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Biomedical subjects

D de Jong

Publications and source records attributed to D de Jong.

At least 19 recordsLinked to original sources
PubMed1997

Hepatocyte growth factor/scatter factor promotes adhesion of lymphoma cells to extracellular matrix molecules via alpha 4 beta 1 and alpha 5 beta 1 integrins.

Hepatocyte growth factor (HGF)/scatter factor (SF) is the ligand for a tyrosine kinase cell surface receptor encoded by the MET protooncogene (c-MET). HGF/SF can induce proliferation and motility in epithelial cells and promotes invasion of carcinoma cells and NIH3T3 fibroblasts transfected with both HGF/SF and c-MET genes. Our results show that HGF/ SF and c-MET also play a role in adhesion and invasion of human lymphoma cells. c-MET mRNA is expressed in hemopoietic cells, such as hemopoietic progenitor cells (CD34+ cells) in bone marrow (BM) and mobilized peripheral blood, immature B cells in cord blood and BM, and germinal center B-centroblasts. In normal peripheral blood B cells, which are c-MET-, c-MET expression was induced by PMA, ConA, HGF/ SF, and Epstein-Barr virus (EBV) infection. Using immunohistochemistry, we detected c-MET on the cell surface of large activated centroblasts in lymph nodes from patients with B-non-Hodgkin's lymphoma and Hodgkin's disease. In the latter group, c-MET expression correlated well with the presence of EBV. Because HGF/SF and c-MET promote metastasis of carcinoma cells, we studied the effects of c-MET stimulation by HGF/SF of B-lymphoma cells on properties relevant for metastasis, ie, adhesion, migration, and invasion. HGF/SF stimulated adhesion of the c-MET+ B-cell lines to the extracellular matrix molecules fibronectin (FN) and collagen (CN) in a dose dependent manner. However, adhesion to laminin was not affected by HGF/SF. Adhesion to FN was mediated by beta 1-integrins alpha 4 beta 1 (VLA4) and alpha 5 beta 1 (VLA5) since blocking antibodies against beta 1- (CD29), alpha 4-(CD49d), or alpha 5- (CD49e) integrin subunits, completely reversed the effect of HGF/SF. Furthermore, HGF/SF induced adhesion was abrogated by addition of genistein, which blocks protein tyrosine kinases, including c-MET. Addition of HGF/SF resulted in a sixfold increase in migration of c-MET B-lymphoma cells through Matrigel, compared to medium alone. In rat fibroblast cultures, HGF/SF doubled the number of c-MET+ B-lymphoma cells that invaded the fibroblast monolayer. In these adhesion, migration and invasion assays HGF/SF had no effect on c-MET- cell lines. In conclusion, c-MET is expressed or can be induced on immature, activated, and certain malignant B cells. HGF/SF increased adhesion of c-MET+ B-lymphoma cells to FN and CN, mediated via beta 1-integrins alpha 4 beta 1 and alpha 5 beta 1, and furthermore promoted migration and invasion.

Cell Adhesion↗
PubMed1997

Histological grading in gastric lymphoma: pretreatment criteria and clinical relevance.

BACKGROUND & AIMS: Stomach-conserving therapy in primary gastric non-Hodgkin's lymphoma (mucosa-associated lymphoid tissue [MALT]-NHL) is increasingly gaining importance as an alternative to surgery. As a consequence, surgical pathologists have to define histological criteria in pretreatment endoscopic biopsy specimen samples not only to make the diagnosis but also to recognize minor tumor components that may infer a significantly adverse impact on prognosis. The aim of this study was to define histological criteria for clinically significant tumor progression in pretreatment endoscopic biopsy specimens. METHODS: In a consecutive series of 106 patients with gastric MALT-NHL, the prognostic impact of large cell components was assessed by semiquantitative analysis of clusters and diffusely intermingled malignant blasts. RESULTS: In low-grade MALT-NHL, a category with a diffuse large cell component of 1%-10% with or without nonconfluent clusters of blasts could be separated with a significantly worse prognosis (10-year disease-specific survival, 90% vs. 75%). No clinical parameters of known prognostic significance could account for this difference. CONCLUSIONS: It is possible to define criteria in endoscopic biopsy specimens to recognize clinically relevant tumor progression. To serve as a guideline in the choice of treatment, these criteria should be validated prospectively in future clinical trials.

