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Biomedical subjects

C Clement

Publications and source records attributed to C Clement.

At least 37 records · Page 2Linked to original sources
PubMed1991

Human recombinant dimeric IL-6 binds to its receptor as detected by anti-IL-6 monoclonal antibodies.

Three different epitopes of the human IL-6 (IL-6) molecule were recognized by the mAb B-E4 (IgG2b), B-E8 (IgG1) and B-F6 (IgG1). The affinities of these three mAb for IL-6 differ little in several assays but if ranked by affinity they fall into the following order B-E8 greater than B-E4 greater than B-F6. B-E4 and B-E8 mAb, recognizing two different epitopes, are inhibiting mAb in the bioassay with the IL-6 depending cell line B9, however B-E8 has an inhibiting activity higher than B-E4. Both human natural IL-6 (HnIL-6) and human recombinant IL-6 (HrIL-6) were inhibited but not the murine natural IL-6 (MnIL-6). Surprisingly, not only the non-inhibiting mAb (B-F6) recognizes the HrIL-6 fixed to the receptor but also the inhibiting mAb B-E4 and B-E8. This together with the results obtained in a sandwich ELISA where the same mAb was used as both catcher and tracer to detect HrIL-6, it was concluded that dimeric HrIL-6 is able to fix the IL-6 receptor. Competition studies between monomeric HnIL-6 and dimeric HrIL-6 showed that the affinity of the dimeric HrIL-6 for the receptor was higher than that of HnIL-6.

Animals↗
PubMed1991

Systolic intra-cavitary gradients following aortic valve replacement: an echo-Doppler study.

Systolic left ventricular flow was studied by pulsed and continuous wave Doppler in 41 patients following aortic valve replacement for severe stenosis (mean valvular area: 0.58 cm2; range 0.3-0.75 cm2). Maximal left ventricular velocities by continuous wave Doppler study, were higher than 2.5 m.s-1 with a sharp peak at end-systole in five patients in basal condition and in four others after amyl nitrite inhalation. Pulsed Doppler study showed that the high velocities started from the apex or mitral papillary muscle level with a marked chamber narrowing at two-dimensional echography. Only one patient had a systolic anterior motion (SAM) of the anterior mitral leaflet with mitral-septal contact. The left ventricular dimensions, as measured by M-mode echography were compared in the various patient groups. High velocities seemed statistically associated with the smaller systolic and diastolic diameters of the left ventricle and outflow tract and the larger relative thickness of the posterior wall. The highest pressure gradients disappeared after correction of hypovolaemia (one patient), clearance of pericardial effusion (one patient), or beta-blocker treatment (three patients). The present study confirms that left intra-ventricular dynamic gradients can occur after clearance of fixed outflow obstruction, for which Doppler examination is a reliable and innocuous diagnostic means. Haemodynamically, this syndrome resembles hypertrophic obstructive cardiomyopathy, but the scarcity of the systolic anterior motion of the mitral leaflets is suggestive of a different mechanism that could be cavity obliteration or mid-ventricular obstruction.

Adult↗
PubMed1991

Experience with subcutaneous erythropoietin in CAPD patients.

Experience in the use of subcutaneous erythropoietin in 18 CAPD patients is presented. The total and mean (SD) durations on CAPD were 419 and 23.3 (20.5) months, respectively. Eleven patients started treatment with normal or elevated iron stores, 7 had an initial iron saturation less than 20%. The initial hematocrit was 22.0 (3.1%). Eleven patients reached a steady state hematocrit (34.1 +/- 3.5%) by the end of the study period, and the mean percentage increase in hematocrit for all 18 patients was 47% over the initial hematocrit. All patients responded to EPO. The initial dose of EPO was 157.6 U/kg/wk, and all patients received oral iron supplements. There was no significant change in the means of any iron parameters. Transfusion requirements decreased from a mean of 0.42 transfusions per month per patient during the 12 months, prior to EPO, to 0.22 during the study. There were no significant changes in blood pressure or other measured parameters. Transient pain at the site of injection was noted infrequently.

Anemia↗
PubMed1988

Synthesis, effectiveness and metabolic fate in cows of the caesium complexing compound ammonium ferric hexacyanoferrate labelled with 14C.

