Scale Freeform Point Clouds

Parametric splines are popular tools for precision optical metrology of complex freeform surfaces. However, as a promising topologically unconstrained solution, existing T-spline fitting techniques, such as improved global fitting, local fitting, and split-connect algorithms, still suffer the problems of low computational efficiency, especially in the case of large data scales and high accuracy requirements. This paper proposes a speed-improved algorithm for fast, large-scale freeform point cloud fitting by stitching locally fitted T-splines through three steps of localized operations. Experiments show that the proposed algorithm produces a three-to-eightfold efficiency improvement from the global and local fitting algorithms, and a two-to-fourfold improvement from the latest split-connect algorithm, in high-accuracy and large-scale fitting scenarios. A classical Lena image study showed that the algorithm is at least twice as fast as the split-connect algorithm using fewer than 80% control points of the latter.

Changing epidemiology of acute kidney injury in critically ill patients with COVID-19: a prospective cohort

BACKGROUND

Acute kidney injury (AKI) is common in critically ill patients with coronavirus disease-19 (COVID-19). We aimed to explore the changes in AKI epidemiology between the first and the second COVID wave in the United Kingdom (UK).

METHODS

This was an observational study of critically ill adult patients with COVID-19 in an expanded tertiary care intensive care unit (ICU) in London, UK. Baseline characteristics, organ support, COVID-19 treatments, and patient and kidney outcomes up to 90 days after discharge from hospital were compared.

RESULTS

A total of 772 patients were included in the final analysis (68% male, mean age 56 ± 13.6). Compared with wave 1, patients in wave 2 were older, had higher body mass index and clinical frailty score, but lower baseline serum creatinine and C-reactive protein (CRP). The proportion of patients receiving invasive mechanical ventilation (MV) on ICU admission was lower in wave 2 (61% vs 80%; p < 0.001). AKI incidence within 14 days of ICU admission was 76% in wave 1 and 51% in wave 2 (p < 0.001); in wave 1, 32% received KRT compared with 13% in wave 2 (p < 0.001). Patients in wave 2 had significantly lower daily cumulative fluid balance (FB) than in wave 1. Fewer patients were dialysis dependent at 90 days in wave 2 (1% vs. 4%; p < 0.001).

CONCLUSIONS

In critically ill adult patients admitted to ICU with COVID-19, the risk of AKI and receipt of KRT significantly declined in the second wave. The trend was associated with less MV, lower PEEP and lower cumulative FB.

TRIAL REGISTRATION

NCT04445259.

Long-term outcomes in patients who received veno-venous extracorporeal membrane oxygenation and renal replacement therapy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a frequent complication in patients with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO). However, little is known of long-term kidney function in ECMO survivors. We aimed to assess the long-term mortality and kidney outcomes in adult patients treated with veno-venous ECMO (VV-ECMO).

Methods

This was a single-centre retrospective study of adult patients (≥ 18 years old) who were treated with VV-ECMO at a commissioned ECMO centre in the UK between 1st September 2010, and 30th November 2016. AKI was defined and staged using the serum creatinine and urine output criteria of the Kidney Diseases: Improving Global Outcomes (KDIGO) classification. The primary outcome was 1-year mortality. Secondary outcomes were long-term mortality (up to March 2020), 1-year incidence of end-stage kidney disease (ESKD) or chronic kidney disease (CKD) among AKI patients who received renal replacement therapy (AKI-RRT), AKI patients who did not receive RRT (AKI-no RRT) and patients without AKI (non-AKI).

Results

A total of 300 patients [57% male; median age 44.5; interquartile range (IQR) 34–54] were included in the final analysis. Past medical histories included diabetes (12%), hypertension (17%), and CKD (2.3%). The main cause of severe respiratory failure was pulmonary infection (72%). AKI occurred in 230 patients (76.7%) and 59.3% received renal replacement therapy (RRT). One-year mortality was 32% in AKI-RRT patients vs. 21.4% in non-AKI patients (p = 0.014). The median follow-up time was 4.35 years. Patients who received RRT had a higher risk of 1-year mortality than those who did not receive RRT (adjusted HR 1.80, 95% CI 1.06, 3.06; p = 0.029). ESKD occurred in 3 patients, all of whom were in the AKI-RRT group. At 1-year, 41.2% of survivors had serum creatinine results available. Among these, CKD was prevalent in 33.3% of AKI-RRT patients vs. 4.3% in non-AKI patients (p = 0.004).