Adult↗
PubMed1997

Release of lipopolysaccharide toxicity-modulating proteins in patients undergoing cardiopulmonary bypass using noncoated and heparin-coated extracorporeal circuits. A clinical pilot study.

STUDY OBJECTIVE: Cardiopulmonary bypass (CPB) induces a generalized inflammatory response, including activation of leukocytes, contributing to postoperative morbidity. The inflammatory pathways leading to this systemic inflammatory response syndrome are considered identical to those involved in septic shock. Therefore, we studied the release of bactericidal/permeability-increasing protein (BPI), lipopolysaccharide binding protein (LBP), and soluble CD14 (sCD14)-all proteins that modulate the effects of lipopolysaccharide (LPS)-in patients undergoing CPB. In addition, the effect of heparin coating of the extracorporeal bypass circuit on the release of these parameters was assessed. DESIGN: Prospective, randomized clinical pilot study. SETTING: Cardiothoracic Surgery Department in a university hospital. PATIENTS: Fourteen patients undergoing elective coronary artery bypass grafting were included. Seven patients underwent CPB using a standard, noncoated extracorporeal circuit, and seven patients had CPB using a heparin-coated extracorporeal circuit (Duraflo II). INTERVENTIONS: Blood samples were taken after induction of anesthesia, just before aortic crossclamping, and 0, 0.5, 1.5, 3, 6, 12, and 24 h after declamping. MEASUREMENTS AND RESULTS: CPB with a noncoated extracorporeal circuit induced a sharp increase in neutrophil-derived BPI, manifest directly after release of the aortic crossclamp, which was significantly attenuated using a heparin-coated system. Also, CPB induced a gradual increase of the acute-phase reactant LBP, which was identical in the noncoated and heparin-coated groups. Systemic release of sCD14 after crossclamp release was significantly higher in the noncoated group compared with the heparin-coated group, but did not rise above baseline levels. CONCLUSIONS: These data confirm that CPB-induced leukocyte activation is attenuated using a heparin-treated extracorporeal circuit and point to the possible role of LPS toxicity-modulating proteins in the systemic inflammatory response after bypass surgery.

Acute-Phase Proteins↗
PubMed1996

Major role for a 3p21 region and lack of involvement of the t(3;8) breakpoint region in the development of renal cell carcinoma suggested by loss of heterozygosity analysis.

In a loss of heterozygosity analysis of 3p, we examined 44 sporadic cases of renal cell carcinoma (RCC) and matched normal tissue with 18 markers distributed over the whole p-arm. The majority of these markers clustered in three regions that have been suggested to be involved in the development of RCC, namely the p25 region, where the von Hippel Lindau (VHL) gene is located; the p21 region, which has been identified as a common region of overlap (SRO) of heterozygous deletions; and the p14 region, which is the location of the constitutional t(3;8) breakpoint occurring in an RCC family. Thirty-one out of these 44 tumors were analyzed with 9 additional markers from the 3p12-14 region to further delimit the SRO in this region. Our analysis shows that when deletions were detected the 3p21 region was always included. The 3p21 markers D3F15S2 and UBEIL were always contained within these 3p21 deletions. The t(3;8) breakpoint region showed the lowest percentage of loss of heterozygosity. Moreover, in three cases the t(3;8) breakpoint region retained heterozygosity, whereas a region more proximal to the breakpoint showed allelic losses. This supports exclusion of the t(3;8) region from a role in the development of sporadic RCC. In a number of tumors, two or three 3p regions with allelic losses were present separated by a region of retention of heterozygosity. In these tumors, deletions at 3p21 occurred in combination with deletions of either the VHL region, or the region proximal to the t(3;8), or both, suggestive of multiple gene involvement in the development of sporadic RCC with a primary role of the 3p21 region.

