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Biomedical subjects

F B Michel

Publications and source records attributed to F B Michel.

At least 145 records · Page 8Linked to original sources
PubMed1993

Chest tumor response during lung cancer chemotherapy. Computed tomography vs fiberoptic bronchoscopy.

Tumor response is one of the most important criteria in the analysis of chemotherapy. A chest computed tomographic (CT) scan and fiberoptic bronchoscopy (FOB) might give different results, as they analyze different aspects of the effects of chemotherapy on lung cancer. The response of the chest tumor in 103 patients with stage III or IV lung cancer (35 with small-cell lung cancer [SCLC] and 68 with non-small-cell lung cancer [NSCLC]) who prospectively entered chemotherapy trials was studied in order to determine the concordance between the chest CT scan and FOB. The chest CT scan allowed an assessment of tumor response in almost all patients, whereas FOB was not able to evaluate this response in 15 of the 103. The frequency of an evaluable endobronchial lesion did not depend on histology (SCLC, 97 percent; NSCLC, 93 percent; chi 2 = 0.85; not significant [NS]) or tumor T classification (T1-2, 83 percent; T3, 94 percent; T4, 97 percent; chi 2 = 1.49; NS). Tumor location in the bronchial airway did not differ when SCLC and NSCLC were compared. Thus, it is not possible to predict a subgroup of patients in whom FOB may be optional. In the group of 88 patients who were evaluable for response using both FOB and CT scan, a statistical concordance of the response classification was observed. The response was overevaluated by CT scan in 22 patients for whom data obtained by FOB appeared to be critical in the evaluation of tumor response. The concordance of response data obtained when the 2 methods were used was lower in NSCLC in comparison with SCLC. Thus, the use of FOB in the analysis of tumor response might be important, especially for NSCLC, inasmuch as FOB modulates the CT-evaluated response.

Adult↗
PubMed1993

Conjunctival provocation tests with codeine phosphate. Effect of disodium cromoglycate.

The reactivity of ocular mast cells is poorly characterized in man. Provocation tests with codeine phosphate, a molecule known to activate connective tissue mast cells, were performed in ten normal subjects. Ten-fold increasing concentrations of codeine phosphate (10(-5) to 10(-1) mg/mL) were tested in both eyes until a positive challenge was observed. Schirmer strips were placed under the eyelid and left for five minutes. A negative control was performed ten days later. All subjects had a strongly positive reaction for the same codeine phosphate concentration (10(-1) mg/mL). Histamine was released in 8/10 subjects (control: 7.06 +/- 4.19 nM/L, codeine phosphate: 18.2 +/- 15.7 nM/L, P < .018), PGD2 was released in 8/10 subjects (control: 0 codeine phosphate: 273.3 +/- 408.9 ng/L). Disodium cromoglycate blocked the release of histamine and PGD2. Codeine phosphate is potent at causing mast cell activation in the eye and this effect is blocked by disodium cromoglycate.

Adult↗
PubMed1993

Assessment of airway inflammation in asthmatic patients by visual endoscopic scoring systems.

Inflammation is a hallmark of bronchial asthma. Inflammatory cells both in bronchoalveolar lavage (BAL) and bronchial biopsies of asthmatic patients have been studied and correlated with functional or clinical parameters. We have recently attempted to assess airway inflammation by a visual endoscopic scoring system. The purpose of this study was to compare our own endoscopic scoring system with the bronchitis index previously described by Thompson and coworkers, and to determine whether these scores were correlated with clinical or functional parameters. Sixty asthmatics of variable severity (forced expiratory volume in one second (FEV1) 33-117% of predicted values) and 30 healthy volunteers were studied. The clinical severity of asthma was assessed by the clinical score as described by Aas in all of the patients, and in the last 15 patients by a daily symptom score. Beta 2-agonist consumption was recorded daily during a period of 7 days before the endoscopic procedure. During this period, circadian variation and day-to-day variation of peak expiratory flow rate (PEFR) were determined. During bronchoscopy, airway inflammation was assessed by two independent observers, prior to BAL, by visual inspection of each lobe and the lingula, and the results were quantitated using the bronchitis index and our endoscopic scoring system. Both endoscopic scores were significantly higher in asthmatics than in controls. A significant correlation was observed between the two endoscopic scores both in asthmatics and in controls. In asthmatics, a weak but significant correlation was found between both endoscopic scores and the daily symptom score, as well as the beta 2-agonist consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Treatment of bronchial inflammation].

