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Biomedical subjects

P Peeters

Publications and source records attributed to P Peeters.

At least 37 records · Page 2Linked to original sources
PubMed1999

Hydroxyethyl starch does not impair immediate renal function in kidney transplant recipients: a retrospective, multicentre analysis.

BACKGROUND: The effect of hydroxyethyl starch (HES) on early allograft function was examined retrospectively in a cohort of 119 renal transplantations realized by local organ exchange between four cooperating centres. METHODS: After exclusions, 109 transplant procedures were subdivided in three groups according to donor colloid loading: (i) HS-group (Haes steril 6%, mean volume (SD): 979 (946) ml, n = 20); (ii) PS-group [Plasmasteril, mean volume (SD): 769 (411) ml, n = 16]; and (iii) control group (gelatin albumin, n=73). RESULTS: Delayed graft function (DGF), defined as the need for dialysis during the first post-transplant week, occurred in 3/20 (15%) cases in the HS-group, in 5/16 (31%) cases in the PS-group and in 14/73 (19%) cases in the control group (P = 0.450). Uni- and multivariate analysis revealed older donor age (P = 0.001) and kidney preservation with histidine-tryptophan-ketoglutarate (HTK) (P = 0.001) as the only factors associated with a higher incidence of DGF. CONCLUSIONS: Renal function as measured by daily serum creatinine concentration and 24 h urinary output up to 14 days post-transplantation in the HS-group was comparable with that of controls. The higher serum creatinine observed during the first seven post-transplant days in the PS-group could be related to higher donor age and haemodynamic instability, and recipient male preponderance, rather than to HES itself.

Adult↗
PubMed1999

Genomic organization of human JAK2 and mutation analysis of its JH2-domain in leukemia.

The Janus kinase family of proteins, with four mammalian members (JAK1, JAK2, JAK3 and TYK2), plays an essential role in the signal transduction pathway from non-catalytic cytokine receptors to the nucleus. We recently reported the involvement of ETV6-JAK2 fusion genes in the development of leukemia of both lymphoid and myeloid origin. Dominant missense mutations of hopscotch, a Drosophila JAK homologue, causing leukemia-like defects were described. One of these mutations affected a conserved residue of the kinase- like JH2 domain and the introduction of this mutation in murine Jak2 resulted in the constitutional activation of its kinase activity. In order to further analyze its role in leukemogenesis, we cloned human JAK2 and determined its genomic organization. Twenty-four exons spanning a region of approximately 150 kb were identified. A mutation analysis of the exons 13 to 19, encoding the kinase-like JH2 domain failed to detect activating mutations in leukemia samples, suggesting that this is a rare event in human leukemia.

Blotting, Northern↗
PubMed1998

Transformation of hematopoietic cell lines to growth-factor independence and induction of a fatal myelo- and lymphoproliferative disease in mice by retrovirally transduced TEL/JAK2 fusion genes.

Recent reports have demonstrated fusion of the TEL gene on 12p13 to the JAK2 gene on 9p24 in human leukemias. Three variants have been identified that fuse the TEL pointed (PNT) domain to (i) the JAK2 JH1-kinase domain, (ii) part of and (iii) all of the JH2 pseudokinase domain. We report that all of the human TEL/JAK2 variants, and a human/mouse chimeric hTEL/mJAK2(JH1) fusion gene, transform the interleukin-3 (IL-3)-dependent murine hematopoietic cell line Ba/F3 to IL-3-independent growth. Transformation requires both the TEL PNT domain and JAK2 kinase activity. Furthermore, all TEL/JAK2 variants strongly activated STAT 5 by phosphotyrosine Western blots and by electrophoretic mobility shift assays (EMSA). Mice (n = 40) transplanted with bone marrow infected with the MSCV retrovirus containing either the hTEL/mJAK2(JH1) fusion or its human counterpart developed a fatal mixed myeloproliferative and T-cell lymphoproliferative disorder with a latency of 2-10 weeks. In contrast, mice transplanted with a TEL/JAK2 mutant lacking the TEL PNT domain (n = 10) or a kinase-inactive TEL/JAK2(JH1) mutant (n = 10) did not develop the disease. We conclude that all human TEL/JAK2 fusion variants are oncoproteins in vitro that strongly activate STAT 5, and cause lethal myelo- and lymphoproliferative syndromes in murine bone marrow transplant models of leukemia.

Animals↗
PubMed1998

Nimesulide-induced acute hepatitis: evidence from six cases.

