Biomedical subjects
Publications and source records attributed to G Huchon.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The inhalation route is widely used for the treatment of obstructive lung diseases, because administered drugs have a high therapeutic index as they reach their target directly; this requires that they be of adequate size to penetrate the conducting airways, i.e. 2-5 microns. Pressurized inhalers were the first reliable metered-dose devices available, and are still the most frequently used. However, metered-dose inhaler (MDI) suspensions will have to be reformulated: they contain chlorofluorocarbons (CFCs), whose production has to be stopped within a few years, as they affect the stratosphere. Another limitation of MDI usage is paradoxical bronchospasm; this phenomenon, however, occurs in a low number of patients and is rarely clinically relevant. The main cause of concern with MDIs is their misuse by more than 50% of patients, which leads to a reduced lung deposition and clinical efficacy. Therefore, other inhalation devices have been developed: spacers, dry-powder inhalers (DPIs), and breath-actuated MDIs have been shown to increase lung deposition of drugs in poor coordinators. However, all have limitations which may have varying consequences on clinical efficacy: cumbersome dimensions of spacers, effect of inspiratory flow rate and humidity on lung deposition of dry powders, need for reformulation with CFC-free gases for breath-actuated pressurized inhalers. Reformulation of MDI aerosols is a complex procedure, which may not be feasible for all drugs. The new products need extensive toxicological and clinical testing, as some of their characteristics may differ from those of their predecessors.
Leukotrienes have multiple effects on the bronchi (inflammation, bronchoconstriction, increased vascular permeability...). They are also directly involved in regulating the composition of bronchial secretions. In vitro studies in animals and in man have demonstrated that sulphidopeptide leukotrienes stimulate active secretion of chloride by airway epithelial cells, an effect that should favor hydration of bronchial secretions. In addition, sulphidopeptide leukotrienes are powerful stimulants for mucin glycoprotein secretion. This effect is limited, at least in vitro, by inhibitors of the lipoxygenase pathway. These results underline the need for clinical studies to better define the role of leukotrienes in bronchial hypersecretion and to evaluate the effect of anti-leukotriene agents.
A tuberculous infection is the result of inhalation of tubercle bacilli either in great numbers or in subjects with diminished immunity. Clinical tuberculosis will only occur in 10 per cent of subjects following a first infection (primary tuberculosis) or subsequently (secondary tuberculosis or by a reactivation of a tuberculous lesion). All the intrathoracic structures may be involved in isolation or in the case of extra thoracic tuberculosis eventually disseminated. The clinical manifestations are most often non-specific. The persistence of respiratory symptoms are nevertheless suggestive, above all in a subject belonging to a group at elevated risk of tuberculosis. The radiological aspects may be very suggestive of tuberculosis. The diagnosis of an infection is based on a study of the skin responses to tuberculin and those on tuberculosis on the evidence of the tubercle bacillus.
A pooled data analysis of two double-blind studies encompassing 1137 episodes of community-acquired pneumonia in hospitalised adults, of which 560 were treated with sparfloxacin and 577 were randomised to comparator antibacterial agents (amoxycillin/clavulanic acid, erythromycin or amoxycillin administered at reference dosages), was performed. The global efficacy rate at the end of treatment in evaluable patients treated with sparfloxacin was 88.3% compared with 84.1% in those who received comparator antibacterial agents. This analysis verified the efficacy of this new aminofluoroquinolone, given orally once daily, in the treatment of community acquired pneumonia. The overall outcome favoured sparfloxacin for use in the empirical treatment of community-acquired pneumonia.
