Liquid Chromatographic Method for the Quantification of Zearalenone in Baby Food and Animal Feed: Interlaboratory Study

An interlaboratory trial for determination of zearalenone (ZON) in baby food and animal feed was conducted. The study involved 39 participants in 16 European Union member states, as well as Turkey, Uruguay, and China, representing a cross-section of industry, and official food control and research institutes. The method is based on immunoaffinity column cleanup followed by high-performance liquid chromatography using fluorimetry (HPLC-Fl). The test portion of the sample is extracted with methanolwater (75 + 25, v/v). The sample extract is filtered, diluted, and passed over an immunoaffinity column. ZON is eluted with methanol. The separation and determination of ZON is performed by reversed-phase HPLC-Fl with an excitation wavelength of 274 nm and an emission wavelength of 446 nm. Test portions of the samples were spiked at levels of 20 and 30 g/kg ZON in baby food and at levels of 100 and 150 g/kg ZON in animal feed. Mean recoveries from each participant ranged from 78 to 119 with an average value of 92 for baby food and from 51 to 122 with an average value of 74 for animal feed. Based on results for spiked samples (blind duplicates at 2 levels), as well as naturally contaminated samples (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) in baby food ranged from 2.8 to 9.0. For animal feed, this value ranged from 5.7 to 9.5. The relative standard deviation for reproducibility (RSDR) in baby food ranged from 8.2 to 13.3, and for animal feed this value ranged from 15.5 to 21.4. The Horwitz ratio (HorRat) in baby food ranged from 0.3 to 0.4, and for animal feed this value ranged from 0.6 to 0.9. The method showed acceptable within-and between-laboratory precision for each matrix, as required by European legislation.

[The Effect of Intraoperative Screw Monitoring (Root Monitoring) with the INS-1 System (NUVASIVE) on the Radiological Outcome of Dorsal Instrumentation of the Lumbar Spine]

INTRODUCTION

Transpedicular screw fixation of spinal segments has been described for a variety of surgical indications and is a key element in spinal surgery. The aim of transpedicular screw fixation is to achieve maximal stability. Screw malposition should be obviated to avoid neurological complications. There are published methods of applying evoked EMG to control screw position in relation to neural structures. These studies demonstrated that an intact bony pedicle wall acts as an electrical isolator between the screw and spinal nerve root. The aim of our study was to evaluate the impact of intraoperative pedicle screw monitoring on screw positioning.

MATERIAL AND METHODS

We enrolled 22 patients in this prospective randomised study, who underwent spinal instrumentation after being split into two equal groups. In the first group, dorsal instrumentation was supplemented with intraoperative nerve root monitoring using the INS-1-System (NuVasive, San Diego USA). In the second group, screws were inserted without additional pedicle monitoring. All patients underwent monosegmental instrumentation with "free hand implanted" pedicle screws. 44 screws were inserted in each group. The screw position was evaluated postoperatively using CT scans. The position of the screws in relation to the pedicle was measured in three different planes: sagittal, axial and coronal. The accuracy of the screw position was described using the Berlemann classification system. Screw position is classified in three groups: type 1 correct screw position, type 2 encroachment on the inner cortical wall, type 3 pedicle cortical perforation. Screw angulation and secondary operative criteria were also evaluated.

RESULTS

The use of neuromonitoring did not influence the distance between the centre of the screws and the pedicle wall. Distances only depended on the implantation side (right and left) and the height of implantation (caudal or cranial screw). Because of the low number of cases, no conclusion could be reached about the influence of root monitoring on the correct positioning of the screws. There was at least a non-significant trend towards more frequent perforation of the pedicle in the monitor group. In the present study, we showed that root monitoring had a significant effect on the scattering of transversal angles. These were increased compared to the control group. Otherwise, the implantation angle was not shown to depend on the use of neuromonitoring. Neuromonitoring did not influence blood loss or operative time.

DISCUSSION

The data did not permit any conclusion as to whether this technique can minimise the frequency of pedicle screw malposition. The four coronal plane distances did not depend on the use of neuromonitoring. The inclination angle was also unaffected by neuromonitoring. The only parameter for which we found any effect was the transverse angle. The mean values were similar in both groups, but the variances were not equal. The effect of monitoring on the only parameter which could not be evaluated by fluoroscopy is thus rather unfavourable.

Analysis of T-2 and HT-2 toxins in oats and other cereals by means of HPLC with fluorescence detection

Bearing in mind the high toxicity of T-2 and HT-2 toxins which occur in cereals (mainly in oats) EU plans legal limits for these mycotoxins. The occurrence data are insufficient because reliable and sensitive analysis methods are not available.A sensitive HPLC gradient method was developed which is applicable with common HPLC equipment (HPLC with fluorescence detection). After extraction of the toxins from sample matrix with methanol/water the diluted extracts were cleaned-up using immunoaffinity columns and then derivatized with 1-anthroylnitrile/DMAP. The T-2 and HT-2 toxins were separated from peaks of the cereal matrix and derivatization reagent by means of a relatively complex HPLC gradient method. The method was validated for oats, wheat, rye, barley, and maize. The recovery rates were in the range of 70-99%, the precision (RSDR) of 3-8%. The limits of detection of T-2 and HT-2 toxins were 1 μg/kg. A total of 119 samples of cereals and cereal products was analyzed according to the optimized method. The analyses of 54 samples of dehulled oats and of 11 samples of processed oat products from food industry had a contamination frequency of 100%. The contents (sum of T-2 and HT-2 toxins) amounted to 3 to 174 μg/kg for the dehulled oats and to 4 to 48 μg/kg for the processed oat products. 29 samples of maize and maize products had a contamination frequency of 80% (2-106 μg/kg in the sum of T-2 and HT-2 toxins). In the samples of wheat and barley the toxins were detected only occasionally (contents: 1-10 μg/kg), in rye not at all.