Conclusions

VV-EMCO patients with AKI-RRT had high long-term mortality. Monitoring of kidney function after hospital discharge was poor. In patients with follow-up creatinine results available, the CKD prevalence was high at 1 year, especially in AKI-RRT patients. More awareness about this serious long-term complication and appropriate follow-up interventions are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01046-0.

Crosstalk decoupling measurement method to determine the six degrees of freedom of motion error of linear stages

The simultaneous measurement of all six degrees of freedom of motion error for a linear stage is significantly faster than methods that measure each degree of freedom separately. However, in current simultaneous measurement methods, error crosstalk issues significantly affect measurement accuracy. In this paper, a direct and simple crosstalk decoupling simultaneous measurement method to determine the six degrees of freedom of motion error of a linear stage is proposed. Based on the combination of single-frequency laser interferometry and laser self-collimation, a novel, to the best of our knowledge, optical configuration with a complete error decoupling relationship is designed, and a mathematical model is derived for error decoupling to address the crosstalk issue. A prototype system based on the new method is developed, and experiments are conducted to verify its effectiveness. Analysis shows that, compared with a commercial laser interferometer for linear stage measurement, the deviations of the positioning, horizontal straightness, vertical straightness, roll, pitch, and yaw errors are±0.50µm, ±0.58µm, ±0.50µm, ±1.02in., ±0.72in., and ±0.87in. respectively, over a 200 mm measurement range.

Cytokines and tryptophan metabolites can predict depressive symptoms in pregnancy

Depression during and after pregnancy affects up to 20% of pregnant women, but the biological underpinnings remain incompletely understood. As pregnancy progresses, the immune system changes to facilitate fetal development, leading to distinct fluctuations in the production of pro-inflammatory factors and neuroactive tryptophan metabolites throughout the peripartum period. Therefore, it is possible that depression in pregnancy could constitute a specific type of inflammation-induced depression. Both inflammatory factors and kynurenine metabolites impact neuroinflammation and glutamatergic neurotransmission and can therefore affect mood and behavior. To determine whether cytokines and kynurenine metabolites can predict the development of depression in pregnancy, we analyzed blood samples and clinical symptoms in 114 women during each trimester and the postpartum. We analyzed plasma IL-1β, IL-2, -6, -8, -10, TNF, kynurenine, tryptophan, serotonin, kynurenic- quinolinic- and picolinic acids and used mixed-effects models to assess the association between biomarkers and depression severity. IL-1β and IL-6 levels associated positively with severity of depressive symptoms across pregnancy and the postpartum, and that the odds of experiencing significant depressive symptoms increased by >30% per median absolute deviation for both IL-1β and IL-6 (both P = 0.01). A combination of cytokines and kynurenine metabolites in the 2nd trimester had a >99% probability of accurately predicting 3rd trimester depression, with an ROC AUC > 0.8. Altogether, our work shows that cytokines and tryptophan metabolites can predict depression during pregnancy and could be useful as clinical markers of risk. Moreover, inflammation and kynurenine pathway enzymes should be considered possible therapeutic targets in peripartum depression.

Surface measuring coherence scanning interferometry beyond the specular reflection limit

The capability of optical surface topography measurement methods for measurement of steep and tilted surfaces is investigated through modelling of a coherence scanning interferometer. Of particular interest is the effect on the interference signal and measured topography when tilting the object at angles larger than the numerical aperture slope limit (i.e. the specular reflection limit) of the instrument. Here we use theoretical modelling to predict the results across a range of tilt angles for a blazed diffraction grating. The theoretically predicted interference patterns and surface height measurements are then verified directly with experimental measurements. Results illustrate the capabilities, limitations and modelling methods for interferometers to measure beyond the specular reflection limit.

