Introduction
Paediatric patients with disorders that involve brain functioning are particularly vulnerable with respect to including them in shared decision‐making. Current tools are mostly paper or ...digital patient information. We lay the groundwork for improving engagement with a concept that we coined ‘the Self‐Portrait’. The main goals were to identify (1) obstacles and (2) design parameters that enable patient participation.
Methods
A research‐through‐design approach was utilized in nine patients with brain‐related disorders (4–12 years), 15 parents and 15 medical professionals, involving contextual research (interviews and observations) within the paediatric hospital and patients' homes and codesign. Sensitizing materials and early instances of design solutions were deployed as catalysts for communication. Five rounds of enriched interviews and design reviews were thematically analysed to answer the research questions.
Results
Obstacles to child involvement were related to children's level of understanding, the time and energy necessary for information processing and lack of perceived relevance of the information. Patients' engagement is supported by design features that extend the time frame of interaction beyond the consultation, transfer information interactively and give control and influence during the consultation.
Conclusion
Obstacles were detected that complicate child engagement, which differ between stakeholders. Promising design features were identified that have the potential to play an important role in enabling active child involvement. These findings show that applying principles of human‐centred design research and codesign can bring together patients, parents and medical professionals around a tool that provides a shared language and focus, which are prerequisites to increase child engagement.
Patient or Public Contribution
Patients, parents and clinicians contributed as design informants during contextual research and design reviews. Clinicians provided feedback on the initial outcomes of thematic analysis. Two researchers assisted in consensus sessions during the thematic analysis.
Objective
SLC13A3 encodes the plasma membrane Na+/dicarboxylate cotransporter 3, which imports inside the cell 4 to 6 carbon dicarboxylates as well as N‐acetylaspartate (NAA). SLC13A3 is mainly ...expressed in kidney, in astrocytes, and in the choroid plexus. We describe two unrelated patients presenting with acute, reversible (and recurrent in one) neurological deterioration during a febrile illness. Both patients exhibited a reversible leukoencephalopathy and a urinary excretion of α‐ketoglutarate (αKG) that was markedly increased and persisted over time. In one patient, increased concentrations of cerebrospinal fluid NAA and dicarboxylates (including αKG) were observed. Extensive workup was unsuccessful, and a genetic cause was suspected.
Methods
Whole exome sequencing (WES) was performed. Our teams were connected through GeneMatcher.
Results
WES analysis revealed variants in SLC13A3. A homozygous missense mutation (p.Ala254Asp) was found in the first patient. The second patient was heterozygous for another missense mutation (p.Gly548Ser) and an intronic mutation affecting splicing as demonstrated by reverse transcriptase polymerase chain reaction performed in muscle tissue (c.1016 + 3A > G). Mutations and segregation were confirmed by Sanger sequencing. Functional studies performed on HEK293T cells transiently transfected with wild‐type and mutant SLC13A3 indicated that the missense mutations caused a marked reduction in the capacity to transport αKG, succinate, and NAA.
Interpretation
SLC13A3 deficiency causes acute and reversible leukoencephalopathy with marked accumulation of αKG. Urine organic acids (especially αKG and NAA) and SLC13A3 mutations should be screened in patients presenting with unexplained reversible leukoencephalopathy, for which SLC13A3 deficiency is a novel differential diagnosis. ANN NEUROL 2019;85:385–395.
Objective
Approximately 7%–50% of children with medulloblastoma (MB) develop postoperative cerebellar mutism syndrome (pCMS). pCMS has a short‐term negative impact on intelligence, but effects on ...long‐term outcomes are contradictory. The aim of this study was to assess long‐term effects of pCMS in MB patients on aspects of intelligence quotient (IQ) and its perioperative risk factors.
Methods
In this single‐center retrospective cohort study, 31 children were included (14 pCMS). Perioperative risk factors included brainstem invasion, vermis incision, hydrocephalus, tumor size, severity of pCMS, neurological symptoms, mean body temperature (BT) on days 1–4 post surgery, and age at resection. Age‐appropriate Wechsler Intelligence tests were assessed at least 2 years after tumor resection.
Results
Mean interval between tumor resection and neuropsychological evaluation was 3.9 years in pCMS and 4 years and 11 months in the no‐pCMS group. No significant differences in IQ scores were found between groups. The pCMS group had a clinically relevant difference of 10 points when compared to age norms on verbal IQ (VIQ). Bilateral pyramidal and swallowing problems were risk factors for lower performance. In the overall group, tumor size, younger age at surgery, and raised mean BT were negatively correlated with aspects of IQ.
Conclusions
We found a clinically significant reduction of VIQ in the pCMS patient group. pCMS patients with a larger tumor size, younger age at surgery, a higher mean BT in the first days after surgery, bilateral pyramidal symptoms, and swallowing problems 10 days post surgery are more at risk for VIQ deficits at long‐term.