[Alumni of medical sciences and their life satisfaction]

OBJECTIVES AND METHODS

Medical doctors are especially burdened with psychological and social aspects of their occupation. These circumstances may lead to low life satisfaction and substance abusing behaviour and burn out symptoms are probable. In this paper we investigate, if alumni of medical sciences show lower life satisfaction compared to their peers. If so, we want to know, which factors influence this result. This survey is based on n = 671 alumni of medicine in seven German universities.

RESULTS

The life satisfaction of alumni differs significantly from the peer sample. Outstanding are the highly significant and powerful differences to the scale "leisure". It was evident by an iterative regression that the variables "extreme input at work", "instrumentality/masculinity", "effort-reward imbalance", "expressivity/femininity" as well as "career self-efficacy-expectation", clarify 43 % of the variance in the group of alumni working by the time of enquiry.

CONCLUSIONS

The results point out, that already alumni of medical science are in the "circle of burn-out". Their life satisfaction is more affected, if the workload is perceived high and the perceived benefits are low. Individual as well as external aspects influence life satisfaction and can be a starting-point for prevention.

Knowledge and attitudes towards preimplantation genetic diagnosis in Germany

BACKGROUND

Preimplantation genetic diagnosis (PGD) is a technique which is often related to emotional debates because of its ethical and social implications. Worldwide there are different forms of legislation; Germany constitutes an interesting case because of the historical background concerning eugenics and dealing with handicapped persons at the time of national socialism. PGD is currently not legal but there are still polarized positions and legalization remains an issue. Studies about the attitudes of the general population towards PGD are rare.

METHODS

Data were collected in a representative survey carried out in November 2003. Subjects were 2110 persons in Germany aged 18-50 years.

RESULTS AND CONCLUSIONS

Respondents had little knowledge about PGD. There were incorrect assumptions about the diagnostic possibilities and a lack of basic genetic knowledge. A tendency towards a general acceptance of PGD for medical indications was found. Non-medical indications such as sex selection were generally not accepted. It could be observed that respondents who already had a notion about PGD overestimated the diagnostic possibilities and would eventually use PGD in the future more than respondents who had never heard about PGD before.

[Not Available]

The fumonisin contents of extrudates and corn flakes were analysed by different analytical methods (AOAC method, ELISA, alcaline hydrolysis of extracts or samples). All methods revealed decrease of fumonisin contents after thermal processing.

[Investigation and evaluation of fumonisin contamination of native and imported cereals]

Cereal varieties cultivated in Germany, such as wheat, rye, grain-maize, barley, and oats were analyzed for fumonisins, including also imported maize from Argentina. In a total of 410 wheat samples and 140 rye samples of two harvesting years (1993, 1994) and in random samples of barley and oats no fumonisins were detected at all. In german grain-maize of 1993, only low fumonisin contents (17-33 ng/g) were detected occasionally. Some grainmaize samples of the 1994 harvest contained significantly higher fumonisin amounts, partly up to the mg/kg-range, which obviously is due to the extremely high temperatures during summer. In some samples of variety tests of the country the fumonisin B1 content amounted up to 4828 ng/g and the total fumonisin content (FB1-FB3) up to 7132 ng/g respectively. In 1994 a total of 317 native grain-maize samples was tested, of it 109 samples of German cultivation and 208 samples from variety tests of different federal states. Maize samples from Baden-Württemberg, which are representative to the maize harvest of this state, had a fumonisin contamination of 14%, the mean value of the contaminated samples amounting to 206 ng/g. Of the imported maize from Argentina, all the investigated 21 samples had a fumonisin content (FB1-FB3) of 14-1106 ng/g, the mean fumonisin content amounting to 175 ng/g.

[Determination of the activities of lipase, lipoxygenase and peroxidase in native and extruded cereal brans]

To avoid fat deterioration in grain products during storage the cereal inherent enzymes lipase, lipoxygenase and peroxidase have to be inactivated. Known methods for the determination of the enzymes activity are tested and their applicability evaluated. Own optimized methods are presented. In laboratory and semiindustrial extrusion tests (laboratory single screw extruder, twin screw extruder, short screw extruder) the degree of enzyme inactivation of wheat bran, rye and maize bran, and oat bran is determined in dependence on the extrusion parameters. The enzymes mentioned already had been inactivated at mild extrusion conditions (temperature < 120 degrees C, moisture 20%, low mechanical stress). Only in brans of high fat content (10-14%) or high moisture (> 25%) minor residual activities of peroxidase and lipase were observed.

[Rheumatic fever. Its current status based on 4 cases]

We report on 4 patients with rheumatic fever hospitalized and investigated in our clinics within a 12 month period between 1990 and 1991. In each case a clinically non-severe sore throat preceded the outbreak of rheumatic fever. In three cases diagnosis was according to the revised Jones criteria. Polyarthritis was the only major symptom in these cases. One patient suffered from monarthritis. Minor symptoms were fever, arthralgia, elevated blood sedimentation rates and elevated values for CRP and for antistreptolysin O. The joint symptoms were treated with nonsteroidal drugs and subsided. One of the patients had a recurrence 9 months after the first attack even though correct secondary prophylaxis with a 4-weekly intramuscular regimen of 1.2 million units of benzathine penicillin was carried out. We discuss some epidemiological aspects and diagnostic difficulties resulting from a changing clinical pattern of the disease, and emphasize the need for streptococcal sore throat treatment and continuous secondary prophylaxis to prevent recurrences.