T-2 toxin, a trichothecene mycotoxin: review of toxicity, metabolism, and analytical methods

This review focuses on the toxicity and metabolism of T-2 toxin and analytical methods used for the determination of T-2 toxin. Among the naturally occurring trichothecenes in food and feed, T-2 toxin is a cytotoxic fungal secondary metabolite produced by various species of Fusarium. Following ingestion, T-2 toxin causes acute and chronic toxicity and induces apoptosis in the immune system and fetal tissues. T-2 toxin is usually metabolized and eliminated after ingestion, yielding more than 20 metabolites. Consequently, there is a possibility of human consumption of animal products contaminated with T-2 toxin and its metabolites. Several methods for the determination of T-2 toxin based on traditional chromatographic, immunoassay, or mass spectroscopy techniques are described. This review will contribute to a better understanding of T-2 toxin exposure in animals and humans and T-2 toxin metabolism, toxicity, and analytical methods, which may be useful in risk assessment and control of T-2 toxin exposure.

Development of a monoclonal antibody-based broad-specificity ELISA for fluoroquinolone antibiotics in foods and molecular modeling studies of cross-reactive compounds

A competitive indirect enzyme-linked immunosorbent assay (ciELISA) using monoclonal antibodies (Mabs) having broad specificity for fluoroquinolone (FQ) antibiotics is described. Four FQs, ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR), and ofloxacin (OFL), were conjugated to bovine serum albumin for immunogens and to ovalbumin for coating antigens. A Mab C4A9H1 raised against the CIP hapten exhibited high cross-reactivity (35-100%) with 12 of 14 FQs and detected these FQs in a ciELISA below their maximum residue levels (MRLs) with good sensitivity at 50% binding inhibition (IC50). The quantitative structure-activity relationship (QSAR) between Mab C4A9H1 and various FQs by comparative molecular field analysis (CoMFA) showed a high predictive ability with a cross-validation q2 value of 0.866. Using a simple purification process and the broad-specificity ciELISA adapted for analysis of FQs in chicken muscle, chicken liver, honey, shrimp, and whole egg samples demonstrated recoveries of 60-93% for CIP, ENR, NOR, OFL, flumequine, and danofloxacin.

Metabolic Detoxification: Mechanism of Insect Resistance to Plant Psoralens

Larvae of the black swallowtail butterfly, Papilio polyxenes Stoll, forage successfully on plants that contain high levels of photosensitizing psoralens. These insects rapidly detoxify psoralens, particularly in the midgut tissue prior to absorption, with the result that appreciable levels of unmetabolized phototoxin do not enter the body circulation where deleterious light-induced interactions with dermal or subdermal tissues would occur.

Induction of cyclin E-cdk2 kinase activity, E2F-dependent transcription and cell growth by Myc are genetically separable events

The c-myc gene has been implicated in three distinct genetic programs regulating cell proliferation: control of cyclin E-cdk2 kinase activity, E2F-dependent transcription and cell growth. We have now used p27(-/-) fibroblasts to dissect these downstream signalling pathways. In these cells, activation of Myc stimulates transcription of E2F target genes, S-phase entry and cell growth without affecting cyclin E-cdk2 kinase activity. Both cyclin D2 and E2F2, potential direct target genes of Myc, are induced in p27(-/-) MycER cells. Ectopic expression of E2F2, but not of cyclin D2, induces S-phase entry, but, in contrast to Myc, does not stimulate cell growth. Our results show that stimulation of cyclin E-cdk2 kinase, of E2F-dependent transcription and of cell growth by Myc can be genetically separated from each other.

Pharmacokinetics of native Escherichia coli asparaginase (Asparaginase medac) and hypersensitivity reactions in ALL-BFM 95 reinduction treatment

Repeated asparaginase treatment has been associated with hypersensitivity reactions against the bacterial macromolecule in a considerable number of patients. Immunological reactions may range from anaphylaxis without impairment of serum asparaginase activity to a very fast decline in enzyme activity without any clinical symptoms. Previous investigations on a limited number of patients have shown high interindividual variability of asparaginase activity time courses and hypersensitivity reactions in about 30% of patients during reinduction treatment. Therefore, monitoring of reinduction treatment was performed prospectively in 76 children with newly diagnosed acute lymphoblastic leukaemia (ALL). According to the ALL-Berlin-Frankfurt-Münster (BFM) 95 protocol, 10 000 U/m2 body surface area of native Escherichia coli asparaginase (Asparaginase medac) was given on d 8, 11, 15 and 18. In 45/76 children, trough and peak activities were determined with every dose, and also on d 4 and d 11 after the last administration. Data on asparaginase activity were not available from the remaining 31 patients, but information with regard to hypersensitivity reactions only was given. Eighteen out of 76 patients (24%) suffered a clinical hypersensitivity reaction; however, no silent inactivation was observed. Activity in the therapeutic range of greater than 100 U/l for at least 14 d was determined in 43 of the 45 patients who were analysed for enzyme activity.

Assignment of anomeric configuration and identification of carbohydrate residues by 13C nmr. 1. Galacto- and glucopyranosides and furanosides

A 13C nmr analysis method is described for the identification of carbohydrate residues in galactosides and glucosides. This method reveals the capability of 13C nmr to distinguish the difference in structural configuration of these carbohydrate residues. Not only can the anomeric configuration be assigned, the furanyl and pyranyl nature of the ring is concomitantly determined. This method is consistent for all reported 13C nmr spectra of nonaromatic galactosides and glucosides.

