Leukocyte immunoglobulin‐like receptor subfamily B member 1 (LILRB1) has been reported to interact with a wide spectrum of HLA class I (HLA‐I) molecules, albeit with different affinities determined ...by allelic polymorphisms and conformational features. HLA‐G dimerization and the presence of intracellular Cys residues in HLA‐B7 have been shown to be critical for their recognition by LILRB1. We hypothesized that dimerization of classical HLA class Ia molecules, previously detected in exosomes, might enhance their interaction with LILRB1. A soluble LILRB1‐Fc fusion protein and a sensitive cellular reporter system expressing a LILRB1‐ζ chimera were employed to assess receptor interaction with different HLA class Ia molecules transfected in the human lymphoblastoid 721.221 cell line. Under these conditions, intracellular Cys residues and HLA‐I dimerization appeared associated with increased LILRB1 recognition. On the other hand, a marginal interaction of LILRB1 with primary monocytic cells, irrespective of their high HLA‐I expression, was enhanced by type I interferon (IFN). This effect appeared disproportionate to the cytokine‐induced increase of surface HLA‐I expression and was accompanied by detection of HLA class Ia dimers. Altogether, the results support that a regulated assembly of these noncanonical HLA‐I conformers during the immune response may enhance the avidity of their interaction with LILRB1.
The LILRB1 (ILT2, LIR1, CD85j) inhibitory receptor interacts with a broad range of HLA class I molecules. Dimerization of HLA class Ia alleles involving intracellular Cys enhances the avidity of the LILRB1 interaction and signaling. Type I IFN promotes HLA class Ia dimerization in macrophages and increased recognition by LILRB1.
OBJECTIVE:To report a case of unexpected shaken baby syndrome, the diagnosis of which was possible after an incidental funduscopic examination.
METHODS:Observational case report. An infant was to be ...sent back home with an apparent unprovoked seizure diagnosis when a funduscopic examination was made because of an incidental research study changing the diagnostic orientation.
RESULTS:Extensive bilateral subretinal hemorrhages in the funduscopic examination allowed shaken baby syndrome unexpected diagnosis. A funduscopic examination is not usually included in the first seizure diagnosis management, even when a retinal bleeding could be present and be the clue for its causative diagnosis.
CONCLUSION:We recommend having in mind the practice of a funduscopic examination in all children with a first apparently unprovoked seizure.
OBJECTIVESThe aim of this study is to determine the prevalence and characteristics of fractures in young infants attended at the pediatric emergency department (PED).
METHODSThis is a retrospective ...study for 2 years (2011–2012) of children younger than 12 months attended with a fracture at the PED. Age, sex, site and type of fracture, mechanism of injury, time interval before seeking medical attention, and management were analyzed.
RESULTSOne hundred one patients were included. They represented 0.3% (95% confidence interval, 0.2%–0.4%) of all children younger than 12 months attended at the PED. The median age was 7.7 months (interquartile range, 5.2–10.1 months); 58 (57.4%) were boys. The most common fracture was skull fracture (58, 57.4%), mostly parietal, followed by long bone fractures (27, 26.7%); transverse and torus fractures were the most common types, located at the diaphysis and distal metaphysis, respectively. The principal mechanism reported was falling (83, 82.2%) mainly from furniture. Fifty-one patients (50.1%) were attended in the first 6 hours after injury. Sixty-five patients (64.4%) were admitted at the hospital and the other 9 (8.9%) were controlled in outpatient visits. One of them was injured because of negligence and another was diagnosed with osteoporosis.
CONCLUSIONSFractures in young infants are uncommon at the PED, the skull fracture being the most common. Pediatricians should alert caretakers of the risks in normal development to prevent these injuries. Fractures caused by child abuse should always be discarded.
