PubMed Health⌕ Search

Biomedical subjects

Myriam Remmelink

Publications and source records attributed to Myriam Remmelink.

15 recordsLinked to original sources
PubMed2006

Imaging infection with 18F-FDG-labeled leukocyte PET/CT: initial experience in 21 patients.

UNLABELLED: The aim of this study was to assess the feasibility and the potential role of PET/CT with (18)F-FDG-labeled autologous leukocytes in the diagnosis and localization of infectious lesions. METHODS: Twenty-one consecutive patients with suspected or documented infection were prospectively evaluated with whole-body PET/CT 3 h after injection of autologous (18)F-FDG-labeled leukocytes. Two experienced nuclear medicine physicians who were unaware of the clinical end-diagnosis reviewed all PET/CT studies. A visual score (0-3)-according to uptake intensity-was used to assess studies. The results of PET/CT with (18)F-FDG-labeled white blood cell ((18)F-FDG-WBC) assessment were compared with histologic or biologic diagnosis in 15 patients and with clinical end-diagnosis after complete clinical work-up in 6 patients. RESULTS: Nine patients had fever of unknown etiology, 6 patients had documented infection but with unknown extension of the infectious disease, 4 patients had a documented infection with unfavorable evolution, and 2 patients had a documented infection with known extension. The best trade-off between sensitivity and specificity was obtained when a visual score of >or=2 was chosen to identify increased tracer uptake as infection. With this threshold, sensitivity, specificity, and accuracy were each 86% on a patient-per-patient basis and 91%, 85%, and 90% on a lesion-per-lesion basis. In this small group of patients, the absence of areas with increased WBC uptake on WBC PET/CT had a 100% negative predictive value. CONCLUSION: Hybrid (18)F-FDG-WBC PET/CT was found to have a high sensitivity and specificity for the diagnosis of infection. It located infectious lesions with a high precision. In this small series, absence of areas with increased uptake virtually ruled out the presence of infection. (18)F-FDG-WBC PET/CT for infection detection deserves further investigation in a larger prospective series.

Adolescent↗
PubMed2005

Prevention of pulmonary vascular remodeling and of decreased BMPR-2 expression by losartan therapy in shunt-induced pulmonary hypertension.

The renin-ANG system has been reported to be overexpressed in pulmonary arterial hypertension (PAH). We investigated the effects of ANG receptor-1 blockade by losartan on hemodynamics and signaling molecules in a piglet overflow model of early PAH. Twenty-six 3-wk-old piglets were randomized to placebo or losartan therapy (1 mg.kg(-1).day(-1)) after anastomosis of the inominate to the main pulmonary artery or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation, followed by pulmonary tissue sampling for morphometry, immunohistochemistry, and real-time quantitative-PCR. Chronic systemic-to-pulmonary shunting increased the pulmonary vascular resistance from 2.5 +/- 0.2 to 6.2 +/- 0.3 mmHg.l(-1).min.m(-2) and arteriolar medial thickness from 13.6 to 25.4%. These changes were associated with increased expressions of ANG II and its type 1 (AT1) and type 2 (AT2) receptors, endothelin-1 (ET-1) and its type B receptor (ETB), and angiopoietin-1, together with decreased expressions of bone morphogeneic protein receptor-1A and -2 (BMPR-1A and BMPR-2, respectively) and unchanged expression of the receptor tyrosine kinase with immunoglobulin and EGF homology domains-2 (Tie 2). Pretreatment with losartan decreased shunt-induced pulmonary vascular resistance and medial thickness by 51% and 35%, respectively. Losartan therapy was associated with persistent overexpressions of ANG II, AT2, ET-1, ETB, and angiopoietin-1 and with a return to normal of the BMPR-2 expression. These results suggest that ANG II contributes to left-to-right, shunt-induced PAH.

Animals↗
PubMed2005

Nuclear galectin-3 expression is an independent predictive factor of recurrence for adenocarcinoma and squamous cell carcinoma of the lung.