Colonization of host phagocytic cells by
Leishmania
metacyclic promastigotes involves several parasite effectors, including the zinc-dependent metalloprotease GP63. The major mode of action of this ...virulence factor entails the cleavage/degradation of host cell proteins. Given the potent proteolytic activity of GP63, identification of its substrates requires the adequate preparation of cell lysates to prevent artefactual degradation during cell processing. In the present study, we re-examined the cleavage/degradation of reported GP63 substrates when GP63 activity was efficiently neutralized during the preparation of cell lysates. To this end, we infected bone marrow-derived macrophages with either wild type,
Δgp63
, and
Δgp63
+
GP63 L
.
major
metacyclic promastigotes for various time points. We prepared cell lysates in the absence or presence of the zinc-metalloprotease inhibitor 1,10-phenanthroline and examined the levels and integrity of ten previously reported host cell GP63 substrates. Inhibition of GP63 activity with 1,10-phenanthroline during the processing of macrophages prevented the cleavage/degradation of several previously described GP63 targets, including PTP-PEST, mTOR, p65RelA, c-Jun, VAMP3, and NLRP3. Conversely, we confirmed that SHP-1, Synaptotagmin XI, VAMP8, and Syntaxin-5 are
bona fide
GP63 substrates. These results point to the importance of efficiently inhibiting GP63 activity during the preparation of
Leishmania
-infected host cell lysates. In addition, our results indicate that the role of GP63 in
Leishmania
pathogenesis must be re-evaluated.
The purpose of the present work was to progress in our understanding of the pathophysiology of L-2-hydroxyglutaric aciduria, due to a defect in L-2-hydroxyglutarate dehydrogenase, by creating and ...studying a mouse model of this disease. L-2-hydroxyglutarate dehydrogenase-deficient mice (l2hgdh-/-) accumulated L-2-hydroxyglutarate in tissues, most particularly in brain and testis, where the concentration reached ≈ 3.5 μmol/g. Male mice showed a 30% higher excretion of L-2-hydroxyglutarate compared to female mice, supporting that this dicarboxylic acid is partially made in males by lactate dehydrogenase C, a poorly specific form of this enzyme exclusively expressed in testes. Involvement of mitochondrial malate dehydrogenase in the formation of L-2-hydroxyglutarate was supported by the commensurate decrease in the formation of this dicarboxylic acid when down-regulating this enzyme in mouse l2hgdh-/- embryonic fibroblasts. The concentration of lysine and arginine was markedly increased in the brain of l2hgdh-/- adult mice. Saccharopine was depleted and glutamine was decreased by ≈ 40%. Lysine-α-ketoglutarate reductase, which converts lysine to saccharopine, was inhibited by L-2-hydroxyglutarate with a Ki of ≈ 0.8 mM. As low but significant activities of the bifunctional enzyme lysine-α-ketoglutarate reductase/saccharopine dehydrogenase were found in brain, these findings suggest that the classical lysine degradation pathway also operates in brain and is inhibited by the high concentrations of L-2-hydroxyglutarate found in l2hgdh-/- mice. Pathological analysis of the brain showed significant spongiosis. The vacuolar lesions mostly affected oligodendrocytes and myelin sheats, as in other dicarboxylic acidurias, suggesting that the pathophysiology of this model of leukodystrophy may involve irreversible pumping of a dicarboxylate in oligodendrocytes. Neurobehavioral testing indicated that the mice mostly suffered from a deficit in learning capacity. In conclusion, the findings support the concept that L-2-hydroxyglutaric aciduria is a disorder of metabolite repair. The accumulation of L-2-hydroxyglutarate exerts toxic effects through various means including enzyme inhibition and glial cell swelling.
5‐Amino‐4‐imidazolecarboxamide‐ribosiduria (AICA)‐ribosiduria is an exceedingly rare autosomal recessive condition resulting from the disruption of the bifunctional purine biosynthesis protein PURH ...(ATIC), which catalyzes the last two steps of de novo purine synthesis. It is characterized biochemically by the accumulation of AICA‐riboside in urine. AICA‐ribosiduria had been reported in only one individual, 15 years ago. In this article, we report three novel cases of AICA‐ribosiduria from two independent families, with two novel pathogenic variants in ATIC. We also provide a clinical update on the first patient. Based on the phenotypic features shared by these four patients, we define AICA‐ribosiduria as the syndromic association of severe‐to‐profound global neurodevelopmental impairment, severe visual impairment due to chorioretinal atrophy, ante‐postnatal growth impairment, and severe scoliosis. Dysmorphic features were observed in all four cases, especially neonatal/infancy coarse facies with upturned nose. Early‐onset epilepsy is frequent and can be pharmacoresistant. Less frequently observed features are aortic coarctation, chronic hepatic cytolysis, minor genital malformations, and nephrocalcinosis. Alteration of the transformylase activity of ATIC might result in a more severe impairment than the alteration of the cyclohydrolase activity. Data from literature points toward a cytotoxic mechanism of the accumulated AICA‐riboside.
