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1.
Maturitas ; 107: 1-6, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29169572

ABSTRACT

OBJECTIVE: To evaluate whether opportunistic salpingectomy in premenopausal women undergoing hysterectomy for benign indications is both hormonally and surgically safe, compared with hysterectomy without salpingectomy. STUDY DESIGN: In this multicentre randomised controlled trial, women were randomised to undergo either hysterectomy with opportunistic bilateral salpingectomy (intervention group) or standard hysterectomy with preservation of the Fallopian tubes (control group). MAIN OUTCOME MEASURES: The primary outcome was the difference in serum anti-Müllerian hormone concentration (ΔAMH), measured pre-surgery and 6 months post-surgery. Secondary outcomes were surgical outcomes and duration of hospital stay. The sample size was powered at 50 participants per group (n=100) to compare ΔAMH after hysterectomy with salpingectomy to ΔAMH after standard hysterectomy. RESULTS: Between March 2013 and December 2016, 104 women, aged 30-55 years, were randomly allocated to hysterectomy with opportunistic bilateral salpingectomy (n=52) or standard hysterectomy (n=52). The baseline characteristics did not differ between the two groups. The median ΔAMH was -0.14pmol/L (IQR -1.47-0.95) in the intervention group and 0.00pmol/L (IQR -1.05-0.80) in the control group (p=0.49). The addition of salpingectomy did not impair surgical results and it did not affect duration of hospital stay. CONCLUSION: Addition of opportunistic bilateral salpingectomy during hysterectomy did not result in a larger effect on ovarian reserve when compared with hysterectomy alone, neither did it affect surgical outcomes. Therefore, opportunistic salpingectomy seems to be a safe procedure in premenopausal women undergoing hysterectomy for benign gynaecological conditions.


Subject(s)
Hysterectomy , Salpingectomy , Adult , Anti-Mullerian Hormone/blood , Female , Genital Diseases, Female/surgery , Humans , Length of Stay , Middle Aged , Ovarian Reserve , Premenopause/blood
2.
Food Chem ; 189: 27-37, 2015 Dec 15.
Article in English | MEDLINE | ID: mdl-26190597

ABSTRACT

Food producing animals are exposed to biologically active plant compounds through feed and roughages, presenting a potential risk to the animal but also consumers of food of animal origin. To evaluate to which plant compounds of concern dairy cows in the Netherlands are exposed, a ranking filter model was developed, combining information on abundance of plant species in vegetation plots in the Netherlands (183,905 plots of three different vegetation types) with plant-compound combinations (700), and with consumption data of fresh grass, grass silage and corn silage by cattle. The most abundant plant genera are those producing cyanogenic glycosides, coumarins and benzofuranocoumarins, being predominantly fodder plants (alfalfa, clover and some grasses) considered to be safe. Highest exposures were estimated for plant genera producing piperidine alkaloids (horsetail), furanocoumarins (parsley and relatives), pyrrolizidine alkaloids (Symphytum, Senecio, Leucanthemum, Eupatorium) and essential oils. The current results allow to prioritise future scientific research on these compounds.


Subject(s)
Animal Feed/analysis , Silage/analysis , Animals , Cattle , Dietary Fiber/analysis , Food Contamination/analysis , Furans/analysis , Furocoumarins/analysis , Medicago sativa/chemistry , Models, Theoretical , Oils, Volatile/analysis , Oxalates/analysis , Poaceae/chemistry , Pyrrolizidine Alkaloids/analysis , Saponins/analysis , Zea mays/chemistry
3.
Article in English | MEDLINE | ID: mdl-23656192

ABSTRACT

To investigate whether clenbuterol-treated calves could contaminate untreated pen mates, three animal experiments were performed. (1) One calf of a pen of five was treated with clenbuterol by injection (Ventipulmin injection, REG NL 2532, 2.5 mL/100 kg) twice a day for 10 days. (2) In two pens, one animal was treated with clenbuterol via oral administration (Ventipulmin syrup, REG NL 2532, 4 mL/125 kg) for 4 weeks. (3) In two pens, one animal was treated with clenbuterol via the milk (Ventipulmin, REG NL 2532, 2.5 mL/100 kg body weight) twice a day for 10 days. Here, the animal was set apart during treatment, cleaned and put back into the group. Levels of clenbuterol were analysed in hair and urine with LC-MS/MS. Clenbuterol administered by injection could not be transferred from treated to untreated calves. In the second experiment, all pen mates were found positive for clenbuterol in the hair. This contamination was probably due to licking the mouth of the treated animal or saliva from the treated animal spoiling the floor. In the third experiment, no pen mates were found positive for clenbuterol in the hair. Clenbuterol was found in the urine and hair of only treated animals.