Discharge Documentation and Follow-Up of Critically Ill Patients With Acute Kidney Injury Treated With Kidney Replacement Therapy: A Retrospective Cohort Study

Leading organisations recommend follow-up of acute kidney injury (AKI) survivors, as these patients are at risk of long-term complications and increased mortality. Information transfer between specialties and from tertiary to primary care is essential to ensure timely and appropriate follow-up. Our aim was to examine the association between completeness of discharge documentation and subsequent follow-up of AKI survivors who received kidney replacement therapy (KRT) in the Intensive Care Unit (ICU). We retrospectively analysed the data of 433 patients who had KRT for AKI during ICU admission in a tertiary care centre in the UK between June 2017 and May 2018 and identified patients who were discharged from hospital alive. Patients with pre-existing end-stage kidney disease and patients who were transferred from hospitals outside the catchment area were excluded. The primary objective was to assess the completeness of discharge documentation from critical care and hospital; secondary objectives were to determine cardiovascular medications reconciliation after AKI, and to investigate kidney care and outcomes at 1 year. The development of AKI and the need for KRT were mentioned in 85 and 82% of critical care discharge letters, respectively. Monitoring of kidney function post-discharge was recommended in 51.6% of critical care and 36.3% of hospital discharge summaries. Among 35 patients who were prescribed renin-angiotensin-aldosterone system inhibitors before hospitalisation, 15 (42.9%) were not re-started before discharge from hospital. At 3 months, creatinine and urine protein were measured in 88.2 and 11.8% of survivors, respectively. The prevalence of chronic kidney disease stage III or worse increased from 27.2% pre-hospitalisation to 54.9% at 1 year (p < 0.001). Our data demonstrate that discharge summaries of patients with AKI who received KRT lacked essential information. Furthermore, even in patients with appropriate documentation, renal follow-up was poor suggesting the need for more education and streamlined care pathways.

Acute kidney injury prevalence, progression and long-term outcomes in critically ill patients with COVID-19: a cohort study

BACKGROUND

There are limited data on acute kidney injury (AKI) progression and long-term outcomes in critically ill patients with coronavirus disease-19 (COVID-19). We aimed to describe the prevalence and risk factors for development of AKI, its subsequent clinical course and AKI progression, as well as renal recovery or dialysis dependence and survival in this group of patients.

METHODS

This was a retrospective observational study in an expanded tertiary care intensive care unit in London, United Kingdom. Critically ill patients admitted to ICU between 1st March 2020 and 31st July 2020 with confirmed SARS-COV2 infection were included. Analysis of baseline characteristics, organ support, COVID-19 associated therapies and their association with mortality and outcomes at 90 days was performed.

RESULTS

Of 313 patients (70% male, mean age 54.5 ± 13.9 years), 240 (76.7%) developed AKI within 14 days after ICU admission: 63 (20.1%) stage 1, 41 (13.1%) stage 2, 136 (43.5%) stage 3. 113 (36.1%) patients presented with AKI on ICU admission. Progression to AKI stage 2/3 occurred in 36%. Risk factors for AKI progression were mechanical ventilation [HR (hazard ratio) 4.11; 95% confidence interval (CI) 1.61-10.49] and positive fluid balance [HR 1.21 (95% CI 1.11-1.31)], while steroid therapy was associated with a reduction in AKI progression (HR 0.73 [95% CI 0.55-0.97]). Kidney replacement therapy (KRT) was initiated in 31.9%. AKI patients had a higher 90-day mortality than non-AKI patients (34% vs. 14%; p < 0.001). Dialysis dependence was 5% at hospital discharge and 4% at 90 days. Renal recovery was identified in 81.6% of survivors at discharge and in 90.9% at 90 days. At 3 months, 16% of all AKI survivors had chronic kidney disease (CKD); among those without renal recovery, the CKD incidence was 44%.