It has been proposed that neonatal thyroid-stimulating hormone (TSH) concentrations are a good indicator of iodine deficiency in the population. A frequency of neonatal TSH concentrations above 5 ...mU/L below 3% has been proposed as the threshold indicating iodine sufficiency. The objective of the present study was to evaluate feasibility and usefulness of nation-wide neonatal TSH concentration screening results to assess iodine status in Belgium. All newborns born in Belgium during the period 2009-2011 (n = 377713) were included in the study, except those suffering from congenital hypothyroidism and premature neonates. The frequency of neonatal TSH concentrations above 5 mU/L from 2009 to 2011 in Belgium fluctuated between 2.6 and 3.3% in the centres using the same TSH assay. There was a significant inverse association between neonatal TSH level and birth weight. The longer the duration between birth and screening, the lower the TSH level. Neonatal TSH levels were significantly lower in winter than in spring or autumn and significantly lower in spring and summer than in autumn while significantly higher in spring compared to summer. In conclusion, despite that pregnant women in Belgium are mildly iodine deficient, the frequency of neonatal TSH concentrations above 5 mU/L was very low, suggesting that the neonatal TSH threshold proposed for detecting iodine deficiency needs to be re-evaluated. Although neonatal TSH is useful to detect severe iodine deficiency, it should not be recommended presently for the evaluation of iodine status in mildly iodine deficient regions.
Pathogen-specific rewiring of host cell metabolism creates the metabolically adapted microenvironment required for pathogen replication. Here, we investigated the mechanisms governing the modulation ...of macrophage mitochondrial properties by the vacuolar pathogen
. We report that induction of oxidative phosphorylation and mitochondrial biogenesis by Leishmania donovani requires the virulence glycolipid lipophosphoglycan, which stimulates the expression of key transcriptional regulators and structural genes associated with the electron transport chain.
-induced mitochondriogenesis also requires a lipophosphoglycan-independent pathway involving type I interferon (IFN) receptor signaling. The observation that pharmacological induction of mitochondrial biogenesis enables an avirulent lipophosphoglycan-defective L. donovani mutant to survive in macrophages supports the notion that mitochondrial biogenesis contributes to the creation of a metabolically adapted environment propitious to the colonization of host cells by the parasite. This study provides novel insight into the complex mechanism by which
metacyclic promastigotes alter host cell mitochondrial biogenesis and metabolism during the colonization process.
To colonize host phagocytes,
metacyclic promastigotes subvert host defense mechanisms and create a specialized intracellular niche adapted to their replication. This is accomplished through the action of virulence factors, including the surface coat glycoconjugate lipophosphoglycan. In addition,
induces proliferation of host cell mitochondria as well as metabolic reprogramming of macrophages. These metabolic alterations are crucial to the colonization process of macrophages, as they may provide metabolites required for parasite growth. In this study, we describe a new key role for lipophosphoglycan in the stimulation of oxidative phosphorylation and mitochondrial biogenesis. We also demonstrate that host cell pattern recognition receptors Toll-like receptor 4 (TLR4) and endosomal TLRs mediate these
-induced alterations of host cell mitochondrial biology, which also require type I IFN signaling. These findings provide new insight into how
creates a metabolically adapted environment favorable to their replication.
To colonize mammalian phagocytic cells, the parasite
remodels phagosomes into parasitophorous vacuoles that can be either tight-fitting individual or communal. The molecular and cellular bases ...underlying the biogenesis and functionality of these two types of vacuoles are poorly understood. In this study, we investigated the contribution of host cell soluble
-ethylmaleimide-sensitive-factor attachment protein receptor proteins to the expansion and functionality of communal vacuoles as well as the replication of the parasite. The differential patterns of recruitment of soluble
-ethylmaleimide-sensitive-factor attachment protein receptor to communal vacuoles harboring Leishmania amazonensis and to individual vacuoles housing L. major led us to further investigate the roles of VAMP3 and VAMP8 in the interaction of
with its host cell. We show that whereas VAMP8 contributes to the optimal expansion of communal vacuoles, VAMP3 negatively regulates L. amazonensis replication, vacuole size, as well as antigen cross-presentation. In contrast, neither protein has an impact on the fate of L. major. Collectively, our data support a role for both VAMP3 and VAMP8 in the development and functionality of L. amazonensis-harboring communal parasitophorous vacuoles.
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