Detectable Unmetabolized Folic Acid and Elevated Folate Concentrations in Folic Acid-Supplemented Canadian Children With Sickle Cell Disease.

Sickle cell disease (SCD) is an inherited hemoglobinopathy caused by a variant (rs344) in the HBB gene encoding the ß-globin subunit of hemoglobin. Chronic hemolytic anemia and increased erythropoiesis and RBC turnover in individuals with SCD can result in increased needs for folate and other B-vitamins. We assessed B-vitamin status, and the distribution of folate forms, including unmetabolized folic acid (UMFA), in Canadian children with SCD supplemented with 1 mg/d folic acid (current routine practice). Non-fasted serum and plasma samples were analyzed for concentrations of folate, and vitamins B-2, B-6, and B-12. Eleven individuals (45% male; SCD type: HbSS n = 8, HbSC n = 2, HbSß0-Thal n = 1), with a median (IQR) age of 14 (7, 18) years, were included. Total folate concentrations were 3-27 times above the deficiency cut-off (10 nmol/L), and 64% of children had elevated folate levels (>45.3 nmol/L). UMFA (>0.23 nmol/L) was detected in all children, and 36% of participants had elevated levels of UMFA (>5.4 nmol/L). All children were vitamin B-12 sufficient (>150 pmol/L), and the majority (55%) had sufficient B-6 status (>30 nmol/L). Among this sample of Canadian children with SCD, there was limited evidence of B-vitamin deficiencies, but UMFA was detectable in all children.

Positive effects of ultrasound-guided peripheral IV insertion on pediatric sickle cell anemia/thalassemia patients receiving automated red cell exchange procedures or chronic transfusion therapy.

BACKGROUND: Peripheral vascular access and venipuncture are major causes of distress and anxiety for children and their parents. This is especially difficult for patients with hemoglobinopathies (thalassemia major and sickle cell disease) who require chronic blood transfusions. These patients require peripheral venous access for regular blood transfusions and (in the case of sickle cell disease) for automated red cell exchange procedures. Peripheral intravenous (PIV) catheters are much preferred to central venous lines as they carry far fewer risks. However, when patients experience multiple unsuccessful attempts to initiate a PIV, it can be traumatizing and cause anxiety for future visits. Establishing therapeutic trust and ensuring a smooth experience are of paramount importance for these chronic patients who require regular blood transfusions. AIM: The purpose of this study was to determine whether ultrasound-guided PIV insertion decreases PIV-associated pain and anxiety, and whether the number of attempts and amount of time spent accessing PIVs in children with difficult peripheral intravenous (DPIV) access is reduced. MATERIALS AND METHODS: This was a pilot study with both retrospective and prospective components. Hemoglobinopathies are relatively rare in our population and our study cohort was small (N = 18). RESULTS: We identified four DPIV access patients. We recorded each time these patients had a PIV inserted as an encounter. DISCUSSION/CONCLUSION: We found that while there was a small amount of time gained by using ultrasound-guided PIV insertion, patient and parent satisfaction was significantly improved.

Folic acid supplementation in children with sickle cell disease: study protocol for a double-blind randomized cross-over trial.

BACKGROUND: Sickle cell disease (SCD) is a genetic disorder which causes dysfunctional red blood cells (RBC) and is thought to increase requirements for folate, an essential B vitamin, due to increased RBC production and turnover in the disease. High-dose supplementation with 1-5 mg/d folic acid, synthetic folate, has been the standard recommendation for children with SCD. There is concern about whether children with SCD need such high doses of folic acid, following mandatory folic acid fortification of enriched grains in Canada, and advancements in medical therapies which extend the average lifespan of RBCs. In animal and human studies, high folic acid intakes (1 mg/d) have been associated with accelerated growth of some cancers, and the biological effects of circulating unmetabolized folic acid (UMFA), which can occur with doses of folic acid ≥ 0.2 mg/d, are not fully understood. The objective of this study is to determine efficacy of, and alterations in folate metabolism from high-dose folic acid in children with SCD during periods of folic acid supplementation versus no supplementation. METHODS: In this double-blind randomized controlled cross-over trial, children with SCD (n = 36, aged 2-19 years) will be randomized to either receive 1 mg/d folic acid, the current standard of care, or a placebo for 12 weeks. After a 12-week washout period, treatments will be reversed. Total folate concentrations (serum and RBC), different folate forms (including UMFA), folate-related metabolites, and clinical outcomes will be measured at baseline and after treatment periods. The sum of the values measured in the two periods will be calculated for each subject and compared across the two sequence groups by means of a test for independent samples for the primary (RBC folate concentrations) and secondary (UMFA) outcomes. Dietary intake will be measured at the beginning of each study period. DISCUSSION: As the first rigorously designed clinical trial in children with SCD, this trial will inform and assess current clinical practice, with the ultimate goal of improving nutritional status of children with SCD. TRIAL REGISTRATION: ClinicalTrials.gov NCT04011345 . Registered on July 8, 2019.

