The acrylamide intake via some common baby food for children in Sweden during their first year of life—an improved method for analysis of acrylamide

The acrylamide levels in breast milk and the main categories of Swedish baby food products, i.e. breast milk substitute (infant formula), gruel, porridge and canned baby food, have been analysed. Furthermore, the acrylamide intake from these products by children up to one year of age has been estimated. Other kind of foods e.g. biscuits, are not included. Because of the expected low concentrations of acrylamide, a new sample extraction method for detection by liquid chromatography, tandem mass spectrometry, was developed and validated. The lower limit of quantification was 0.5 microg kg(-1) for liquid samples and 2 microg kg(-1) for other samples. The average levels found for gruel, porridge and canned baby food, all ready to eat, were 1.4, 26, and 7.8 microg/kg respectively. We found great variations in the acrylamide levels between and in different food categories, <0.5-64 microg/kg. For all breast milk samples except one the acrylamide level was below the limit of quantification (0.5 microg/kg). In three out of eight analysed samples of breast milk substitute, the acrylamide content was verified and possible to quantify. Assuming an acrylamide level of 0.25 microg/kg in breast milk, the mean acrylamide intake during the first six months for children who were exclusively breast-fed was estimated to be 0.04 microg/kg b.w./day. The mean acrylamide intake from breast milk and commercially made baby food during the whole first year varies due to the length of breast-feeding and the choice of baby food. The intake level range was estimated to be 0.04-1.2 microg/kg b.w/day. The mean intake between seven and twelve months of age was estimated to be about 0.5 microg/kg b.w./day.

Dietary intake of acrylamide in Sweden

High levels of acrylamide have been found in foods heated at high temperatures, especially in carbohydrate rich foods. Several kinds of foods (industrially produced) representing different food/product groups available on the Swedish market have been analysed for acrylamide. A considerable variation in levels of acrylamide between single foodstuffs (different brands) within food categories were found, which also applies for levels in different food categories. Using recent Swedish food consumption data the dietary intake of acrylamide for the Swedish adult population was assessed based on foodstuffs with low to high levels of acrylamide (<30-2300 microg/kg), such as processed potato products, bread, breakfast cereals, biscuits, cookies, snacks and coffee. The estimated dietary intake of acrylamide per person (total population) given as the 5th, 50th and 95th percentile were 9.1, 27 and 62 microg/day respectively, from those food/product groups (mean 31 microg/day). No acrylamide was found in many other foodstuffs analysed and those were therefore not included in the dietary intake assessment of acrylamide. However, an additional minor contribution of a few microg/day of acrylamide from foods/products like poultry, meat, fish, cocoa powder and chocolates cannot be excluded. An average daily intake of 35 microg corresponds to 0.5 microg per kg body weight and day (body weight 70 kg). Risk assessments of acrylamide, made by US EPA and WHO, imply that this dietary intake of acrylamide could be associated with potential health risks.

Efficient and sensitive screening and confirmation of residues of selected polyether ionophore antibiotics in liver and eggs by liquid chromatography-electrospray tandem mass spectrometry

A method using liquid chromatography tandem mass spectrometry (LC-MS-MS) with electrospray (ES) for the determination of traces of narasin, monensin and salinomycin in chicken liver and eggs was developed, validated and used for routine surveillance. The essence of this paper is to demonstrate that one single method can serve very well for two entirely different purposes, i.e., screening and confirmation. Highly reliable confirmation of the identity at low concentrations was demonstrated when residues of narasin were detected and quantified (0.2 to 11 ng g(-1)) in 50% of the Swedish eggs analysed in 1999. Four daughter ions were detected with ion ratios meeting suggested confirmation criteria for the European Union, even at 0.2 ng g(-1). The method was found to be highly cost-effective since both screening and confirmation of 98 liver samples were performed in only two analytical runs (the Swedish national surveillance scheme of 1999, report level 5 ng g(-1)). The high performance of the method for the different applications was possible due to a combination of the power of ES-LC-MS-MS, a procedure involving screening of pooled samples, and method optimisation of the work-up (automated solid phase extraction), LC and MS parameters. Validation data for narasin (0.5 to 20 ng g(-1)) in eggs are presented (accuracy 94 to 108%, relative standard deviation 4 to 10%, limit of detection 0.026 ng g(-1)). The time for an LC-MS-MS run was 4 min, corresponding to 48 s per sample in a pool.

