Determination of Chlormequat and Mepiquat in Foods by Liquid Chromatography/Mass Spectrometry or Liquid Chromatography/Tandem Mass Spectrometry: Interlaboratory Study

Interlaboratory validation studies have been performed on 2 methods for the determination of chlormequat (CLQ) and mepiquat (MPQ). Both methods used identical extraction procedures and stable isotope internal standardization but differed in the use of liquid chromatography/mass spectrometry (LC/MS) or LC/tandem mass spectrometry (LC/MS/MS) for the determination, the amount of internal standard used, and the expected limit of detection. After addition of deuterated internal standards, CLQ and MPQ were extracted with methanol–water and determined by LC/MS or LC/MS/MS with positive electrospray ionization. Eight European laboratories participated in the LC/MS method study, analyzing mushroom, pear, wheat flour, and fruit puree with residues of CLQ in the range 0.040–1.19 mg/kg and of MPQ in the range 0.041–0.39 mg/kg. For CLQ, the Horwitz ratio (HoRat) values for individual test materials/levels were in the range 0.85–1.13 with amean of 1.00, showing good method performance. For MPQ, the Ho values for mushroom, pear (both levels), and wheat flour were in the range 0.83–0.94, again indicating good method performance. For the determination of MPQ in infant food (fruit puree) at 0.041 mg/kg, the Ho was 1.7 when a value of 0 reported by one participant was excluded. In the LC/MS/MS study, in which 11 laboratories participated, a separate sample set was analyzed with residues of CLQ in the range 0.007–1.03 mg/kg and of MPQ in the range 0.008–0.72 mg/kg. Ho values for CLQ were in the range 0.27–1.36 and for MPQ in the range 0.51–2.10, all corresponding to acceptable method performance.

Stability of the non-ionic surfactant polysorbate 80 investigated by HPLC-MS and charged aerosol detector

An analytical method using HPLC coupled with a charged aerosol detector (CAD) and a mass selective detector (MSD) was developed to characterize the non-ionic surfactant polysorbate 80 (PS 80). The molecular structure and heterogeneous composition due to isomers and various lengths of PEG-chains make it difficult to develop sensitive and specific analytical methods. Hence, there is only limited knowledge about the stability and purity of this compound. Polysorbate 80 does not possess any chromophore, thus UV detection is not applicable. Therefore, CAD and MSD have been used for determination. The aim of this study was to characterize polysorbate 80 and to examine its stability at pH 1.0 and 37 degrees C simulating harsh gastric conditions. It was shown that this surfactant is liable to degradation under these conditions. Within 8 h monoesters of PS 80 were hydrolyzed to an extent of 9.5% (+/- 3.0%), whereas incubation in water did not result in any detectable degradation. Furthermore, we demonstrated that HPLC-MS is a suitable technique to investigate ethoxylated compounds like polysorbates.

Effects of three fungicides alone and in combination on glutathione S-transferase activity (GST) and cytochrome P-450 (CYP 1A1) in the liver and gill of brown trout (Salmo trutta)

In order to evaluate the gill glutathione S-transferase (GST) activity as a biomarker of effect of fungicide exposure in juvenile brown trout (Salmo trutta), the fungicides propiconazole [(R,S)-1-[2-(2,4-diclophenyl)-4-propyl-1,3-dioolan-2-ylmetyl]-1H-1,2,4-triazole] and fenpropimorph [(+/-)-cis-4-[3-(4-tert-butylphenyl)-2-metyl propyl]-2,6 dimetylmorfolinc] were administrated in the water separately and together in a static system (80 microg/l for each pesticide) for 5 days. The combined fungicides gave a significant decrease in gill GST activity towards 1-chloro-2,4-dinitrobenzene (CDNB), whilst hepatic GST-activity was not significantly changed. Furthermore, continuous exposure to 540 ug/l thiabendazole[2-(thiazol-4'-yl)benzimidazole] in a flow-through system for 4 days significantly increased the gill glutathione S-transferase (GST) activity towards CDNB, whilst hepatic GST and cytochrome P450 (CYP 1A) activities were not increased by the treatment.