Carcinoma, Renal Cell↗
PubMed1996

Effect of the putative dopamine D1 agonist and D2 antagonist FCE 23884 on Parkinson's disease.

The ergoline derivative FCE 23,884 acts as a dopamine D1 agonist in untreated parkinsonian animals and as a D2 antagonist in animals whose dopamine system is intact or levodopa treated. To evaluate whether this dual action might benefit patients with Parkinson's disease (PD) who have developed levodopa-induced dyskinesias, the motor effects of FCE 23,884 were examined in seven such individuals using a double-blind, placebo-controlled design. At doses up to the maximum tolerated dose (3.5 +/- 0.5 mg), FCE 23,884 monotherapy did not affect parkinsonian severity. On the other hand, coadministration of FCE 23,884 with a mildly dyskinetic dose of levodopa, infused intravenously under steady-state conditions, reduced the antiparkinson response by 54 +/- 19% and tended to diminish dyskinesia severity. The results thus fail to suggest any useful role for FCE 23,884 in the symptomatic treatment of PD. Although D2 receptor blockade provided by FCE 23,884 antagonizes both the antiparkinson and dyskinesigenic responses to levodopa, the degree of D1 receptor stimulation appears insufficient to ameliorate parkinsonian symptomatology.

Aged↗
PubMed1996

Laparoscopic rectopexy for complete rectal prolapse. Clinical outcome and anorectal function tests.

BACKGROUND: The purpose of this study was to evaluate the clinical outcome of laparoscopic rectopexy and its effect on anorectal function investigations. METHODS: Twelve patients with complete rectal prolapse without constipation underwent laparoscopic rectopexy. Pre- and postoperative evaluation included scoring of incontinence, anorectal manometry, and anal endosonography. RESULTS: No recurrences of rectal prolapse were seen (median follow-up 19 months). Continence improved in eight of nine preoperatively incontinent patients. Two patients had mild constipation after surgery. Median maximum basal pressure measured by anorectal manometry increased from 20 to 25 mmHg (p = 0.005) and the rectoanal inhibitory reflex improved in seven patients (p = 0.03). Rectal sensitivity did not change significantly. Endosonography showed asymmetry and thickening of the internal anal sphincter and submucosa preoperatively. After surgery the maximum internal anal sphincter thickness decreased from 3.0 mm to 2.6 mm (p = 0.02). CONCLUSIONS: Laparoscopic rectopexy improved continence in our patients. Anorectal function tests show a partial recovery of the internal anal sphincter. Laparoscopic rectopexy combines the low morbidity of minimal invasive surgery with the good outcome of abdominal rectopexy.

Aged↗
PubMed1996

Gastric non-Hodgkin lymphomas of mucosa-associated lymphoid tissue are not associated with more aggressive Helicobacter pylori strains as identified by CagA.

Primary gastric non-Hodgkin lymphoma of mucosa-associated lymphoid tissue (MALT-NHL) is strongly related to Helicobacter pylori (H pylori) infection. CagA positive H pylori strains appear to be more aggressive, as reflected by a greater degree of gastric inflammation and higher levels of Il-8 production. Using a polymerase chain reaction-based assay, cagA status was determined in H pylori strains of 12 patients with gastric MALT-NHL, 38 patients with peptic ulcer disease, and 39 patients with non-ulcer dyspepsia. CagA-positive H pylori strains were significantly more frequent in peptic ulcer disease than in non-ulcer dyspepsia (Fisher's exact test p <0.001). An increased frequency of CagA-positive strains was not identified in gastric MALT-NHL compared to non-ulcer dyspepsia patients (Fisher's exact test P <.3). Therefore, it can be concluded that infection with more aggressive strains is associated with the development of peptic ulcer disease, but plays a minor role, if any, in the development of gastric MALT-NHL.

Adult↗
PubMed1996

Primary health care replacing hospital care--the effect on quality of care.