Inflammation is a general defence mechanism. It is constant in asthma where it is characterized by the presence of eosinophils in sputum and blood. Treatment of bronchial inflammation is one of the master pieces of therapeutic strategy and relies on inhaled corticosteroids in most cases. These drugs are remarkably effective and can be used for long periods with little or no side-effects, but compliance with treatment must be checked regularly. In all cases, even when corticosteroids are the mainstay of maintenance treatment, bronchodilators must be used simultaneously. The triggering factors must be taken into account and re-evaluated according to the course of the disease. In the short-term all efforts must concentrate on educating the patients and making sure that they comply with their treatment. In the mid-term new, more effective steroids with even less side-effects than the others can be tried. In the long-term anti-inflammatory agents might multiply and be prescribed in combinations for successful cure of a multifactorial syndrome.

Asthma↗
PubMed1992

[Mediators and neuromediators in asthma].

The physiopathological mechanisms underlying the multifactorial syndrome that is asthma are very complex and protean. Most probably, they are genetically determined, but they are largely modulated by the environment and by the inflammation of bronchi in which allergy occupies a special place. Chemical mediators of cellular origin interact with each other and with the cells that live or are recruited in the airways. Among these mediators histamine and arachidonic acid metabolites seem to play a predominant role, but the clinical use of antagonists has not confirmed the data obtained in vitro and in vivo in animals and even man. Cytotoxic mediators (cationic proteins, free oxygen radicals) are though to exert their noxious effect directly on the bronchial epithelium. No single neuromediator of the adrenergic and cholinergic system can explain the dysfunctions observed in asthma. Mediators of the non-adrenergic non-cholinergic system seem to be more interesting owing to their potential interaction with cells and with chemical mediators which contribute to the development of a true neurogenic inflammation.

Asthma↗
PubMed1992

Inhibitory effect of cetirizine on the bronchial eosinophil recruitment induced by allergen inhalation challenge in allergic patients with asthma.

In patients with asthma there is a recruitment of eosinophils in bronchoalveolar lavage fluid (BALF) after the late asthmatic reaction (LAR). Cetirizine is a selective H1 antagonist that inhibits the eosinophil recruitment induced by allergen in the skin. The aim of this study was to evaluate whether cetirizine was able to inhibit the LAR-induced inflammatory reaction. Twelve allergic asymptomatic subjects with asthma (aged 18 to 58 years) without any treatment were enrolled in the study; FEV1 was greater than 83% predicted in each case. An allergen inhalation-challenge test was performed to assess the presence of an LAR. In a double-blind, randomized, placebo-controlled study, the patients were treated for 8 days with either cetirizine, 15 mg twice a day (six patients, group 1), or placebo (six patients, group 2). On day 8, a second allergen inhalation-challenge test with the same allergen was performed, and BAL was realized 24 hours later; as usual 250 ml of saline was instilled by 50 ml aliquots, and the first recovery was analyzed separately. In each case, the LAR observed after treatment was similar to the first one. In placebo-treated patients, an increased number of cells, mainly eosinophils, was observed in the first recovery of BALF compared with the number in subsequent recoveries. These numbers were significantly higher than numbers observed in cetirizine-treated patients. Cetirizine did not modify significantly the allergen inhalation-challenge test, but it inhibited the recruitment of inflammatory cells, mainly eosinophils.

Administration, Inhalation↗
PubMed1992

Systemic reactions occurring during immunotherapy with standardized pollen extracts.

Specific immunotherapy with standardized extracts administered by a rush protocol can induce systemic reactions (SRs). A prospective study was conducted in 454 pollen-allergic patients (aged 5 to 62 years) (1) to compare the incidence of SRs during a 3-day rush or step protocol, (2) to determine if patients presenting pollen asthma or those allergic to multiple pollen species would have an increased incidence of SRs, and (3) to attempt to decrease SRs. According to their sensitivity, patients received standardized extracts of orchard grass, and/or Parietaria, and/or olive, and/or plane-tree pollen with the same allergenically bioequivalent maintenance dose. Patients 10 years of age and older received 2000 BU; patients younger than 10 years, 1000 BU. The occurrence of SRs was carefully monitored. The incidence of SRs per patient ranged from 2.6% to 31.1%. With the rush protocol, there was a significant decrease in SRs after premedication (p less than 0.015). Severe SRs decreased further when the increase in doses was stopped because large local reactions occurred. Step protocol was only slightly better tolerated than rush protocol. Bronchial adverse reactions occurred more often in patients presenting asthma during previous pollen seasons. No reaction started 45 minutes or later after the last injection.