Sorption of bentazone, dichlorprop, MCPA, and propiconazole in reference soils from Norway

Sorption-desorption kinetic and isotherm studies were performed by the batch equilibrium technique in three Norwegian soils. The soils were a fine sandy loam, a loam, and a soil of highly decomposed organic material. Two commercially formulations were used, Triagran-P and Tilt, containing either a mixture of bentazone [3-isopropyl-1H-2, 1,3-benzothiadiazin-4(3H)-one 2,2-dioxide], dichlorprop [(R)-2-(2, 4-dichlorophenoxy)-propionic acid], and MCPA [(4-chloro-2-methylphenoxy)acetic acid], or propiconazole [(+/-)1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole] alone. Sorption-desorption equilibrium occurred within 10 h for all pesticides. The Freundlich isotherms indicated nonlinear sorption of bentazone, dichlorprop, MCPA, and propiconazole. For all pesticides the highest Freundlich adsorption coefficient (K(F)) values were in the soil with highest organic content and lowest pH. For the fine sandy loam and loam, which are representative Norwegian agricultural soils, the results indicate that bentazone, dichlorprop, and MCPA are mobile with KF values ranging from 0.07 to 1.50 mg1-1/n kg(-1) L1/n. Propiconazole is much less mobile with KF values ranging from 27.00 to 36.02 mg1-1/n kg(-1) L1/n in the agricultural soils.

Determination of bentazone, dichlorprop, and MCPA in different soils by sodium hydroxide extraction in combination with solid-phase preconcentration

A method for the extraction of bentazone, dichlorprop, and MCPA in three selected Norwegian soils of different textures is described. Initially three different extraction methods were tested on one soil type. All methods gave recoveries >80% for the pesticide mixture, but extraction with sodium hydroxide in combination with solid-phase preconcentration was used for further recovery tests with soils of different properties spiked at four herbicide concentration levels (0.001-10 microg/g of wet soil). The method was rapid and easy and required a minimum of organic solvents. The recoveries were in the range of 82-109, 80-123, and 45-91% for the soils containing 1.4 (Hole), 2.5 (Kroer), and 37.8% (Froland) organic carbon, respectively. Limits of quantification using GC-MS were 0.0003 microg/g of wet soil for bentazone and 0.0001 microg/g of wet soil for both dichlorprop and MCPA.

Effects of dexamethasone on proliferation, chemotaxis, collagen I, and fibronectin-metabolism of human fetal lung fibroblasts

Premature infants at risk for bronchopulmonary dysplasia (BPD) are often treated with dexamethasone (Dex), which has been shown to suppress inflammatory processes in the lung. To elucidate a possible direct influence on the fibroproliferative component of the disease, we studied the effects of Dex in therapeutic and supratherapeutic dosages (5-50 nmol/L) on proliferation, chemotaxis, procollagen I, and fibronectin metabolism of human fetal lung fibroblasts in vitro. Proliferation was inhibited by Dex in a dose-dependent manner. Chemotactic activity in response to conditioned medium of human fetal fibroblasts also showed a dose-dependent inhibition after pretreatment with Dex. The amount of procollagen I C-terminal propeptide and fibronectin per cell in the cell culture supernatant was increased in the presence of Dex. Our results show that Dex does not uniformly suppress the fibroproliferative activity of human fetal lung fibroblasts, which may explain in part the unsatisfactory long-term effects of Dex treatment in BPD.