Subject(s)
Adrenergic beta-Agonists/analysis , Clenbuterol/analysis , Drug Residues/analysis , Animals , Cattle , Chromatography, Liquid , Hair/chemistry , Tandem Mass Spectrometry
4.
Article in English | MEDLINE | ID: mdl-22296620

ABSTRACT

The effect of 17ß-19-nortestosterone (17ßNT) treatment of barrows on residue levels and growth was evaluated. Five barrows were treated three times during the fattening period with 17ßNT phenylpropionate (Nandrosol, nandrolone phenylpropionate 50 mg/ml,1 mg/kg body weight). Another five barrows were untreated and five boars (untreated) were kept as positive control. Boars and treated barrows showed a 13 and 9% improvement in growth compared to untreated barrows, with mean final body weights of 121.6, 117.8 and 109.0 kg, respectively. The bulbourethral glands of the treated barrows were three times heavier than untreated barrows. The histology of the prostate and bulbourethral gland of the treated barrows was comparable to the boars, whereas the control barrows showed atrophic glands. Levels of 17ßNT ester in hair from treated barrows were high, whereas boars and untreated barrows did not show levels above LLQ. It is concluded that analysis of hair can detect illegal treatment with 17ßNT ester in barrows. The size of the bulbourethral gland can also be used for screening in the slaughterhouse.


Subject(s)
Anabolic Agents/pharmacology , Genitalia, Male/drug effects , Hair/chemistry , Nandrolone/analogs & derivatives , Sus scrofa/growth & development , Weight Gain/drug effects , Anabolic Agents/analysis , Anabolic Agents/pharmacokinetics , Anabolic Agents/urine , Animals , Bulbourethral Glands/cytology , Bulbourethral Glands/drug effects , Bulbourethral Glands/growth & development , Crime , Crosses, Genetic , Food Contamination/prevention & control , Genitalia, Male/cytology , Genitalia, Male/growth & development , Male , Meat-Packing Industry/methods , Nandrolone/analysis , Nandrolone/pharmacokinetics , Nandrolone/pharmacology , Nandrolone/urine , Netherlands , Orchiectomy/veterinary , Organ Size/drug effects , Prostate/cytology , Prostate/drug effects , Sus scrofa/metabolism , Testis/cytology , Testis/drug effects , Testis/growth & development , Tissue Distribution
5.
Drug Test Anal ; 4(6): 515-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21381222

ABSTRACT

Isoxsuprine is a beta-agonist that can be used for growth promotion in cattle, but it is also used as registered veterinary medicine. To investigate if veterinary treatment of cows could lead to residues of isoxsuprine in the hair of their newborn calves, an animal experiment was performed. Four cows, treated on veterinary indication with isoxsuprine lactate (Duphaspasmin) before a caesarian section, were included in the experiment. Hair samples from cows and from their calves were analyzed. The animals were shaved every week for 16 weeks and levels of isoxsuprine were measured in hair. In the cows, the levels of isoxsuprine were highest (>15 µg/kg) just after administration of the isoxsuprine lactate. After two weeks in two cows, a sort of plateau was reached and then the levels decreased. After approximately 10-15 weeks the levels were around the CCα level of the method used (0.5 µg/kg). In calves, for the first two weeks after birth, no isoxsuprine was found above CCα level in three of the four animals. At about 20-30 days old, a maximum concentration of 4 µg/kg was found. Then the levels dropped again under the CCα level, after 60 days no levels above CCα level were found. In one animal, the levels never reached CCα level. We conclude that veterinary treatment of cows with isoxsuprine may temporarily lead to low levels of isoxsuprine in the hair of their newborn calves which can be measured for a maximum of 60 days after birth.