BACKGROUND: The purpose of this study was to identify factors on which European general practitioners (GPs) base their decisions to admit to hospital patients with lower respiratory tract infections (LRTI). METHODS: A survey was carried out from December 1993 to January 1994 to identify factors that affect GPs' decisions to admit to hospital patients with LRTI by collecting data on 2056 patients from 605 GPs in France, Germany, Italy, Spain, and the UK. RESULTS: Only 93 (4.5%) of the patients included in the study were admitted to hospital. Univariate analysis showed that age > 60 years, institutionalisation of the patient, concomitant diseases, cardiac insufficiency, asthma, a diagnosis of pneumonia, and clinical signs such as chest pain, cyanosis, tachypnoea and hypotension significantly (odds ratio (OR) > 2.0, p < 0.002) influenced the decision to admit to hospital. No influence could be shown for sex, smoking habits, history of bronchiectasis or chronic bronchitis, the presence of fever, chills, myalgia, cough or purulent sputum, and the diagnoses of acute bronchitis, influenza or exacerbation of chronic bronchitis. In the multivariate analysis only the presence of chest pain (OR 2.3, 95% confidence interval (CI) 1.5 to 3.5), cyanosis (OR 4.1, 95% CI 2.4 to 7.1), dyspnoea (OR 4.9, 95% CI 3.1 to 7.9), and hypotension (OR 2.9, 95% CI 1.6 to 5.2), as well as a diagnosis of pneumonia (OR 6.6, 95% CI 4.3 to 10) (all p < 0.00001) remained as factors that significantly affected the decision to admit to hospital. CONCLUSIONS: Clinical signs of severe infection and a diagnosis of pneumonia are the main factors that induce GPs to admit patients with LRTI to hospital in Europe.
Obstructive sleep apnea syndrome (OSAS) is a chronic disorder in which the subject experiences an abnormally large number of episodes of more or less complete and prolonged ventilatory arrest due to pharyngeal obstruction leading to fragmented sleep pattern and reduced arterial oxygen saturation. OSAS produces invalidating daytime symptoms and appears to be associated with cardiovascular complications and overmortality. Diagnosis is based on an exploration of the sleeping pattern with recording of ventilation function, arterial oxygen saturation, heart rate, and electrophysiological characteristics (polysomnography). Prevalence of a high apnea index (more than 5 per hour of sleep) associated with day-time somnolence may be as high as 3% of the population in the 30 to 60 year age range. Current treatment is mainly based on nasal continuous positive airway pressure given via the nasal route during sleep and pharyngeal surgery (uvulopalatopharyngoplasty). Surgery is reserved for subgroups of patients with anatomic abnormalities and free of contraindications for anesthesia. Continuous positive pressure is always effective in case of symptomatic apnea and has a favorable effect on several associated complications. It can be proposed for any patient with OSAS but its use is limited due to incomplete compliance (approximately 70%). It appears that patients with particularly severe disease benefit most. Thus the ANDEM experts recommend treatment for all symptomatic patients with 30 or more episodes of apnea or hypopnea per hour of sleep during night-time exploration. Below this threshold, electrophysiological recordings are required to eliminate another cause of fragmented sleep which could explain the symptomatology despite a moderately elevated apnea index. Once the treatment has been started, regular surveillance is recommended. In addition, general health and nutritional counselling (weight reduction, smoking cessation, interruption of alcohol consumption and use of sedatives) should be proposed but usually have minimal and transitory effect.
The treatment of community-acquired pneumonia is empirical in most cases and must cover a wide range of potential pathogens, such as Streptococcus pneumoniae, including penicillin-resistant strains, Haemophilus influenzae and intracellular microorganisms. The objective of this double-blind, randomized, parallel group study was to compare the efficacy and safety of sparfloxacin (400 mg loading dose, followed by 200 mg o.d.) with that of oral amoxycillin-clavulanic acid (500/125 mg t.i.d.) or oral erythromycin (1 g b.i.d.), during 7-14 days in 808 patients with confirmed community-acquired pneumonia. The overall success rates for sparfloxacin (87%), amoxycillin-clavulanic acid (80%) and erythromycin (85%) were similar in evaluable patients, and the equivalence hypothesis used for the statistical analysis showed at least an equivalent efficacy for the three antibiotics tested. The analysis of microbiologically documented infections (40% of the patients) showed that overall success rates were similar for S. pneumoniae and H. influenzae infections. Treatment withdrawal was necessary in 3.5, 2.5 and 7.7% of the patients treated with sparfloxacin, amoxycillin-clavulanic acid and erythromycin, respectively. This study indicates that sparfloxacin was at least as effective as amoxycillin-clavulanic acid or erythromycin in the treatment of mild-to-moderate community-acquired pneumonia and that the adverse effects were similar in the three groups.
