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J Raus

Publications and source records attributed to J Raus.

At least 37 records · Page 2Linked to original sources
PubMed1998

Identification of some important metabolites of boldenone in urine and feces of cattle by gas chromatography-mass spectrometry.

17 alpha-Boldenone (17 alpha-BOL) and/or 17 beta-boldenone (17 beta-BOL) appear occasionally in fecal matter of cattle. In addition to 17 alpha-BOL, a whole array of boldenone related substances can be found in the same samples. In vitro experiments with microsomal liver preparations and isolated hepatocytes combined with the excretion profiles found in urine and feces samples of in vivo experiments made it possible to identify several metabolites of 17 beta-BOL in 17 beta-BOL positive feces samples. In one animal treated with 17 beta-BOL, no 17 beta-BOL or its metabolites were present before treatment and most of these compounds disappeared gradually in time after the treatment was stopped. It is not clear what the origin is of 17 alpha-BOL and boldenone metabolites in samples screened routinely for the abuse of anabolic steroids and considered to be 'negative' because of the absence of 17 beta-BOL since other workers showed some evidence that 17 alpha-BOL can be of endogenous origin. However, in our hands, most of these 17 alpha-BOL positive samples, obtained during routinely performed screenings of cattle, contained large amounts of delta 4-androstene-3,17-dione (AED), which normally is absent from routinely screened negative samples. Furthermore, AED was absent in all samples obtained from the animals treated with 17 beta-BOL. We have no direct evidence that 17 alpha-BOL or 17 beta-BOL is of endogenous origin.

Anabolic Agents↗
PubMed1998

Metabolites in feces can be important markers for the abuse of anabolic steroids in cattle.

In Belgium, to control the abuse of anabolic steroids in cattle, urine samples have been gradually replaced by feces samples, because the latter can be obtained more easily from living animals. Urine and feces samples were collected from heifers after administration of boldenone, norethandrolone or ethylestrenol. Metabolites present in feces or urine were determined by GC-MS. Large qualitative and quantitative differences in the metabolic profiles were observed. In feces, in contrast to urine, the parent compounds or their major metabolites were detectable only shortly after administration. On the other hand, metabolites resulting from the reduction of the 3-oxo group and the unsaturated carbon-carbon bonds, present on the A-ring, allow for long-term detection in feces. A-ring reduced metabolites have been identified in samples found positive for norgestrel, boldenone, methylboldenone and methyltestosterone, respectively. These results are in agreement with concomitant in vivo experiments.

Anabolic Agents↗
PubMed1998

In vitro liver models are important tools to monitor the abuse of anabolic steroids in cattle.

Current veterinary residue analysis mainly focuses on the monitoring of residues of the administered parent compound. However, it is possible that larger amounts of metabolites are excreted and that they can have a prolonged excretion period. In order to unravel specific metabolic steps and to identify possible biological markers, two in vitro liver models were used, i.e. monolayer cultures of isolated hepatocytes and liver microsomes, both prepared from liver tissue of cattle. Chostebol, boldenone, norethandrolone (NE) and ethylestrenol (EES) were used as model substrates. Results show that the metabolic profiles derived from in vitro experiments are predictive for the in vivo metabolic pathways of the steroids evaluated in this study. By means of this strategy, it is possible to identify 17 alpha-ethyl-5 beta-estrane-3 alpha,17 beta-diol (EED) as a common biological marker for NE and EES. By in vivo experiments it was shown that EED is particularly important for the detection of the abuse of NE or EES because of its high excretion levels and its prolonged presence as compared with the parent compounds or any other metabolite.

Anabolic Agents↗
PubMed1998

Interference of Helix pomatia extracts on the determination of methandriol in veterinary residue control analysis.

Aqueous solutions containing methandriol (MAD) were incubated with Succus helix pomatia (SHP) or beta-glucuronidase from Escherichia coli (EC). SHP, used for enzymatic hydrolysis of urinary steroid conjugates for residue analysis of anabolic agents, caused transformation of MAD into methyltestosterone. No conversion occurred when bacterial beta-glucuronidase from E. coli was used.

Anabolic Agents↗
PubMed1998

Cyclical etidronate increases bone density in the spine and hip of postmenopausal women receiving long term corticosteroid treatment. A double blind, randomised placebo controlled study.