Adolescent↗
PubMed1992

Indirect evidence of nasal inflammation assessed by titration of inflammatory mediators and enumeration of cells in nasal secretions of patients with chronic rhinitis.

Pathophysiologic mechanisms of perennial rhinitis are poorly understood. The characterization of inflammation was studied in nasal lavage of patients with perennial rhinitis by the enumeration of cells involved in the allergic inflammation and the measurement of six mediators released in nasal secretions to determine whether some mediators were relevant for the etiologic diagnosis and the occurrence of symptoms. Ten healthy subjects and 57 patients with perennial rhinitis were placed into four groups according to the symptoms they presented at the time of the study and the origin of the allergy. Allergy was characterized by the history, skin prick tests to standardized allergens, and RAST. Eosinophil protein X (EPX), tryptase, histamine, myeloperoxidase, prostaglandin D2, and leukotriene C4/D4 (LTC4/D4) were measured in nasal lavage by enzyme assay or radioimmunoassay. Eosinophils and neutrophils were enumerated after cytocentrifugation of the lavage fluid and May Grunwald Giemsa staining. Tryptase, myeloperoxidase and EPX but not histamine levels were increased in all four patient groups. Eosinophils, LTC4/D4, and prostaglandin D2 were significantly (p < 0.001, p < 0.03, and p < 0.01) increased in allergic and symptomatic patients. EPX was significantly increased in symptomatic allergic and nonallergic patients. This study suggests the involvement of mast cells, neutrophils, and eosinophils, but the latter cells appear to have a more prominent role. The importance of EPX and LTC4/D4 in the characterization of chronic symptomatic rhinitis was also observed.

Adolescent↗
PubMed1992

Arachidonate 5-lipoxygenase metabolism in human neutrophils from patients with asthma: in vitro effect of nedocromil sodium.

Among the cells which participate in amplification of the local inflammatory reaction in asthma, neutrophils (PMN) are pro-inflammatory cells that can generate inflammatory mediators and arachidonic acid derivatives in particular. In asthmatic patients (AP) with attacks, the capacity of blood PMN to produce 5-lipoxygenase metabolites was investigated and compared to the response in healthy subjects (HS). PMN from 6 AP and from 6 HS were stimulated by calcium ionophore A23187 and arachidonate 5-lipoxygenase metabolites were analyzed by reverse-phase HPLC. LTB4, 6-trans LTB4, omega OH-LTB4 and 5-HETE were identified. In AP, total LTB4 synthesis was enhanced as compared to synthesis with PMN in HS. But the total 5-HETE synthesis by PMN from AP was decreased. Thus, the inflammatory potential of PMN from AP was enhanced in comparison to HS. The anti-inflammatory effect of nedocromil sodium (NS) was studied in the 5-lipoxygenase metabolism of arachidonic acid. NS (10(-4) mol/l) inhibited total LTB4 synthesized by PMN in AP but not in HS. We conclude that NS affects leukotriene synthesis only in cells with enhanced inflammatory potential.

Adult↗
PubMed1992

Chest tumor response measurement during lung cancer chemotherapy. Comparison between computed tomography and standard roentgenography.

Chemotherapy of lung cancer has, until now, been an experimental approach that requires careful evaluation of tumor response. The growing number of lung cancer patients now undergoing chemotherapy has led to a rapid increase in the number of computed tomography (CT) scans performed. Eighty consecutive lung cancer patients (55 non-small cell and 25 small cell lung cancers) were included in a prospective study to analyze whether the standard chest roentgenography is as effective as computed tomography in evaluating tumor response. Both standard chest roentgenography and CT scanning were performed before the chemotherapy began and were repeated after 10 to 12 wk of treatment. Response evaluations were performed according to the World Health Organization recommendations. When two-dimensional measurements were possible, the indicator lesions were defined as measurable tumors. Both roentgenography methods were used, independently, to classify the response into the following categories: complete response, partial response, minor response, stable disease, and progressive disease. A comparison of CT scans versus standard chest roentgenography as a measurement of indicator lesion showed a concordance of borderline significance (kappa = 0.146, p less than 0.05); a significant asymmetry was demonstrated (McNemar = 35.6, p less than 0.001), indicating that CT scanning may be a more appropriate method for measuring tumors than standard chest roentgenography. Moreover, no concordance was observed comparing CT scan and standard chest roentgenography measurability in the subgroups of patients with T3 or T4 tumor, hilar tumor, and patients with pleural effusion or atelectasis in which the McNemar test of symmetry constantly showed a better measurability using CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