Subject(s)
Cesarean Section/veterinary , Hair/chemistry , Isoxsuprine/analogs & derivatives , Tocolytic Agents/pharmacokinetics , Animals , Animals, Newborn , Cattle , Cesarean Section/methods , Female , Isoxsuprine/administration & dosage , Isoxsuprine/pharmacokinetics , Male , Pregnancy , Time Factors , Tocolytic Agents/administration & dosage
6.
J Steroid Biochem Mol Biol ; 125(3-5): 192-201, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21272641

ABSTRACT

The application of anabolic steroids in food producing animals is forbidden in the EU since 1988, but the abuse of such drugs is a potential problem. The existing test systems are based on known compounds and can be eluded by newly emerging substances. The examination of physiological effects of anabolic hormones on different tissues to indirectly detect misuse might overcome this problem. Two studies were conducted with post-pubertal 24-months old Nguni heifers and pre-pubertal female 2-4 weeks old Holstein Friesian calves, respectively. The animals of the accordant treatment groups were administered combinations of estrogenic and androgenic compounds. The measurement of the gene expression pattern was undertaken with RT-qPCR. Target genes of different functional groups (receptors, angiogenesis, steroid synthesis, proliferation, apoptosis, nutrient metabolism and others) have been quantified. Several biochemical pathways were shown to be influenced by anabolic treatment. Both studies identified significant regulations in steroid and growth factor receptors (AR, ERß, LHR, FSHR, Flt-1, PR, IGF-1R, Alk-6), angiogenic and tissue remodeling factors (VEGFs, FGFs, BMPs, ANGPT-2, MMPs, TIMP-2, CTSB), steroid synthesis (S5A1, HSD17, CYP19A1), proliferation (TNFα, IGF-1, IGFBPs, p53, c-fos; CEBPD, c-kit), apoptosis (CASP3, FasL, p53) and others (C7, INHA, STAR). Several genes were regulated to opposite directions in post-pubertal compared to pre-pubertal animals. PCA for Nguni heifers demonstrated a distinct separation between the control and the treatment group. In conclusion, anabolics modify hormone sensitivity and steroid synthesis, and they induce proliferative effects in the whole reproductive tract (uterus and ovary) as well as anti-angiogenic effects in the ovary. However, the extent will depend on the developmental stage of the animals.


Subject(s)
Androgens/pharmacology , Endometrium/drug effects , Estrogens/pharmacology , Ovary/drug effects , Animals , Cattle , Drug Combinations , Estradiol/analogs & derivatives , Estradiol/pharmacology , Female , Ovary/metabolism , Pregnancy , Signal Transduction/drug effects , Testosterone/analogs & derivatives , Testosterone/pharmacology , Trenbolone Acetate/analogs & derivatives , Trenbolone Acetate/pharmacology
7.
Mol Genet Metab ; 99 Suppl 1: S86-9, 2010.
Article in English | MEDLINE | ID: mdl-20123477

ABSTRACT

In untreated phenylketonuria (PKU), deficiency of phenylalanine hydroxylase (PAH) results in elevated blood phenylalanine (Phe) concentrations and severe mental retardation. Current dietary treatment prevents mental retardation, but cognitive outcome remains suboptimal. The mechanisms by which elevated blood Phe concentrations disturb cerebral metabolism and cognitive function have not been fully elucidated. In this review, we discuss different hypotheses on the pathogenesis of PKU, focusing on the effects of disturbed large neutral amino acid (LNAA) transport from blood to brain on cerebral neurotransmitter and protein synthesis. Although the definitive roles of these processes in PKU pathogenesis are not fully understood yet, both substantially influence clinical outcome.


Subject(s)
Cognition Disorders/complications , Phenylketonurias/complications , Amino Acids, Neutral/metabolism , Blood-Brain Barrier , Humans , Phenylketonurias/diet therapy
8.
Bioinformatics ; 25(22): 2975-82, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19696044

ABSTRACT

MOTIVATION: Many enzymes are not absolutely specific, or even promiscuous: they can catalyze transformations of more compounds than the traditional ones as listed in, e.g. KEGG. This information is currently only available in databases, such as the BRENDA enzyme activity database. In this article, we propose to model enzyme aspecificity by predicting whether an input compound is likely to be transformed by a certain enzyme. Such a predictor has many applications, for example, to complete reconstructed metabolic networks, to aid in metabolic engineering or to help identify unknown peaks in mass spectra. RESULTS: We have developed a system for metabolite and reaction inference based on enzyme specificities (MaRIboES). It employs structural and stereochemistry similarity measures and molecular fingerprints to generalize enzymatic reactions based on data available in BRENDA. Leave-one-out cross-validation shows that 80% of known reactions are predicted well. Application to the yeast glycolytic and pentose phosphate pathways predicts a large number of known and new reactions, often leading to the formation of novel compounds, as well as a number of interesting bypasses and cross-links. AVAILABILITY: Matlab and C++ code is freely available at https://gforge.nbic.nl/projects/mariboes/