BACKGROUND/AIMS: A number of nonsteroidal anti-inflammatory drugs have been reported to provoke hepatic injury. Nimesulide is a new agent of the sulfonanilide class, and is a more selective inhibitor of cyclooxygenase type 2 than of type 1. Well-documented cases of acute hepatitis have not yet been reported with this drug. We report on six patients who developed acute liver damage after initiation of nimesulide. METHODS: Between April 1996 and January 1997, six patients with apparent nimesulide-induced liver injury were admitted. Clinical, laboratory, serologic, radiological, and histologic data of all six cases were extensively analyzed. The causal relationship between nimesulide and liver injury was assessed, using a scoring system elaborated by the French and International consensus meeting group. RESULTS: Four women developed a centrilobular (three) or panlobular (one) bridging necrosis, whereas two men showed a bland intrahepatic cholestasis. Jaundice was the presenting symptom in five of the six cases. One patient with hepatocellular necrosis and one with cholestasis had hallmarks of hypersensitivity with an increased blood and tissue eosinophilia. The causal relationship could be designated as "highly probable" in one, "probable" in four, and "possible" in one patient. One patient died from a pancreatic tumor 5 months after the diagnosis of toxic liver injury. In all other patients, liver tests returned to completely normal values within a late follow-up period of 6 to 17 months. CONCLUSIONS: Nimesulide-induced liver injury can present with hepatocellular necrosis or with pure cholestasis. From clinical and histologic data, it appears that both immunologic and metabolic idiosyncratic reactions can be invoked as the pathogenic mechanisms of nimesulide-induced liver disease.

Acute Disease↗
PubMed1998

Enalapril increases antioxidant enzyme activity in renal cortical tissue of five-sixths-nephrectomized rats.

In rats with five-sixths nephrectomy (remnant kidney), blood pressure, glomerulosclerosis, and proteinuria are significantly reduced by administration of the angiotensin-converting enzyme inhibitor enalapril, during 16 weeks after reduction of the nephron number. The activity of catalase in remnant-kidney cortex homogenate is not influenced by enalapril treatment; the activities of superoxide dismutase and glutathione peroxidase are significantly increased. Elevated lipid peroxidation in cortex homogenates, evaluated by malondialdehyde and 4-hydroxynonenal concentrations, is not changed by treatment. Supplementation of dietary vitamin E to enalapril treatment does not alter antioxidant enzyme activities when compared to enalapril monotherapy. These results show that enalapril improves the balance between reactive oxygen intermediates and antioxidant enzymes in the remnant-kidney cortex of the rat. This finding may in part explain the protective effect of angiotensin-converting enzyme inhibitors on the progression of glomerulosclerosis.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Fusion of TEL, the ETS-variant gene 6 (ETV6), to the receptor-associated kinase JAK2 as a result of t(9;12) in a lymphoid and t(9;15;12) in a myeloid leukemia.

Translocations in hematologic disease of myeloid or lymphoid origin with breakpoints at chromosome band 12p13 frequently result in rearrangements of the Ets variant gene 6 (ETV6). As a consequence either the ETS DNA-binding domain or the Helix-Loop-Helix (HLH) oligomerization domain of ETV6 is fused to different partner genes. We show here that a t(9;12)(p24;p13) in a case of early pre-B acute lymphoid leukemia and a t(9;15;12)(p24;q15;p13) in atypical chronic myelogenous leukemia in transformation involve the ETV6 gene at 12p13 and the JAK2 gene at 9p24. In each case different fusion mRNAs were found, with only one resulting in an open reading frame for a chimeric protein consisting of the HLH oligomerization domain of ETV6 and the protein tyrosine kinase (PTK) domain of JAK2. The cloning of the complete human JAK2 coding and genomic sequences and of the genomic junction fragments of the translocations allowed a characterization of the different splice events leading to the various mRNAs. JAK2 plays a central role in non-protein tyrosine kinase receptor signaling pathways, which could explain its involvement in malignancies of different hematologic lineages. Besides hop in Drosophila no member of the JAK family has yet been implicated in tumorigenesis.

Amino Acid Sequence↗
PubMed1997

Fusion of ETV6 to MDS1/EVI1 as a result of t(3;12)(q26;p13) in myeloproliferative disorders.

We identified a fusion between ETV6 on 12p13 and MDS1/EVI1 on 3q26 in a t(3;12)(q26;p13) found in two cases of myeloproliferative disorder. The resulting chimeric transcript consists of the first two exons of ETV6 fused to MDS1 sequences, which in turn is fused to the second exon of the EVI1 gene. It has recently been reported that MDS1 can be expressed in normal tissues both as a single gene and fused to EVI1. ETV6 does not contribute any known functional domain to the predicted fusion protein. Association with blast crisis and myelodysplastic syndrome-derived leukemia, bad prognosis, and relative complex karyotype are in agreement with observations made in other cases of t(3;12)(q26;p13). Furthermore, a comparison can be made with the formation of an AML1/MDS1/EVI1 fusion gene in translocations (3;21)(q26;q22).

