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J Pages

Publications and source records attributed to J Pages.

At least 19 recordsLinked to original sources
PubMed2003

CT doses in children: a multicentre study.

We evaluated examination protocols used for common CT procedures of paediatric patients at different hospitals in Belgium in order to determine whether adjustments related to patient size are made in scanning parameters, and to compare patient doses with proposed reference levels. Three paediatric hospitals and one non-paediatric hospital participated in the study. Weighted CT dose-index (CTDI(w)), dose-length product (DLP) and effective dose (E) were evaluated for three patient ages (1 year, 5 years and 10 years) and three common procedures (brain, thorax and abdomen). CTDI(w) and DLP values higher than the reference levels were found for all types of evaluated examination. E ranged from 0.4 mSv to 2.3 mSv, 1.1 mSv to 6.6 mSv, and 2.3 mSv to 19.9 mSv for brain, thorax and abdomen examinations, respectively. All centres but one adapted their protocols as a function of patient size. However, no common trend in the selection of protocols was observed. Some centres divided the whole range of patient size into only two/three groups by age, while others classified the patients into six groups by weight. It was also observed that some centres used the same mAs for the total range of patient sizes and decreased the pitch factor for small children, which resulted in higher doses. This indicates the importance of careful selection of technical scan parameters. If CT parameters used for paediatric patients are not adjusted on the basis of examination type, age and/or size of the child, then some patients will be exposed to an unnecessarily high radiation dose during CT examinations.

Adolescent↗
PubMed2002

Patient and staff exposure during endoscopic retrograde cholangiopancreatography.

Despite a number of efforts being put into the radiological protection of both patient and staff during interventional radiological (IR) procedures during recent years, information about radiation exposure during endoscopic retrograde cholangiopancreatography (ERCP) procedures remains scarce. The purpose of this study was to estimate both patient and staff radiation doses during therapeutic ERCP procedures by direct measurement and to compare these results with data from other IR procedures. For 54 patients, effective dose and skin dose were estimated by measuring the dose-area product. For staff, entrance surface doses to the lens of the eye, thyroid and hands were estimated by thermoluminescent dosemeters. A median effective dose of 7.3 mSv and a median entrance surface dose of 271 mGy per procedure were estimated for patients. The gastroenterologist received a median dose of 0.34 mGy to the lens of the eye, 0.30 mGy to the skin at the level of the thyroid and 0.44 mGy to the skin of the hands, per procedure. When comparing the dosimetric quantities presented in this study with data from other IR procedures, it is clear that patient skin doses and doses to staff are high owing to the use of inappropriate X-ray equipment. ERCP requires the same radiation protection practice as all IR procedures. It should be consistently included in future multicentre IR patient and staff dose survey studies at national or international level.

Adult↗
PubMed2000

[Effective dose and dose to the crystalline lens during angiographic procedures].

Interventional radiology presents the highest dose levels for the staff and for the patient. For a total of 34 angiographic examinations the doses at the forehead and at the neck of a radiologist have been measured. The effective dose and the dose to the eye lens have been estimated over a period of one year. Doses to the lens of the eye close to the limit of 150 mSv proposed by the ICRP have been observed. There is an imminent need for the radiologist to wear also lead glasses to avoid formation of cataracts at long term.

Angiography↗
PubMed1989

Bone marrow metastases in small cell lung cancer: detection with magnetic resonance imaging and monoclonal antibodies.

The detection of bone marrow involvement might be of prognostic value and may influence therapeutic decisions in small cell lung cancer. By unilateral bone marrow aspiration and biopsy, evidence of bone marrow metastases is seen in 15-30% of patients with this disease. Since magnetic resonance imaging of the lower body and immunostaining with monoclonal antibodies have recently been shown to be very sensitive detection methods, we investigated the value of these two techniques in detecting bone marrow involvement in 35 consecutive patients with small cell lung cancer. The results were compared to those obtained with conventional cytohistological analysis. In all cases when cytology and/or bone marrow biopsy were positive, monoclonal antibodies immunostaining and magnetic resonance imaging also detected malignant cells. Furthermore, evidence of bone marrow involvement was shown with magnetic resonance imaging and/or immunostaining in 10 of 26 cases (38%) where routine procedures were unable to detect malignant cells. In one of these 26 patients, magnetic resonance imaging and immunostaining provided the only evidence of metastatic disease. These data suggest that the rate of bone marrow metastases is underestimated by routine procedures. Further investigation is needed to determine whether or not these new non-invasive methods have prognostic value or affect therapeutic choices in small cell lung carcinoma.