In order to change current practice concerning hospital stays, a project was initiated in which shortening hospital stay was combined with shifting care to primary health care. Research was aimed at assessing quality of care of shortened hospital stays with home care by the community nurse and/or the general practitioner (GP). A randomized clinical trial was conducted with three subgroups: 1. traditional hospital stay; 2. hospital admission on the day of surgery, discharge the day after; two consultations at the outpatient department; one visit by the community nurse before surgery, two visits after; 3. mostly as for 2. with two GP visits replacing the two consultations at the outpatient department. The selected surgical procedures were: laparoscopic cholecystectomy, varicose veins, removal of osteosynthesis material, hernia surgery and other minor surgery (normal hospital stay 4-6 days). Every motivated patient meeting the inclusion criteria entered the study. During one year 120 patients were thus selected. Only minor differences were found between the three subgroups in the resulting quality of care. It is concluded that late admission and early discharge even without after discharge care is feasible in most cases for healthy patients.

Health Services Research↗
PubMed1996

Human immunodeficiency virus type 1 drug susceptibility determination by using recombinant viruses generated from patient sera tested in a cell-killing assay.

A simple approach for the determination of drug susceptibilities by using human immunodeficiency virus type 1 (HIV-1) RNA from the sera of patients is described. HIV-1 RNA was extracted from patient sera, and the 5' part of the reverse transcriptase (RT) gene was transcribed into DNA and amplified in a nested PCR. The amplified fragment covers the 3' part of the protease gene and amino acids 1 to 304 of the RT gene. This fragment can be introduced through homologous recombination, as described previously, into a novel HIV-1 reference strain (pHXB2 delta 2-261RT) from which amino acids 2 to 261 of RT have been deleted. The resulting recombinant virus expresses all properties of the HXB2 reference strain except for those encoded by the introduced part of the patient RT gene. Recombinant viruses were subsequently tested for drug susceptibility in a microtiter format killing assay [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay] as well as in the standard HeLa CD4+ plaque reduction assay. Similar susceptibility profiles were obtained by each assay with recombinant viruses derived from patients receiving alternating nevirapine and zidovudine treatment or lamivudine-zidovudine combination therapy. In conclusion, this approach enables high-through-put determination of the drug susceptibilities of serum RNA-derived RT genes, independent of the patient's viral background, and generates the possibility of relating changes in susceptibility to changes in viral genotypes.

Anti-HIV Agents↗
PubMed1996

Primary non-Hodgkin lymphoma of the stomach: endoscopic pattern and prognosis in low versus high grade malignancy in relation to the MALT concept.

BACKGROUND: Various histological classifications developed for nodal lymphomas failed to be of value in extranodal lymphomas. More recently, gastric lymphoma is considered to represent a distinctive group derived from mucosa associated lymphoid tissue (MALT). AIM: To study the prognostic value of malignancy grading based on the concept that most gastric lymphomas are of MALT origin, the endoscopic as well as clinical characteristics in 114 patients with primary gastric non-Hodgkin's lymphoma were evaluated. RESULTS: In univariate analysis, patients with low grade lymphoma (n = 51) were younger, had less advanced stage, and less frequently bulky disease than those with high grade lymphoma (n = 63). In multivariate analysis weight loss and increased erythrocyte sedimentation rate were significantly less frequent in low grade (45% and 22%) compared with high grade lymphoma (75% and 53%). In low grade lymphoma endoscopic findings were often interpreted as a benign condition (27 of 51), in contrast with high grade lymphoma, where carcinoma was most frequently (37 of 63) suspected. In low grade lymphoma complete remission rate was 92%, and five year survival 75%, In high grade lymphoma results were significantly less favourable (p = 0.0001): complete remission in 68%, and a five year survival of 46%. CONCLUSION: Malignancy grading was strongly correlated with treatment outcome; endoscopically low grade lymphoma was often hard to distinguish from benign conditions, whereas high grade lymphoma often revealed carcinoma-like features.

Adult↗
PubMed1996

Ordering of polymorphic markers in the chromosome region 3p21.

