Analysis of isothiocyanate mercapturic acids in urine: a biomarker for cruciferous vegetable intake     

Vermeulen M  van Rooijen HJ  Vaes WH 《Journal of agricultural and food chemistry》2003,51(12):3554-3559

Cruciferous vegetables contain glucosinolates, which are degraded to isothiocyanates. These are easily absorbed, conjugated to glutathione, and excreted into the urine as their corresponding mercapturic acids. We have developed and validated a solid phase extraction-high-performance liquid chromatography-electrospray ionization mass spectrometry/mass spectrometry method for the specific analysis of individual isothiocyanate mercapturic acids in urine. The range of reliable analysis was 1.0-310 microM in urine. Urine samples fortified with three different levels of isothiocyanate mercapturic acids were measured on six different days by three independent technicians. The relative standard deviation (RSD) of repeatability was 12, 6, and 3%; the RSD of reproducibility was 19, 14, and 8%, and spike recoveries were 103, 104, and 103%, respectively, for 1.04, 10.5, and 313 microM levels. In 24 h urine collected from two volunteers after they consumed broccoli and cauliflower, clearly sulforaphane mercapturic acid (133 micromol) and allyl isothiocyanate mercapturic acid (4.7 micromol) were found. This procedure demonstrates a reliable and efficient method to study the intake and mode of action of isothiocyanates in animal studies and clinical trials.  相似文献   

Total CK and CK‐BB activity in serum from sheep with Scrapie     

I. J. R. Visser  D. J. Vermeulen  P. Vellema  E. Gruys 《The Veterinary quarterly》2013,33(4):157-158

Summary

Plasma metabolite levels were measured in buffalo and cross‐bred cattle after daily intraruminal administration of fenbendazole at 0.5 mg/kg body weight. An equilibrium between the absorption of fenbendazole and disposition of its metabolites could be observed between days 3 to 6 and remained almost unchanged thereafter. The buffaloes had a lower uptake of the anthelmintic and lower plasma levels of its metabolites than in cattle. The findings were compared with those obtained after a single intraruminal therapeutic dose of fenbendazole.  相似文献   

Use of the SCUAF model to simulate natural miombo woodland and maize monoculture ecosystems in Zimbabwe     

S. J. Vermeulen  P. Woomer  B. M. Campbell  W. Kamukondiwa  M. J. Swift  P. G. H. Frost  C. Chivaura  H. K. Murwira  F. Mutambanengwe  P. Nyathi 《Agroforestry Systems》1993,22(3):259-271

Soil Changes Under Agroforestry (SCUAF), a computer model designed to predict changes in erosion, soil carbon and soil nitrogen over time within various agroforestry systems and climatic regimes, was assessed using input data from an undisturbed miombo woodland and an adjacent maize field in Zimbabwe. Predicted changes in soil carbon were in a realistic range for both miombo and maize treatments. However, the accuracy of the model may be a reflection of the detail required in its initialisation. Several problematic relationships were found within the model, in particular inconsistent patterns between nitrogen uptake and plant productivity under complex fertilisation simulations and a lack of attenuation of productivity in the simulation of miombo woodland as it approached maturity.  相似文献   

Purification of Cowdria ruminantium by lectin cellular affinity chromatography     

N M Vermeulen  A W Neitz  G J Viljoen 《The Onderstepoort journal of veterinary research》1987,54(3):233-246

This review covers the isolation of Cowdria ruminantium by lectin cellular affinity chromatography from different Amblyomma hebraeum sources. Cellular affinity chromatography has been reviewed with special attention being given to the application of this technique in the isolation of rickettsiae.  相似文献   

Isolation of Cowdria ruminantium by cellular affinity chromatography and detection by an enzyme-linked immunosorbent assay     

G J Viljoen  N M Vermeulen  P T Oberem  L Prozesky  J A Verschoor  J D Bezuidenhout  J F Putterill  L Visser  A W Neitz 《The Onderstepoort journal of veterinary research》1985,52(4):227-232

The isolation of Cowdria ruminantium by means of wheat germ lectin affinity chromatography as described in this paper permits the recovery of partially purified viable organisms under mild conditions in short time. These conclusions are based upon results of analyses of column fractions by intravenous inoculation into sheep, protein determination, electronmicroscopy and enzyme-linked immunosorbent assay. The entire purification procedure could be completed in 4-5 hours using only either infected sheep tissue or nymphae as starting material.  相似文献   

Renal function, insulin secretion, and glucose tolerance in mild streptozotocin diabetes in the dog.     

