Vitamin D Toxicity from an Unusual and Unexpected Source: A Report of 2 Cases.

INTRODUCTION: Hypervitaminosis D is a relatively uncommon etiology of hypercalcemia. Toxicity is usually caused by very high doses, mostly secondary to erroneous prescription or administration of vitamin D, and less commonly, contaminated foods or manufacturing errors of vitamin D-containing supplements. CASE PRESENTATION: A 16-year-old male, previously healthy, presented with 2-week history of nonspecific symptoms (fatigue, gastrointestinal complaints). Investigations showed acute kidney injury and hypercalcemia (total calcium 3.81 mmol/L). Further diagnostic workup revealed markedly elevated 25-hydroxyvitamin D levels (1,910 nmol/L). He denied taking any vitamin D supplements; however, he reported consumption of creatine and protein supplements. Mass spectrometry analysis of the creatine supplement estimated a vitamin D content of 425,000 IU per serving (100 times the upper tolerable daily dose). A few months later, another previously healthy adolescent presented with severe hypercalcemia and acute kidney injury secondary to hypervitaminosis D. He was also using a creatine supplement, from the same manufacturer brand and lot. Both patients were treated with intravenous hydration, calcitonin, and pamidronate. They maintained normocalcemia after their initial presentation but required low-calcium diets and laboratory testing for months after this exposure. DISCUSSION/CONCLUSION: We present 2 cases of hypervitaminosis D caused by a manufacturing error of a natural health product which did not claim to contain vitamin D. The use of dietary supplements is highly prevalent; this should be incorporated while taking medical history, and considered a potential source of toxicity when an alternative source cannot be found, regardless of the product label.

Impact of Antioxidant Feed and Growth Manipulation on the Redox Regulation of Atlantic Salmon Smolts.

Accumulating evidence indicates a close relationship between oxidative stress and growth rate in fish. However, the underlying mechanisms of this relationship remain unclear. This study evaluated the combined effect of dietary antioxidants and growth hormone (GH) on the liver and the muscle redox status of Atlantic salmon. There were two sequential experimental phases (EP) termed EP1 and EP2, each lasting for 6 weeks. In EP1, Atlantic salmon were fed either low-(L, 230 mg/kg ascorbic acid (Asc), 120 mg/kg α-tocopherol (α-TOH)), or high-(H, 380 mg/kg Asc, 210 mg/kg α-TOH)vitamin diets. The vitamins were supplemented as stable forms and the feeding was continued in EP2. In EP2, half of the fish were implanted with 3 µL per g body weight of recombinant bovine GH (Posilac®, 1 mg rbGH g BW-1) suspended in sesame oil, while the other half were held in different tanks and sham-implanted with similar volumes of the sesame oil vehicle. Here, we show that increasing high levels of vitamin C and E (diet H) increased their content in muscle and liver during EP1. GH implantation decreased vitamin C and E levels in both liver and muscle but increased malondialdehyde (MDA) levels only in the liver. GH also affected many genes and pathways of antioxidant enzymes and the redox balance. Among the most consistent were the upregulation of genes coding for the NADPH oxidase family (NOXs) and downregulation of the oxidative stress response transcription factor, nuclear factor-erythroid 2-related factor 2 (nrf2), and its downstream target genes in the liver. We verified that GH increases the growth rate until the end of the trail and induces an oxidative effect in the liver and muscle of Atlantic salmon. Dietary antioxidants do lower oxidative stress but have no effect on the growth rate. The present study is intended as a starting point to understand the potential interactions between growth and redox signaling in fish.

Multicenter data to improve health for pediatric renal transplant recipients in North America: Complementary approaches of NAPRTCS and IROC.

Kidney transplantation increases life expectancy and improves quality of life for children with end-stage kidney disease, yet sequelae of transplantation and treatment make it difficult for transplant recipients to enjoy health and quality of life similar to their healthy peers. The NAPRTCS network was among the first to use multicenter data to inform improvements in care and outcomes for children with a kidney transplant through observational research. Now, with new technologies and unprecedented access to data, it is possible to create learning health systems as envisioned by the US National Academy of Sciences to seamlessly integrate research and continuous improvement of clinical care. In this review, we present two pre-eminent North American networks focused on using multicenter data to drive improved care and outcomes for children with a kidney transplant. Whereas, for the past 30 years NAPRTCS has focused on discovery of best practices through observational research and clinical trials, the Improving Renal Outcomes Collaborative, established in 2016, engages patients, families, clinicians, and researchers in redesigning the healthcare delivery system to enable practice change and continuous improvement of health outcomes. We discuss the history and past contributions of these networks, as well as current activities, barriers, and potential future solutions to more fully realize the vision of a true learning health system for pediatric kidney transplant recipients.