Adult↗
PubMed1997

Hemophagocytic syndrome and T-cell lymphoma after kidney transplantation: a case report.

Lymphoma in immunocompromised transplant patients is a feared cause of morbidity and mortality. Superimposed on the lymphoma and the transplantation immunosuppression is a rare condition: hemophagocytic syndrome (HS). HS is characterized by fever, hepatosplenomegaly and lymphadenopathy, skin rashes, jaundice, coagulopathy, and phagocytosis of blood elements with pancytopenia. Here we describe a rare but fatal case of a kidney transplant patient who developed T-cell lymphoma and HS, without evidence of EBV replication. A short review of the diagnosis, treatment, and prognosis of HS is given.

Fatal Outcome↗
PubMed1996

Biallelic alterations of both ETV6 and CDKN1B genes in a t(12;21) childhood acute lymphoblastic leukemia case.

Recently, a new recurrent t(12;21)(pl3;q22) has been identified in a B-cell lineage childhood acute lymphoblastic leukemia (ALL). The translocation results in a fusion of two known genes, ETV6/TEL (12p13) and AML1 (21q22), previously shown to be involved in the pathogenesis of myeloid disorders. We report results of cytogenetic fluorescence in situ hybridization and molecular studies of a B-cell childhood common ALL with a cryptic 12;21 translocation. Aberrations identified in this case involve both chromosomes 12 and include not only the ETV6-AML1 gene fusion and two different microdeletions of ETV6 but also the hemizygous loss of CDKN1B, D12S119, and KRAS2 loci and a putative rearrangement of the second CDKN1B allele as a result of an inv(12)(p13q24). Moreover, it was shown that the AML1-ETV6 reciprocal chimeric transcript was not present in the malignant cells, and hence may not play a major role in leukemogenesis. In addition, the putative loss of wild-type function of CDKN1B and ETV6 could indicate a synergistic effect of both genes in the pathogenesis of this leukemia case.

Adolescent↗
PubMed1996

Identification of a gene encoding a homocitrate synthase isoenzyme of Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, most of the LYS structural genes have been identified except the genes encoding homocitrate synthase and alpha-aminoadipate aminotransferase. Expression of several LYS genes responds to an induction mechanism mediated by the product of LYS14 and an intermediate of the pathway, alpha-aminoadipate semialdehyde (alpha AASA) as an inducer. This activation is modulated by the presence of lysine in the growth medium leading to an apparent repression. Since the first enzyme of the pathway, homocitrate synthase, is feedback inhibited by lysine, it could be a major element in the control of alpha AASA supply. During the sequencing of chromosome IV of S. cerevisiae, the sequence of ORF D1298 showing a significant similarity with the nifV gene of Azotobacter vinelandii was reported. Disruption and overexpression of ORF D1298 demonstrate that this gene, named LYS20, encodes a homocitrate synthase. The disrupted segregants are able to grow on minimal medium and exhibit reduced but significant homocitrate synthase indicating that this activity is catalysed by at least two isoenzymes. We have also shown that the product of LYS20 is responsible for the greater part of the lysine production. The different isoforms are sensitive to inhibition by lysine but only the expression of LYS20 is strongly repressed by lysine. The N-terminal end of homocitrate synthase isoform coded by LYS20 contains no typical mitochondrial targeting sequence, suggesting that this enzyme is not located in the mitochondria.

Amino Acids↗
PubMed1996

Granulocytic sarcoma (chloroma): a report of two cases.

Granulocytic sarcoma or chloroma is defined as an extramedullary solid tumor, composed of granulocytic precursor cells at various levels of differentiation. Granulocytic sarcoma is mostly associated with acute and chronic leukemia, rarely with polycythemia vera and myelofibrosis. The use of special immuno-histochemical stains is mandatory, because this tumor is often misdiagnosed as malignant lymphoma. We report two cases of granulocytic sarcoma (tonsil and ovary) associated with chronic myelogenous leukemia. We describe the first reported association of atypical CML and granulocytic sarcoma.

Adult↗
PubMed1996

Epidural abscess: case report and review of the literature.

Spinal epidural abscess is an uncommon site of infection, resulting in back pain, fever, weakness and loss of sensibility. These signs should suggest the diagnosis, and quick confirmation by MRI should be performed. Immediate surgical decompression and antibiotherapy is necessary, because this is the base of a possible successful functional recovery. Empiric therapy consisting of high dose of penicillinase-resistant antibiotics is advised because most often an epidural abscess is caused by Staphylococcus aureus. However, because other bacteria can be involved, an aminoglycoside or a cephalosporin should be added to the empiric treatment, until the results of the cultures are known. When diagnosis and therapy are delayed, permanent paralysis and death are common.

Abscess↗
PubMed1996

The 6-minute walk as an appropriate exercise test in elderly patients with chronic heart failure.

