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T Raffin

Publications and source records attributed to T Raffin.

15 recordsLinked to original sources
PubMed1998

[Morphometric study of the wall of the caudal vena cava after the implantation of a filter in the sheep].

The long stabilizers of the VT-LGM filter rest on large areas of the vascular wall. The morphometric study of the layers of the vascular wall, after implantation of filter in 15 ewes, divided into 3 groups of follow-up (2, 4 or 8 weeks) of 5 animals, was made at 3 levels opposite the filter and 1 level outside of it. Changes are seen for all the layers. Filter produces intimal hyperplasia. Stabilizers are quickly isolated from the blood flow. The thickness of the intimal hyperplasia grows for 4 weeks. It is more important at the base of the filter than at its head. There is also hyperplasia of the media with no change according to the follow-up or the level opposite the filter. The adventitia becomes thinner without variation of time or level of the filter. Smooth muscle cells of the adventitia become less frequent and smaller. Their density in front of the stabilizers, is the smallest by 4 week follow-up and remains the same along the stabilizer. The full thickness of the wall is bigger opposite the stabilizers than between them. The filter produces changes that are limited in time and in space. The most important changes are seen at 4 weeks after insertion and opposite the stabilizers.

Animals↗
PubMed1997

The importance of sputum cytology in the diagnosis of lung cancer: a cost-effectiveness analysis.

STUDY OBJECTIVE: To assess the potential health and cost effects of initial testing with sputum cytology to diagnose lung cancer. DESIGN: Cost-effectiveness analysis. DATA SOURCES: Surveillance Epidemiology and End Results (SEER) program; cost data from Northern California Kaiser Permanente Hospitals and Universities of Stanford and Iowa; National Center for Health Statistics; and a MEDLINE search. INTERVENTIONS: The use of sputum cytologies preceding other tests (ie, fine-needle aspiration, bronchoscopy, thoracoscopy) in patients with suspected lung cancer. MAIN OUTCOME MEASURES: Mortality associated with testing and initial surgical treatment (eg, performance of thoracoscopy to remove a local-stage, centrally located cancer), cost of testing and initial treatment, life expectancy, lifetime cost of medical care, and cost-effectiveness. RESULTS: In central lesions, sputum cytology as the first test was the dominant strategy because it both lowers medical-care costs ($2,516 per patient) and lowers the mortality risk (19 deaths in 100,000 patients) of the evaluation without adversely affecting long-term survival. In peripheral lesions, sputum cytology costs less then $25,000 per year of life saved if the pretest probability of cancer exceeds 50%. The estimated annual savings of adopting sputum cytology as the first test for diagnosing lung cancer in the United States is at least $30 million. CONCLUSIONS: Experience in regional centers indicates that sputum cytologic testing is infrequently ordered before implementing invasive diagnostic techniques, even in patients with central lung masses. The study findings suggest that sputum cytology as the first test in suspected lung cancer is likely to be cost saving without adversely affecting patient outcomes.

Biopsy, Needle↗
PubMed1991

Isoproterenol prevents oxidant-induced injury in isolated rabbit lungs.

Increased vascular permeability in the adult respiratory distress syndrome is due in part to toxic oxygen metabolites. In the present study, we produced lung injury in the isolated rabbit lung with hydrogen peroxide (H2O2) and examined its prevention with isoproterenol. Pulmonary arterial pressure (Ppa) and the fluid filtration coefficient (Kf) were measured as indices of lung injury. Rabbits were divided into two groups, and 7 mmol/l H2O2 was administered in both groups. In one group, isoproterenol (2 micrograms/ml) was administered 10 min before H2O2 injury. Ppa increased transiently after H2O2 administration in the control group but was unchanged in the isoproterenol group. Kf was significantly increased by H2O2 administration in the control group but not in the isoproterenol group. We conclude that H2O2 increases pulmonary vascular permeability and that isoproterenol may protect against H2O2-induced pulmonary injury.

Animals↗
PubMed1987

IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF detected by ELISA in rheumatoid arthritis.