Subject(s)
Computational Biology/methods , Enzymes/chemistry , Databases, Factual , Glycolysis , Metabolic Networks and Pathways , Pentose Phosphate Pathway , Saccharomyces cerevisiae/metabolism , Software
9.
Anal Bioanal Chem ; 395(4): 1075-87, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19705109

ABSTRACT

The abuse of synthetic esters of natural steroids such as testosterone and estradiol in cattle fattening and sports is hard to detect via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. An interesting alternative can be provided by the analysis of the administered synthetic steroids themselves, i.e., the analysis of intact steroid esters in hair by liquid chromatography tandem mass spectrometry (LC/MS/MS). However, retrospective estimation of the application date following a non-compliant finding is hindered by the complexity of the kinetics of the incorporation of steroid esters in hair. In this study, the incorporation of intact steroid esters in hair following pour-on treatment has been studied and critically compared with results from intramuscular treatment. To this end animals were pour-on treated with a hormone cocktail containing testosterone cypionate, testosterone decanoate and estradiol benzoate in different carriers. The animals were either treated using injection and pour-on application once or three times having 1 week between treatments using injection and pour-on application. Animals were slaughtered from 10-12 weeks after the last treatment. Both hair and blood plasma samples were collected and analysed by LC/MS/MS. From the results, it is concluded that after single treatment the levels of steroid esters in hair drop to CCbeta levels (5-20 microg/kg) after 5-7 weeks. When treatment is repeated two times, the CCbeta levels are reached after 9-11 weeks. Furthermore, in plasma, no steroid esters were detected; not even at the low microgramme per litre level but--in contrast with the pour-on application--after i.m. injection, significant increase of 17beta-testosterone and 17beta-estradiol were observed. These observations suggest that transport of steroid esters after pour-on application is not only performed by blood but also by alternative fluids in the animal so probably the steroid esters are already hydrolysed and epimerized before entering the blood.


Subject(s)
Esters/blood , Estradiol/analogs & derivatives , Hair/chemistry , Testosterone/blood , Administration, Topical , Animals , Cattle , Chromatography, Liquid , Estradiol/administration & dosage , Estradiol/blood , Tandem Mass Spectrometry , Testosterone/administration & dosage , Testosterone/analogs & derivatives
10.
Food Chem Toxicol ; 47(5): 992-1008, 2009 May.
Article in English | MEDLINE | ID: mdl-18790713

ABSTRACT

A number of recent food safety incidents have involved chemical substances, while various activities aim at the early identification of emerging chemical risks. This review considers recent cases of chemical and biochemical risks, as a basis for recommendations for awareness and prevention of similar risks at an early stage. These cases include examples of unapproved genetically modified food crops, intoxications with botanical products containing unintentionally admixed toxic herbs, residues of unapproved antibiotics and contaminants in farmed aquaculture species such as shrimp and salmon; and adverse effects of chemical and biological pesticides of natural origin. Besides case-specific recommendations for mitigation of future incidents of the same nature, general inferences and recommendations are made. It is recommended, for example, to establish databases for contaminants potentially present within products. Pro-active reconnaissance can facilitate the identification of products potentially contaminated with hazardous substances. In international trade, prevention and early identification of hazards are aided by management systems for product quality and safety, rigorous legislation, and inspections of consignments destined for export. Cooperation with the private sector and foreign authorities may be required to achieve these goals. While food and feed safety are viewed from the European perspective, the outcomes also apply to other regions.


Subject(s)
Animal Feed/standards , Consumer Product Safety , Food Contamination/prevention & control , Food Supply/standards , Aquaculture/standards , Food Microbiology , Food, Genetically Modified , Humans , Pesticide Residues/analysis , Plants, Genetically Modified , Product Surveillance, Postmarketing , Risk Assessment
11.
Anal Bioanal Chem ; 392(3): 417-25, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18648778

