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H Peeters

Publications and source records attributed to H Peeters.

At least 19 recordsLinked to original sources
PubMed2006

Altered gut transcriptome in spondyloarthropathy.

BACKGROUND: Intestinal inflammation is a common feature of spondyloarthropathy (SpA) and Crohn's disease. Inflammation is manifested clinically in Crohn's disease and subclinically in SpA. However, a fraction of patients with SpA develops overt Crohn's disease. AIMS: To investigate whether subclinical gut lesions in patients with SpA are associated with transcriptome changes comparable to those seen in Crohn's disease and to examine global gene expression in non-inflamed colon biopsy specimens and screen patients for differentially expressed genes. METHODS: Macroarray analysis was used as an initial genomewide screen for selecting a comprehensive set of genes relevant to Crohn's disease and SpA. This led to the identification of 2625 expressed sequence tags that are differentially expressed in the colon of patients with Crohn's disease or SpA. These clones, with appropriate controls (6779 in total), were used to construct a glass-based microarray, which was then used to analyse colon biopsy specimens from 15 patients with SpA, 11 patients with Crohn's disease and 10 controls. RESULTS: 95 genes were identified as differentially expressed in patients with SpA having a history of subclinical chronic gut inflammation and also in patients with Crohn's disease. Principal component analysis of this filtered set of genes successfully distinguished colon biopsy specimens from the three groups studied. Patients with SpA having subclinical chronic gut inflammation cluster together and are more related to those with Crohn's disease. CONCLUSION: The transcriptome in the intestine of patients with SpA differs from that of controls. Moreover, these gene changes are comparable to those seen in patients with Crohn's disease, confirming initial clinical observations. On the basis of these findings, new (genetic) markers for detection of early Crohn's disease in patients with SpA can be considered.

Adult↗
PubMed2005

CARD15 polymorphisms are associated with anti-Saccharomyces cerevisiae antibodies in caucasian Crohn's disease patients.

Carriage of CARD15 gene polymorphisms and the serological marker anti-Saccharomyces cerevisiae antibodies (ASCA) are two markers for Crohn's disease (CD). Similar phenotypes have been associated with both markers. In the present study we analysed whether both markers were associated with each other and, if so, whether this association could be explained by a direct link or by an indirect association with those phenotypes. Therefore, we included 156 consecutive Caucasian CD patients and assessed the prevalence of the three common single nucleotide polymorphisms in the CARD15 gene. Serum samples were analysed for IgA and IgG ASCA by ELISA. CD patients with CARD15 polymorphisms were more frequently ASCA positive (OR 2.7 (1.4-5.2); P = 0.002) and had higher titres for ASCA IgA (P = 0.005) and ASCA IgG (P < 0.001) compared to patients carrying the wild type polymorphisms. Multivariate analysis demonstrated that this association was independent from ileal disease, penetrating disease and stricturing disease, the need for resective bowel surgery, familial cases, smoking habits and early age at onset. Homozygotes or compound heterozygotes for CARD15 polymorphisms had significantly more frequent ASCA positivity compared to single heterozygotes (OR 9.1 (1.1-74.2), P(c) (corrected P-value) = 0.030). These data indicate that there is a significant association between the carriage of CARD15 polymorphisms and ASCA, independent of the described phenotypes. Moreover, ASCA positivity is more frequent in CD patients carrying 2 CARD15 polymorphisms compared to single heterozygotes.

Adolescent↗
PubMed2004

CARD15 gene polymorphisms in patients with spondyloarthropathies identify a specific phenotype previously related to Crohn's disease.

BACKGROUND: The association between spondyloarthropathy and Crohn's disease is well known. A risk for evolution to Crohn's disease has already been shown in the subgroup of patients with spondyloarthropathy associated with chronic gut inflammation. OBJECTIVE: To investigate whether the reported polymorphisms in the CARD15 gene, a susceptibility gene for Crohn's disease, are associated with the presence of preclinical intestinal inflammation observed in spondyloarthropathies. METHODS: 104 patients with spondyloarthropathies were studied. All underwent ileocolonoscopy with biopsies between 1983 and 2004. The prevalence of three single nucleotide polymorphisms in the CARD15 gene (R702W, G908R, and 1007fs) was assessed using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR); the patients were compared with an ethnically matched Crohn's disease population and a control population. RESULTS: The carrier frequency of R702W, G908R, or 1007fs variants in the spondyloarthropathy populations (20%) was similar to the control population (17%), but increased to 38% in the spondyloarthropathy subgroup with chronic gut inflammation. This frequency was significantly higher than in the other spondyloarthropathy subgroups (p = 0.001) or the control group (p = 0.006), but not different from the Crohn's disease group (49%) (NS). This indicates that CARD15 polymorphisms are associated with a higher risk for development of chronic gut inflammation. CONCLUSIONS: CARD15 gene polymorphisms clearly identify a subgroup of patients with spondyloarthropathies associated with chronic intestinal inflammation.

