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Dive into the research topics where P. Clement is active.

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Featured researches published by P. Clement.


Allergy | 1997

An approach to the understanding of the nasal early‐phase reaction induced by nasal allergen challenge

Deyun Wang; Johan Smitz; S. Waterschoot; P. Clement

Quantitative determinations of the inflammatory mediators in nasal secretions were performed and correlated with the objective nasal symptoms within 1 h after nasal allergen challenge (NAC). Twenty‐six patients with seasonal allergic rhinitis were enrolled outside the pollen season. All measurements were performed before (as a baseline control) and at 1, 5, 10, 30, and 60 min after NAC. This study aimed to clarify the pathogenic mechanism of the early‐phase reaction (EPR) by monitoring the evolution of early‐phase mediators in nasal secretions and the presence of nasal symptoms during this period. The results showed that, after NAC, the maximal mediator concentration was already reached after 1 min for histamine (124 ng/g), 5 min for tryptase (56 μU/g), and 5‐10 min for leukotriene C4 (40 ng/g). Itching and sneezing started as early as 20‐30 s, and they were predominant symptoms within 5 min. Rhinorrhea and nasal obstruction started a few minutes after NAC and lasted until more than 1 h after NAC. There was no significant correlation between any single mediator and nasal symptoms during the sampling period. In conclusion, this study demonstrated that during the EPR the presence of nasal symptoms involves a complex mechanism, reflecting the interaction between the mediators released by inflammatory cells, and the receptors on different target organs. When evaluating symptoms during the EPR, one must consider not only the severity of these symptoms but also the time period within which these symptoms occur. For the symptoms of nasal obstruction and rhinorrhea, the early‐phase reaction often lasted more than 1 h.


International Journal of Pediatric Otorhinolaryngology | 1999

Bacteriology of the middle meatus in children

Frans Gordts; Ibrahim Abu Nasser; P. Clement; Denis Pierard; Leonard Kaufman

Little is known about the bacteriology of the middle meatus in children. Therefore, middle meatal samples were obtained from 50 children who underwent adenoidectomy or adenotonsillectomy, while a group of 50 children submitted to minor non-ENT surgical procedures, were used as a control group. Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae were the most frequent cultured organisms, not only in the ENT group (in 68, 50 and 60% of the children respectively) but also in the control group (40, 34 and 50%). These three potential pathogens were more frequently seen among the children of the ENT group but only for H. influenzae was the observed difference statistically significant (P = 0.009). On semiquantitative analysis, there seemed to be more negative cultures or cultures with only a few colonies in the control group, while the richer cultures were obtained from the ENT group. Again, only for H. influenzae, these differences reached a statistical significance (P = 0.003). Streptococcus viridans and Neisseria species, both organisms that might be able to inhibit colonisation by some of the pathogens, were more frequently cultured in the control than in the ENT group: Strep. viridans 30 vs. 10% (P = 0.025) and Neisseria species 14 vs. 2% (P = 0.069).


European Archives of Oto-rhino-laryngology | 1995

Concentrations of chemical mediators in nasal secretions after nasal allergen challenges in atopic patients

Deyun Wang; P. Clement; Johan Smitz; Marie Paule Derde

By using a microsuction technique, a quantitative determination of chemical mediators in nasal secretions was performed in 18 hay-fever patients and in a control group of 10 healthy volunteers. The authors then compared these quantitative data for mediators with objective nasal findings counting the number of sneezes, passive anterior rhinomanometry (PAR) and nasal inspiratory peak flow. A sampling protocol was designed with a follow-up of 3 days after nasal allergen challenge (NAC) in order to investigate both early and late allergic reactions. Median baseline concentrations of five major mediators were obtained: histamine, 19 ng/g; leukotriene C4 (LTC4), 5.7 ng/g. tryptase, 0; prostaglandin D2 (PGD2), 477 pg/g; eosinophil cationic protein (ECP), 105 ng/g. Significant increases in histamine (214 ng/g) , LTC4 (20 ng/g) and tryptase (28 μU/g) were found, but a significant decrease occurred in ECP (47 ng/g) and PGD (226 pg/g) immediately after NAC in the patients studied. Most ECP concentrations (94%) increased slowly 1 h after NAC and reached a significantly higher level 24 h later. In evaluating nasal symptoms, sneezes were present in a high percentage of cases (76%) during the early phase but were uncommon during the late phase (29%). Total nasal obstruction occurred in 94% during the early phase. In contrast, unilateral nasal obstruction presented in 82% during the late phase, whereas total nasal obstruction was present only in 41%. The most common type of late phase nasal obstruction shown by PAR was alternating nasal obstruction.