ABSTRACT

Prohormones such as dehydroepiandrosterone (DHEA) are steroid precursors that do not show hormonal activity by themselves. Abuse of these prohormones in cattle fattening is hard to prove because of strong in vivo metabolism and the difficulty to detect metabolites which are not significantly above endogenous levels. The aim of the present work was to develop an in vitro assay capable of detecting the indirect hormonal activity of prohormones that might be present in feed supplements and injection preparations. Sample extracts were incubated with a bovine liver S9 fraction in order to mimic the in vivo metabolic activation. Subsequently incubated extracts were exposed to a highly androgen-specific yeast bioassay to detect hormonal activity. Metabolic activation of DHEA, 4-androstene-3,17-dione (4-adione) and 5-androstene-3,17-diol (5-adiol) resulted in an increased androgenic activity caused by the formation of the active androgen 17beta-testosterone (17beta-T), as shown by ultra-performance liquid chromatography and time-of-flight mass spectrometry with accurate mass measurement. The developed in vitro system successfully mimics the hydroxysteroid dehydrogenase (HSD)- and cytochrome P450-mediated in vivo metabolic transitions, thus allowing assessment of both bioactivity and chemical identification without the use of animal experiments. Screening of unknown supplement samples claimed to contain DHEA resulted in successful bioactivation and positive screening results according to the androgen yeast biosensor.


Subject(s)
Androgens/analysis , Androgens/metabolism , Biological Assay/methods , Liver/metabolism , Androgens/chemistry , Animals , Cattle , Chromatography, Liquid , Liver/chemistry , Mass Spectrometry , Molecular Structure
12.
J Vet Med A Physiol Pathol Clin Med ; 54(5): 238-46, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17523956

ABSTRACT

An animal experiment has been performed with 42 veal calves, 21 males and 21 females, which were fed and housed according to European regulations for veal calves. The animals were kept in six groups of seven animals and fed milk replacer supplemented with three different levels of lactulose (0%, 1% and 3%) and some roughage. At the start of the experiment the animals were 1-3 weeks of age and they were slaughtered at 26 weeks. From male animals prostate, bulbo-urethal gland and testes were sampled, from female animals Bartholin's gland, uterus, cervix and ovaries were sampled. From all animals thyroid, thymus, adrenals, liver and kidneys were sampled. Histological investigation of the prostates and bulbo-urethral glands showed normal histology. This means that dilated tubules, strong secretion, increased mucinous glandular tissue and severe hyperplasia and squamous metaplasia, as is regularly observed in practice in the Netherlands, were not present in these animals. None of these prostates would be judged as positive in the screening for hormones as is performed by the Dutch Food and Consumer Product Safety Authority (VWA). The female calves also showed normal histology of Bartholin's gland except for three animals that appeared to be in oestrus and showed some metaplasie of the ducts but with a normal gland to duct ratio. These animals would be judged as suspect. The liver and kidney showed minor alterations due to slight infections during the experimental period. This experiment showed that it is possible to raise veal calves according to the practice without getting positive histology in the prostate or Bartholin's gland.


Subject(s)
Cattle/growth & development , Endocrine System/pathology , Genitalia/pathology , Growth Hormone/administration & dosage , Animal Feed , Animals , Animals, Newborn/growth & development , Bulbourethral Glands/pathology , Female , Immunohistochemistry/veterinary , Male , Ovary/pathology , Prostate/pathology
13.
Food Addit Contam ; 23(11): 1123-31, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17071514

ABSTRACT

Within the European Union, the control for residues of illegal hormones in food-producing animals is based on urine analysis for a few target analytes using gas chromatography/mass spectrometry and/or liquid chromatography-tandem mass spectrometry. Recently, we developed a robust yeast bioassay screening tool for estrogens, which was validated as a qualitative screening method in accordance with EC decision 2002/657/EC. In this study, we present long-term performance data and a comparison of urine data obtained with this bioassay, and data from an established gas chromatography-tandem mass spectrometry (GC/MS/MS) confirmatory analysis method. More than 120 calf urine samples from a controlled reference experiment were analysed using both protocols. According to the GC/MS/MS method, only the natural estrogens 17alpha-estradiol and estrone were present in the non-compliant samples. The bioassay was less sensitive than GC/MS/MS for the relatively weak estrogenic compound 17alpha-estradiol, in accordance with expectations. Assuming that application of the mass spectrometric method is considered beyond reasonable doubt, the bioassay performed very well: only 5.6% of the calf urine samples found compliant in GC/MS/MS were screened false suspect in the bioassay screening method. The bioassay results of non-compliant urine samples under routine conditions were as predicted, taking into account the relative estrogenicity of the natural estrogens 17alpha-estradiol and estrone vs. 17beta-estradiol. Only one sample was screened false negative for 17alpha-estradiol and estrone. Application of this fast and simple estrogen bioassay in routine surveillance and control can significantly reduce GC/MS/MS sample workload and allow higher percentages of animals to be screened for potential hormone abuse.