Adolescent↗
PubMed2004

Colon mucosa of patients both with spondyloarthritis and Crohn's disease is enriched with macrophages expressing the scavenger receptor CD163.

BACKGROUND: Crohn's disease is associated with an increased number of macrophages in ileal and colonic mucosa. Data on macrophages in gut mucosa of patients with spondyloarthritis (SpA) are scarce. OBJECTIVE: To investigate macrophages and other antigen presenting cells in gut mucosa from patients with SpA and Crohn's disease, given the relationship between both entities. METHODS: Biopsy specimens from patients with SpA, Crohn's disease, ulcerative colitis, and from controls were immunohistochemically stained with different markers for macrophages and dendritic cells. Slides were scored semiquantitatively on a four point scale. RESULTS: SpA and Crohn's disease were associated with large numbers of CD68+ macrophages. Colon mucosa of both patients with SpA and Crohn's disease, but not ulcerative colitis, showed increased numbers of macrophages expressing the scavenger receptor CD163. CONCLUSIONS: Macrophages expressing the scavenger receptor CD163 are increased in colonic mucosa in SpA and in Crohn's disease, highlighting the relationship between these entities. The increased number of CD163+ macrophages in colon mucosa of patients with SpA suggests this is another argument for a role of macrophage scavenger receptors in this group of diseases.

Adolescent↗
PubMed2004

Radiological sacroiliitis, a hallmark of spondylitis, is linked with CARD15 gene polymorphisms in patients with Crohn's disease.

BACKGROUND: Sacroiliitis is a common extraintestinal manifestation of Crohn's disease but its association with the HLA-B27 phenotype is less evident. Polymorphisms in the CARD15 gene have been linked to higher susceptibility for Crohn's disease. In particular, associations have been found with ileal and fibrostenosing disease, young age at onset of disease, and familial cases. OBJECTIVES: To investigate whether the presence of sacroiliitis in patients with Crohn's disease is linked to the carriage of CARD15 polymorphisms. METHODS: 102 consecutive patients with Crohn's disease were clinically evaluated by a rheumatologist. Radiographs of the sacroiliac joints were taken and assessed blindly by two investigators. The RFLP-PCR technique was used to genotype all patients for three single nucleotide polymorphisms (SNP) in the CARD15 gene. Every SNP was verified by direct sequencing. The HLA-B27 phenotype was determined. RESULTS: Radiological evidence of sacroiliitis with or without ankylosing spondylitis was found in 23 patients (23%), of whom only three were HLA-B27 positive. In contrast, 78% of patients with sacroiliitis carried a CARD15 variant v 48% of those without sacroiliitis (p = 0.01; odds ratio 3.8 (95% confidence interval, 1.3 to 11.5)). Multivariate analysis (logistic regression) showed that the association between sacroiliitis and CARD15 polymorphisms was independent of other CARD15 related phenotypes (ileal and fibrostenosing disease, young age at onset of disease, familial Crohn's disease) (p = 0.039). CONCLUSIONS: CARD15 variants were identified as genetic predictors of Crohn's disease related sacroiliitis. An association was demonstrated between these polymorphisms and an extraintestinal manifestation of Crohn's disease.

Adolescent↗
PubMed2003

Variable phenotype in Greig cephalopolysyndactyly syndrome: clinical and radiological findings in 4 independent families and 3 sporadic cases with identified GLI3 mutations.

Greig cephalopolysyndactyly (GCPS) (OMIM 175700) is an autosomal dominant disorder characterized by a distinct combination of craniofacial, hand and foot malformations. In this report, clinical and radiological findings of 12 patients with GCPS derived from 4 independent families and 3 sporadic cases with documented GLI3 mutations are presented with particular emphasis on inter- and intrafamilial variability. In a particularly instructive family in which 9 members of 4 generations could be studied clinically and molecularly, a missense mutation (R625W) is transmitted and shows a partially penetrant pattern. In a branch of the family, the GCPS phenotype skips a generation via a normal female carrier without clinical signs providing evidence that GCPS does not always manifest full penetrance as generally supposed.

Alleles↗
PubMed2003

PA26 is a candidate gene for heterotaxia in humans: identification of a novel PA26-related gene family in human and mouse.