The tumor stage is the most powerful prognostic tool for predicting the survival rates of lung carcinoma patients. However, prognosis of individual patients is difficult in part because of the marked clinical heterogeneity among such patients. Galectins are involved in cell growth, apoptosis and cell migration features, and their diagnostic and prognostic values have already been demonstrated in various types of cancers. In the present paper we analyze the potential prognostic value of immunohistochemical galectin-3 expression in lung adenocarcinomas and squamous cell carcinomas. In all, 165 squamous cell carcinomas and 121 adenocarcinomas were immunostained for galectin-3. In each case the immunohistochemical analyses consisted of an evaluation of the percentage of tumor cells stained and the intensity of staining. An IP score (ie Intensity x Percentage) was thus determined for each lung carcinoma. A large majority of cases displayed galectin-3 expression. While the cytoplasmic staining in the squamous cell carcinomas was focal and moderately intense, the staining in the adenocarcinomas was diffuse and intense. The IP scores were significantly (P=0.0001) higher in the adenocarcinomas than in the squamous cell carcinomas. The difference in nuclear expression profiles between the two cancer types was statistically significant (P=0.0005). Cox multivariate analysis carried out on the patients' genders, the TNM classification and the galectin-3-related variables showed that of the galectin-3-related variables, only the nuclear location of galectin-3 was identified as a prognostic indicator of recurrence independent of the clinicopathological features characterizing the patients (P=0.02). The prognostic contribution of this latter variable was enhanced when the patients with relapse-free follow-ups longer than 8 months were considered (P=0.005). Galectin-3 immunohistochemical expression differs between squamous cell carcinomas and adenocarcinomas, but the nuclear expression of galectin-3 behaves as a significant prognostic predictor for all the cases as a group.

Adenocarcinoma↗
PubMed2005

Identification by means of cDNA microarray analyses of gene expression modifications in squamous non-small cell lung cancers as compared to normal bronchial epithelial tissue.

The present work analyzed the gene pattern profiles in 6 squamous non-small cell lung cancers (NSCLCs) versus 4 normal lung epithelial tissues by means of cDNA microarrays. In addition to cDNA microarray analyses, quantitative RT-PCR and immunohisto-chemical analyses were used to validate some of the results obtained. Our data enabled 7 genes to be selected by looking at the genes which were detected as being expressed in all the tumors and not expressed in all the normal samples, or inversely. Additionally, 19 genes were detected as being overexpressed in the tumors when compared to the normal tissue specimens. Of these 26 genes, 16 are not yet suspected of influencing NSCLC biology. These genes are involved in cell proliferation (G2 cyclin), signal transduction (SMARCC2, TM4SF3), apoptosis (CFLAR/FLIP), cell cytoskeleton (cytokeratins-14 and 16, alpha-tubulin isoform 1 and S100A10), cell adhesion (JUP), invasion (cathepsins H and O) and other biological processes (OAZ1, IGHG3, SCYA5/RANTES, beta-sarcoglycan and transcobalamin I). In conclusion, we identified a number of genes as being differentially expressed in squamous NSCLCs as compared to normal lung epithelial tissue. Some of these genes (such as those involved in invasion) could be used as new prognostic markers and others, like CFLAR/FLIP, could even constitute new therapeutic targets.

Bronchi↗
PubMed2004

Development of a chemoresistant orthotopic human nonsmall cell lung carcinoma model in nude mice: analyses of tumor heterogenity in relation to the immunohistochemical levels of expression of cyclooxygenase-2, ornithine decarboxylase, lung-related resistance protein, prostaglandin E synthetase, and glutathione-S-transferase-alpha (GST)-alpha, GST-mu, and GST-pi.

BACKGROUND: Nonsmall cell lung carcinomas (NSCLCs) are associated with very dismal prognoses, and adjuvant chemotherapy, including irinotecan, taxanes, platin, and vinca alkaloid derivatives, offer patients only slight clinical benefits. Part of the chemoresistance of NSCLC results from the expression in NSCLC cells of a very large set of endogenous proteins, which antagonize chemotherapy-mediated attacks on these tumor cells. METHODS: The authors set up an orthotopic model of a human NSCLC by grafting A549 cells into the lungs of nude mice. They tried treating these A549 NSCLC orthotopic xenograft-bearing nude mice on the basis of various chemotherapeutic protocols, including chronic administrations of taxol, oxaliplatin, and irinotecan. A cyclooxygenase-2 (COX-2) inhibitor (NS-398) also was assayed in combination with taxol. The immunohistochemical expression levels of COX-2, prostaglandin E synthetase (PGES), ornithine decarboxylase (ODC), the lung-related resistance protein (LRP), and glutathione-S-transferase-alpha (GST-alpha), GST-mu, and GST-pi were quantitatively determined by means of computer-assisted microscopy in control and drug-treated NSCLC orthotopic xenografts. RESULTS: The orthotopic A549 xenograft model developed in 100% of the grafted mice, leading to brain metastases in approximately 61% mice and to liver metastases in approximately 40% of mice. The model was resistant to taxol and oxaliplatin and was only weakly sensitive to irinotecan. High levels of chemoresistant markers (i.e., COX-2, PGES, ODC, LRP, GST-alpha, GST-mu, and GST-pi) were observed in the nontreated A549 xenografts, although with dramatic variations in individual expression. Taxol and oxaliplatin significantly increased the levels of expression of COX-2, PGES, GST-mu, and GST-pi in a number of different experimental protocols. CONCLUSIONS: The A549 orthotopic xenograft model could be used to evaluate investigational chemotherapeutic agents to identify drugs rapidly that are more active than the drugs currently in use in hospitals.