Subject(s)
Biological Assay/methods , Drug Residues/analysis , Estrogens/urine , Food Contamination/analysis , Animals , Cattle , Female , Food Contamination/prevention & control , Gas Chromatography-Mass Spectrometry , Male , Sensitivity and Specificity , Yeasts/metabolism
14.
Vet Res Commun ; 30(6): 587-98, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16838201

ABSTRACT

In veal calf production plant-based proteins are frequently included in milk replacer fed to the animals. Since soy products, which are mostly used, are known for their high levels of phyto-oestrogens, the effects of these feeds on the veal calf prostate were examined. Goal was to determine whether these compounds could interfere with histological screening for oestrogenic growth promoters. In a feeding experiment, four groups of veal calves fed plant-based protein-supplemented milk replacer (PBM), containing 5% soy concentrate, 5% soy isolate, 5% wheat gluten and 2% potato protein, for 4 weeks were compared to animals fed dairy-based control feed (DBM); animals treated with estradiol benzoate, diethylstilbestrol and ethinylestradiol served as positive controls. Daidzein and genistein levels measured in feed and urine showed high levels of genistein and daidzein in the soy isolate and soy concentrate supplemented feeds. Genistein and daidzein were also found in the urine of the animals that were fed these feeds. Haematoxylin-eosin-stained prostate sections of PBM-fed animals showed slight hyperplasia and some dilated tubules as compared to the DBM-fed group, but no metaplasia, which is used for screening for oestrogenic hormones. The positive controls showed extensive squamous metaplasia. Immunohistochemical staining for cytokeratin 5 (using RCK 103 monoclonal antibody) in basal cells showed a normal staining pattern of basal cells in the DBM-fed calves and extensive basal cell proliferation and squamous metaplasia in the oestrogen-treated positive control animals. PBM-fed calves showed no increase of basal cell staining but showed elongations of the basal cells in most animals, sometimes resulting in circular figures. It is concluded that the feeds examined in this study did not interfere with histological screening for oestrogens in male veal calves.


Subject(s)
Animal Nutritional Physiological Phenomena , Cattle/growth & development , Phytoestrogens , Prostate/drug effects , Prostate/pathology , Animal Feed/analysis , Animals , Animals, Newborn/growth & development , Cattle/anatomy & histology , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/metabolism , Estrogens, Non-Steroidal/pharmacology , Estrogens, Non-Steroidal/urine , Genistein/analysis , Immunohistochemistry/veterinary , Isoflavones/analysis , Male , Phytoestrogens/analysis , Phytoestrogens/metabolism , Phytoestrogens/pharmacology , Phytoestrogens/urine , Random Allocation , Glycine max/chemistry , Weight Gain/drug effects
15.
J Vet Med A Physiol Pathol Clin Med ; 51(2): 58-63, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15153074

ABSTRACT

Histopathology of male cattle previously found positive for béta-boldenone in urine in the Netherlands and in Italy was studied. The animals were derived from practice and several weeks had passed after the finding of béta-boldenone before the animals were examined. The animals consisted of 34 male veal calves and one finishing bull. In the prostate gland hypersecretion, cyst formation (45%) and hyperplasia of the urethral epithelium was observed, in the bulbo-urethral gland similar alterations were present. The testis showed reduced development and degeneration of the germinal epithelium (70%), leading to debris and syncytial cell formation in the lumina. Stromal proliferation was evident. In some animals the liver was sampled and showed periportal fibrosis, bile duct proliferation and sometimes necrosis. The bull also showed degeneration of the germinal epithelium of the testis and absence of sperm production, the prostate gland showed some secretion and had an atrophic appearance. It is concluded that béta-boldenone may lead to degeneration of the germinal epithelium of the testis and hypersecretion and cyst formation in the prostate and bulbo-urethral gland, which alterations may heal in time.


