Knowledge of the sequence of signal-intensity (SI) changes on conventional and diffusion-weighted MR imaging (DWI) following perinatal arterial ischemic stroke (PAIS) is limited, adding to the ...difficulty in timing the onset of PAIS. We hypothesized that SI changes seen on early sequential MR imaging following PAIS should follow a similar time course. The aim of this study was to evaluate the time course of SI changes by using a simple classification that could be assessed visually from conventional imaging and DWI in term-born neonates with symptomatic unilateral PAIS.
Infants > or =36 weeks gestation with unilateral PAIS in the territory of a main cerebral artery with a first MR imaging performed within the first postnatal month were included in this study. All subsequent scans up to 3 months postnatal age were also evaluated. For the conventional MR imaging scans, a visual SI scoring system was used (-1 = lower, 0 = equal, 1 = higher) compared with the contralesional hemisphere. For the DWIs, SI of the infarcted tissue was classified into the 3 groups: 1) severe hyperintensity (HI), 2) moderate and mild HI, and 3) no HI.
We analyzed 43 scans (mean age at first scanning, 4 days) from 21 term infants. Changes in SI on conventional T1 and T2 images were remarkably consistent among infants. The cortex was of low SI on T1 and high SI on T2 until day 6 when SIs reversed and cortical highlighting was seen for 1-2 months. The white matter was high SI on T1 in the first 8-9 days and on T2 for >2 weeks before becoming low SI. Secondary SI changes remote from the infarction were seen in the thalamus and brain stem in the first week, and atrophy was seen after 4 weeks. All DWIs showed high SI of the affected region until at least day 4, which fell to equal or below that of the contralesional hemisphere by day 12.
The pattern of SI change on conventional imaging and DWI following PAIS was remarkably consistent among patients, suggesting that PAIS in symptomatic term-born infants occurs within a very limited timeframe around birth.
The aim of this study was to establish whether abnormal signal intensity in the posterior limb of the internal capsule (PLIC) on magnetic resonance imaging is an accurate predictor of ...neurodevelopmental outcome at 1 year of age in infants with hypoxic-ischemic encephalopathy (HIE).
We have examined 73 term neonates with HIE between 1 and 17 days after birth with cranial magnetic resonance imaging and related the magnetic resonance imaging findings to neurodevelopmental outcome at 1 year of age.
All infants with an abnormal signal intensity in the PLIC developed neurodevelopmental impairment although in 4 infants with very early scans the abnormal signal was not apparent until up to 4 days after birth. A normal signal intensity was associated with a normal outcome in all but 4 cases; 3 of these infants had minor impairments and all had persistent imaging changes within the white matter. The 4th infant with a normal signal intensity on day 2 died before a further image could be obtained. The absence of normal signal predicted abnormal outcome in term infants with HIE with a sensitivity of 0.90, a specificity of 1.0, a positive predictive value of 1.0, and a negative predictive value of 0.87. The test correctly predicted outcome in 93% of infants with grade II HIE, according to the Sarnat system. Applying a Bayesian approach, the predictive probability of the test (the probability that the test would predict an outcome correctly) was distributed with a mean of 0.94 and 95% confidence limits of 0.89 to 1.0.
Abnormal signal intensity in the PLIC is an accurate predictor of neurodevelopmental outcome in term infants suffering HIE.
The Gram-negative bacterium Yersinia pestis is the causative agent of the systemic invasive infectious disease classically referred to as plague, and has been responsible for three human pandemics: ...the Justinian plague (sixth to eighth centuries), the Black Death (fourteenth to nineteenth centuries) and modern plague (nineteenth century to the present day). The recent identification of strains resistant to multiple drugs and the potential use of Y. pestis as an agent of biological warfare mean that plague still poses a threat to human health. Here we report the complete genome sequence of Y. pestis strain CO92, consisting of a 4.65-megabase (Mb) chromosome and three plasmids of 96.2 kilobases (kb), 70.3 kb and 9.6 kb. The genome is unusually rich in insertion sequences and displays anomalies in GC base-composition bias, indicating frequent intragenomic recombination. Many genes seem to have been acquired from other bacteria and viruses (including adhesins, secretion systems and insecticidal toxins). The genome contains around 150 pseudogenes, many of which are remnants of a redundant enteropathogenic lifestyle. The evidence of ongoing genome fluidity, expansion and decay suggests Y. pestis is a pathogen that has undergone large-scale genetic flux and provides a unique insight into the ways in which new and highly virulent pathogens evolve.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Invasive lobular carcinoma (ILC) accounts for 5–15% of invasive breast cancers. Typical ILC is oestrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative. Atypical ...biomarker profiles (ER- and HER2+, ER+ and HER2+ or triple negative) appear to differ from typical ILCs. This study compared subtypes of ILC in terms of clinical and pathological parameters, and response to neoadjuvant chemotherapy (NACT) according to biomarker profile.