BACKGROUND: The value of the 6-minute walk in a population of elderly patients with chronic heart failure (CHF) has not yet been established, as it has been in a younger population. METHODS: In a prospective trial, 2 exercise tests were compared: the 6-minute walk (6 MW) and a treadmill test with progressive increments in workload. 37 patients (mean age 81.3, SD 5.6 years): 11 untrained controls, 16 patients with New York Heart Association (NYHA) class II and 10 patients with NYHA class III participated. The main outcome measures were the distance walked in 6 minutes, the symptomatic VO2max in the progressive treadmill test and the degree of CHF as scored by the NYHA classification and the Boston Study Group (BSG) score. RESULTS: For both the 6 MW and the treadmill test there was a significant difference in distance between NYHA class II and III patients (p < .001), between the controls and NYHA class III patients (p < .001), but not between the controls and NYHA class II patients. The distance walked in the 6 MW was well correlated with the distance walked in the treadmill test (p < .001). Eight participants (22%), however, were unable to perform this treadmill test and 6 participants (17%) covered very low distances compared to the 6 MW. The VO2max was lower in NYHA class III than in class II patients (p = .032). NYHA classification and BSG score correlated reasonably well. CONCLUSION: A treadmill exercise test with VO2max measurement in elderly patients with CHF is difficult to accomplish. On the contrary, the 6 MW gives a good impression of the remaining exercise capacity. It is well correlated with the treadmill test. The 6 MW is well tolerated by elderly patients and differentiates between NYHA classes II and III. Untrained controls could not be differentiated from NYHA class II patients.

Aged↗
PubMed1996

Genomic organization of TEL: the human ETS-variant gene 6.

We have constructed a detailed map of the genomic region containing the ETS-variant gene 6 (ETV6), involved in translocations and deletions associated with hematologic malignancies. Thirty-eight cosmids were characterized belonging to two contigs spanning 340 kb, and an EcoRl restriction map was developed. The gap between the two contigs, 2 kb in size, was closed by PCR. The contigs contain the complete coding sequence and the 5' and 3' UTRs of ETV6. Eight exons accounting for the ETV6 cDNA sequence were identified. The helix-loop-helix (HLH) motif is coded by exons 3 and 4, whereas exons 6-8 code for the ETS DNA-binding domain. All introns show consensus 5' donor and 3' acceptor splice sites. Introns 1 and 2 span 100 and 82 kb, respectively, and introns 3-7 range from 15 to 1.3 kb. An alternative exon 1 (exon 1B) is localized in intron 2. The 5' end of the ETV6 gene is associated with a CpG island characterized by the presence of four Notl, four Sacll, and three BssHll recognition sites and several SP1- and AP2-binding motifs. Alternative polyadenylation at the 3' end of the ETV6 gene generates the three transcripts of 6200, 4300, and 2400 nucleotides, respectively. The ETV6 gene spans 240 kb and is flanked at its 5' and 3' end by D12S1697 and D12S98, respectively. The markers D12S1095 and D12S89 are located in the first intron. Two new DNA polymorphisms were identified in the ETV6 gene, which will be useful for the analysis of loss of heterozygosity reported for the ETV6 gene in leukemia.

Base Sequence↗
PubMed1996

99Tcm-DMSA renal scintigraphy for acute pyelonephritis in adults: planar and/or SPET imaging?

A number of authors have indicated a more sensitive detection of renal cortical defects using single photon emission tomography (SPET) compared with planar imaging when performing 99Tcm-dimer-captosuccinic acid (99Tcm-DMSA) renal scintigraphy. The place of SPET in the evaluation of kidneys in adults suspected of acute pyelonephritis (APN) remains controversial, however. The aim of this study was to address the role of SPET in adult patients suspected of having APN. Planar and SPET 99Tcm-DMSA renal imaging was performed in 53 patients. The data sets were separated and presented in random order to three independent observers. The kidneys were divided into three segments, which were classified as normal, definitely abnormal or equivocal. Ir. a second step, the number of lesions (definite or equivocal) on planar and SPET imaging were counted. The overall concordance between the planar and SPET imaging scores was 90.9, 89.9 and 87.7% for the three observers, respectively. Inter-observer discordance was recorded in a small percentage of both planar and SPET images. The number of lesions, based on the average of the three observers, was 22 for planar and 25 for SPET imaging. Obvious differences between observers were noted. The planar images were more often interpreted as equivocal by the least experienced observer. The more experienced observers gained limited additional information using SPET routinely. Most equivocal lesions on the planar scintigrams were observed in the lower segment. For SPET, no such distribution was noted. High-quality 99Tcm-DMSA images allow the detection of the same number of lesions as SPET in adults suspected of APN.

Acute Disease↗