Automated extraction of acetylgestagens from kidney fat by matrix solid phase dispersion

A new extraction method for the acetylgestagens medroxyprogesterone acetate (MPA), chloromadinone acetate and megestrol acetate, from kidney fat, has been developed. The method is a combination of matrix solid phase dispersion and solid phase extraction and is simpler and safer than previous methods, especially as it can be automated. The recovery was estimated as 59 +/- 5% (mean +/- standard deviation) for MPA. For screening purposes detection can be achieved using a commercially available enzyme immunoassay kit giving detection limits in the range of 1.0-2.0 ng g-1.

A human serine endopeptidase, purified with respect to activity against a peptide with phosphoserine in the P1' position, is apparently identical with prolyl endopeptidase

The present work describes the detection, purification, and characterization of a serine endopeptidase with preference for a phosphoserine in the P1' position of the substrate. During probing for the enzyme in crude extracts, as well as during its 64,000-fold purification, 32P-labeled guanidovaleryl-Arg-Ala-Ser(P)-isobutyl amide (I) was used to measure the cleavage of the Ala-Ser(P) bond. With this substrate, kcat was 1.7 s-1 and Km was 30 microM at the pH optimum, 7.5. The enzyme was classified as a serine peptidase from its reaction with a set of inhibitors, among which diisopropyl fluorophosphate was effective at low (20 microM) concentration. The endopeptidase showed an Mr of 74,000 under native as well as denaturing and reducing conditions, indicating that the native enzyme consists of only one major polypeptide chain. The molecular size and inhibition profile suggested identity of this enzyme with prolyl endopeptidase (EC 3.4.21.26). This was supported by its activity against specific substrates, such as succinyl-Gly-Pro-Leu-Pro-7-amido-4-methylcoumarin (kcat = 7.2 s-1 and Km = 290 microM), and by the inhibition of the latter activity by I. Compared with the cleavage of 100 microM I, Gly-Val-Leu-Arg-Arg-Ala-Ser-Val-Ala-Gln-Leu, after phosphorylation by cAMP-dependent protein kinase, was cleaved at the Ala-Ser(P) bond at a relative rate of 0.43, while cleavage of the Ala-Ser bond of the unphosphorylated undecapeptide was undetectable, i.e. less than 0.03. The pentapeptide Arg-Arg-Pro-Ser-Val was rapidly cleaved at the Pro-Ser bond (relative rate, 2.2). Still, the cleavage of the Pro-Ser(P) bond of the corresponding phosphorylated pentapeptide was even higher (relative rate, 4.0). These data suggest that phosphorylation of a serine residue in the P1' position of at least a few substrates of prolyl endopeptidase will increase the rate of their cleavage.

Monoclonal antibodies to conserved regions of the major core protein (gag24) of HIV-1 and HIV-2

Five mouse monoclonal antibodies were raised against a recombinant protein comprising the complete sequence of gag24 protein from HTLV-IIIB. All monoclonal antibodies recognized the native protein in enzyme-linked immunosorbant assay (ELISA) and Western blots. All monoclonal antibodies also cross-reacted with an human immunodeficiency virus type 2 (HIV-2) strain in western blots, whereas only one antibody detected HIV-2 p25 in ELISA. By using synthetic peptides, cross-reacting epitopes were mapped and three regions were defined. The conserved immunogenic sites were located in the carboxyterminal region of the protein. Inhibition experiments with human sera showed that this region is also immunogenic in humans.

Surgical treatment of post abortum endometriosis of the bladder and postoperative bladder function

During the years 1953-1967, 17 women with endometriosis of the urinary bladder were treated with extirpation of the endometrial tissue, including partial or total resection of the trigone. In all cases the endometriosis had followed vaginal hysterotomy for legal abortion. Urethrocystoscopy was performed and the residual urine and bladder capacity were measured in all the patients one month and one year after the bladder operation. At follow-up in 1978 only 4 of the 17 women were available for urodynamic studies. Combined urethrocystometry, recording of the urethral pressure profile and measurement of the maximal urethral pressure in supine and standing positions were performed in these four patients, using the technique of Ulmsten et al. In all cases in the series, including those with trigone extirpation, all the tested parameters were normal. The writers therefore conclude that even total trigone resection can be done without disturbance to the bladder function.