OBJECTIVE: To study the effect of cyclic etidronate in secondary prevention of corticosteroid induced osteoporosis. METHODS: A double blind, randomised placebo controlled study comparing cyclic etidronate and placebo during two years in 37 postmenopausal women receiving long term corticosteroid treatment, mainly for polymyalgia rheumatica (40% of the patients) and rheumatoid arthritis (30%). Bone density was measured in the lumbar spine, femoral neck, and femoral trochanter. RESULTS: After two years of treatment there was a significant difference between the groups in mean per cent change from baseline in bone density in the spine in favour of etidronate (p = 0.003). The estimated treatment difference (mean (SD)) was 9.3 (2.1)%. Etidronate increased bone density in the spine (4.9 (2.1)%, p < 0.05) whereas the placebo group lost bone (-2.4 (1.6)%). At the femoral neck there was an estimated difference of 5.3 (2.6)% between the groups (etidronate: 3.6% (1.4)%, p < 0.05, placebo: -2.4 (2.1)%). The estimated difference at the trochanter was 8.2 (3.0) (etidronate: 9.0 (1.5)%, p < 0.0001, placebo: 0.5 (2.3)%). No significant bone loss occurred in the hip in placebo treated patients. CONCLUSIONS: Cyclic etidronate is an effective treatment for postmenopausal women receiving corticosteroid treatment and is well tolerated.

Aged↗
PubMed1998

Myelin reactive T cells in the autoimmune pathogenesis of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) leading to demyelination. Although it is widely accepted that demyelination in MS results from an active inflammatory process, the cause of the inflammation is still not completely resolved. Findings in experimental autoimmune encephalomyelitis (EAE), an animal model of MS, and observations in human MS have led to the hypothesis that MS is an autoimmune disease mediated by autoreactive T cells with specificity for myelin antigens. The identity of the brain antigen(s) which is (are) the primary target(s) of the autoimmune process is not known, but current evidence indicates that myelin basic protein (MBP) is a likely candidate. In this paper we will overview some of the experimental evidence suggesting that MBP reactive T cells hold a central position in the pathogenesis of MS, and discuss some of the currently tested therapeutic strategies in MS which are directed towards the pathogenic MBP reactive T cells. Although there appears to be no direct correlation between anti-MBP T cell responses and clinical disease activity, some recent observations suggest that monitoring of anti-MBP T cell responses could be helpful to study immunological efficacy of experimental immunotherapies in MS.

Autoantibodies↗
PubMed1998

Cytokine mRNA profile of myelin basic protein reactive T-cell clones in patients with multiple sclerosis.

Autoimmune mechanisms involving T-cell responses to (a) myelin autoantigen(s), such as myelin basic protein (MBP), are thought to contribute to the pathogenesis of multiple sclerosis (MS). Cytokines may play a central role in the regulation of the pathogenic autoimmune responses in MS and the mediation of tissue damage in the disease. To study the cytokine expression of myelin reactive T-cells in MS, we determined the cytokine mRNA levels in a panel of blood derived MBP-specific T-cell clones derived from MS patients (33 clones) and normal controls (21 clones), using a novel quantitative RT-PCR method. Our results demonstrate that MBP-specific T-cells, both from MS patients and control subjects, predominantly display a Th1- or Th0-like cytokine pattern. Although MS clones express higher levels of TNFalpha and IL-10 mRNA, these differences do not reach statistical significance. Interestingly, significantly increased TNFalpha and IFNgamma mRNA levels were observed among clones derived from HLA-DR2 positive versus HLA-DR2 negative MS patients. This HLA halpotype is known to be associated with MS. The high levels of TNFalpha and IFNgamma mRNA observed in MBP-reactive T-cell clones from MS patients indicate an important role of these cytokines in the disease process. Our data lend further support to the pathogenic role of MBP-reactive T-cells in MS.

Adult↗
PubMed1997

Cytokine profile of myelin basic protein-reactive T cells in multiple sclerosis and healthy individuals.

Myelin basic protein (MBP)-reactive T cells have been implicated in the autoimmune pathogenesis of multiple sclerosis (MS). In this study, we examined the cytokine profile of 531 primary MBP-reactive T-cell lines and 72 independently established clones from 32 patients with MS and 18 healthy controls (NS) by using highly sensitive enzyme-linked immunosorbent assays. An increased number of primary T-cell lines producing interferon-gamma (IFN gamma) and/or interleukin-4 (IL-4) in response to MBP were found in patients with MS compared with controls. No distinct Th1 or Th2 subtypes could be demonstrated among the MBP-reactive clones. IL-4 was more frequently observed among MS-derived clones. Clones derived from MS patients produced increased levels of IL-2, IL-4, tumor necrosis factor-alpha (TNF alpha), IFN gamma, and IL-10, but not IL-6. It is interesting that MBP-reactive T cells from MS patients expressing the disease-associated HLA-DRB1*15 allele produced increased quantities of TNF alpha, a cytokine suggested to play an important role in inflammation and demyelination. When challenged with either MBP or a bacterial superantigen, the clones expressed similar levels of the proinflammatory cytokine IFN gamma. Our study suggests a functional difference in T-cell responses to MBP in patients with MS compared with healthy individuals, and provides further insights into the role of MBP-reactive T cells and their cytokine profile in the inflammatory processes of MS.