CONCLUSIONS

During the first COVID-19 wave, AKI was highly prevalent among severely ill COVID-19 patients with a third progressing to severe AKI requiring KRT. The risk of developing CKD was high. This study identifies factors modifying AKI progression, including a potentially protective effect of steroid therapy. Recognition of risk factors and monitoring of renal function post-discharge might help guide future practice and follow-up management strategies. Trial registration NCT04445259.

Locally adaptive thresholding centroid localization in confocal microscopy

We introduce an iteration-free approach, based on a centroid algorithm with a locally adaptive threshold, for nanometer-level peak position localization of the axial response signal in confocal microscopy. This approach has localization accuracies that are near theoretical limits, especially when there is a small number of sampling points within the discrete signal. The algorithm is also orders of magnitude faster compared to fitting schemes based on maximum likelihood estimation. Simulations and experiments demonstrate the localization performance of the approach.

Two-dimensional spectral signal model for chromatic confocal microscopy

In chromatic confocal microscopy, the signal characteristics influence the accuracy of the signal processing, which in turn determines measurement performance. Thus, a full understanding of the spectral characteristics is critical to enhance the measurement performance. Existing spectral models only describe the signal intensity-wavelength characteristics, without taking the displacement-wavelength relation into consideration. These models require prior knowledge of the optical design, which reduces the effectiveness in the optical design process. In this paper, we develop a two-dimensional spectral signal model to describe the signal intensity-wavelength-displacement characteristics in chromatic confocal microscopy without prior knowledge of the optical design layout. With this model, the influence of the dimensional characteristics of the confocal setup and the displacement-wavelength characteristics and monochromatic aberrations of the hyperchromatic objective are investigated. Experimental results are presented to illustrate the effectiveness of our signal model. Using our model, further evaluation of the spectral signal can be used to enhance the measurement performance of chromatic confocal microscopy.

Associations between estrogen and progesterone, the kynurenine pathway, and inflammation in the post-partum

BACKGROUND

Depression during and after pregnancy is common, affecting at least 15% of women. Features of depression in pregnancy range from mild symptoms of disrupted mood and interest to severe depression and suicidal behavior. Previous studies suggest hormone- and immune dysregulations might contribute to post-partum depression, but consistent evidence is lacking.

METHODS

A total of 163 women were included in the study in the post-partum. Peri-partum depression (PPD) was diagnosed using SCID interviews and depressive symptoms were quantified using the Edinburgh Perinatal Depression Rating Scale (EPDS), retrospectively long-term, as well as acutely. Plasma estrogen, progesterone, pro- and anti-inflammatory cytokines and kynurenine metabolites were measured in the post-partum.

RESULTS

Higher estrogen and progesterone in the post-partum were linked to more severe depressive symptoms over pregnancy. In the post-partum, estrogen was positively correlated with the pro-inflammatory cytokine IL-6 and negatively correlated with kynurenine and picolinic acid. Conversely, progesterone was negatively correlated with IL-1β and several metabolites in the kynurenine pathway, including quinolinic acid.

LIMITATIONS

Associative study design, did not attempt to assess causality. Did not adjust hormone levels for medication effects.

CONCLUSIONS

Our study suggests that higher sex hormones in the post-partum are linked to depression severity over pregnancy. Estrogen was coupled with a pro-inflammatory profile and neurotoxic kynurenine metabolites, whereas progesterone was linked to an anti-inflammatory profile in the post-partum.

Scattering and three-dimensional imaging in surface topography measuring interference microscopy

Surface topography measuring interference microscopy is a three-dimensional (3D) imaging technique that provides quantitative analysis of industrial and biomedical specimens. Many different instrument modalities and configurations exist, but they all share the same theoretical foundation. In this paper, we discuss a unified theoretical framework for 3D image (interferogram) formation in interference microscopy. We show how the scattered amplitude is linearly related to the surface topography according to the Born and the Kirchhoff approximations and highlight the main differences and similarities of each. With reference to the Ewald and McCutchen spheres, the relationship between the spatial frequencies that characterize the illuminating and scattered waves, and those that characterize the object, are defined and formulated as a 3D linear filtering process. It is shown that for the case of near planar surfaces, the 3D filtering process can be reduced to two dimensions under the small height approximation. However, the unified 3D framework provides significant additional insight into the scanning methods used in interference microscopy, effects such as interferometric defocus and ways to mitigate errors introduced by aberrations of the optical system. Furthermore, it is possible to include the nonlinear effects of multiple scattering into the generalized framework. Finally, we consider the inherent nonlinearities introduced when estimating surface topography from the recorded interferogram.