J J Kaneko  D Mattheeuws  R P Rottiers  A Vermeulen 《American journal of veterinary research》1978,39(5):807-809

A mild, stable diabetes mellitus was induced in dogs, using a small (20 mg/kg of body weight) dose of streptozotocin in a standard volume of 200 ml infused in 15 minutes. The stability of the diabetes was evidenced by the results of a standard intravenous glucose-tolerance test, insulin response to the glucose load, and urinary glucose excretion. The results of the urinary clearances for urea, creatinine, and phosphate indicated minimal renal toxicosis and that the toxicosis was localized to the tubules.  相似文献   

The presence of Cowdria ruminantium antigen in various tissues of Amblyomma hebraeum imagines as detected by an enzyme-linked immunosorbent assay     

G J Viljoen  A W Neitz  J D Bezuidenhout  P T Oberem  N M Vermeulen 《The Onderstepoort journal of veterinary research》1988,55(4):239-240

Investigation into the presence of C. ruminantium antigen, using an enzyme-linked immunosorbent assay (ELISA) in various tick tissues and haemolymph of adult Amblyomma hebraeum ticks revealed that the organism invades a number of body parts and can be demonstrated in A. hebraeum. In females, the gut, salivary glands, hypodermis and synganglion and in males, the salivary glands and gut showed the highest concentration.  相似文献   

Theoretical aspects of the enzyme-linked immunosorbent assay technique and its use in the detection of Cowdria ruminantium antigen and antibody in reacting animals   总被引：1，自引：0，他引：1  

G J Viljoen  N M Vermeulen  A W Neitz 《The Onderstepoort journal of veterinary research》1987,54(3):305-312

Numerous parameters affect the enzyme-linked immunosorbent assay activity and the assay conditions must therefore be carefully controlled to obtain reproducible results. These parameters include temperature, pH, ionic strength, buffer composition, cofactors, substrate depletion, product inhibition, increasing reversal of reaction as product concentration increases, adsorption of enzyme to solid supports, denaturation and non-enzymatic background rate. An ELISA was used to detect Cowdria ruminantium antibodies during the course of heartwater disease. IgM antibodies reached a maximum on the 4th day after infection and disappeared on the 7th day. IgG antibodies first appeared on the 8th day and continued to increase during the remainder of the observation period of 28 days. The presence of C. ruminantium in the blood fractions of diseased animals was demonstrated by an enzyme-linked immunosorbent assay. The earliest detection of C. ruminantium antigen was in plasma and serum on the 4th day after inoculation. Of all the blood fractions investigated, the red blood cell fraction showed the highest concentration and this reached a maximum on the 12th day after infection.  相似文献   

Detailed analysis of an experimental challenge model for Leishmania infantum (JPC strain) in dogs     

Poot J  Rogers ME  Bates PA  Vermeulen A 《Veterinary parasitology》2005,130(1-2):41-53

In this study, disease progression after intravenous or subdermal infection of dogs with Leishmania infantum JPC strain was monitored. A challenge performed on 14 dogs via the intravenous route with 5 x 10(7) stationary phase promastigotes of the L. infantum JPC strain was 100% successful. During a follow up period of 1.5 years, several parameters were evaluated in order to find the most reliable disease markers. Parasite detection by culture and histology were found to be very sensitive (100%). Additionally, regular physical examination, serology and serum gamma-globulin levels were found to be useful parameters in the evaluation of disease severity and are recommended for inclusion in vaccination-challenge experiments. Although this intravenous challenge model has practical limitations, the data set confirms it is the best experimental model currently available for vaccine development. Two intravenously infected dogs were treated with corticosteroids for 5 months. This treatment was shown to enhance all aspects of a Leishmania infection. Five more dogs were infected by sub-dermal injection of promastigotes mixed with a proteophosphoglycan-matrix (PSG) secreted by Leishmania that assists in transmission and infection by sand fly bite. The resulting parasite burdens were low and the animals remained asymptomatic during a 2-year follow up period. However, this procedure did result in infection in 80% of the dogs and is appealing for future development as a natural challenge model in vaccine development.  相似文献   

Coffee berry disease in Kenya. I. Colletotrichum spp. colonizing the bark of Coffea arabica     

H. Vermeulen 《European journal of plant pathology / European Foundation for Plant Pathology》1970,76(5):277-284

Several species ofColletotrichum occur in maturing bark ofCoffea arabica branches in Kenya. TheColletotrichum population inhabits the bark tissue external to the developing phellogens in the cortex. TheColletotrichum species are unable to invade green bark tissue, where the phellogen has not yet been differentiated, while colonization ceases on the phelloderm of the true bark. Only one of theColletotrichum species discussed in this paper,C. coffeanum, can infect green coffee berries. Shortly after the initiation of the first phellogen in the cortex the parasite is in a small area in the bark. It cannot be found in bark tissues where more phellogens have been formed and where the colour of the bark has changed from yellow-green to brown or black. From the bark ofC. liberica trees, grown in Kenya, andC. arabica cv. ’lsBourbon’, grown in greenhouses in the Netherlands one of the saprophytic components of theColletotrichum population could be isolated. It was impossible to induce ddie-back symptoms or mere infection by inoculation of green internodes even after wounding of live branches ofC. arabica with any of theColletotrichum components colonizing the bark. It is suggested that die-back systems of coffee in Kenya are primarily caused by unfavourable growing conditions.  相似文献