Adding ammonium ferric hexacyanoferrate (AFCF) to cows' fodder produced after the Chernobyl nuclear accident prevented milk contamination by increasing the faecal elimination of 137Cs. Synthesis of ammonium ferric hexa[14C]-cyanoferrate (AF14CF) and its purification were performed for the study of the metabolic fate of this complex, and the evaluation of the possible release of cyanide. The stability of this colloidal product, tested by anaerobic incubation in rumen juice in vitro, showed no release of free cyanide from AF14CF, but hexacyanoferrate was identified in the rumen juice and 0.13% of the added radioactivity was converted to labelled CO2. AF14CF administered per os to two cows showed a nearly quantitative excretion of radioactivity in faeces during the first 3 d (91-95%). A very low but significant level of radioactivity appeared in plasma, blood cells, expired CO2 and was detected in organs taken 9 d after administration. Total cumulative radioactivity in urine and milk amounted to 0.19-0.47% and 0.068-0.071% respectively for the two cows. Labelled hexacyanoferrate and thiocyanate were identified in the urine and also in faeces. In spite of this relative instability of AFCF in the rumen of cows, the poor absorption of AF14CF degradation products showed that AFCF constitutes an efficient and safe food additive to prevent the absorption of radioactive caesium from ruminant feed and its secretion in milk.

Accidents↗
PubMed1986

Relationship between ER-ICA and conventional steroid receptor assays in human breast cancer.

We applied a new immunocytochemical assay for estrogen receptors (ER-ICA) to 82 human breast tumors. Results were correlated with cytosolic estrogen receptors (ERc) and nuclear ER (ERn) determined on the same sample respectively by the radioligand binding assay and by an ER enzyme immunoassay (ER-EIA). All ER-ICA-positive tumors contained more than 10 fmol/mg of protein of ERc and were therefore considered as ERc positive. In contrast, 15.4% of ERc-positive cases were ER-ICA negative. Comparison of ER-ICA results with ERn showed extensive agreement of negativity (92%), whereas 38% of ER-ICA-positive tumors were ER-EIA negative. However, the latter had ERc levels above the positivity threshold. Quantitative features of the immunocytochemical staining such as intensity and percentage of labelled cells, considered separately, did not reflect the amount of ERc or ERn. Cellularity was not significantly correlated with ER-ICA and biochemical results.

Breast Neoplasms↗
PubMed1982

Evaluation of the cutaneous-irritation potential of 56 compounds.

The primary cutaneous irritation of 56 chemicals was tested in the rabbit using three different procedures. The three protocols selected for the tests were the method published by the French authorities for the testing of cosmetics and toiletries (Journal Officiel 21 April 1973, p. 3862; ibid 5 June 1973, p. 3953) and the methods proposed for the testing of chemicals by the Association Française de Normalisation (AFNOR) and, in 1979, by the Organisation for Economic Co-operation and Development. The results of the three sets of tests were compared and the effects of differences in procedure and numbers of animals were studied, together with the possible relation between irritancy and the pH of the test material. It was concluded that the AFNOR protocol best met the requirements for such tests and that gloves should be worn for the handling of all substances classified as moderately or severely irritant on that scale.

Animals↗
PubMed1982

Evaluation of the ocular-irritation potential of 56 compounds.

The ocular irritancy of 56 chemicals was tested in the rabbit eye, with and without rinsing, using a procedure that complied with the main requirements of three protocols, namely those proposed by the Association Française de Normalisation (AFNOR) in 1982 and by the Organisation for Economic Co-operation and Development in 1979 for the testing of chemicals and that published by the French authorities (Journal Officiel 21 April 1971, p. 3862; ibid 5 June 1973, p. 3953) for the testing of cosmetics and toiletries. The results obtained were used to establish the extent to which the assessment of a chemical's irritation potential was affected by the differences between the three protocols in respect of the observation times prescribed, the inclusion and timing of rinsing, the number of animals used and the interpretation procedure. Conclusions were also drawn about the influence of the physical state and pH of a material on its potential irritancy and about the level of irritancy that necessitates the use of eye protection.

Animals↗
PubMedDate not supplied

Lowering of body temperature affects human platelet functions and norepinephrine release.

