Dried Blood Spot Sampling for Monitoring Children With Immune-Mediated Glomerulopathies and After Kidney Transplantation.

Introduction: Monitoring kidney function and immunosuppressant levels in children post-kidney transplantation or those with glomerulopathies is challenging due to frequent venipunctures and clinic visits. Capillary dried blood spot sampling (DBS) offers a potential alternative.

Methods: In this prospective single-center study, 89 children (38% female and 62% male) requiring therapeutic drug monitoring (TDM) and kidney function assessment were enrolled.

Tissue Specific Distribution and Activation of Toxins in Horses Suffering from Atypical Myopathy.

Equine atypical myopathy is caused by hypoglycin A (HGA) and methylenecyclopropylglycine (MCPrG), the known protoxins of sycamore maple (). Various tissues from five atypical myopathy cases were analyzed but only HGA was found. Whether deamination of MCPrG has already occurred in the intestine as the first stage of metabolization has not been investigated.

Severe Inhibition of Long-Chain Acyl-CoA Enoylhydratase (EC 4.2.1.74) in a Newborn Foal Suffering From Atypical Myopathy.

In horses, congenital defects of energy production from long-chain fatty acids have not been described so far. In contrast, inhibition of fatty acid degradation caused by the toxins hypoglycin A and methylenecyclopropylglycine from various maple species are observed frequently. These non-proteinogenic aminoacids are passed on placentally to fetuses or with collostrum or milk to newborn foals.

Study on the Metabolic Effects of Repeated Consumption of Canned Ackee.

Ackee fruits (), an important food source in some tropical countries, can be the cause of serious poisoning. Ackees contain hypoglycin A and methylenecyclopropylglycine. Experiments were undertaken by a volunteer to elucidate the metabolic details of poisoning.

A new method for quantifying causative and diagnostic markers of methylenecyclopropylglycine poisoning.

Background: Up to now quantification of hypoglycin A in serum and urine in the range of nmols to μmols per liter plus the measurement of accumulated acyl conjugates have been used for the diagnosis of poisoning by fruits or seeds of in humans and animals. A second poison, methylenecyclopropylglycine, however, is known to occur in this material. The objective of our study was to develop and evaluate a method for the quantification of this compound suitable for test materials obtained from animals and man.

Quantification of Methylenecyclopropyl Compounds and Acyl Conjugates by UPLC-MS/MS in the Study of the Biochemical Effects of the Ingestion of Canned Ackee (Blighia sapida) and Lychee (Litchi chinensis).

Consumption of ackee (Blighia sapida) and lychee (Litchi chinensis) fruit has led to severe poisoning. Considering their expanded agricultural production, toxicological evaluation has become important. Therefore, the biochemical effects of eating 1 g/kg canned ackee, containing 99.

Quantification of hypoglycin A as butyl ester.

L-α-amino-methylenecyclopropyl propionic acid (Hypoglycin A, HGA) has been found to be the toxic compound in fruits of the Sapindaceae family causing acute intoxication when ingested as food or feed. Clinical symptoms are consistent with acquired multiple acyl-CoA dehydrogenase deficiency (MADD). Ultra performance liquid chromatography-tandem mass spectrometry was used to measure HGA after butylation.

Towards newborn screening for ornithine transcarbamylase deficiency: fast non-chromatographic orotic acid quantification from dried blood spots by tandem mass spectrometry.

Background: Orotic acid (OA) is the key parameter in the detection of ornithine transcarbamylase deficiency (OTC-D). Inclusion of OA into newborn screening compatibility with existing analytical procedures is necessary.

Methods: OA was eluted from dried blood spots with methanol containing deuterated [1,3-(15)N2] OA as internal standard.

UPLC-MS/MS analysis of C5-acylcarnitines in dried blood spots.

Background: Metabolic screening including newborn screening requires further differentiation of C5-acylcarnitines in order to separate different metabolic disorders and to detect interferents like pivalic acid originating from antibiotics.

Methods: For individual quantification of C5-acylcarnitine isoforms in dried blood spots we combined UPLC using a C18 column and gradient elution with tandem mass spectrometry in ESI+mode.

Results: Results were linear, coefficients of determination (R(2))>0.

Rapid steroid hormone quantification for congenital adrenal hyperplasia (CAH) in dried blood spots using UPLC liquid chromatography-tandem mass spectrometry.

Newborn screening for congenital adrenal hyperplasia (CAH) is usually done by quantifying 17α-hydroxyprogesterone using immunoassay. However, this test produces high rates of false positive results caused by cross reacting steroids. Therefore we have developed a selective and specific method with a short run time (1.

Fast and direct quantification of adrenal steroids by tandem mass spectrometry in serum and dried blood spots.

We present a fast and reproducible method for steroid analysis (corticosterone, deoxycorticosterone, progesterone, 17alpha-hydroxyprogesterone, 11-deoxycortisol, 21-deoxycortisol, androstenedione, testosterone, dihydrotestosterone and cortisol) in small volumes of serum and in dried blood spot samples by LC-MS/MS. No derivatisation was needed. LC separation was achieved by using an Atlantis C18 column and water-methanol-formic acid gradient as a mobile phase and a flow rate of 250 microL/min over a run time of 6 min.