Subject(s)
Anabolic Agents/pharmacokinetics , Cattle/metabolism , Growth Substances/pharmacokinetics , Testosterone/analogs & derivatives , Testosterone/pharmacokinetics , Anabolic Agents/urine , Animals , Growth Substances/urine , Italy , Male , Netherlands , Prostate/metabolism , Testis/metabolism , Testosterone/urine , Urethra/metabolism
16.
Biotechnol Prog ; 19(4): 1136-41, 2003.
Article in English | MEDLINE | ID: mdl-12892473

ABSTRACT

A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out, and flux control was shown to be dependent on the metabolite levels. Due to thermodynamic constraints, flux control may reside at the first step in the pathway, i.e., at the xylose reductase, even when the intracellular xylitol concentration is high. On the basis of the kinetic analysis, the general dogma specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of Aspergillus nidulans grown on media containing xylose, and a concentration up to 30 mM was found. Applying MCA showed that the first polyol dehydrogenase (XDH) in the catabolic pathway of xylose exerted the main flux control in the two strains of A. nidulans and A. niger NW324, but the flux control was exerted mainly at the first enzyme of the pathway (XR) of A. niger NW 296.


Subject(s)
Aspergillus/growth & development , Aspergillus/metabolism , Bioreactors/microbiology , Combinatorial Chemistry Techniques/methods , Models, Biological , Multienzyme Complexes/metabolism , Xylitol/metabolism , Xylose/metabolism , Aspergillus/cytology , Computer Simulation , Feedback/physiology , Reproducibility of Results , Sensitivity and Specificity
17.
J Vet Med A Physiol Pathol Clin Med ; 49(9): 466-9, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12489869

ABSTRACT

Adult female beef cattle found positive for stanozolol in the urine were investigated for liver pathology. In all the animals toxic hepatitis was found, including cholestasis, periportal fibrosis and inflammation, focal necrosis and blood filled lacunae. As no clinical data of the cows were available, apart from the history of illegal stanozolol abuse, it is not possible to attribute all changes to the illegal hormone treatment. Moreover, the cows have probably been treated with a cocktail, and apart from stanozolol more anabolic steroids may have been used. Management factors, viral and bacterial infections, former caesarean sections and especially feeding regime may also be responsible for the lesions described. Striking similarities with data from hepatotoxicity found in human body builders using similar agents, however, suggest a major role of stanozolol as causative agent.


Subject(s)
Anabolic Agents/adverse effects , Cattle Diseases/chemically induced , Cattle Diseases/epidemiology , Chemical and Drug Induced Liver Injury/veterinary , Stanozolol/adverse effects , Anabolic Agents/urine , Animals , Cattle , Cattle Diseases/pathology , Chemical and Drug Induced Liver Injury/epidemiology , Chemical and Drug Induced Liver Injury/etiology , Female , Industry/legislation & jurisprudence , Liver/pathology , Meat , Netherlands/epidemiology , Stanozolol/urine
18.
Eur J Biochem ; 268(20): 5414-23, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11606204

ABSTRACT

The Aspergillus niger D-xylulose kinase encoding gene has been cloned by complementation of a strain deficient in D-xylulose kinase activity. Expression of xkiA was observed in the presence of L-arabinose, L-arabitol and D-xylose. Expression of xkiA is not mediated by XLNR, the xylose-dependent positively-acting xylanolytic regulator. Although the expression of xkiA is subject to carbon catabolite repression, the wide domain regulator CREA is not directly involved. The A. niger D-xylulose kinase was purified to homogeneity, and the molecular mass determined using electrospray ionization mass spectrometry agreed with the calculated molecular mass of 62816.6 Da. The activity of XKIA is highly specific for D-xylulose. Kinetic parameters were determined as Km(D-xylulose) = 0.76 mM and Km(ATP) = 0.061 mM. Increased transcript levels of the genes encoding arabinan and xylan degrading enzymes, observed in the xylulose kinase deficient strain, correlate with increased accumulation of L-arabitol and xylitol, respectively. This result supports the suggestion that L-arabitol may be the specific low molecular mass inducer of the genes involved in arabinan degradation. It also suggests a possible role for xylitol in the induction of xylanolytic genes. Conversely, overproduction of XKIA did not reduce the size of the intracellular arabitol and xylitol pools, and therefore had no effect on expression of genes encoding xylan and arabinan degrading enzymes nor on the activity of the enzymes of the catabolic pathway.