Starting from five markers, with a well-defined order from distal to proximal 3p21, nine other markers could be inserted in this 3p21 map. Five were precisely mapped genetically. The other markers were ordered by FISH and/or deletion hybrid mapping. The overall 3p21 order from distal to proximal is as follows: D3S1298-D3S1260-(D3S966, D3S1448 (= D3S1449)-D3S1029-D3S32-D3S643-D3F15S2 -D3S2968-D3S1235-D3S1289-D3S1447-D3S1295.

Chromosome Mapping↗
PubMed1996

Clinical significance of bcl2 and p53 protein expression in diffuse large B-cell lymphoma: a population-based study.

PURPOSE: We studied the prognostic significance of bcl2 and p53 protein expression in relation to clinical and pathologic characteristics in patients with diffuse large B-cell lymphoma (LCL). PATIENTS AND METHODS: Three hundred seventy-two patients with LCL were retrieved from a population-based registry for non-Hodgkin's lymphoma (NHL). bcl2 and p53 protein expression was studied on paraffin-embedded tumor tissue by immunohistochemistry in relation to clinical factors. Response to therapy and survival were analyzed in 165 patients who were uniformly staged and treated and for whom all prognostic data were available according to the International Prognostic Index (IPI). RESULTS: Forty-five percent of tumors showed strong expression of the bcl2 protein (bcl2++), with a higher frequency in patients with primary nodal involvement. Disease-free survival (DFS) was significantly better in bcl2-negative/intermediate (bcl2-/+) cases as compared with bcl2++ cases (P = .0011). At 5 years, bcl2-/+ patients showed a DFS rate of 74%, in contrast to bcl2++ patients with a DFS rate of 41% (P = .002). Bcl2 was the strongest independent prognostic value in a multivariate analysis, with a relative risk (RR) of 3.0 in comparison to p53 expression and the clinical factors of the IPI. Overall survival (OS) was not significantly influenced by bcl2 protein expression. p53 protein expression was found in 13% of cases, with a higher frequency in patients with extensive disease. p53 expression did not influence the chance to achieve complete remission (CR) and survival. CONCLUSION: bcl2 protein is frequently expressed in LCL and is a strong independent prognostic factor for DFS. p53 expression is related with high tumor burden, but is not an independent risk factor for CR and survival.

Adult↗
PubMed1996

Extensive mutation scanning of RET in sporadic medullary thyroid carcinoma and of RET and VHL in sporadic pheochromocytoma reveals involvement of these genes in only a minority of cases.

Sporadic medullary thyroid carcinoma (MTC) and pheochromocytoma (PC) have been reported to be associated with some specific RET gene mutations. To assess the role of RET in the development of MTC and PC, we screened 14 sporadic MTC, two MTC-derived cell lines, and 5 sporatic PC cases of RET mutations by a systematic analysis of the whole coding sequence, including all intron-exon junctions. In only 6 of the 14 sporadic MTC we were able to detect a RET mutation. Apart from the MET918-->Thr mutation in 5 of the MTC cases, we found a 3-bp deletion in exon 11, only present in the tumor, in another case. Analysis of 2 cell lines revealed the Met918-->Thr mutation in 1 and a Cys634-->Trp mutation in the other cell line. A possible somatic nature of these mutations could not be confirmed because in neither case was constitutive DNA available. We conclude that a large proportion of sporadic MTC must be due to mutations in an unidentified gene(s) other than RET. In none of the sporadic PC cases was a RET mutation found. As PC is a frequent complication in families suffering from von Hippel Lindau disease, for which mutations of the VHL gene are responsible, we also screened the 5 sporadic PC cases for VHL mutations. This revealed a Gly164-->Ser mutation in a single specimen. Thus, in PC, a large majority of tumors are due to mutations in an unidentified gene(s) other than RET and VHL.

Adrenal Gland Neoplasms↗
PubMed1995

A novel human cDNA highly homologous to the fish hormone stanniocalcin.