Investigation on fungicide residues in greenhouse-grown strawberries

Maximum residue limits (MRL's) for different agricultural food products in Norway are harmonized with EU standards. In field-grown strawberries in Norway, tolylfluanid has a 7 day quarantine from last application to harvest, while other approved fungicides have 14 days quarantine. Greenhouse production of strawberries is newly introduced to the country. Residue levels in strawberries of the cultivar Korona grown in a commercial greenhouse were investigated 4, 7, and 14 days after application of eight different fungicides at rates recommended by the manufacturers and at half rates. Iprodione, tolylfluanid, and vinclozolin were tested in two experiments, while chinomethionat, chlorothalonil, imazalil, penconazole, and triadimefon were tested once. For chinomethionat, imazalil, iprodione, penconazole, and vinclozolin, the residue levels were below MRL 2 weeks after application. Application of triadimefon in normal rate gave residues below MRL 14 days after application. However, its metabolite, triadimenol, was above MRL at the same time. Tolylfluanid gave very high residue levels, and except from half concentration in the second experiment, all other residue levels were above MRL. Seven days after application, residues in both experiments were approximately 3 times higher than MRL when normal rate of tolylfluanid was applied. For chlorothalonil at the recommended rate, the residue level was above MRL at any sampling time, while half rate gave residues below MRL 14 days after treatment. In view of the present results, tolylfluanid, chlorothalonil, and triadimefon will need longer time from last application to harvest and/or reduced application rates in greenhouse-grown compared to field-grown strawberries. In addition or as an alternative, recommended rates could be lowered.

Effects of ipsilateral anterior thigh soft tissue stretching on passive unilateral straight-leg raise

STUDY DESIGN

Randomized 3-group pretest-posttest with blind assessment of outcome.

OBJECTIVES

The purpose of this study was to examine the effect of sagittal plane hold-relax exercise applied to the ipsilateral anterior thigh, and prone positioning on passive unilateral straight-leg raise measurements.

BACKGROUND

Straight-leg raising has been viewed as a measurement for hamstring muscle length, but literature suggests that other structures may affect this measurement.

METHODS AND MEASURES

Sixty subjects (45 men, 15 women) qualified for inclusion into the study based on a straight-leg raise measurement of < or = 65 degrees. Subjects were randomly assigned to one of three groups: control, static stretch, or sagittal plane hold-relax exercise. Pretest and posttest straight-leg raise measurements of the right lower extremity were performed for each subject.

RESULTS

A 1-way ANOVA of the change scores showed a significant difference between groups. A Tukey post hoc analysis of the change scores showed that both treatment groups' means differed significantly from the control group and from each other, with the sagittal plane hold-relax group exhibiting the largest change (mean of 7.8 degrees +/- 2.8 degrees).

CONCLUSIONS

The results of this study show that sagittal plane hold-relax exercise and passive prone results of this study show that sagittal plane hold-relax and passive prone positioning can significantly increase straight-leg raise range of motion, however the sagittal plane hold-relax stretching of the anterior thigh is more effective than passive prone positioning.

Localisation of aryl sulfotransferase expression in human tissues using hybridisation histochemistry and immunohistochemistry

To date, the laboratory has cloned seven unique human sulfotransferases; five aryl sulfotransferases (HAST1, HAST2, HAST3, HAST4 and HAST4v), an estrogen sulfotransferase and a dehydroepiandrosterone sulfotransferase. The cellular distribution of human aryl sulfotransferases in human hepatic and extrahepatic tissues has been determined using the techniques of hybridization histochemistry and immunohistochemistry. Human aryl sulfotransferase expression was detected in liver, epithelial cells of the gastrointestinal mucosal layer, epithelial cells lining bronchioles and in mammary duct epithelial cells.

Low-resolution gamma-ray measurements of uranium enrichment

We have developed smaller, lighter hardware (MCA and shielded detectors) that has been successfully transferred to the commercial sector. We have developed software that has received limited testing, the next release should be sufficiently robust for wide release to the general public. We have had initial success with more sophisticated analysis methods. We are pursuing medium-resolution tors and response function fitting in the expectation that both will cause significant improvements in this measurement technique.