Subject(s)
Arabinose/metabolism , Aspergillus niger/enzymology , Genes, Fungal/genetics , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Polysaccharides/metabolism , Xylose/metabolism , Adenosine Diphosphate/metabolism , Adenosine Monophosphate/metabolism , Aspergillus niger/genetics , Aspergillus niger/growth & development , Aspergillus niger/metabolism , Cloning, Molecular , DNA/metabolism , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Fungal , Mutation/genetics , Phosphotransferases (Alcohol Group Acceptor)/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , Spectrometry, Mass, Electrospray Ionization , Transcription, Genetic/genetics , Up-Regulation
19.
Drug Metab Dispos ; 29(7): 936-44, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11408357

ABSTRACT

Structure activity relationships (SAR), three-dimensional structure activity relationships (3D-QSAR), and pharmacophores represent useful tools in understanding cytochrome P450 (CYP) active sites in the absence of crystal structures for these human enzymes. These approaches have developed over the last 30 years such that they are now being applied in numerous industrial and academic laboratories solely for this purpose. Such computational approaches have helped in understanding substrate and inhibitor binding to the major human CYPs 1A2, 2B6, 2C9, 2D6, 3A4 as well as other CYPs and additionally complement homology models for these enzymes. Similarly, these approaches may assist in our understanding of CYP induction. This review describes in detail the development of pharmacophores and 3D-QSAR techniques, which are now being more widely used for modeling CYPs; the review will also describe how such approaches are likely to further impact our active site knowledge of these omnipresent and important enzymes.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Binding Sites , Cytochrome P-450 Enzyme System/chemistry , Models, Chemical , Quantitative Structure-Activity Relationship
20.
Heart ; 85(3): 278-85, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11179265

ABSTRACT

OBJECTIVE: To examine whether successful coronary reperfusion after thrombolytic treatment in patients with confirmed acute myocardial infarction can be diagnosed from the plasma marker fatty acid binding protein (FABP), for either acute clinical decision making or retrospective purposes. DESIGN: Retrospective substudy of the GUSTO trial. SETTING: 10 hospitals in four European countries. PATIENTS: 115 patients were treated with thrombolytic agents within six hours after the onset of acute myocardial infarction. Patency of the infarct related artery was determined by angiography within 120 minutes of the start of thrombolysis. MAIN OUTCOME MEASURES: First hour rate of increase in plasma FABP concentration after thrombolytic treatment, compared with increase in plasma myoglobin concentration and creatine kinase isoenzyme MB (CK-MB) activity. Infarct size was estimated from the cumulative release of the enzyme alpha hydroxybutyrate dehydrogenase in plasma during 72 hours, or from the sum of ST segment elevations on admission. Logistic regression analyses were performed to construct predictive models for patency. RESULTS: Complete reperfusion (TIMI 3) occurred in 50 patients, partial reperfusion (TIMI 2) in 36, and no reperfusion (TIMI 0+1) in 29. Receiver operating characteristic (ROC) curve analyses showed that the best performance of FABP was obtained when TIMI scores 2 and 3 were grouped and compared with TIMI score 0+1. The performance of FABP as a reperfusion marker was improved by combining it with alpha hydroxybutyrate dehydrogenase infarct size, but not with an early surrogate of infarct size (ST segment elevation on admission). In combination with infarct size FABP performed as well as myoglobin (areas under the ROC curve 0.868 and 0.857, respectively) and better than CK-MB (area = 0.796). At optimum cut off levels, positive predictive values were 97% for FABP, 95% for myoglobin, and 89% for CK-MB (without infarct size, 87%, 88%, and 87%, respectively), and negative predictive values were 55%, 52%, and 50%, respectively (without infarct size, 44%, 42%, and 34%). CONCLUSIONS: FABP and myoglobin perform equally well as reperfusion markers, and successful reperfusion can be assessed, with positive predictive values of 87% and 88%, or even 97% and 95% when infarct size is also taken into account. However, identification of non-reperfused patients remains a problem, as negative predictive values will generally remain below 70%.


Subject(s)
Carrier Proteins/blood , Fatty Acids/blood , Myocardial Infarction/blood , Neoplasm Proteins , Thrombolytic Therapy , Tumor Suppressor Proteins , Vascular Patency , Biomarkers/blood , Coronary Angiography , Creatine Kinase/blood , Creatine Kinase, MB Form , Fatty Acid-Binding Protein 7 , Fatty Acid-Binding Proteins , Female , Humans , Hydroxybutyrate Dehydrogenase/metabolism , Isoenzymes/blood , Logistic Models , Male , Middle Aged , Myocardial Infarction/classification , Myocardial Infarction/therapy , Myocardial Reperfusion , Myoglobin/blood , Predictive Value of Tests , ROC Curve , Retrospective Studies , Sensitivity and Specificity , Severity of Illness Index , Treatment Outcome
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