Antibodies, Monoclonal↗
PubMed1988

Gallium-67 scanning in the staging of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis.

Gallium-67 citrate is known to localize within inflammatory sites. Gallium-67 scanning is used for the evaluation of lung inflammation (i.e. alveolitis) during interstitial lung diseases. We investigated 27 patients with cryptogenetic fibrosing alveolitis (n = 17) and hypersensitivity pneumonitis (n = 10) using gallium-67 lung scanning and lung function tests (forced vital capacity, diffusing capacity, resting and exercise blood gases). Investigations were performed before and after one year of methylprednisolone treatment. None of eight healthy volunteers had any abnormal gallium-67 uptake. In all patients with cryptogenetic fibrosing alveolitis an initial abnormal gallium-67 uptake was observed (mean fixation index: 163 +/- 18). In addition, analysis of lung function tests a year after initial evaluation showed that unchanged or improving patients presented initially with a lower gallium-67 index than patients with evidence of deterioration (153.9 +/- 23.7 vs 251.0 +/- 23.3.; p less than 0.01). Similarly, among patients with hypersensitivity pneumonitis the index was lower in unchanged or improving patients than in those with deterioration (74.9 +/- 22 vs 226.7 +/- 4.9; p less than 0.05). Thus gallium-67 scanning is useful in the management of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis.

Alveolitis, Extrinsic Allergic↗
PubMed1987

Significant reduction in the binding of a monoclonal antibody (LYP 18) directed against the IIb/IIIa glycoprotein complex to platelets of patients having undergone extracorporeal circulation.

Extracorporeal circulation (ECC) used in open heart surgery gives rise to several hemostatic defects. This work investigates the effect of ECC on patient platelets membrane glycoproteins IIb/IIIa. A monoclonal antibody (LYP 18) directed against the IIb/IIIa complex was used on patient platelets in binding and flow cytometry studies, before and at the end of ECC. An antithrombospondin (LYP 8) monoclonal antibody and a monoclonal antibody (LYP 7) directed against an alpha-granule glycoprotein of 136 kdaltons, present on the platelet surface after secretion, were used in binding studies together with electron microscopy to assess the release of alpha-granules. Results obtained in 7 patients show a significant reduction (p less than 0.02) in the number of LYP 18 monoclonal antibody binding to platelets having undergone ECC (n = 49,725 +/- 16,275) compared to platelets drawn before ECC (n = 72,671 +/- 13,302). Flow cytometry studies indicate a decrease (p less than 0.02) in the percentage of platelets bearing the LYP 18 determinant following ECC (75 +/- 12% vs 66 +/- 14%). Binding of monoclonal antibodies LYP 8 and LYP 7 and electron microscopy studies of patient platelets having undergone ECC do not show degranulation. These results suggest possible cleavage of the IIb/IIIa complex following ECC but no release of alpha-granules.

Aged↗
PubMed1987

[Hypereosinophilia in bronchoalveolar lavage. Diagnostic value and correlations with blood eosinophilia].

An eosinophilia of 3% or more was present in 13.3% of a series of 1,084 broncho-alveolar lavages done in our department. An eosinophilia of less than 10% was of no diagnostic value. Idiopathic diffuse interstitial fibrosis, hypersensitivity pneumonitis, and asthma were the principal diagnoses encountered in cases with an eosinophilia of between 10 and 40%. An eosinophilia of greater than 40% was mainly observed in cases of chronic idiopathic eosinophilic pneumonia. A linear correlation (p less than 0.01; r = 0.545) was found between the blood eosinophils and that of the broncho-alveolar lavage; the existence of isolated cases where these two were dissociated raised the possibility of chemotactic factors acting independently on the blood and alveolar compartments.

Bronchoalveolar Lavage Fluid↗
PubMed1987

[Analysis by broncho-alveolar lavage of the pulmonary uptake of gallium 67 in idiopathic diffuse interstitial fibrosis and sarcoidosis].