Highly-active antiretroviral therapy (HAART) can induce a characteristic lipodystrophy syndrome characterized by peripheral fat wasting and central adiposity, usually associated with hyperlipidaemia ...and insulin resistance 1,2. Indirect data have led some authors to propose that mitochondrial dysfunction could play a role in this syndrome 3,4.To date, as recently outlined by Kakuda et al. 5 in this journal, HIV-infected patients developing lipodystrophy have not been studied for mitochondrial changes or respiratory chain capacity...
Aim To determine the prevalence of retinal haemorrhages in infants with pertussis infection with the purpose of clarifying the differential diagnosis of the cases of abusive head trauma. Methods ...Prospective study of children aged 15 days to 2 years admitted to our hospital with a diagnosis of pertussis over a period of 4 years (May 2004–May 2008). All children underwent one detailed ophthalmological examination within 72 h of admission. If retinal haemorrhages were detected, further investigation was undertaken to rule out systemic disorder or maltreatment. Results 35 children with pertussis infection were examined. None was found to have retinal haemorrhages. Therefore, applying Wilson's method, the data suggest with 95% confidence that the true effect estimate for retinal haemorrhage occurring due to symptomatic pertussis infection requiring admission to hospital is no higher than 9.9%. Conclusions Pertussis infections are unlikely to cause retinal haemorrhages in children under 2 years of age.
Exposure to nucleoside analogues in fetal or early life has been associated with rare clinically significant mitochondrial toxic effects, mainly neurologic symptoms. Lactate (LA) measurements have ...been used to monitor nucleoside-related mitochondrial toxicity. Our aim was to determine the prevalence, clinical evolution, and risk factors for hyperlactatemia in our cohort of human immunodeficiency virus (HIV)-uninfected children who were exposed to antiretrovirals.
We conducted a prospective observational study of 127 HIV-uninfected infants who were born to HIV-infected women. Clinical symptoms suggesting mitochondrial dysfunction were analyzed in routine follow-up, and LA and alanine plasma levels were obtained at 6 weeks, 3 months, 6 months, and 12 months in all patients. Elevated alanine levels, together with hyperlactatemia, suggest chronic mitochondrial injury.
Most (85%) women received highly active antiretroviral therapy (HAART) during pregnancy (mean duration: 31 weeks) and zidovudine during labor (93%). Most (96%) children received zidovudine alone. Hyperlactatemia with hyperalaninemia was detected in 63 children in at least 1 of the measurements. Mean LA levels were significantly higher in children who were exposed to nucleoside analogue reverse transcriptase inhibitors than in control subjects (2.88 vs 1.61 at 6 weeks, 2.78 vs 1.49 at 3 months, 1.89 vs 1.39 at 6 months, and 1.71 vs 1.24 at 12 months; peak levels: 8.06, 10.1, 7.28, and 4.48 mmol/L, respectively). In 44 patients, LA levels progressed spontaneously to normality within the first year of life. Three girls presented a slight and self-limited delay in psychomotor development, with LA peak levels of 7.3, 4.0, and 4.6 mmol/L. Only the gestational use of didanosine was associated with a higher risk of hyperlactatemia.
In our series, almost half of the children (63 of 127) who were exposed to nucleoside analogues developed benign and self-limited hyperlactatemia. When symptomatic, nucleoside analogue-induced toxicity affected neurologic development.
Asynchronous Multigrid Methods Wolfson-Pou, Jordi; Chow, Edmond
2019 IEEE International Parallel and Distributed Processing Symposium (IPDPS)
Conference Proceeding
Reducing synchronization in iterative methods for solving large sparse linear systems may become one of the most important goals for such solvers on exascale computers. Research in asynchronous ...iterative methods has primarily considered basic iterative methods. In this paper, we examine how multigrid methods can be executed asynchronously. We present models of asynchronous additive multigrid methods, and use these models to study the convergence properties of these methods. We also introduce two parallel algorithms for implementing asynchronous additive multigrid, the global-res and local-res algorithms. These two algorithms differ in how the fine grid residual is computed, where local-res requires less computation than global-res but converges more slowly. We compare two types of asynchronous additive multigrid methods: the asynchronous fast adaptive composite grid method with smoothing (AFACx) and additive variants of the classical multiplicative method (Multadd). We implement asynchronous versions of Multadd and AFACx in OpenMP and generate the prolongation and coarse grid matrices using the BoomerAMG package. Our experimental results show that asynchronous multigrid can exhibit grid-size independent convergence and can be faster than classical multigrid in terms of solve wall-clock time. We also show that asynchronous smoothing is the best choice of smoother for our test cases, even when only one smoothing sweep is used.