Portable amperometric immunosensor for histamine detection using Prussian blue-chitosan-gold nanoparticle nanocomposite films

Histamine (HA) is a biogenic amine that can accumulate to high concentration levels in food as a result of microbial activity and can cause toxic effects in consumers. In this work, a portable electrochemical immunosensor capable of detecting HA with high sensitivity and selectivity was developed. Prussian blue-chitosan-gold nanoparticle (PB-CS-AuNP) nanocomposite films with excellent biocompatibility were synthesized and characterized by scanning electron microscopy and energy dispersive X-ray analysis. The PB-CS-AuNP were coated onto a screen-printed electrode by one-step electrodeposition and used to conjugate the HA ovalbumin conjugate (HA-Ag). HA was determined by a competition between the coating HA-Ag and the HRP labeled HA antibody (HRP-HA-Ab). After careful optimization of assay conditions and Box-Behnken analysis, the developed immunosensor showed a linear range from 0.01 to 100μg/mL for HA in fish samples. The average recoveries from spiked samples ranged from 97.25% to 105%. The biosensor also showed good specificity, reproducibility, and stability, indicating its potential application in monitoring HA in a simple and low cost manner.

Plerixafor with and without chemotherapy in poor mobilizers: results from the German compassionate use program

The CXCR4-inhibitor plerixafor mobilizes hematopoietic stem cells amplifying the effects of granulocyte-CSF (G-CSF). Before approval plerixafor was used in a compassionate use program (CUP) for patients who failed a previous mobilization. In the German CUP 60 patients from 23 centers (median age 56.5 years (2-75)) were given 240 μg/kg plerixafor SC 9-11 h before apheresis. A total of 78.3% (47/60) received G-CSF for 4 days before plerixafor administration; 76.6% of those (36/47) yielded at least 2.0 × 10(6) CD34(+) cells/μL. The median cell yield was 3.35 × 10(6) CD34+ cells/kg (0-29.53). Nine patients received plerixafor alone or with G-CSF for less than 4 days mobilizing a median of 3.30 × 10(6) CD34+ cells/kg (1.6-5.6). There was no significant difference between G-CSF application for 4 days and for a shorter period of time (P=0.157). A total of 47 patients received plerixafor plus G-CSF combined with chemotherapy yielding a median of 3.28 × 10(6) CD34+ cells/kg (0-24.79). In all, 40 of 60 patients (66.7%) proceeded to transplantation, and achieved a timely and stable engraftment. Side effects were rare and manageable. In conclusion, mobilization with plerixafor in poor mobilizers is safe and results in a sufficient stem cell harvest in the majority of patients.

HPLC analysis of linear furocoumarins (psoralens) in healthy celery (Apium graveolens)

Four linear furocoumarins (psoralen, bergapten, xanthotoxin, and isopimpinellin) were isolated from three varieties of healthy, commercially grown celery (Apium graveolens). Psoralen has not previously been reported to occur in celery. Combined levels of these photomutagenic and photocarcinogenic furocoumarins measured by normal-phase HPLC did not exceed 1.3 ppm in any of the celery varieties studied.

Dermatitis in grocery workers associated with high natural concentrations of furanocoumarins in celery

A vesicular, peeling rash characteristic of a phytophototoxic dermatitis developed on the hands and arms of 30 of 127 grocery workers. The rash subsequently healed with residual hyperpigmentation. Produce workers had the highest attack rate, 100% (8 of 8, p less than 0.0001). Although contact with celery had the highest relative risk for disease (relative risk, 6.3; 95% confidence interval, 2.6, 19.2) and the strongest dose-response effect, an association with celery alone could not be shown because workers were also exposed to other produce. However, anecdotal evidence also suggested that celery might be involved. The disease-resistant, high-quality brand of celery carried by these stores had higher levels of furanocoumarins, potent photosensitizers and a known cause of phytophotodermatitis, than other brands (p = 0.01). A randomly selected nationwide sample of stores in this chain showed dermatitis in 13 of 17 states and 26% of produce workers surveyed. Plant breeding to produce a more disease-resistant celery stock may lead to increased levels of endogenous furanocoumarins, resulting in phytophotodermatitis in grocery workers.

Psychosocial problems in adults with epilepsy: comparison of findings from four countries

Psychosocial problems in groups of adults with epilepsy from Canada, Finland, the German Democratic Republic, and the United States were evaluated by the Washington Psychosocial Seizure Inventory. A number of similarities in psychosocial concerns were found across the four countries. At the forefront for each group were emotional problems, followed by concerns pertaining to adjustment to the seizures themselves. Where far-reaching governmental support of a financial and vocational nature was lacking, difficulties in these areas were also noted. In all cases, few problems were found in matters pertaining to family relationships and to medical care. Hypotheses to account for differences between the groups were discussed.

In vitro metabolism of a linear furanocoumarin (8-methoxypsoralen, xanthotoxin) by mixed-function oxidases of larvae of black swallowtail butterfly and fall armyworm

Studies were made of the comparative in vitro metabolism of [(14)C]xanthotoxin and [(14)C]aldrin by homogenate preparations of midguts and bodies (carcass minus digestive tract and head) of last-stage larvae of the black swallowtail butterfly (Papilio polyxenes Fabr.) and the fall armyworm [Spodoptera frugiperda (J. E. Smith)]. The two substrates were metabolized by 10,000g supernatant microsomal preparations from both species. Evidence gained through the use of a specific inhibitor and cofactor indicated that mixed-function microsomal oxidases were major factors in the metabolism and that the specific activity of this enzyme system was considerably higher in midgut preparations fromP. polyxenes than in similar preparations fromS. frugiperda. Aldrin was metabolized 3-4 times faster byP. polyxenes, and xanthotoxin 6-6.5 times faster.