The pulmonary fixation of Gallium 67 has been studied by broncho-alveolar lavage (LBA) in a group of 10 cases of stage II pulmonary sarcoid, proven histologically, and in a group of 11 cases of idiopathic diffuse interstitial fibrosis (FID). The pulmonary activity of Gallium 67 was measured in vitro in a quantitative manner on a centrifuged clump and a supernatant of LBA as well as on the serum and in vivo in a semi-quantitative manner by the Line index. The alveolar Gallium activity has been correlated with different cytological and biochemical parameters of the lavage liquid. There was a narrow correlation in the serum between the Gallium 67 activity and the level of circulating transferrin. The fixation of Gallium in the cellular clump of LBA depends on the number of macrophages present in the clump and the total available radioactivity. The macrophages of the sarcoid and fibrosis cases picked up the gallium in a similar fashion, with an affinity all the more important as the total available radioactivity was weak. The radioactivity of the supernatant of the lavage liquid was quantitatively important and narrowly tied to the diffusible proteins present in the lavage. There was no correlation between the semi-quantitative Line index and the cytological or biochemical data in the fibrosis cases. In the sarcoid cases there was an inverse correlation with the polymorphonuclear leukocyte count. The semi-quantitative index was only correlated with alveolar gallium fixation level in the fibrosis group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Monoclonal autoantibodies against mouse red blood cells: a family of structurally restricted molecules.

Cultured mouse peritoneal cells from unstimulated mice developed plaque-forming activity against isologous bromelain-treated erythrocytes. Several IgM monoclonal autoantibodies obtained by fusion of peritoneal cells from NZB or CBA origin with BALB/c myeloma cells were purified by affinity chromatography on trimethyl ammonium (TMA) column on the basis of their cross-reactivity with TMA, phosphorylcholine (PC) or choline haptens. Binding affinity for PC hapten was of the order of 10(3) M-1. Idiotypic studies with a polyclonal rabbit anti-idiotypic reagent revealed strong cross-reactions with all hybridoma autoantibodies thus far tested. In addition, the rabbit anti-idiotypic serum detected idiotypes or cross-reactive idiotypes in the sera of NZB and CBA as well as BALB/c mice. N-terminal amino acid sequence analyses of three hybridoma autoantibodies from NZB mice and one from CBA mice were carried out. The sequences of the first 32 residues of the four heavy chains showed that three were identical while one had one amino acid interchange; they belong to the VHIII-subgroup. The light chains were identical in the first 35 residues with the exception of a substitution at position 3 in two light chains and are members of the VK-9-subgroup. These results entirely support the idiotypic data. These monoclonal autoantibodies from NZB and CBA mice although isolated and eluted from PC-related haptens do not have any apparent structural nor idiotypic relationship to PC-specific antibodies. Idiotypic and V-region N-terminal sequence data suggest that these autoantibodies constitute a highly restricted family of molecules likely to be encoded by unique germ-line genes which may be expressed as such or as somatic variants in different mouse strains.

Aging↗
PubMed1985

Pulmonary sarcoidosis: flow cytometry measurement of lung T cell activation.

Lung T cell activation is considered a major factor in the pathogenesis of pulmonary sarcoidosis. Our study was designed to investigate several parameters of T cell activation among blood and alveolar cell populations, including expression of HLA-DR or MLR antigens, increased cell size, and presence of dividing cells. Blood sampling and bronchoalveolar lavages were performed in 20 patients with pulmonary sarcoidosis. Cell populations were analyzed by flow cytometry using immunofluorescence labeling with monoclonal antibodies to lymphocyte differentiation or activation antigens. Cell types were identified by their light-scattering properties. Cell cycle analysis was done after staining with acridine orange. Bronchoalveolar lavage contained a higher proportion of small T4-positive lymphocytes, and large cells of the same phenotype were detected in three patients. T cells bearing HLA-DR antigens were detected in six of 14 bronchoalveolar lavage samples. A marked increased of MLR-positive cells was found in the peripheral blood of eight of eight patients and in the bronchoalveolar lavage of five of seven patients. Increased percentages of cells in the S + G2 + M phases were found in blood lymphocytes from three patients and in half the bronchoalveolar lavage samples. Therefore, a variety of activation markers may be expressed by alveolar T cells. Their qualitative and quantitative assessment may provide additional criteria for staging the intensity of the alveolitis, and the possible relationship between these markers and disease progression or activity deserves long-term clinical investigation.

Adult↗
PubMed1985

[Pneumopathy caused by hypersensitivity to isocyanates. Value and dangers of a realistic provocation test].