Animals↗
PubMed2004

Signaling molecules in overcirculation-induced pulmonary hypertension in piglets: effects of sildenafil therapy.

BACKGROUND: The phosphodiesterase type-5 (PDE-5) inhibitor sildenafil has been reported to improve pulmonary arterial hypertension (PAH), but the mechanisms that account for this effect are incompletely understood. Severe pulmonary hypertension has been characterized by defects in a signaling pathway involving angiopoietin-1 and the bone morphogenetic receptor-2 (BMPR-2). We investigated the effects of sildenafil on hemodynamics and signaling molecules in a piglet overcirculation-induced model of early PAH. METHODS AND RESULTS: Thirty 3-week-old piglets were randomized to placebo or sildenafil therapy 0.75 mg/kg TID after anastomosis of the left subclavian artery to the pulmonary arterial trunk or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation followed by pulmonary tissue sampling for morphometry, immunohistochemistry or radioimmunoassay, and real-time quantitative-polymerase chain reaction. Chronic systemic-to-pulmonary shunting increased pulmonary mRNA for angiopoietin-1, endothelin-1 (ET-1), angiotensin II, inducible nitric oxide synthase, vascular endothelial growth factor, and PDE-5. Pulmonary messenger RNA for BMPR-1A and BMPR-2 decreased. Pulmonary angiotensin II, ET-1, and vascular endothelial growth factor proteins increased. Pulmonary artery pressure increased from 20+/-2 to 33+/-1 mm Hg, and arteriolar medial thickness increased by 91%. The expressions of angiopoietin-1, ET-1, and angiotensin II were tightly correlated to pulmonary hypertension. Sildenafil prevented the increase in pulmonary artery pressure, limited the increase in medial thickness to 41%, and corrected associated biological perturbations except for the angiopoietin-1/BMPR-2 pathway, PDE-5, and angiotensin II. CONCLUSIONS: Sildenafil partially prevents overcirculation-induced PAH and associated changes in signaling molecules. Angiotensin II, PDE-5, and angiopoietin-1/BMPR-2 signaling may play a dominant role in the early stages of the disease.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2004

Human pancreatic duct cells exert tissue factor-dependent procoagulant activity: relevance to islet transplantation.

Activation of the coagulation cascade contributes to early graft loss and intraportal thrombotic events in clinical islet transplantation. Although these complications were shown to be related to the presence of tissue factor in human islet preparations, the contribution of duct cells, which represent a major contaminant of clinical islet isolates, has not been specified so far. Herein, we used flow cytometry, immunohistochemistry, RT-PCR, and functional coagulation assays to demonstrate that duct cells exert a potent factor VII-dependent procoagulant activity related to their expression of tissue factor. Both the classical membrane-bound and the recently described soluble form of tissue factor were shown to be synthesized by duct cells. We conclude that contaminating duct cells contribute to early beta-cell damage after islet transplantation through their involvement in tissue factor-mediated thrombotic and inflammatory events.

Blood Coagulation Tests↗
PubMed2003

Bosentan for the prevention of overcirculation-induced experimental pulmonary arterial hypertension.

BACKGROUND: The dual endothelin-receptor antagonist bosentan has been reported to improve pulmonary arterial hypertension, but the role of endothelins in the pathogenesis of the condition remains uncertain. We investigated the roles of endothelin-1 (ET-1), nitric oxide (NO), vascular endothelial growth factor (VEGF), and tenascin in overcirculation-induced pulmonary hypertension in piglets, as a model of early pulmonary arterial hypertension, with or without bosentan therapy. METHODS AND RESULTS: Thirty 3-week-old piglets were randomized to placebo or to bosentan 15 mg/kg BID after the anastomosis of the left subclavian artery to the pulmonary arterial trunk or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation followed by cardiac and pulmonary tissue sampling for morphometry, immunohistochemistry, and real-time quantitative PCR. Chronic systemic-to-pulmonary shunting increased circulating plasma ET-1, pulmonary mRNA for ET-1, ET(B) receptor, inducible NO synthase, VEGF, and pulmonary ET-1 and VEGF proteins. There were increases in myocardial mRNA for ET(A) receptor and VEGF and in myocardial VEGF protein. Pulmonary and myocardial tissue mRNA for tenascin did not change. Normalized-flow pulmonary artery pressure increased from 20 (2) to 33 (1) mm Hg [mean (SEM)], arteriolar medial thickness increased on average by 83%, and these changes were completely prevented by bosentan therapy. Right ventricular end-systolic elastance increased in proportion to pulmonary arterial elastance with or without bosentan. CONCLUSIONS: Experimental overcirculation-induced pulmonary arterial hypertension appears to be causally related to an activation of the pulmonary ET-1 system and as such is completely prevented by the dual endothelin receptor antagonist bosentan.