All patients with ILC treated in a single centre from January 2005 to December 2020 were identified from a prospectively maintained database. Clinicopathologic and outcome data was collected and analysed according to tumour biomarker profile.
A total of 582 patients with ILC were treated. Typical ILC was observed in 89.2% (n = 519) and atypical in 10.8% (n = 63). Atypical ILCs were of a higher grade (35% grade 3 vs 9.6% grade 3, p < 0.001).
A larger proportion of atypical ILC received NACT (31.7% vs 6.9% p < 0.001). Atypical ILCs showed a greater response to NACT (mean RCB (Residual Cancer Burden Score) 2.46 vs mean RCB 3.41, p = 0.0365), and higher pathological complete response rates (15% vs 0% p = 0.017). Despite this, overall 5-year disease-free survival (DFS) was higher in patients with typical ILC (91% vs 83%, p = 0.001).
Atypical ILCs have distinct characteristics. They are more frequently of a higher grade and demonstrate a superior response to NACT. Despite the latter, atypical ILCs have a worse 5-year DFS which should be taken into consideration in terms of prognostication and may assist patient selection for NACT.
•ILC is a unique clinical entity and should be considered separately to IBS-NST for research and treatment purposes.•Biomarker profile influences ILC disease behaviour and may have an effect on response to neoadjuvant chemotherapy.•Tumour size and lymph node status are independent predictors of recurrence free survival in ILC.
Plain language summary
Heart problems are common in newborn babies, affecting approximately 5–10 in 1000 babies. Some are more serious than others, but most babies born with heart problems do not ...have other health issues. Of those babies who have a serious heart problem, almost 1 in 4 will have heart surgery in their first year. In the UK, pregnant women are offered a scan at around 20 weeks to try and spot any heart problems. In most cases there is not a clear reason for the problem, but sometimes other issues, such as genetic conditions, are discovered. In recent years the care given to these babies after they are born has improved their chances of surviving. However, it is recognised that babies born with heart problems have a risk of delays in their learning and development. This may be due to their medical condition, or as a result of surgery and complications after birth.
In babies with heart problems, there is a need for more research on ultrasound and magnetic resonance imaging (MRI) to understand how the brain develops and why these babies are more likely to have delays in learning and development. This paper discusses the way ultrasound and MRI are used in assessing the baby's brain. Ultrasound is often used to spot any problems, looking at how the baby's brain develops in pregnancy. Advances in ultrasound technologies have made this easier. MRI is well‐established and safe in pregnancy, and if problems in the brain have been seen on ultrasound, MRI may be used to look at these problems in more detail. While it is not always clear what unusual MRI findings can mean for the baby in the long term, increased understanding may mean parents can be given more information about possible outcomes for the baby and may help to improve the counselling they are offered before their baby's birth.
To define magnetic resonance imaging (MRI) appearances of the brain in extremely preterm infants between birth and term, a sequential cohort of infants born at a gestational age <30 weeks was studied ...with a dedicated neonatal magnetic resonance scanner. Images of infants (n = 41) with a median gestational age of 27 weeks (range 23 to 29 weeks) were initially obtained at a median age of 2 days (range 1 to 20 days) and then repeatedly studied; 29 (71%) infants had MRI at a median gestational age of 43 weeks (range 38 to 52 weeks) (term MRI). On the initial MRI scan 28 of 41 infants had abnormalities: either intraventricular hemorrhage, germinal layer hemorrhage, ventricular dilatation, or diffuse and excessive high signal intensity in the white matter on T
2 -weighted images. When magnetic resonance images for preterm infants at term gestation were compared with those of infants in the control group born at term, 22 of 29 infants had dilatation of the lateral ventricles, 24 of 29 had squaring of the anterior or posterior horns of the lateral ventricles, 11 of 29 had a widened interhemispheric fissure or extracerebral space, and 22 of 29 had diffuse and excessive high signal intensity in the white matter. There were no cases of cystic periventricular leukomalacia. We conclude that MRI abnormalities are commonly seen in the brain of preterm infants on whom images are obtained within 48 hours of birth and that further abnormalities develop between birth and term. A characteristic appearance of diffuse and excessive high signal intensity in the white matter on T
2 -weighted images is associated with the development of cerebral atrophy and may be a sign of white matter disease. These MRI appearances may help account for the high incidence of neurodevelopmental impairment in extremely preterm infants. (J Pediatr 1999;135:351-7)
Large medical image datasets form a rich source of anatomical descriptions for research into pathology and clinical biomarkers. Many features may be extracted from data such as MR images to provide, ...through manifold learning methods, new representations of the population's anatomy. However, the ability of any individual feature to fully capture all aspects morphology is limited. We propose a framework for deriving a representation from multiple features or measures which can be chosen to suit the application and are processed using separate manifold-learning steps. The results are then combined to give a single set of embedding coordinates for the data. We illustrate the framework in a population study of neonatal brain MR images and show how consistent representations, correlating well with clinical data, are given by measures of shape and of appearance. These particular measures were chosen as the developing neonatal brain undergoes rapid changes in shape and MR appearance and were derived from extracted cortical surfaces, nonrigid deformations, and image similarities. Combined single embeddings show improved correlations demonstrating their benefit for further studies such as identifying patterns in the trajectories of brain development. The results also suggest a lasting effect of age at birth on brain morphology, coinciding with previous clinical studies.