Stanniocalcin is a glycoprotein hormone previously considered present only in bony fish where it is secreted by the corpuscles of Stannius, endocrine organs involved in Ca2+ homeostasis. In fish, stanniocalcin was thought to be an adaptation for Ca2+ regulation in aquatic environments, and its effects include inhibition of gill Ca2+ transport. We have obtained a human cDNA clone coding for a protein highly homologous to fish stanniocalcin. The mRNA is expressed in many human tissues, with the highest levels in ovary, prostate and thyroid. In vitro human cell culture studies show that the mRNA is positively regulated by extracellular Ca2+ in the medium. We conclude that a human protein similar to the fish hormone is expressed in multiple tissues rather than by a specialized endocrine organ.

Amino Acid Sequence↗
PubMed1995

Lymphoma-associated translocation t(14;18) in blood B cells of normal individuals.

Successive oncogenic steps are necessary to generate cancer. In many B-cell lymphomas, chromosomal translocations are considered to be an early oncogenic hit. We investigated whether the lymphoma-associated t(14;18) involving the BCL2 oncogene can occur outside the context of malignancy. To this end, we extensively screened blood cells from healthy blood donors by a very sensitive seminested polymerase chain reaction (PCR) for breakpoint junctions at JH1-5 on 14q32 and the major breakpoint region of BCL2 on 18q21. In each individual, mononuclear cells, granulocytes, flow-sorted B cells, and T cells were separately tested in five to seven independently performed PCRs (in total, 0.5 x 10(6) to 1.0 x 10(6) cells per fraction per individual). Amplification products that hybridized with an internal BCL2 probe and a JH probe were sequenced. Six of nine individuals harbored t(14;18) breakpoints. Translocations were restricted to B cells, with an estimated frequency of 1 in 10(5) or less circulating B cells. In total, 23 of 51 experiments on B cells were positive in contrast to 1 of 48 on T cells and 2 of 47 experiments on granulocytes. Consistent with the presence of 4.7% to 13.0% B cells in the mononuclear cell fractions, only very few (4 of 47) tests were positive in these fractions. Sequence analysis showed that four of six individuals harbored two to five unrelated t(14;18)-carrying B-cell clones. All breakpoints had a structure similar to that in follicular lymphoma. We propose that B cells with the t(14;18) translocation are regularly generated in normal individuals, but that only very few cells with the translocation will acquire the additional oncogenic hits necessary to establish the malignant phenotype.

Adult↗
PubMed1995

Localization in situ of the co-stimulatory molecules B7.1, B7.2, CD40 and their ligands in normal human lymphoid tissue.

Functional interactions between B and T lymphocytes are known to depend on the expression of co-stimulatory molecules B7.1/CD80, B7.2/CD86 and their counter-receptors CD28 and CTLA4, as well as CD40 and its ligand CD40L. To study the role of these molecules in situ, an immunohistochemical analysis was carried out on normal human lymphoid tissue. In the germinal centers (GC), B7.1 and B7.2 were differentially expressed. In the dark zone, centroblasts were predominantly B7.1+, while centrocytes in the light zone were B7-2+, resulting in reversed gradients of both markers in GC. Follicle mantle cells were negative for B7.1 and B7.2. Macrophages and interdigitating dendritic cells (IDC) in T cell zones both expressed B7.1 and B7.2. Moreover, clusters of B7.2+ T cells were demonstrated in interfollicular areas. Intrafollicular CD4+ T cells in GC, predominantly in the apical light zone, expressed CD28 and CTLA4, as did the majority of interfollicular T cells. CTLA4 showed a striking excentric cytoplasmic staining, which was also seen on T cells activated in vitro. CD40 was expressed on all B cells and more strongly on macrophages and IDC. Moreover, small clusters of T cells in a rim outside the GC showed CD40 expression. CD40L was expressed both on intrafollicular CD4+ T cells as well as on T cells in T cell zones. The differential distribution of co-stimulatory molecules in different compartments of normal human lymphoid tissue in situ indicates that these interactions play a distinctive role in different stages of B cell differentiation and in the immune response.

Abatacept↗