Heterotaxia is an aetiologically heterogeneous condition caused by an abnormal left-right axis formation, resulting in reversed left-right polarity of one or more organ systems. In a patient with heterotaxia and a de novo reciprocal translocation t(6;18)(q21;q21), we found that the PA26 gene was disrupted by the 6q21 breakpoint. Northern blot analysis showed decreased expression of the PA26 gene in an Epstein-Barr virus-transformed cell line of this patient. During early embryogenesis of Xenopus, the orthologue of PA26, XPA26 is exclusively expressed in the notochord, a midline structure. This further supports a possible role of PA26 in human situs determination. Mutation analysis of human PA26 gene in 40 unrelated individuals with unexplained heterotaxia failed to identify mutations, indicating that PA26 mutations are not a frequent cause of heterotaxia in humans. Analysis of the PA26 gene structure resulted in the identification of a novel PA26-related gene family, which we have named the sestrin family, and which comprises three closely related genes in human and in mouse.

Animals↗
PubMed2001

Recurrent involvement of chromosomal region 6q21 in heterotaxy.

We present a patient with heterotaxy and a de novo, apparently balanced reciprocal translocation with breakpoints at 6q21 and 20p13. Another patient with heterotaxy was previously reported with a de novo balanced translocation involving chromosome band 6q21. The breakpoints in both patients on 6q21 were found to be located in the same chromosomal region spanning maximally 2 Mb. We speculate that the two breakpoints lead to the disruption of the function of a single gene, either directly or through long distance effects. Alternatively, the present observation suggests additional heterogeneity in heterotaxy in humans.

Abnormalities, Multiple↗
PubMed2000

Urodynamic assessment of voiding dysfunction and dysfunctional voiding in girls and women.

Voiding dysfunction is defined as impaired bladder emptying, and presents with a mixture of lower urinary tract symptoms. Dysfunctional voiding is a condition in which there is a lack of coordination between the sphincter and detrusor during emptying in a patient without overt uropathy or neuropathy. Assessment of voiding dysfunction is important in women and girls in the prevention and treatment of urinary incontinence, retention, urinary tract infection and subsequent kidney damage. Accurate diagnosis is essential in order to select the correct treatment. Screening can be done by history-taking: symptom scores can help to guide the screening. More objective measures are uroflowmetry, ultrasonography and video-urodynamics. The latter is the gold standard for the diagnosis of voiding dysfunction and consists of simultaneous registration of pressure in the bladder and rectum and external sphincter behavior, either by electromyographic recording of pelvic floor activity or by pressure recording at the external sphincter, during the whole bladder cycle of filling and emptying. On fluoroscopy the bladder can be visualized throughout the filling and emptying phase. In dysfunctional voiding, hypertonicity and instability of the external urethral sphincter during filling cystometry and impaired external sphincter relaxation during emptying are pathognomonic findings. Pressure-flow analysis reveals no obstruction and the detrusor contractility is low.

Adolescent↗
PubMed1999

Reference curve and diagnostic sensitivity for a new ultrasound device for the phalanges [correction of phalanages], the DBMsonic 1200, in Belgian women.

Quantitative ultrasound (US) applied in bone mass measurements is promising because it is a radiation-free and cheap technique that may provide information on bone quality. The DBMsonic 1200 (IGEA, Carpi) is such a new ultrasound device that measures mean amplitude-dependent speed of sound through the distal metaphyses of the four proximal phalanges (nondominant hand). We determined the standarded precision and constructed a reference curve for Belgian women. The diagnostic sensitivity was tested in established osteoporotic patients with at least one vertebral fracture, expressed as area under the curve (ROC) and compared with other bone mass measurement techniques such as dual-energy X-ray absorptiometry (DXA) and US of the heel. For a group of 93 women with different pathologies, the standardized precision obtained was 4.2 +/- 4.3%. Within this group, the standardized precision was 3.7 +/- 3.1% for 28 normals and 5.8 +/- 4.9% for 12 osteoporotic patients. The reference curve was constructed in 310 normal women (age range 21-84 years). The diagnostic sensitivity of this ultrasound device was compared with that obtained with spinal DXA and proximal femur results of the same individuals, as well as with ultrasound measurements of the calcaneus, and investigated in the osteoporotic patients older than 50 years and in age-matched controls. The area under the curve was 80.3% (SE 3.9%) for the DBMsonic 1200, 77.4% (SE 1.4%) for DXA of the spine, 79.5% (SE 3.9%) for DXA of the femoral neck and 70.1% (SE 4.9%) for US of the heel. Our data show an acceptable and comparable standardized precision in relation to other available data for the same device. In the group of osteoporotic women over 50 years of age we have found similar diagnostic sensitivity for the US measurements of the phalanges as for DXA of the lumbar spine and femoral neck. There is a minor, but no significantly higher diagnostic sensitivity than for ultrasound of the calcaneus. We conclude that this tool is promising for discriminating normal and osteoporotic female patients.

Absorptiometry, Photon↗
PubMed1999

Left posterior fascicular tachycardia: a diagnostic and therapeutic challenge.

