A simple HPLC method for the isolation and quantification of the allergens tuliposide A and tulipalin A in Alstroemena

A practical, rapid, reliable and sensitive method for the isolation and determination of the allergens tuliposide A and α-methylene-γ-butyrolactone (tulipalin A), by reversed-phase high-performance liquid chromatography (RP-HPLC), has been developed in order to select Alstroemeria species for breeding purposes. From the aqueous extracts of flowers, stems and leaves, of several Alstroemeria species, the contents of 6-tuliposide A and tulipalin A were determined by isocratic RP-HPLC, using distilled water as mobile phase. The compounds were detected by an UV detector at 208 nm. Differences in 6–tuliposide A and tulipalin A content were found among the species investigated, with the highest concentrations in stems and flowers. The absence of other tuliposides (e.g., 1-tuliposide A, 1- and 6-tuliposide B) in extracts was proven by TLC, RP-HPLC, ¹H- and ¹³C-NMR. 6-Tuliposide A and tulipalin A were identified by ¹H- and ¹³C-NMR and comparison with authentic material, respectively. With this HPLC method, it is possible to investigate a large number of plants for their contents of tuliposide A and tulipalin A, within a minimum of time, and to isolate them directly from aqueous extracts.     

Characteristics of recovery of adrenocortical function after treatment for Cushing's syndrome due to pituitary or adrenal adenomas

OBJECTIVE: Surgical cure of Cushing's syndrome (CS) is followed by adrenocortical insufficiency, which may be long-lasting. The aim was to elucidate recovery of adrenocortical function, defined as a normal cortisol response to ACTH stimulation, and the relation to ACTH in patients cured for CS due to pituitary Cushing's disease (CD) or adrenal (AA) adenomas. DESIGN: A retrospective study including 32 patients considered surgically cured for CS (18 CD, 14 AA). RESULTS: Twelve (67%) patients with CD recovered within median 24 months (range 7 months-4(1)/(2) years) whereas six did not recover within 3-12 years. Plasma ACTH (p-ACTH) at time of recovery was not different from p-ACTH in patients not recovering (P = 0.9). Eleven (79%) patients with AA recovered within 24 months (10 months-4 years) whereas three did not recover within 4-10 years. p-ACTH at time of recovery was higher compared to patients not recovering (P < 0.04). No differences were observed comparing CD and AA patients concerning preoperative 24-h urinary free cortisol (UFC) excretion, postoperative unstimulated s-cortisol or recovery time. By contrast, p-ACTH measured at time of recovery was higher in AA compared to CD (median 12.3 vs. 4.6 pmol/l) (P < 0.001), whereas plasma dehydroepiandrosterone sulfate (p-DHEAS) was lower in AA compared to CD (median 300 vs. 1500 nmol/l) (P = 0.02). CONCLUSION: Recovery of secondary adrenal insufficiency is a slow process in both CD and AA. ACTH measured at time of recovery was significantly higher and DHEAS significantly lower in patients with AA compared to CD, which may suggest different mechanisms of the recovery process and different set points in the glucocorticoid feedback inhibition of ACTH secretion.     

Excretion pattern of branched-chain amino acid metabolites during the course of acute infections in a patient with methylmalonic acidaemia

A 1-year-old boy with a typical B₁₂-responsive form of methylmalonic acidaemia was hospitalized twice due to acute bacterial infections. On both occasions, the child was lethargic with a severe ketoacidosis on admission. Intensive therapy with protein restriction, intravenous administration of electrolytes and antibiotics was effective within 4 days on both occasions. The urinary excretion of organic acids showed the same pattern on both occasions. There were rising excretion concentrations, reaching a peak value within the first 24-hour period, for the following compounds: 3-hydroxybutyric acid, 3-hydroxypropionic acid, 3-hydroxyisobutyric acid and 3-hydroxyisovaleric acid. Excretion concentrations of the following rose for 48 h: isobutyric acid, 2-methylbutyric acid, isovaleric acid, lactic acid and the 2-oxo-acids. There was no increase until 12–24 h after the onset of severe illness in the excretion of propionic acid and methylmalonic acid. Propionic acid excretion was maximal at about 48 h, while peak excretion of methylmalonic acid was delayed until about 72 h after the onset of severe illness; at this time there was clinical improvement. The biochemical implications of this excretion pattern are discussed. This work has been supported by a grant from the Danish Medical Research Council.