Animals↗
PubMed2003

Gouty involvement of flexor tendons.

This article presents three patients suffering from complications related to tophi deposited within the hand and wrist synovium and flexor tendons. One patient had no previous history of gout or acute arthritis, with uricemia within normal values upon admission. The pathophysiology and treatment of gout in these special circumstances are discussed.

Carpal Tunnel Syndrome↗
PubMed2003

Co-existent gout and septic arthritis at the wrist: a case report.

This article presents an exceptional clinical manifestation of gout in the wrist. The patient suffered from an association of septic and urate-crystal-induced arthritis. At the time, the serum uric acid concentration was still normal. The association of septic and urate-crystal-induced arthritis has been reported in other locations. The pathophysiology of the precipitation of urate crystals in the presence of an infectious process is discussed.

Anti-Bacterial Agents↗
PubMed2002

Peripheral blood mononuclear cell proliferation to heat shock protein-70 derived from autologous lung carcinoma.

In animals, tumor-derived heat shock proteins (HSP) induce immune-mediated protection against autologous cancer. We investigated whether HSP-70 derived from human lung carcinoma are also complexed to tumor-specific antigens. Peripheral blood mononuclear cells collected 10 days after surgery from patients with lung cancer were stimulated with HSP-70 purified from autologous and heterologous tumors. The stimulation index (SI) obtained when stimulating cells with autologous tumor-derived HSP-70 averaged 3.07 +/- 0.75 in patients with lung cancer and 1.57 +/- 0.33 in control subjects (p < 0.001 by analysis of variance). No significant stimulation was observed with HSP-70 derived either from the majority of heterologous tumors or from autologous tumor-free lung tissue. SI decreased from 3.59 +/- 0.65 to 1.65 +/- 0.38 in six patients tested again 3 months after surgery (p = 0.02 by Wilcoxon test for paired data). HSP-70 derived from lung carcinoma are shown to be associated with T cell antigens. The T cell reactivity appears transient and restricted to antigens complexed to HSP-70 derived from autologous tumors only. This suggests that the antigenicity of human lung tumors is unique, which may be crucial for the design of new vaccines.

Adenocarcinoma↗
PubMedDate not supplied

Post-transplant lymphoproliferative disorders after lung transplantation: first-line treatment with rituximab may induce complete remission.

BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD) are potentially lethal complications of solid organ transplantation. We, here, report on our experience with rituximab, an anti-CD20 monoclonal antibody, as first-line treatment for PTLD in six lung transplant recipients. PATIENTS AND METHODS: Two of the patients developed PTLD during the first year after transplantation, while four developed late-onset PTLD. One patient presented with PTLD localized to the graft, one had unilateral cervical lymph nodes, and the others presented with multi-organ involvement. All patients had diffuse large B-cell lymphoma. Immunosuppressive therapy was reduced and rituximab was administered at a dose of 375 mg/m(2)/wk for 4 wk. RESULTS: One patient did not respond to the first two courses of rituximab, received conventional chemotherapy, and achieved complete remission; four patients achieved complete remission after four courses with a median relapse-free survival of 34 months (range: 14-55); and one patient did not respond and died. The diagnosis of complete remission was established by conventional imaging techniques combined to whole-body positron emission tomography scan. CONCLUSIONS: We conclude that reduction in immunosuppression combined to first-line treatment with rituximab may induce long-term complete remission in lung transplant recipients presenting PTLD.

Adult↗
PubMedDate not supplied

Laser-assisted microdissection applied to frozen surgical pathologic specimens - methodological aspects on RT-PCR.

Laser-assisted microdissection has become a unique technique for an accurate gene-expression profiling analysis in human tissues. The introduction of this approach requires the development of a reliable, efficient, and reproducible procedure for tissue processing. We report a systematic evaluation of the different relevant steps required to obtain sufficient quantity and good quality RNA for reverse transcriptase-polymerase chain reaction when using frozen surgical pathologic tissues as starting material. We propose an optimized and very efficient method with respect to time and effort that can easily be put into practice in research laboratory as well as in any pathology laboratory.

Colon↗