Evaluating the cytotoxicity of Ge–Sb–Se chalcogenide glass optical fibres on 3T3 mouse fibroblasts

In vivo cancer detection based on the mid-infrared molecular fingerprint of tissue is promising for the fast diagnosis and treatment of suspected cancer patients. Few materials are mid-infrared transmissive, even fewer, which can be converted into functional, low-loss optical fibres for in vivo non-invasive testing. Chalcogenide-based glass optical fibres are, however, one of the few. These glasses are transmissive in the mid-infrared and are currently under development for use in molecular sensing devices. The cytotoxicity of these materials is however unknown. The cytotoxicity of Ge–Sb–Se chalcogenide optical glass fibres on 3T3 mouse fibroblast cells is here investigated. Fibres exposed to four different pre-treatment conditions are used: as-drawn (AD), propylamine-etched (PE), oxidised-and-washed (OW) and oxidised (Ox). To achieve the latter two conditions, fibres are treated with H₂O₂(aqueous (aq.)) and dried to produce a surface oxide layer; this is either washed off (OW) or left on the glass surface (Ox). Cellular response is investigated via 3 day elution and 14 day direct contact trials. The concentration of the metalloids (Ge, Sb and Se) in each leachate was measured via inductively coupled plasma mass spectrometry. Cell viability is assessed using the neutral red assay and scanning electron microscopy. The concentration of Ge, Sb and Se ions after a 3 day dissolution was as follows. In AD leachates, Ge: 0.40 mg L⁻¹, Sb: 0.17 mg L⁻¹, and Se: 0.06 mg L⁻¹. In PE leachates, Ge: 0.22 mg L⁻¹, Sb: 0.15 mg L⁻¹, and Se: 0.02 mg L⁻¹. In Ox leachates, Ge: 823.8 mg L⁻¹, Sb: 2586.6 mg L⁻¹, and Se: 3750 mg L⁻¹. Direct contact trials show confluent cell layers on AD, PE and OW fibres after 14 days, while no cells are observed on the Ox surfaces. A >50% cell viability is observed in AD, PE and OW eluates after 3 days, when compared with Ox eluates (<10% cell viability). Toxicity in Ox is attributed to the notable pH change, from neutral pH 7.49 to acidic pH 2.44, that takes place on dissolution of the surface oxide layer in the growth media. We conclude, as-prepared Ge–Sb–Se glasses are cytocompatible and toxicity arises when an oxide layer is forced to develop on the glass surface.

We present a study that aims to evaluate the cytotoxicity of Ge₂₀Sb10Se₇₀ at% glass optical fibres on 3T3 mouse fibroblast cells. To observe the toxicity of these optical fibres, 3T3 fibroblast proliferation was investigated.

Differences in cervical cancer screening and follow-up for black and white women in the United States

OBJECTIVE

To study differences in screening adherence and follow-up after an abnormal Pap test in Non-Hispanic Black (Black) and Non-Hispanic White (White) women.

METHODS

An observational cohort study using 2010 National Health Interview Survey cancer module to examine HPV knowledge, screening behavior, and follow-up to abnormal Pap test in Black and White women 18 years of age or older without a hysterectomy. We fit logistic regression models to examine associations between race and primary outcome variables including: HPV awareness, Pap test in the last three years, provider recommended Pap test, received Pap test results, had an abnormal Pap test, recommended follow-up, and adhered to the recommendation for follow-up.