One hundred patients with rheumatoid arthritis (RA), of whom 73 were seropositive by latex or Waaler-Rose (WR) assays, or both, 100 healthy subjects, and 102 diseased controls (22 patients with systemic lupus erythematosus (SLE) and 80 with bronchial asthma) were evaluated for the presence of IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF by an enzyme linked immunosorbent assay (ELISA). Ninety two per cent, 65%, 68%, and 66% of the patients with RA were found to be positive for IgM, IgA, IgE, and IgG respectively. A positive correlation existed between the levels of IgM RF and IgA RF on the one hand and disease activity on the other, and the levels of IgM RF and IgA RF correlated with the levels of circulating immune complexes as measured by a C1q binding assay. The presence of extra-articular features also correlated positively with the levels of IgA RF and IgE RF. Five out of six patients with Sjögren's syndrome had very high levels of IgA RF. Of 47 patients typed for HLA-DR, DR1 and DR2 were significantly more frequent in those with the highest levels of IgM RF. Conversely, DR3 was associated with low levels or absence of IgA RF and IgE RF. These results suggest that immune response genes may regulate the level of different RF isotypes. The frequencies of IgM, IgA, IgE, and IgG RF were 59%, 36%, 9%, and 27% respectively in SLE and 25%, 2.5%, 70%, and 59% in bronchial asthma.

Adult↗
PubMed1984

Improvement of enzyme-linked antiglobulin test by using an antiglobulin linked to glucose oxidase: description of the technique.

The classic enzyme-linked antiglobulin test (ELAT) used to detect and quantify the amount of IgG antibodies on red blood cells (RBC) is sensitive to hemolysis and erythrocyte enzymatic activities. We describe a new ELAT by using glucose oxidase (GO) linked to antihuman IgG. The optical density base line of GO-ELAT, alkaline phosphatase-ELAT and peroxidase-ELAT were, respectively, 0.180, 0.350 and 0.550. This very low baseline of GO-ELAT was due to the absence of hemolysis (the pH of the GO substrate is 6.5). This technique is ten times more sensitive than the indirect antiglobulin test and detects up to 1 ng/ml of anti-D alloantibodies. Additional advantages of the technique are (1) there is no intrinsic GO enzyme in RBC, and (2) it is not necessary to fix the RBC.

Alkaline Phosphatase↗
PubMed1984

Binding capacity of sera from systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) to C3c. Evaluation by enzyme linked immunosorbent assay (ELISA).

Immunoconglutinins (IKs) are autoantibodies directed against antigenic determinants on C3 complement component. An ELISA was performed to detect IKs in sera from 50 RA patients, 50 SLE patients and 50 normal subjects. Comparison showed significantly higher levels in patients than in normal subjects (p less than 0.001) and higher IKs levels in RA than in SLE (p less than 0.001). IKs were not related to others biological tests, except a statistically significant inverse correlation between IKs and circulating immune complexes levels detected by conglutinin binding assay in RA.

Adult↗
PubMed1983

Detection of immune complexes by their complement-dependent binding to bovine conglutinin: technical aspects of a solid-phase immunoenzyme microassay and its application to normal and pathological sera.

A micromethod for the solid-phase conglutinin binding assay (Con BA) for the detection of circulating immune complexes (CIC) is described, in which the use of microplates, glucose oxidase-coupled anti-human immunoglobulins and automatic OD recorder contributed to the speed and low cost of this reproducible and sensitive test. The Con BA values of a large population of healthy blood donors had a wide distribution which in our series of 189 appeared to be trimodal. The Con BA values clearly reflected the levels of the main Ig classes (M, G, and A). This was confirmed by follow up of 6 individuals with high initial Con BA values. For 4 of them, a parallel decrease in Con BA value and IgG concentration was observed. In the 2 others, the sustained high level of Con BA remained unexplained. Complement components and activity of these sera were within normal limits. Because of fluctuation in the aggregated human gamma-globulins (AHG) reference curve, expression of results was based upon the standard deviation of 6 normal sera. In view of the above results, these sera were selected from those with the lowest Con BA values. On the basis that Con BA and C1q BA may detect CIC differing in their ag/ab ratio, sera from rheumatoid arthritis and chronic active B hepatitis patients with or without conventional rheumatoid factors (RF) were analyzed by both Con BA and C1q BA. RF-containing sera, likely to contain CIC in antigen excess, contributed exclusively to the highest C1q BA and lowest Con BA values. In contrast C1q BA-Con BA+ sera were preferentially RF negative. It is proposed that the complexes thus detected may be of idiotype-anti-idiotype nature.