[Diclofenac in the short-term prevention of recurrent colic from ureteral calculi. A placebo controlled double-blind study]

We have conducted a double-blind randomised placebo controlled trial with oral diclofenac to study the prophylactic effect on recurrence of renal colic and rate of spontaneous stone expulsion. 41 patients were given 50 mg oral diclofenac three times a day for seven days after being discharged for a colic episode from Oslo Emergency Hospital and 39 patients were given matching placebo tablets. The number of new ureteral colic episodes per accumulated patient treatment days was 64/287 in the diclofenac group and 119/273 in the placebo group (p < 0.01). The difference was greatest during the first four days of treatment. A similar trend was found for pain intensity, with the greatest difference on day one. There was no difference in reported type or frequency of side effects in the two treatment groups. Stone expulsion rate was almost identical. The effect of the treatment was not affected by fluid intake. Re-admission rates to Oslo Emergency Hospital or other hospitals were 10 and 67% (p < 0.001).

HIV-1 gp41 binding to human T- and B-lymphocytes and monocytes is modulated by phorbol myristate acetate (PMA)

HIV-1 gp41 independently of CD4 binds to human T cells, B cells and monocytic cells. Since PMA downmodulates CD4 (HIV receptor) expression and inhibits HIV-1 dependent syncytia formation, we wanted to examine whether PMA could affect gp41 binding protein expression on human cells. The strong binding of HIV-1 recombinant soluble gp41 (rsgp41; Env aa539-684) to monocytes (CD14+) and B-lymphocytes (CD19+) and B lymphoblastoid cells (Raji) could be clearly decreased by treating the cells with PMA for 48 h, while the weak binding to T lymphocytes was slightly increased by this treatment. The PMA inhibitory- and enhancing-effects could be avoided by pretreatment with staurosporine (protein kinase C inhibitor). The PMA treatment of Raji and U937 (monocytic) cells resulted in a 50-60% decrease of gp41 binding proteins (gp41bps) detectable in cell lysates of these cells in comparison with lysates of buffer-treated cells, while in the case of H9-cells PMA treatment resulted in an increase of available gp41bps by about 35% in comparison with buffer-treated H9. Staurosporine pre-treatment could prevent these effects of PMA. Further studies of rsgp41-eluates from these buffer-treated or PMA-treated cells demonstrated that PMA modulated mainly expression of rsgp41bps of 37, 45, 50 and 62 kDa. These results indicate that PMA exerts different effects on human T, B and monocytic cells. Production by and expression on cells of HIV-1 gp41bps appear to depend on protein kinase C, supporting that the four proteins on human cells may act as receptor proteins for HIV-1 gp41.

Comparison of a rapid hepatitis B immunization schedule to the standard schedule for adults

We report a prospective, randomized, single-blinded trial comparing immunogenicity of rapid (0, 1, and 2 months) versus standard schedule (0, 1, 6 months) hepatitis B vaccinations of healthy adults with recombinant hepatitis B vaccine (Engerix-B, 20 micrograms i.m.) (230 of 234) negative to hepatitis B were randomized and completed the study. Groups were similar in age, weight, race, and obesity rate, but the rapid schedule group had more women. Both groups reached > or = 100 mIU/mL at a similar rate, but a higher seroprotection rate at > or = 500 mIU/mL was reached by the standard schedule. No demographic variables influenced the effect of dose schedule on anti-hepatitis B titer. We conclude that rapid schedule vaccination gives a rate that is quicker than, and identical to, the rate of seroprotection of the standard schedule vaccination.

Intramuscular diclofenac versus intravenous indomethacin in the treatment of acute renal colic

OBJECTIVE

We have conducted a clinical trial to compare the pain-relieving effect and safety of diclofenac administered intramuscularly to indomethacin given intravenously.