Adult↗
PubMed1997

Clonal expansion of mycobacterial heat-shock protein-reactive T lymphocytes in the synovial fluid and blood of rheumatoid arthritis patients.

OBJECTIVE: To examine the reactivity pattern and T cell receptor (TCR) characteristics of mycobacterial heat-shock protein 65 (hsp65)-reactive T cells generated from paired synovial fluid (SF) and peripheral blood (PB) samples obtained from rheumatoid arthritis (RA) patients and from healthy subjects. METHODS: The reactivity pattern of hsp65-reactive T cell clones generated under limiting-dilution conditions was analyzed in 3H-thymidine incorporation assays. The TCR variable regions of these hsp65-reactive T cells were characterized by polymerase chain reaction with TCR AV- and BV-specific primers and by DNA sequence analysis of the third complementarity-determining region (CDR3). RESULTS: The hsp65-reactive T cells derived both from RA patients and controls preferentially recognized the 1-170 and 303-540 regions of hsp65 and did not cross-react with human hsp60. The hsp65-reactive T cell clones derived from RA patients displayed a restricted TCR AV and BV gene usage, which can be attributed to the limited clonal origin(s) of the independent T cell clones, as evidenced by CDR3 sequence analysis. These clonally expanded T cells were found in both PB and SF and in different inflamed joints of RA patients. CONCLUSION: Our study suggests that there is in vivo clonal activation and expansion of mycobacterial hsp65-reactive T cells in patients with RA.

Antigens, Bacterial↗
PubMed1997

Quadriceps and grip strength are related to vitamin D receptor genotype in elderly nonobese women.

Osteoporotic fragility fractures are related to bone density and injury, which are both related to muscle strength. The influence of genetic factors, such as the vitamin D receptor (VDR) polymorphism on bone mineral density (BMD), is documented but still controversial, and is not known for muscle strength. In the present study, we investigated the association between the VDR BsmI polymorphism and BMD (femoral neck [FN], lumbar spine [LS], and proximal forearm [FA]) and muscle strength (quadriceps and grip strength) in 501 healthy women older than 70 years. No association was found between the VDR genotypes and BMD in elderly women. However, in nonobese women (body mass index <30 kg/cm2), the BMD in the FN was 5% higher in women with the bb BsmI genotype than in women with the BB genotype (p < 0.05). After correction for muscle strength, no association was found. A significant association between the VDR genotypes and quadriceps and grip strength was observed. In nonobese women, a 23% difference in quadriceps strength (p < 0.01) and 7% in grip strength (NS) was observed between the bb and BB genotype of the VDR. After correction for confounding factors and BMD, this association was significant for quadriceps and grip strength. These results indicate a major association of an allelic variant at the VDR locus with muscle strength in elderly nonobese women, which could explain a small association between VDR polymorphism with BMD in the femoral neck in nonobese women. No such associations were found in obese women, suggesting that factors related to obesity obscure such an association.

Aged↗
PubMed1997

Influence of the vitamin D receptor gene alleles on bone mineral density in postmenopausal and osteoporotic women.

It is well established that genetic factors contribute to bone turnover and bone density. Evidence exists suggesting that a major part of this genetic influence may be due to polymorphisms in the vitamin D receptor (VDR) gene. However, it is not clear whether the VDR genotype effect persists in elderly women. In the present study, the relationship between the BsmI, ApaI, and TaqI polymorphisms in the VDR gene, and the bone mineral density (BMD) at the lumbar spine, the femoral neck (FN), and the proximal radius was investigated in a large group of elderly women (75.5 +/- 5.0 years) of Caucasian origin and in 84 Type I osteoporotic women (66.6 +/- 8.4 years). We did not find a correlation between the VDR genotypes and BMD in elderly women. However, a significantly higher FN-BMD was observed in obese (body mass index [BMI] > 30 kg/m2) versus nonobese (BMI < 30 kg/m2) women (p < 0.01). This relationship was observed for all BsmI genotypes. Furthermore, the FN-BMD of nonobese women with bb BsmI genotype was 5% higher than that of women with the BB genotype (p = 0.04). We conclude that the VDR gene polymorphisms influence the FN-BMD in nonobese postmenopausal women. In a second part of the study, possible correlations between the VDR gene polymorphisms and osteoporosis Type I were analyzed. Our data could not reveal any association between these parameters.