Antigen-Antibody Complex↗
PubMed1982

Hyperoxic-induced alterations in lung cell structure and function. Effects on cellular cyclic AMP content and comparison to alterations produced by exogenous cyclic AMP.

Hyperoxic exposure in vitro of two lung-derived cell types (the epithelial-derived L2 cells and WI-38 fibroblasts) inhibits cellular replication, produces striking morphologic changes and may result in cell death; these effects have been observed consistently in other cell types. Hyperoxic exposure of L2 cells is associated with an increase in cellular cyclic AMP content (cellular cyclic AMP content 454 +/- 115 fmol/micrograms DNA in cells exposed to pO2 677 Torr for 96 h compared to 136 +/- 17 fmol/microgram DNA in air-grown cells). Hyperoxic exposure of WI-38 fibroblasts is not associated with increased cyclic AMP content. Although cultivation of L2 cells in the presence of exogenous dibutyryl cyclic AMP does inhibit replication and produce morphologic alterations, similar effects are produced by sodium butyrate alone. Hyperoxic exposure alters cyclic AMP metabolism in some cell types, but the structural and functional alterations observed in L2 cells and WI-38 fibroblasts following hyperoxic exposure are not produced by changes in cellular cyclic AMP content.

Anaerobiosis↗
PubMed1978

Bioenergetic pattern of isolated type II pneumocytes in air and during hypoxia.

The bioenergetic pattern of a cell clone derived from rat lung with ultrastructural and biochemical characteristics like those of type II pneumocytes (T-II-P), has been studied in a tissue culture system. During air cultivation, these cells have a high rate of aerobic and anaerobic glycolysis associated with high activities of two rate-limiting enzymes in glycolysis (pyruvate kinase [PyKi] and phosphofructokinase [PFK]). This is present despite the rates of oxygen consumption and activities of cytochrome oxidase (CyOx) similar to other lung cells. Presumably the high rate of aerobic glycolysis explains the substantial lactate production previously described in lung slices and in the intact perfused lung. Hypoxic cultivation results in a decrease in CyOx. Acute re-exposure to air does not restore the oxygen consumption to normal, presumably as a result of decreased mitochondrial O(2) utilization associated with decreased CyOx activity. As a result, hypoxically cultivated T-II-P cells have a decreased capacity for mitochondrial ATP generation in air as compared to air-cultivated cells. During hypoxia, aerobic and anaerobic glycolysis are further increased as well as the activities of PyKi and PFK. The high rate of glycolysis and high activities of PyKi and PFK in cultivated T-II-P appear to reflect intrinsic genetic regulation. The decreased CyOx activity and increased PyKi and PFK activities in hypoxic T-II-P appear to reflect alterations in enzyme biosynthesis/biodegradation regulated by O(2) availability.

Animals↗
PubMedDate not supplied

Caval incorporation of the LGM Vena Tech filter: an experimental study.

PURPOSE: To analyze LGM Vena Tech filter incorporation and the rapidity of the process. MATERIALS AND METHODS: A filter was inserted into the infrarenal inferior vena cava (IVC) of 15 ewes assigned to one of three groups depending on the length of follow-up (2, 4, or 8 weeks). Radiologic data concerning IVC diameter and filter patency, stability, and incorporation were obtained before and after insertion and before euthanasia. Histopathologic analysis concerned wall thickness and smooth muscle cell area (SMCA) at three levels of the filter and at one point outside the filter. RESULTS: All filters remained patent during follow-up. Incorporation of struts was dependent on time (P = .006), level of the filter (P = .0001), and strut surface (P < .0001). Neointimal thickness increased during follow-up (P = .0002), being more marked in the midportion of the filter (P = .0037). Adventitial thinning was observed (P = .0001), corresponding to a significant decrease in SMCA (P < .0001) above the struts as a function of the length of the follow-up period (P = .0021). CONCLUSIONS: The LGM Vena Tech filter was well tolerated and is suitable for incorporation into the IVC wall of normal animals without risk of any deleterious reactions due to biological incompatibility.

Animals↗