METHODS

The study was designed as a randomized single-blind trial. It was carried out at Oslo Emergency Hospital (outpatient setting or stay < 24 h). 41 patients with a mean age of 41.6 years received 75 mg diclofenac and 42 patients with a mean age of 45.2 years were given 50 mg indomethacin. The two groups were similar in regard to baseline characteristics except gender distribution.

RESULTS

Statistically significant reduction in pain intensity was achieved after 5 min in the diclofenac group (p < 0.01), and after 10 min in the indomethacin group (p < 0.01). The probability of having pain after 1 h was 52% in the indomethacin group and 37% in the diclofenac group (p = 0.11). Rescue medication with pethidine after 2 h was given in 9 and 5 patients, respectively. Four patients in the diclofenac group reported one occurrence of adverse effect each, while 9 patients on indomethacin experienced 14 occurrences, mainly dizziness and nausea.

CONCLUSION

These findings together with a simpler mode of administration indicate that diclofenac may be preferred in the analgesic treatment of renal colic.

HIV-1 gp41 selectively inhibits spontaneous cell proliferation of human cell lines and mitogen- and recall antigen-induced lymphocyte proliferation

Human immunodeficiency virus type 1 (HIV-1) transmembrane glycoprotein 41 (gp41) contains an immunosuppressive domain (Env amino acids 583-599). Previous studies by us and others using recombinant soluble gp41 (rsgp41; amino acids 539-684) and immunosuppressive peptide (1SP; a gp41 peptide, amino acids 583-599) have shown that HIV-1 gp41 by the immunosuppressive domain could bind to several proteins on human T, B and monocyte cell lines, and also to normal human peripheral blood mononuclear cells. In this study we demonstrated that HIV-1 rsgp41 could inhibit spontaneous cell proliferation of human T cell lines H9 and Jurkat, B cell lines Raji and Daudi, monocyte cell line U937, but could not inhibit cell proliferation of human fibroblast cell line HEF and green monkey kidney cell line Cos-1. HIV-1 rsgp41 could inhibit also concanavalin A (Con A)-, phytohaemagglutinin (PHA)- and tetanus toxoid (TT)-induced cell proliferation of normal human peripheral blood lymphocytes, with 50% inhibition at a concentration of 8 microM, but could not inhibit pokeweed mitogen (PWM)-induced lymphocyte proliferation. Furthermore, recombinant soluble gp36 of HIV-2 like HIV-1 rsgp41 could inhibit Con A-, but not PWM-induced lymphocyte proliferation. These results indicate that HIV-1 gp41-induced inhibition of proliferation is selective in so far as the effect of PWM is not altered while the effects of several other stimuli are.

Oral diclofenac in the prophylactic treatment of recurrent renal colic. A double-blind comparison with placebo

We have conducted a double-blind, randomized, placebo-controlled trial with oral diclofenac to study the prophylactic effect on renal colic recurrence and spontaneous stone expulsion rate. Forty-one patients were given 50 mg oral diclofenac 3 times a day for 7 days after being discharged for a colic episode from Oslo Emergency Hospital (< 24 h stay) and 39 patients were given matching placebo tablets. The number of new renal colic episodes per accumulated patient treatment days was 64/287 in the diclofenac group and 119/273 in the placebo group (p < 0.01). This difference was greatest during the first 4 treatment days. A similar trend was found for pain intensity (0-10 cm VAS) with the greatest difference on day 1 (4.3 vs. 2.8, p = 0.05). Side effects, mainly gastrointestinal, were reported for 14% of the treatment days in both treatment groups. Stone expulsion rate was almost identical (28 vs. 29 days), regardless of stone size. Readmission rate to Oslo Emergency Hospital/other hospitals were 10 and 67% (p < 0.001). In conclusion, oral treatment with diclofenac was effective as short-term prophylaxis of new colic episodes, especially during the first 4 days, and reduces the number of hospital readmissions significantly. The stone passage rate appears not to be affected.