A wide QRS complex tachycardia with right bundle-branch block morphology and left axis deviation observed in a young patient without structural heart disease may pose a diagnostic and therapeutic challenge. The surface ECG may provide several diagnostic clues to make a correct diagnosis of left posterior fascicular tachycardia and may help to differentiate it from both a supraventricular tachycardia with aberrant conduction and a typical ventricular tachycardia related to coronary artery disease. Although this tachycardia is sensitive to verapamil, this medication may probably cause transient infertility in males. The presence of a Purkinje potential preceding the QRS complex during tachycardia and optimal pace mapping may guide radio-frequency ablation resulting in a definite cure.

Adult↗
PubMed1998

Validation of a telephone zygosity questionnaire in twins of known zygosity.

The aim of this study was to validate a zygosity questionnaire that can be administered over the telephone. Mothers of same-sexed twins of known zygosity and chronicity between 2 and 31 years of age were interviewed on a nine-item questionnaire. From the answers one unweighted and four weighted indices were computed. As single questions, the mother's opinion and the "two peas in a pod" question differentiated best between monozygotic and dizygotic twins. One independent well-trained observer assessed the zygosity based on the questionnaire and made the correct diagnosis in 96% of the cases. A weighted index of eight similarity questions yielded an accuracy of 98%. This study shows that the zygosity of same-sexed twins more than 2 years old and without gross physical malformation can reliably be determined by a telephone questionnaire with a high accuracy.

Adolescent↗
PubMed1992

[Mortality of cattle following feeding of moldy flower bulbs].

Five of eight meat cattle died suddenly without showing prior symptoms of disease. The sudden death occurred in connection with the feeding of mouldy tulip bulbs. A short review is given of the use of flower bulbs as cattle feed, the use of herbicides/fungicides in bulb cultivation, and the relevant legislation. Several toxicological aspects that should be taken into consideration when flower bulbs are used as cattle feed are discussed. Both the Central Veterinary Institute and the State Institute for Public Health and Environmental Hygiene showed, in experiments with mice, the presence of a toxin in extracts of the mouldy tulip bulbs. This toxin is probably produced by moulds present in the tulip bulbs. The death of the animals was probably caused by an as yet unidentified mycotoxin.

Animal Feed↗
PubMed1991

[The cat has not always done it. A case of alpha-chloralose poisoning in wild birds].

Neglected hens caused annoyance at a graveyard. Following veterinary advice, the authorities used alpha-chloralose-dressed feed in an attempt to sedate the animals, thus facilitating transport to a more suited place. However, the feed was also consumed by other birds. Moreover, the dosage alpha-chloralose appeared to be too high. Hence the resulting mortality struck both the hens and the wild birds. Obviously, alpha-chloralose should not be used for these applications.

Animals↗
PubMed1988

Synthesis of beauvericin by a multifunctional enzyme.

Beauvericin synthetase, a multifunctional enzyme catalyzing depsipeptide formation in Beauveria bassiana was purified to near homogeneity. The enzyme consists of a single polypeptide chain with a molecular mass of about 250 kdaltons. The mechanism of beauvericin formation is very similar to that of the cyclohexadepsipeptide enniatin. The constituents of the beauvericin molecule, L-phenylalanine and D-alpha-hydroxyisovaleric acid are activated as thioesters via the corresponding adenylates. N-Methylation takes place at the thioester bound stage of the phenylalanine residues. Omission of the methyl donor S-adenosyl-L-methionine results in the formation of demethylbeauvericin. Studies on substrate specificity revealed that phenylalanine could be replaced by a number of other aromatic or aliphatic amino acids like beta-phenylserine, ortho-, meta-, para-fluorophenylalanine, isoleucine, norleucine and leucine. Valine, the constituent amino acid of enniatin B was not accepted by the enzyme.

Anti-Bacterial Agents↗
PubMed1986

Biosynthesis of cyclosporin A: partial purification and properties of a multifunctional enzyme from Tolypocladium inflatum.

An enzyme fraction most probably involved in the biosynthesis of cyclosporin A was purified 540-fold from Tolypocladium inflatum. The enzyme was capable of forming covalent enzyme-substrate complexes and catalyzed the ATP-pyrophosphate exchange reactions dependent on the unmethylated constituent amino acids of cyclosporin A. Evidence was obtained that covalent binding of substrate amino acids occurred via thioester linkage. Furthermore, the N-methylation of thio-esterified valine, leucine, and glycine residues with S-adenosyl-L-methionine was demonstrated. De novo synthesis of cyclosporin A was not observed but the formation of the diketopiperazine cyclo-(D-Ala-MeLeu) from D-alanine and L-leucine under the consumption of ATP and S-adenosyl-L-methionine. This cyclodipeptide represents a partial sequence of cyclosporin A. Molecular mass determinations revealed the enzyme activity to be lying in the range of about 700 kDa.

Carbon Radioisotopes↗