Acute Shoshin beriberi syndrome immediately post-kidney transplant with rapid recovery after thiamine administration.

Pediatric kidney transplant surgery is usually well tolerated, despite suboptimal physical conditioning that may result from uremia and nutritional deficiencies that accompany end-stage kidney failure. Nutritional supplementation is used to overcome such deficiencies, especially for children needing dialysis. Thiamine, a water-soluble vitamin also known as vitamin B1, is a critical cofactor in energy metabolism and may be competitively inhibited by the antimetabolite oxythiamine, a uremic toxin that accumulates in kidney failure. We report a case of a thiamine deficiency syndrome leading to overwhelming cardiac dysfunction, metabolic instability, and hemodynamic compromise, after otherwise uneventful kidney transplant surgery. Prior to transplant, this 14-year-old boy was treated with peritoneal dialysis and received thiamine supplementation. Post-transplant, the patient first developed hyperglycemia, then lactic acidosis, and subsequently hemodynamic instability despite escalating treatment with volume resuscitation and inotropic medication. He made a rapid and complete recovery after administration of IV thiamine. This is the first reported case of Shoshin beriberi syndrome in a pediatric kidney transplant recipient. Inadequate dialysis may have been a key factor, with toxin accumulation and thiamine transporter downregulation contributing to his status. Functional thiamine deficiency should be considered as a potential treatable cause of early post-transplant hemodynamic instability.

A Holistic Approach to Risk for Early Kidney Injury in Indigenous Youth With Type 2 Diabetes: A Proof of Concept Paper From the iCARE Cohort.

BACKGROUND: Indigenous youth with type 2 diabetes (T2D) are disproportionately affected by early onset albuminuria and are at high risk of kidney failure in early adulthood. Traditional biological approaches have failed to fully explain the renal morbidity seen in this population. The improving renal Complications in Adolescents with type 2 diabetes through REsearch cohort (iCARE) study was therefore designed in collaboration with patients, to more holistically evaluate risk factors for renal morbidity. We hypothesize that both biological factors and mental health influence renal outcomes, mediated via inflammatory pathways. OBJECTIVE: The objective of this study was to evaluate the iCARE analytic framework which evaluates relationships between biological factors, mental health, inflammation, and albuminuria utilizing a structural equation modeling (SEM) approach. METHODS: The first 187 youth with T2D (10-25 years) from the Manitoba iCARE cohort are presented here to evaluate our theoretical and analytic framework. An SEM was chosen to evaluate the statistical significance of proposed associations. The primary outcome was a nonorthostatic urine albumin:creatinine ratio ≥2 mg/mmol. Main exposures (ie, latent factors) included psychological health (distress, perceived stress, positive mental health and resilience), hypertension (24 hour monitored), and inflammatory markers (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], fibrinogen). Hemoglobin A1c (HbA1c) and duration of diabetes were covariates. RESULTS: Within the initial cohort (median age = 15 years, duration of diabetes = 2.3 years, 66.8% female), 30.5% (n = 57) had nonorthostatic albuminuria (ALB), and the majority of ALB was persistent (confirmed in 2/3 samples over a 6-month period; n = 47). Youth with ALB had higher HbA1c (10.9% vs 8.9%; P < .001), more hypertension (94.2% vs 78·2%; P = .02), longer duration of diabetes (3.4 vs 2.4 years; P = .01), higher distress (9.2 vs 7.3; P = .02), and stress scores (28.7 vs 26.4; P = .03), and elevated inflammatory markers (CRP: 4.9 vs 3.1 mg/L; P = .01, fibrinogen: 3.7 vs 3.3 µmol/L; P = .02). Factors directly associated with ALB in the SEM were hypertension (0.28; P = .001), inflammation (0.41; P < .001), and HbA1c (0.50; P < .001). Psychological health was independently associated with inflammation (-0.20; P < .001) but not directly associated with ALB. CONCLUSIONS: Albuminuria is highly prevalent in Indigenous youth with T2D. This preliminary analysis supports a theoretical framework linking glycemic control, hypertension, and inflammation, potentially mediated by psychological factors with albuminuria. These data support the need for more holistic models of evaluation and care for youth with T2D and multifactorial interventions to prevent complications.