Aged↗
PubMed1997

Autoimmune pathogenesis of multiple sclerosis: role of autoreactive T lymphocytes and new immunotherapeutic strategies.

Accumulating evidence indicates that multiple sclerosis (MS) is an autoimmune disease mediated by autoreactive T lymphocytes with specificity for myelin antigens. Initially, the evidence to support this hypothesis was based mainly on experiments performed in experimental allergic encephalomyelitis (EAE), the animal model of MS. In this model it was demonstrated that T cells reactive to several myelin antigens are encephalitogenic. Many recent immunological and immunohistochemical studies in MS have yielded further data to support this view. For instance, it was demonstrated that activated myelin basic protein (MBP) and proteolipid protein (PLP)-specific T cells accumulate in the central nervous system (CNS), and that clonally expanded MBP-specific T cells persist for several years in the blood of patients with MS. Furthermore, T cells with specificity for MBP were identified in the brain lesions of the patients. It is not yet clear how these autoreactive T cells are activated in the periphery, but several studies have suggested that viral antigens mimicking the myelin epitopes, or superantigens may be involved. Furthermore, we and others have provided evidence showing that the regulatory mechanisms that control autoreactive T cells in healthy subjects are potentially defective in MS patients. In addition to myelin reactive T cells, B cells producing myelin-specific antibodies and gamma delta T cells may also play an important role in the autoimmune cascade. Based on the recent insights in the disease mechanisms, new experimental therapies were developed to target specifically the pathogenic lymphocytes in MS. Some therapies yielded encouraging data in pilot studies, whereas phase III trials of other drugs showed beneficial effects on the disease course. In this article, we overview the most recent data on the role of autoreactive lymphocytes in the pathogenesis of the disease, and discuss some of the recently developed immunotherapeutical strategies in MS.

Adoptive Transfer↗
PubMed1996

Vaccination with autoreactive T cell clones in multiple sclerosis: overview of immunological and clinical data.

Although the etiology and pathogenesis of Multiple Sclerosis (MS) remain elusive, accumulating evidence indicates that MS is a chronic inflammatory disease with an autoimmune component, mediated by autoreactive T lymphocytes specific for myelin antigens. The triggering T cell autoantigen has not been identified yet, but recent immunological studies in MS and parallel experiments in experimental allergic encephalomyelitis (EAE), the animal model of MS, have indicated that myelin basic protein (MBP) can be considered as one of the major candidate autoantigens in the pathogenesis of the disease. Based on these observations, several therapeutic strategies have been developed aimed at the specific elimination or inactivation of MBP reactive T cells in MS. One of these approaches involves the immunization of MS patients with autologous attenuated autoreactive T cells to induce an immune response specifically targeted at these autoreactive T cells. This method, termed T cell vaccination, has been shown to prevent and treat EAE. We have recently conducted a pilot trial of T cell vaccination in a limited group of MS patients to evaluate the immunological responses to the injected cells. The data obtained indicate that this type of vaccination induces an effective anti-clonotypic T cell response leading to a specific depletion of circulating MBP reactive T cells. Preliminary data on the clinical effects are promising, encouraging further clinical trials.

Amino Acid Sequence↗
PubMed1996

Quantification of cytokine messenger RNA in transfected human T cells by RT-PCR and an automated electrochemiluminescence-based post-PCR detection system.

A fast method is reported for the precise and accurate quantification of cytokine mRNA, based on a quantitative polymerase chain reaction (PCR) assay. Post-PCR detection of the amplification products is achieved using an automated electrochemiluminescent (ECL) detection system. The target is amplified using a biotinylated forward and a tris(2,2'-bipyridine)ruthenium (II) (TBR)-labeled reverse primer. The amplification products are then captured on streptavidin coated paramagnetic beads and quantified by measuring the ECL signal of the TBR label. The results obtained are reproducible and accurate over a wide range (3 orders of magnitude) of concentrations. Quantitative results can be obtained using a standard curve which is generated with a synthetic external standard. This technique was applied to quantify tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin-2(IL-2) mRNA levels in human T cells transfected with the corresponding genes.

Automation↗