RESULTS

Analyzing data for 7509 women, Black women had lower odds ratios [OR] for: 1) HPV awareness (71% vs 83%; OR = 0.42; 95% CI = 0.36-0.49); 2) reporting Pap screening was recommended (59% vs 64%; OR = 0.76; 95% CI = 0.66-0.88), and 3) acknowledging receipt of Pap results (92% vs 94%; OR = 0.64; 95% CI = 0.49-0.83). Group differences persisted after covariates adjustment. In adjusted models, Black women had higher odds of reporting recent Pap screening (84% vs 77%; OR = 1.7; 95% CI = 1.42-2.03), but reported lower odds of receiving a follow-up recommendation subsequent to abnormal test (78% vs 87%; OR = 0.54; 95% CI = 0.31-0.95).

CONCLUSION

Black women reported higher cervical cancer screening adherence but lower rates of being informed of an abnormal Pap test and contacted for follow-up treatment. We recommend a multilevel approach to deliver culturally appropriate education and communication for patients, physicians, clinicians in training, and clinic level ancillary staff.

Advances in optical metrology and instrumentation: introduction

Optical measurement and characterization are two of the pillars of metrology. The ability to measure precisely with high dynamic range and accuracy betters our understanding of nature and the universe. In this feature issue, we present a collection of articles that delves into the fundamental techniques used to advance the field.

Multi-view fringe projection system for surface topography measurement during metal powder bed fusion

Metal powder bed fusion (PBF) methods need in-process measurement methods to increase user confidence and encourage further adoption in high-value manufacturing sectors. In this paper, a novel measurement method for PBF systems is proposed that uses multi-view fringe projection to acquire high-resolution surface topography information of the powder bed. Measurements were made using a mock-up of a commercial PBF system to assess the system's accuracy and precision in comparison to conventional single-view fringe projection techniques for the same application. Results show that the multi-view system is more accurate, but less precise, than single-view fringe projection on a point-by-point basis. The multi-view system also achieves a high degree of surface coverage by using alternate views to access areas not measured by a single camera.

On-machine surface defect detection using light scattering and deep learning

This paper presents an on-machine surface defect detection system using light scattering and deep learning. A supervised deep learning model is used to mine the information related to defects from light scattering patterns. A convolutional neural network is trained on a large dataset of scattering patterns that are predicted by a rigorous forward scattering model. The model is valid for any surface topography with homogeneous materials and has been verified by comparing with experimental data. Once the neural network is trained, it allows for fast, accurate, and robust defect detection. The system capability is validated on microstructured surfaces produced by ultraprecision diamond machining.

Fluid management knowledge in hospital physicians: 'Greenshoots' of improvement but still a cause for concern

Fluid management is an essential competency for hospital doctors, but previous studies suggest junior clinicians lack the necessary 'knowledge' and 'prescription skills' to complete this task, resulting in preventable morbidity and mortality. In this study, preregistration (n=146), core (n=66) and specialty (n=133) medical trainees and general medical consultants (n=11) completed a structured questionnaire exploring fluid management training, confidence, serious adverse event experience and a 20-item fluid management 'knowledge' test. Results were compared with those of intensive care consultants (n=20). Most clinicians reported limited training and extensive 'unreported' serious adverse events experience. Knowledge about fluid and electrolyte requirements, fluid composition and chloride toxicity had improved compared to historical reports but overall test scores (median (interquartile range (IQR)): with a maximum score of 20) were low. Foundation year trainees scored 7 (IQR 5-8), core medical trainees scored 9 (IQR 6-10), specialist registrars scored 8 (IQR 6-10) and general medical consultants scored 8 (IQR 6-12) compared with the intensive care consultant score of 16 (IQR 14-16). Although weakly correlated, fluid management 'confidence' appeared higher than 'knowledge' tests would justify. These results suggest that physicians' fluid management knowledge is inadequate, including that of senior colleagues, compounded by poor training and failure to learn from serious adverse events.