CONTEXTE: L'albuminurie à déclenchement précoce affecte de façon disproportionnelle les jeunes autochtones atteints de diabète de type 2 (T2D). Ces derniers présentent également un risque plus élevé d'insuffisance rénale au début de l'âge adulte. Les approches biologiques traditionnelles n'ont pas été en mesure d'expliquer entièrement la morbidité rénale observée dans cette population. Ainsi, l'étude de cohorte iCARE (improving renal Complications in Adolescents with type 2 diabetes through REsearch) a été conçue en collaboration avec les patients pour évaluer de façon plus globale les facteurs de risque de morbidité rénale. Nous posons l'hypothèse que les résultats rénaux sont influencés à la fois par la santé mentale du patient et des facteurs biologiques, avec médiation par les voies inflammatoires. OBJECTIF: Évaluer le cadre d'analyse iCARE qui examine les liens entre les facteurs biologiques, la santé mentale, l'inflammation et l'albuminurie à l'aide d'une approche de modélisation par équation structurelle (SEM). MÉTHODOLOGIE: Les 187 premiers jeunes autochtones atteints de T2D (âgés de 10 à 25 ans) de la cohorte manitobaine iCARE sont présentés ici pour évaluer notre cadre théorique et analytique. Une SEM a été choisie pour évaluer la pertinence statistique des associations suggérées. Le résultat principal était un rapport urinaire albumine/créatinine non orthostatique d'au moins 2 mg/mmol. Les principaux risques (c.-à-d. les facteurs latents) comprenaient la santé mentale (détresse, stress perçu, bien-être mental et résilience), l'hypertension (suivie sur 24 heures) et les taux de marqueurs inflammatoires (CRP, ESR, fibrinogène). L'hémoglobine A1c (HbA1c) et la période depuis l'apparition du diabète constituaient les covariables. RÉSULTATS: Les sujets retenus (66,8 % de sujets féminins) avaient 15 ans d'âge médian et étaient diabétiques depuis 2,3 ans. Dans cette cohorte, 30,5 % (n = 57) présentaient une albuminurie non orthostatique (confirmée dans 2/3 des échantillons sur une période de six mois) qui s'est avérée persistante dans la majorité des cas (n = 47). Les jeunes souffrant d'albuminurie présentaient des taux plus élevés d'HbA1c (10,9 c. 8,9 %; P < ,001), davantage d'hypertension (94,2 c. 78,2 %; P = ,02), étaient diabétiques depuis plus longtemps (3,4 c. 2,4 ans; P = ,01), vivaient davantage de détresse (9,2 c. 7,3; P = ,02), et présentaient des scores pour le stress (28,7 c. 26,4; P = ,03) et des taux de marqueurs inflammatoires plus élevés (CRP : 4,9 c. 3,1 mg/L; P = ,01, fibrinogène : 3,7 c. 3,3 µmol/L; P = ,02). Avec la SEM, les facteurs directement associés à l'albuminurie étaient l'hypertension (0,28; P = ,001), l'inflammation (0,41; P < ,001) et l'HbA1c (0,50; P < ,001). La santé psychologique a été associée à l'inflammation de manière indépendante (−0,20; P < ,001), mais n'a pas été directement associée à l'albuminurie. CONCLUSION: L'albuminurie est très répandue chez les jeunes autochtones atteints de T2D. Cette analyze préliminaire vient étayer un cadre théorique qui établit un lien entre l'albuminurie et le contrôle de la glycémie, l'hypertension et l'inflammation; lien potentiellement médié par des facteurs psychologiques. Ces données appuient la nécessité d'avoir des modèles plus holistiques d'évaluation et de prise en charge des jeunes atteints de T2D, et des interventions multifactorielles visant à prévenir les complications.

Dietary linoleic acid and α-linolenic acid differentially affect renal oxylipins and phospholipid fatty acids in diet-induced obese rats.