Allergy | 1998

Efficacy and onset of action of fluticasone propionate aqueous nasal spray on nasal symptoms, eosinophil count, and mediator release after nasal allergen challenge in patients with seasonal allergic rhinitis

Deyun Wang; F. Duyck; Johan Smitz; P. Clement

We studied the effect and onset of action of fluticasone propionate aqueous nasal spray (FPANS) on mediator release and eosinophil accumulation in nasal secretions and on nasal symptoms of patients with seasonal allergic rhinitis after nasal allergen challenge (NAC). At the end of the pollen season, 28 patients were randomized in a double‐blind and crossover design to receive 7 days treatment with FPANS (200 μg, once daily) and matching placebo. NACs were performed before and at 6 h and 1. 2. 3. and 7 days during treatment with FPANS or placebo. Nasal secretions were collected for a quantitative determination of mediators and eosinophil count before and 5 min after each challenge. Nasal symptoms were assessed by scales grading the severity of symptoms at the same time. Results showed that for mediator concentrations there was a significant decrease of leukotriene C4 (P<0.001) at 7 days after the first administration of FPANS as compared to placebo. Two days after FPANS. both eosinophil counts and eosinophil cationic protein (ECP) concentrations were lower than those of placebo (eosinophils; f=0.032; ECP; F=0.038). The onset became even more important at day 7 (eosinophils; P=0.001; ECP; P=0.009) during the FPANS treatment period. For the subjective nasal symptoms, a significant reduction of symptom scores for nasal obstruction occurred also at day 3 (F=0.017) and for sneezing at day 7 (f=0.003). There was not yet any significant improvement of the objective nasal airway resistance after the different NACs during the study period. In conclusion, this study demonstrated that topical fluticasone propionate is effective in the treatment of mucosal inflammation induced by NAC. For optimal control of nasal symptoms induced by repeated maximal allergen challenges, a treatment period of more than 1 week is required.


American Journal of Rhinology | 1992

Age-Related CT-scan Study of the Incidence of Sinusitis in Children

P. J. Van Der Veken; P. Clement; Th. Buisseret; B. Desprechins; Leonard Kaufman; Marie Paule Derde

Because standard radiographies are not able to give exact information about the diseased state of the sinuses, 196 children with chronic nasal complaints, aged from 3 to 14 years were examined with computed tomographic scan. The aim of the study was to investigate whether an age-related pattern in the occurrence of rhinosinusitis in children could be found. The patient group was subdivided into six age groups (3 to 4, 5 to 6, 7 to 8, 9 to 10, 11 to 12, and 13 to 14 years). Especially younger children, until the age of 7 to 8 years seem to be prone to inflammatory changes of all their sinuses. In older children, mainly the maxillary sinuses stay frequently involved. Septal deviations occur in 16% of the youngest to 72% in the oldest age group. The occurrence of bullous conchae increases with age too, although less prominently.


Clinical & Experimental Allergy | 1995

Prostaglandin D2 measurement in nasal secretions is not a reliable marker for mast cell activation in atopic patients

Deyun Wang; Johan Smitz; P. Clement

Background Prosia gland in D2 (PGD2) is a very important mast cell product during the early‐phase nasal allergic reaction. However, the quantification of PGD2 in nasal secretions has not yet been well established.


Stem-, spraak- en taalpathologie. - Nijmegen, 1992, currens | 2005

The Dysphonia Severity Index Used With a Percentage Scale

Jan Raes; F.L. Wuyts; Marc S. De Bodt; P. Clement


Rhinology | 1995

Chronic nasal obstruction in children. A fiberscopic study.

Wang Dy; P. Clement; L. Kaufman; Marie Paule Derde


Rhinology | 1989

Nasal provocation with histamine: a comparison of the determination of the threshold of reactivity by three methods of rhinomanometry.

Frans Gordts; P. Clement; Derde Mp


Rhinology | 1989

Recurrent polyposis nasi. Documentation

P. Clement; Paul Van der Veken; J. Verstraelen; Thérèse Buisseret; Alan Cox; Nicole Frecourt; Leonard Kaufman; Marie Paule Derde

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Deyun Wang

Free University of Brussels

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Johan Smitz

Vrije Universiteit Brussel

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Marie Paule Derde

Free University of Brussels

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Leonard Kaufman

Free University of Brussels

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Frans Gordts

Free University of Brussels

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Jan Raes

Free University of Brussels

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Denis Pierard

Free University of Brussels

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Ibrahim Abu Nasser

Free University of Brussels

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L. Kaufman

Vrije Universiteit Brussel

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