Width determination for deep grooves based on a variable point spread function imaging model

In three-dimensional confocal microscopy, two-dimensional width measurement can be significantly influenced by the groove height. The groove height not only results in deformation of the input light field due to the effect of edge occlusions, but also introduces a defocus error to the detection plane. This paper proposes a new, to the best of our knowledge, edge-setting method to determine groove width, which engineers the point spread function to correct for the groove edge obstruction effect and develops an edge obstruction imaging model (EOIM) based on the variable point spread function. This model gives a relationship between the groove height and the normalized intensity at the groove edge and can use this relationship to determine the groove edge position that would result from focusing at the groove's lower surface. Experimental results show that an EOIM-based width determination method is more accurate than the traditional 1/4 edge-setting method. Compared to the 1/4 edge-setting method, the deviation from a reference width measured with traceable scanning electron microscopy is reduced by a factor of 2.1 with a 1.3 times smaller standard deviation.

Sterilisation of intellectually disabled women

Objective

To point out the proportion of intellectually disabled women (IDW) who are sterilised, and the medical and social factors associated with an increased probability to be sterilised.

Study design

A population-based study among 97% of IDW aged 18–46, attending government-accredited institutions in the region of Brussels-Capital and the province of Walloon Brabant (Belgium).

Results

Among the IDW included in this study, 22.2% are sterilised, which is superior to the 7% in the general Belgian population. Factors associated with an increased probability to be sterilised are: living in an institution, having a higher intellectual quotient (IQ), being enrolled in an institution where sexual intercourse is authorised and attending an institution where contraception is required. The last three factors are significant only among women living in institutions and the last two, only in women with severe disability. Among IDW using contraception, no factor was associated with a greater probability to be sterilised.

Conclusion

The prevalence of sterilisation among IDW is three times higher than that in the Belgian population and it is mainly correlated with factors related to the institution where these women live, especially the severely disabled.

Noise Reduction in Coherence Scanning Interferometry for Surface Topography Measurement

Coherence scanning interferometry is one of the most accurate surface measuring technologies, and it is increasingly applied to challenging surface structures, such as additive manufactured parts and transparent films, directly in environments that resemble production areas more than metrology labs. Environmental disturbances may further compromise measurement accuracy. Data acquisition strategies to reduce measurement noise in coherence scanning interferometry include averaging a sequence of repeated topography measurements or increasing the sampling frequency of the fringe signal during a single data acquisition—sometimes referred to as oversampling. In this paper, we improve the understanding of the mechanisms of the two noise reduction methods and compare their effects on surface topography measurement in the presence of environment-induced vibration. The results provide guidance for good practice in the reduction of uncertainty in surface measurement for a wide range of applications.

Inflammation and kynurenine pathway dysregulation in post-partum women with severe and suicidal depression

Depression during pregnancy and the post-partum is common, with severe cases resulting in suicidal behavior. Despite the urgent and unmet medical need, the biological underpinnings of peri-partum depression remain unclear. It has been suggested that it is triggered by dynamic changes of the immune system during pregnancy and at delivery. Therefore, we investigated whether a pro-inflammatory status in plasma, together with changes in the kynurenine pathway activity, is associated with the development of severe depression and suicidal behavior in the post-partum. Our cross-sectional study targets a unique, understudied population in which the pronounced severity of symptoms required hospitalization. We analyzed plasma IL-1β, IL-2, IL-6, IL-8, TNF-α, tryptophan, serotonin, kynurenine, nicotinamide, quinolinic- and kynurenic acids in post-partum women diagnosed with peripartum onset depression (PPD) and healthy controls (n = 165). We assessed depression severity using the Edinburgh Postnatal Depression Scale and suicidality using the Columbia-Suicide Severity Rating Scale. We found that increased plasma IL-6 and IL-8 and reductions of serotonin, IL-2 and quinolinic acid were associated with the severity of depressive symptoms and increased the risk for PPD. Moreover, women with lower serotonin levels were at an increased risk for suicidal behavior, even when adjusting for depression severity, psychosocial factors, age BMI, and medication. Our results indicate that severe depression in the post-partum involves dysregulation of the immune response and the kynurenine pathway, with a concomitant reduction in serotonin levels. We propose that inflammatory cytokines and the kynurenine pathway are potential treatment targets in PPD, opening up the possibility of novel therapeutic strategies targeting the peripartum.