Analysis of oxylipins derived from fatty acids may provide insight into the biological effects of dietary lipids beyond their effects on tissue fatty acid profiles. We have previously observed that diets with higher amounts of α-linolenic acid (ALA; 18:3n3) are associated with reduced obesity-related glomerulopathy (ORG). Therefore, to examine the renal oxylipin profile, the effects of dietary linoleic acid (LA; 18:2n6) and ALA on oxylipins and renal phospholipid fatty acid composition, and the relationship between oxylipins and ORG, diet-induced obese rats displaying ORG were fed 8 different diets for 8 wk as follows (oil/oil = combination of two oils) [shown as ALA/LA (in g) per 100 g oil]: canola/flax (20/18), canola (8/18), soy (9/53), high-oleic canola/canola (5/16), high-oleic canola (2/15), lard/soy (1/8), and safflower (0.2/73). Targeted lipidomic analysis by HPLC-tandem mass spectrometry revealed that LA and ALA oxylipins comprised 60% of the total renal oxylipin profile examined. Of the >60 oxylipins screened, only those derived either directly or indirectly from ALA were associated with less glomerulomegaly, indicative of reduced ORG progression. Both the amount and ratio of dietary LA and ALA influenced renal polyunsaturated fatty acids (PUFAs); in contrast, only fatty acid amount altered oxylipins derived from these fatty acids, but there was no apparent competition by LA or ALA on their formation. Dietary LA incorporation into renal phospholipids was higher than for ALA, but ALA oxylipin:ALA ratios were higher than the analogous LA ratios for select lipoxygenase reactions. This indicates that the effect of dietary ALA on renal oxylipins exceeded what was reflected in renal PUFA composition. In conclusion, dietary LA and ALA have differential effects on renal oxylipins and PUFAs, and ALA-derived oxylipins are associated with renoprotection in this model of ORG.

The Atlantic salmon protein tyrosine kinase Tyk2: molecular cloning, modulation of expression and function.

Tyk2, a member of the Janus Kinase (JAK) family of protein tyrosine kinases, is required for interferon-α/ß binding and signaling in higher vertebrates. Currently, little is known about the role of the different JAKs in signaling responses to interferon (IFN) in lower vertebrates including fish. In this paper we report the identification and characterization of Atlantic salmon (Salmo salar) Tyk2. Four cDNA sequences, two containing an open reading frame encoding full-length Tyk protein and two with an up-stream in frame stop codon, were identified. The deduced amino acid sequences of the salmon full-length Tyk2 proteins showed highest identity with Tyk2 from other species and their transcripts were ubiquitously expressed. Like in mammals the presented data suggests that salmon Tyk2 is auto-phosporylated when ectopically expressed in cells. In our experiments, full-length salmon Tyk2 overexpressed in CHSE-cells phosphorylated itself, while both a kinase-deficient mutant and the truncated Tyk2 (Tyk-short) were inactive. Interestingly, the overexpression of full length Tyk2 was shown to up-regulate the transcript levels of the IFN induced gene Mx, thus indicating the involvement of salmon Tyk2 in the salmon IFN I pathway.

Following autophagy step by step.

Autophagy is an evolutionarily conserved lysosomal degradation route for soluble components of the cytosol and organelles. There is great interest in identifying compounds that modulate autophagy because they may have applications in the treatment of major diseases including cancer and neurodegenerative disease. Hundeshagen and colleagues describe this month in BMC Biology a screening assay based on flow cytometry that makes it possible to track distinct steps in the autophagic process and thereby identify novel modulators of autophagy.

Pinealectomy induces malformation of the spine and reduces the mechanical strength of the vertebrae in Atlantic salmon, Salmo salar.

This study describes the long-term effects of surgical ablation of the pineal gland on the spine of 3-yr-old Atlantic salmon (Salmo salar L.) with a mean weight of 3.2 kg. Radiographic examinations showed that 82% of the pinealectomized fish developed marked lateral (scoliosis) and dorso-ventral spinal curvatures. The proportions of the individual vertebral bodies and their mechanical properties were also altered. The stiffness, yield limit and resilience of the vertebral bodies, as measured by compression in the cranio-caudal direction, were significantly lower in the pinealectomized than in the sham-pinealectomized group. Calcium, phosphorous and total mineral content of the vertebral bodies were also significantly lower in the pinealectomized fish, while these parameters were similar in scales in the two groups. Alterations of the spinal curve accompanied by changes in the proportions, mechanical strength and mineral content of the vertebral bodies of the pinealectomized salmon indicate that melatonin has several functions related to vertebral bone growth. As the lesions found in salmon are similar to the spinal malformations observed in avian species and mammals after pinealectomy, this study strengthens the hypothesis of a phylogenetically conserved function of the pineal gland related to skeletal development.