Organic isocyanates are responsible for bronchial pathology and in rare cases of hypersensitivity pneumonia. We present a new observation supported by a complete lung function assessment, histology of a transbronchial biopsy and a positive bronchial challenge test. The progress of the disorder was followed by repeated lung function measurements and bronchoalveolar lavage. The alveolar response at first showed an alveolar leukocytosis, then a mixed picture, finally becoming a pure lymphocytosis. The activity of the alveolar cells was assessed for T lymphocytes by cytofluorimetry, the presence of DRa like and LMR antigens and lastly for macrophages with Gallium scans. The inflammatory response was followed by analysing the proteins in the lavage liquid. The value of studying alveolar cell-activity and equally alveolar protein content is underlined in this study and reminds one of the character, sometimes unpredicted and dangerous, of challenge tests using isocyanates.

Bronchi↗
PubMed1984

Activated lung lymphocytes in hypersensitivity pneumonitis.

T-lymphocyte activation was investigated in peripheral blood and bronchoalveolar lavage (BAL) of four patients with hypersensitivity pneumonitis. The study was performed by flow cytometry with the use of immunofluorescence labeling with monoclonal antibodies to lymphocyte differentiation or activation antigens. Simultaneous measurement of DNA and RNA content by acridine orange staining was used for cell-cycle analysis. The various cell types were identified by their light-scattering properties. T cell activation was demonstrated in the BAL of all patients by the presence of T cells (OKT3 positive) bearing class II histocompatibility antigen (HLA-DR) and activated T cell markers (MLR 1-3). Lymphocyte proliferation was evidenced in BAL but not in blood of patients by an increased percentage of cells in S + (G2 + M) phases. In addition, T-lymphocyte subsets analysis revealed no abnormalities in the blood and no major imbalance in the BAL despite a slightly increased OKT4/OKT8 ratio. The finding of T cell activation and lymphocyte proliferation in hypersensitivity pneumonitis alveolitis is consistent with the contribution of a local type IV immune reaction to the pathogenesis of this disease.

Alveolar Process↗
PubMed1983

A convenient enzyme-linked immunosorbent assay for testing whether monoclonal antibodies recognize the same antigenic site. Application to hybridomas specific for the beta 2-subunit of Escherichia coli tryptophan synthase.

Seven hybridoma clones, producing antibodies directed against the beta 2-subunit of Escherichia coli tryptophan synthase, have been obtained from mouse cells. To test whether the corresponding monoclonal antibodies recognize different epitopes on beta 2, an ELISA double antibody binding system has been developed and is reported here. The antigen is first coated onto a microtitration plate. Two monoclonal antibodies are then added either separately or simultaneously, and the amount of bound antibody is quantitatively measured by use of immunoglobulin (rabbit anti-mouse IgG) linked to beta-galactosidase. Additivity of the bound enzymatic activity is observed when the monoclonal antibodies bind to distinct epitopes. Using this test, it is shown that, of the 7 anti-beta 2 monoclonal antibodies obtained, 5 recognize the same antigenic site and the 2 others recognize a second site.

Animals↗
PubMed1982

Relationship between choline derivatives and mouse erythrocyte membrane antigens revealed by mouse monoclonal antibodies. I. Anticholine activity of anti-mouse erythrocyte monoclonal antibodies.

Different clones of mouse hybridomas, derived from the fusion of unstimulated mouse peritoneal cells with mouse myeloma cells, producing IgM monoclonal antibodies directed against the membrane of bromelain-treated mouse erythrocytes (MRBC(Br)) have been previously established. We have recently shown that one of these hybridomas produce, in ascites, antibodies cross-reacting with phosphorylcholine derivatives (trimethylammonium (TMA) derivatives). In this work the cross-reactivity for TMA derivatives of the monoclonal antibodies produced by 4 anti-MRBC(Br) hybridomas have been studied at the cell level (plaque-forming cells). Phosphorylcholine, choline bromide and p-aminophenyl-trimethylammonium were found to be potent specific inhibitors of plaque formation (anti MRBC(Br)). The hemolytic activities of ascites and tissue culture supernatants were studied and their inhibition by TMA derivatives was determined. Immunoglobulins from ascites purified on TMA immunoadsorbent column were analyzed by two-dimensional gel electrophoresis, their spectrotype was compared to the spectrotype of immunoglobulins from tissue culture supernatants from the same hybridoma radioactively tagged by internal incorporation of [14C]leucine. It could be shown without ambiguity that the PTMA column retained an IgM with the same characteristics as the IgM secreted in vitro.

Animals↗