To analyze our institution's work-up for patients with a diagnosis of subdural haematoma (SDH) in order to determine how many of them are secondary to child abuse, as well as to examine their final ...functional outcome.
Retrospective review of children under 2 years of age diagnosed as having SDH between 1995 and 2005.
A total of 35 cases were identified. Fifteen patients that had underlying conditions that predispose them to bleed were excluded. Among the remaining 20 patients, seizures and head trauma were the main causes for consultation. All patients had a coagulation study and a head computed tomography carried out, 11 of these had a magnetic resonance imaging and 1 had a post-mortem examination. Bilateral SDHs in different stages of evolution was the most common pattern of intracranial haemorrhage. Fourteen infants had a skeletal survey, 4 had a bone scintigraphy and 19 had an ophthalmoscopic examination. Fractures were diagnosed in 7 patients and retinal haemorrhages in 11. The final diagnoses were: 10 shaken baby syndromes, 4 idiopathic SDH, 3 strokes, 2 coagulopathies and 1 accidental head injury. Upon follow-up, 1 patient had died and 9 had sustained permanent disabilities.
Cases of infantile SDH are usually thoroughly investigated. In spite of this, sometimes it is not possible to determine the SDH aetiology. Nonetheless, shaken baby syndrome remains the most frequent cause of SDH in infants, and it carries a poor prognosis.
OBJECTIVE:To determine the prevalence of retinal hemorrhages in apparent life-threatening events (ALTEs) with the purpose of facilitating the differential diagnosis of the cases of nonaccidental head ...trauma.
METHODS:Prospective study on children aged 15 days to 2 years admitted to our hospital with a diagnosis of an ALTE over a period of 2 years (May 2004-May 2006). All the children underwent detailed ophthalmologic examination within 72 hours of admission. If retinal hemorrhages were detected, further investigation was undertaken to rule out systemic disorder or maltreatment.
RESULTS:One hundred eight children with an ALTE were examined. No patient was found to have retinal hemorrhages nor was any found to have experienced child abuse. Therefore, using the Hanley rule of 3, we can be confident to an upper limit of 95% that the chance of retinal hemorrhages occurring as a result of an ALTE alone is at the most 0.028.
CONCLUSIONS:Apparent life-threatening events alone are unlikely to cause retinal hemorrhages in children younger than 2 years. Therefore, if retinal hemorrhages are detected, investigation into the possibility of nonaccidental injury is essential.
Asynchronous iterative methods for solving linear systems have been gaining attention due to the high cost of synchronization points in massively parallel codes. Since future parallel computers will ...likely achieve exascale performance, synchronization may become the primary bottleneck. Historically, theory on asynchronous iterative methods has focused on proving that an asynchronous version of a fixed point method will converge. Additionally, some theory has shown that asynchronous methods can be faster, which has been supported by shared memory experiments. In this paper, we introduce a new way to model asynchronous Jacobi using propagation matrices, which are similar in concept to iteration matrices. With this model, we show that asynchronous Jacobi can reduce the error even if some processes are delayed for a long period of time, which could be due to a hardware malfunction or a large imbalance. We also show that asynchronous Jacobi can converge when synchronous Jacobi does not. We compare model results to shared and distributed memory implementation results, and show that in practice, asynchronous Jacobi's convergence rate improves as we increase the number of processes.