The LUX-ZEPLIN (LZ) experiment Akimov, D.Yu; Angelides, N.; Araújo, H.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2020, Letnik:
953, Številka:
C
Journal Article
Recenzirano
Odprti dostop
We describe the design and assembly of the LUX-ZEPLIN experiment, a direct detection search for cosmic WIMP dark matter particles. The centerpiece of the experiment is a large liquid xenon time ...projection chamber sensitive to low energy nuclear recoils. Rejection of backgrounds is enhanced by a Xe skin veto detector and by a liquid scintillator Outer Detector loaded with gadolinium for efficient neutron capture and tagging. LZ is located in the Davis Cavern at the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota, USA. We describe the major subsystems of the experiment and its key design features and requirements.
Objective To document co‐twin death/pregnancy loss and brain injury after single intrauterine death (sIUD) in monochorionic pregnancies.
Design A total of 135 pregnancies with sIUD were reviewed ...for co‐twin IUD, miscarriage and abnormal antenatal and postnatal neuro‐imaging.
Setting A tertiary referral fetal medicine unit from 2000 to 2007.
Population or Sample All cases referred with a single fetal death in monochorionic pregnancy, including those where sIUD was spontaneous or occurred after fetoscopic laser treatment, or resulted from selective termination by cord occlusion with bipolar diathermy or intrafetal vascular ablation with interstitial laser.
Methods Clinical details and ultrasound findings of the study population were retrieved from ultrasound and institutional databases. Delivery and neonatal outcome data were obtained from discharge summaries supplemented by individual chart review.
Main outcome measures Co‐twin death or pregnancy loss and neurologic injury assessed on antenatal ultrasound and MR‐imaging.
Results A total of 81 sIUDs resulted from vascular occlusive feticide (diathermy or interstitial laser), 22 followed placental laser and 32 were spontaneous. In 22 pregnancies (16.8%), the co‐twin died in utero and eight pregnancies miscarried (6.1%). Antenatal magnetic resonance (MR) imaging in 76/91 (83.5%) continuing pregnancies detected antenatal brain injury in five (6.6%). Three infants (two not scanned antenatally) had abnormalities detected postnatally. Brain abnormality was detected less often after procedure related (2.6%, 2/77) than spontaneous sIUD (22.2%, 6/27, P = 0.003) and after early compared with late gestation sIUD (3.6%, 4/111 versus 20.0%, 4/20; P = 0.02).
Conclusions We confirm substantial co‐twin loss (22.9%) after monochorionic sIUD, but a low risk of antenatally acquired MRI‐identified brain injury, suggesting this risk has been overestimated. Procedures restricting inter‐twin transfusion reduce, but do not negate risk of brain injury.
Neonatal stroke Rutherford, M A; Ramenghi, L A; Cowan, F M
Archives of disease in childhood. Fetal and neonatal edition
97, Številka:
5
Journal Article
Recenzirano
Neonatal stroke encompasses a range of focal and multifocal ischaemic and haemorrhagic tissue injuries. This review will concentrate on focal brain injury that occurs as a consequence of arterial ...infarction, most frequently the left middle cerebral artery, or more rarely as a consequence of cerebral sinus venous thrombosis (CSVT). Both conditions are multifactorial in origin. The incidence of both acquired and genetic thrombophilic disorders in both mothers and infants is high although rarely causal in isolation. Neurodevelopmental morbidity occurs in over 50% of children. Specific therapy in the form of anticoagulation is currently only recommended in CSVT and needs to be carefully monitored in the presence of haemorrhage.
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