A senataxin-associated exonuclease SAN1 is required for resistance to DNA interstrand cross-links.

Interstrand DNA cross-links (ICLs) block both replication and transcription, and are commonly repaired by the Fanconi anemia (FA) pathway. However, FA-independent repair mechanisms of ICLs remain poorly understood. Here we report a previously uncharacterized protein, SAN1, as a 5' exonuclease that acts independently of the FA pathway in response to ICLs. Deletion of SAN1 in HeLa cells and mouse embryonic fibroblasts causes sensitivity to ICLs, which is prevented by re-expression of wild type but not nuclease-dead SAN1. SAN1 deletion causes DNA damage and radial chromosome formation following treatment with Mitomycin C, phenocopying defects in the FA pathway. However, SAN1 deletion is not epistatic with FANCD2, a core FA pathway component. Unexpectedly, SAN1 binds to Senataxin (SETX), an RNA/DNA helicase that resolves R-loops. SAN1-SETX binding is increased by ICLs, and is required to prevent cross-link sensitivity. We propose that SAN1 functions with SETX in a pathway necessary for resistance to ICLs.

Prevalence of Vitamin D Deficiency Varies Widely by Season in Canadian Children and Adolescents with Sickle Cell Disease.

Sickle cell disease (SCD) is an inherited disorder caused by a variant (rs334) in the ß-globin gene encoding hemoglobin. Individuals with SCD are thought to be at risk of vitamin D deficiency. Our aim was to assess serum 25-hydroxyvitamin D (25OHD) concentrations, estimate deficiency prevalence, and investigate factors associated with 25OHD concentrations in children and adolescents with SCD attending BC Children's Hospital in Vancouver, Canada. We conducted a retrospective chart review of SCD patients (2-19 y) from 2012 to 2017. Data were available for n = 45 patients with n = 142 25OHD measurements assessed using a EUROIMMUN analyzer (EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany). Additional data were recorded, including age, sex, and season of blood collection. Linear regression was used to measure associations between 25OHD concentration and predictor variables. Overall, mean ± SD 25OHD concentration was 79 ± 36 nmol/L; prevalence of low 25OHD concentrations (<30, <40, and <75 nmol/L) was 5%, 17% and 50%, respectively. Mean 25OHD concentrations measured during Jul-Sep were higher (28 (95% confidence interval CI: 16-40) nmol/L higher, P < 0.001) compared to Jan-Mar. Vitamin D deficiency rates varied widely by season: Based on 25OHD <30 nmol/L, prevalence was 0% in Oct-Dec and 6% in Jan-Mar; based on <40 nmol/L, prevalence was 0% in Oct-Dec and 26% in Jan-Mar.

Standing in the gap: ref lections on translating the Jung-Neumann correspondence.

This paper considers the experience of translating the correspondence between C.G. Jung and Erich Neumann as part of the Philemon series. The translator explores the similarities between analytical work and the task of translation by means of the concepts of the dialectical third and the interactional field. The history and politics of the translation of analytic writing and their consequences for the lingua franca of analysis are discussed. Key themes within the correspondence are outlined, including Jung and Neumann's pre-war exploration of Judaism and the unconscious, the post-war difficulties around the publication of Neumann's Depth Psychology and a New Ethic set against the early years of the C.G. Jung Institute in Zurich, and the development of the correspondents' relationship over time.