The effect of lowering body temperature on plasma epinephrine, norepinephrine, and platelet density distribution and volume was studied in a placebo-controlled double-blind study. Lowering of body core temperature was induced by either exposure to a cold environment at a temperature of 5 degrees C (CT) or by a single dose of the 5-HT1A agonist ipsapirone (IPS). A third group exposed to an ambient temperature of 28 degrees C was given placebo (PLAC). All of the three groups were investigated in a climate chamber. In the CT group the density distribution of blood platelet subpopulations was shifted to an increase in less dense platelets that were more sensitive towards aggregation-inducing agents. The mean platelet volume in this subpopulation was decreased. Epinephrine was not affected, whereas the increase of norepinephrine was correlated with an increase of platelets that were more sensitive to aggregation-inducing agents in the CT group but not in the PLAC and IPS groups.

Adult↗
PubMedDate not supplied

Value of assessment of pretest probability of deep-vein thrombosis in clinical management.

BACKGROUND: When ultrasonography is used to investigate deep-vein thrombosis, serial testing is recommended for those who test negative initially. Serial testing is inconvenient for patients and costly. We aimed to assess whether the calculation of pretest probability of deep-vein thrombosis, with a simple clinical model, could be used to improve the management of patients who present with suspected deep-vein thrombosis. METHODS: Consecutive outpatients with suspected deep-vein thrombosis had their pretest probability calculated with a clinical model. They then underwent compression ultrasound imaging of proximal veins of the legs. Patients at low pretest probability underwent a single ultrasound test. A negative ultrasound excluded the diagnosis of deep-vein thrombosis whereas a positive ultrasound was confirmed by venography. Patients at moderate pretest probability with a positive ultrasound were treated for deep-vein thrombosis whereas patients with an initial negative ultrasound underwent a single follow-up ultrasound 1 week later. Patients at high pretest probability with a positive ultrasound were treated whereas those with negative ultrasound underwent venography. All patients were followed up for 3 months for thromboembolic complications. FINDINGS: 95 (16.0%) of all 593 patients had deep-vein thrombosis; 3%, 17%, and 75% of the patients with low, moderate, and high pretest probability, respectively, had deep-vein thrombosis. Ten of 329 patients with low pretest probability had the diagnosis confirmed, nine at initial testing and one at follow-up. 32 of 193 patients with moderate pretest probability had deep-vein thrombosis, three diagnosed by the serial (1 week) test, and two during follow-up. 53 of 71 patients with high pretest probability had deep-vein thrombosis (49 by the initial ultrasound and four by venography). Only three (0.6%) of all 501 (95% CI 0.1-1.8) patients diagnosed as not having deep-vein thrombosis had events during the 3-month follow-up. Overall only 33 (5.6%) of 593 patients required venography and serial testing was limited to 166 (28%) of 593 patients. INTERPRETATION: Management of patients with suspected deep-vein thrombosis based on clinical probability and ultrasound of the proximal deep veins is safe and feasible. Our strategy reduced the need for serial ultrasound testing and reduced the rate of false-negative or false-positive ultrasound studies.

Algorithms↗
PubMedDate not supplied

[Clinical imaging correlations in lacunar infarcts].

PURPOSE: This paper is a study concerning the clinical-imagistic correlations in lacunar infarcts causes and associated lesions in these ones. We made an attempt to find out and emphasize the risk factors, causes and pathogenic mechanisms involved in lacunar syndromes. MATERIALS AND METHODS: We studied 138 patients with lacunar infarcts diagnosed by clinical examination and computer tomography. The investigation of risk factors evidenced arterial hypertension in 75 cases (54%). The clinical features of lacunar syndromes were: 1) pure motor stroke 41c; 2) pure sensory stroke 8c; 3) ataxic hemiparesis 9c; 4) dysarthria-clumsy hand 1c; 5) sensorimotor stroke 21c; 6) Landry syndrome 1c. RESULTS: We correlated the clinical manifestations and complementary investigations what enabled us to charge in determining of lacunar infarcts: focal microangiopathy-small artery disease (75c), cardio-embolic mechanism (12c), arterio-arteriolar embolic mechanism (15c). The risk factors and pathogenic mechanisms need more adequate research in order to find appropriate prevention and medical attendance.

Adult↗