UNLABELLED: In asymptomatic smokers, epithelial permeability in the distal lung regions is increased. To date, the effect of smoking on the epithelial permeability in proximal lung regions is still debated. The measurement of bronchial clearance of inhaled radiolabeled diethylene-triaminepentaacetic acid (BC-DTPA) can be used to assess epithelial permeability of proximal bronchi, but there are two potential limitations to this method: in vivo breakdown of 99mTc-DTPA in smokers and mucociliary transport of DTPA. METHODS: Eight nonsmokers and eight asymptomatic smokers were studied. We used a spinning disk system to generate an aerosol of large particles of 99mTc-DTPA or 113mIn-DTPA (MMAD 6.3 microns). To measure the bronchial clearance of 99mTc-DTPA and 113mIn-DTPA, we analyzed the perihilar regions of the lung. To determine the contribution of mucociliary transport, we measured the activity over a tracheal region of interest (ROI) in eight nonsmokers. RESULTS: Technetium-99m-DTPA bronchial clearance did not differ in smokers (1.16 +/- 0.54%/min; mean +/- s.d.) or nonsmokers (1.29 +/- 0.51%/min; ns). The 113mIn-DTPA bronchial clearances in nonsmokers (1.24 +/- 0.51%/min) and in smokers (1.01 +/- 0.66%/min) were similar to the 99mTc-DTPA bronchial clearances (ns). In the tracheal ROI, we found no increase in activity. CONCLUSION: In smokers, BC-DTPA was not increased compared to nonsmokers. In contrast to distal lung regions, there was no evidence of breakdown of the 99mTc-DTPA complex in the proximal regions of smokers' lungs. Mucociliary clearance does not significantly contribute to BC-DTPA.
To investigate Freund's adjuvant-induced changes in respiratory epithelial permeability, we determined the respiratory epithelium clearance of 99mTc-DTPA (RC-DTPA) in rats and the localization of horseradish peroxidase (HRP) across the lung epithelium. RC-DTPA was determined before and after intravenous injection of saline (control) or complete Freund's adjuvant (CFA). Although the respiratory epithelium was not disrupted, RC-DTPA was increased 15 min after injection of CFA and was still high after 3 d but had returned to normal after 7 d, after which it again increased and stayed high from Day 42 through Day 112. Cell number obtained by bronchoalveolar lavage increased from 15 min to 3 d after injection of CFA. Lung granulomatosis was observed 14 to 112 d after injection of CFA; changes in RC-DTPA correlated with changes in alveolar cells. HRP was present in bronchiolar intercellular spaces only in the CFA group. We conclude that (1) RC-DTPA increases in rat lung CFA granulomatosis 15 min to 3 and 42 to 112 d following injection, (2) the increase in RC-DTPA is not related to a rupture of epithelium but (3) is proportional to the cell influx into the lung, and (4) is possibly caused by the opening of tight junctions in small airways.
Explore the source record for details and available documents.
Metered-dose inhalers are the most widely-used mode of administration of bronchodilators and anti-inflammatory agents in the treatment of asthma. However, their use is complex and about 50% of the patients do not use their metered-dose inhaler(s) properly. The most frequent errors include inadequate coordination between actuation and inspiration, rapid inspiration, absence of breathhold, and actuation of the aerosol on more than one occasion during the same inspiration. The misuse of metered-dose inhalers results in a loss of efficacy of the drug. It is, therefore, recommended that the patient be carefully trained in the proper use of metered-dose inhalers at the time of prescription. If a patient is unable to use a metered-dose inhaler properly, despite education, it may be advisable to employ a different inhalation system.
Explore the source record for details and available documents.
Bilateral single lung transplantation (BSLT) (the procedure of choice for double lung replacement) and single lung transplantation (SLT) have at present a low incidence of anastomotic problems. In our experience, we have recorded no death related to anastomotic problems and 4 complications occurred for 33 anastomoses with a follow up of at least 2 months. A stent was temporarily inserted for two patients. The decrease of anastomotic complications is confirmed in the literature. It is one of the reasons why the number of SLT and BSLT performed all over the world increases rapidily to the detriment of heart lung transplantation.