Spider silk-like proteins derived from transgenic Nicotiana tabacum.

The high tensile strength and biocompatibility of spider dragline silk makes it a desirable material in many engineering and tissue regeneration applications. Here, we present the feasibility to produce recombinant proteins in transgenic tobacco Nicotiana tabacum with sequences representing spider silk protein building blocks . Recombinant mini-spidroins contain native N- and C-terminal domains of major ampullate spidroin 1 (rMaSp1) or rMaSp2 flanking an abbreviated number (8, 16 or 32) of consensus repeat domains. Two different expression plasmid vectors were tested and a downstream chitin binding domain and self-cleavable intein were included to facilitate protein purification. We confirmed gene insertion and RNA transcription by PCR and reverse-transcriptase PCR, respectively. Mini-spidroin production was detected by N-terminus specific antibodies. Purification of mini-spidroins was performed through chitin affinity chromatography and subsequent intein activation with reducing reagent. Mini-spidroins, when dialyzed and freeze-dried, formed viscous gelatin-like fluids.

Decreased tryptophan metabolism in patients with autism spectrum disorders.

BACKGROUND: Autism spectrum disorders (ASDs) are relatively common neurodevelopmental conditions whose biological basis has been incompletely determined. Several biochemical markers have been associated with ASDs, but there is still no laboratory test for these conditions. METHODS: We analyzed the metabolic profile of lymphoblastoid cell lines from 137 patients with neurodevelopmental disorders with or without ASDs and 78 normal individuals, using Biolog Phenotype MicroArrays. RESULTS: Metabolic profiling of lymphoblastoid cells revealed that the 87 patients with ASD as a clinical feature, as compared to the 78 controls, exhibited on average reduced generation of NADH when tryptophan was the sole energy source. The results correlated with the behavioral traits associated with either syndromal or non-syndromal autism, independent of the genetic background of the individual. The low level of NADH generation in the presence of tryptophan was not observed in cell lines from non-ASD patients with intellectual disability, schizophrenia or conditions exhibiting several similarities with syndromal autism except for the behavioral traits. Analysis of a previous small gene expression study found abnormal levels for some genes involved in tryptophan metabolic pathways in 10 patients. CONCLUSIONS: Tryptophan is a precursor of important compounds, such as serotonin, quinolinic acid, and kynurenic acid, which are involved in neurodevelopment and synaptogenesis. In addition, quinolinic acid is the structural precursor of NAD+, a critical energy carrier in mitochondria. Also, the serotonin branch of the tryptophan metabolic pathway generates NADH. Lastly, the levels of quinolinic and kynurenic acid are strongly influenced by the activity of the immune system. Therefore, decreased tryptophan metabolism may alter brain development, neuroimmune activity and mitochondrial function. Our finding of decreased tryptophan metabolism appears to provide a unifying biochemical basis for ASDs and perhaps an initial step in the development of a diagnostic assay for ASDs.

Computational tools and resources for metabolism-related property predictions. 2. Application to prediction of half-life time in human liver microsomes.

BACKGROUND: The most important factor affecting metabolic excretion of compounds from the body is their half-life time. This provides an indication of compound stability of, for example, drug molecules. We report on our efforts to develop QSAR models for metabolic stability of compounds, based on in vitro half-life assay data measured in human liver microsomes. METHOD: A variety of QSAR models generated using different statistical methods and descriptor sets implemented in both open-source and commercial programs (KNIME, GUSAR and StarDrop) were analyzed. The models obtained were compared using four different external validation sets from public and commercial data sources, including two smaller sets of in vivo half-life data in humans. CONCLUSION: In many cases, the accuracy of prediction achieved on one external test set did not correspond to the results achieved with another test set. The most predictive models were used for predicting the metabolic stability of compounds from the open NCI database, the results of which are publicly available on the NCI/CADD Group web server ( http://cactus.nci.nih.gov ).