Spin coating of non-Newtonian fluids with a moving front.

We investigate axisymmetric spin coating of power law and Ellis fluids. The flow is driven by centrifugal force, gravity and surface tension. For power law and Ellis models a single equation for the fluid film height is obtained. For a Newtonian fluid the flux only involves linear derivative terms which allows the flux to be easily split for a numerical scheme. For power law and Ellis models the derivatives appear as nonlinear terms. To overcome this we develop an alternative numerical scheme to solve for the film height. Neglecting surface tension and gravity the power law model shows a central spike which is reduced by the introduction of surface tension and gravity. In certain cases the shear thinning power law model predicts slower spreading than the Newtonian model. The Ellis fluid shows no central spike, even for zero surface tension and the film always spreads further than the Newtonian fluid.

Increased endothelin-1 associated with bacterial infection in lung transplant recipients.

BACKGROUND: Endothelin-1 (ET-1) has fibrogenic and inflammatory properties. Its pathogenic role in pulmonary fibrosis and certain inflammatory airway diseases is now well known. Its production is, in part, triggered by infectious processes. Episodes of infection are suspected to be involved in the development of bronchiolitis obliterans syndrome (BOS), which is the main feature of chronic lung rejection and the major factor limiting the long-term survival of transplanted patients. We postulated that ET-1 is upregulated during infectious complications arising from the graft and that this could partly explain the remodeling of airway structures observed in BOS. We, therefore, set up this study to assess ET-1 expression in relation to complications of the graft in human lung transplant recipients. METHODS: ET-1 mRNA was quantified by reverse transcription-competitive polymerase chain reaction in cells from 119 samples of bronchoalveolar lavage (BAL) fluid from 17 lung transplant recipients. ET-1 and big ET-1 proteins were assessed in BAL cell culture supernatants by enzyme immunoassay. Transbronchial biopsies (n=21) were stained immunohistochemically for ET-1 receptors. RESULTS: Episodes of bacterial infection strongly correlated with increased ET-1 mRNA and protein expression. ET-1 receptors were also upregulated during these episodes, especially on endothelial and smooth muscle cells. Five of the seven patients with the highest ET-1 levels subsequently developed BOS. CONCLUSIONS: These results raise the possibility that ET-1, part of whose production is triggered by infectious postgraft complications, might play a role in the development of BOS through its potential effects on airway remodeling.

Insulinlike growth factor-1 in lung transplants with obliterative bronchiolitis.

Bronchiolitis obliterans syndrome (BOS) is the major complication limiting survival of lung transplant recipients (Tx patients). The mechanisms underlying this fibrotic process are not known. We assessed IGF-1 and IGFBP-3 expression, critical mediators in different models of pulmonary fibrosis, in nine Tx patients. Three of them developed a BOS at 8, 14, and 17 mo postgraft, respectively. Two of the remaining six displayed a recurrent cytomegalovirus (CMV) infection, and four are in stable condition. IGF-1 mRNA expression was quantitated by RT-PCR in cells from four to six BAL per patient performed during the first 6 mo postgraft. Contrasting with a constantly low expression of IGF-1 mRNA in BAL cells from the six patients without BOS, the three patients with BOS presented marked peaks of IGF-1 on two to five occasions during the study period. These peaks, 3- to 13-fold increased compared with values from the former patients, preceded the diagnosis of BOS by 7, 13, and 17 mo, respectively. On the other hand, IGFBP-3 was highly and exclusively expressed in the three patients with BOS, the mRNA as well as the gene product as demonstrated by Western blotting. Our data strongly argue for a role of IGF-1 and IGFBP-3 in the fibrotic process underlying BOS, and for their possible value as an early marker of this complication.

Peaks of transforming growth factor-beta mRNA in alveolar cells of lung transplant recipients as an early marker of chronic rejection.

BACKGROUND: Chronic lung rejection (CLR) induces a fibroproliferative disorder leading to the occlusion of small airways. It has emerged as the major factor limiting the survival of lung transplant recipients. Predictive markers of CLR are lacking, and its diagnosis is generally ascertained when the fibrosis process is irreversible. METHODS: We have quantified the expression of transforming growth factor-beta (TGF-beta), a critical mediator of fibrogenesis, in alveolar cells from lung transplant recipients using a competitive reverse transcriptase polymerase chain reaction method. RESULTS: We have shown that patients with CLR presented marked peaks of TGF-beta mRNA expression, in contrast with patients without CLR. These peaks preceded the diagnosis of CLR by several months in two of three patients who died within 2 years of diagnosis. CONCLUSIONS: Our data suggest that TGF-beta expression in alveolar cells could serve as an early predictive and prognostic marker of chronic lung rejection.

Is intrinsic asthma a hereditary disease?

Although studies of families, inbred populations and twins have established that asthma has a hereditary basis, little evidence has shown that intrinsic asthma has an increased familial occurrence. To document this issue, we compared the prevalence of asthma in families of intrinsic asthmatics, extrinsic asthmatics and non-asthmatics. The intrinsic asthma group included those with negative skin tests to common aero-allergens (n = 117). The extrinsic asthma group included those with one or more positive skin tests (n = 164). The non-asthmatic group (n = 224) was recruited at a check-up center. The siblings of each subject completed a standardized questionnaire on history of asthma. The results showed that asthma was more prevalent (P less than 0.001) in siblings of intrinsic asthmatics (8.9%) than in siblings of the non-asthmatic group (2.4%). The prevalence of asthma in siblings of intrinsic and extrinsic asthmatics was similar. In conclusion, both intrinsic and extrinsic asthma have an increased family occurrence.

Value of ELISA using A60 antigen in the diagnosis of active pulmonary tuberculosis.

This investigation was undertaken to assess the effectiveness of an enzyme-linked immunosorbent assay (ELISA) using A60 antigen in ascertaining diagnosis in hospitalized patients suspected to have pulmonary tuberculosis (TB) but with negative sputum stains. Cultures were performed to confirm active or inactive disease. IgG and IgM antibody activity was determined by adding a 1:100 dilution of serum to plates coated with A60 antigen. After addition of peroxidase-conjugated antihuman IgG or IgM and color development, optical density (OD) was determined. A total of 83 patients was studied, taking into account their current disease status and prior history. Using as a cutoff value the mean value +/- 2 SD measured in the negative culture, no TB history group, that is, OD = 0.50 for IgG measurements and 0.43 for IgM measurements, the sensitivity, specificity, and positive predictive value of IgG measurements were equal to 48, 71, and 50%, respectively. Using IgM measurements, these parameters were equal to 76, 98, and 95%, respectively. Combining the results of IgG and IgM measurements, sensitivity, specificity, and positive predictive value were equal to 68, 100, and 100%, respectively. Thus, the ELISA described here can greatly facilitate the diagnosis of TB in patients with negative smears.

Prevalence of allergy to Hymenoptera stings.

In this study, we evaluated the prevalence of systemic reactions to hymenoptera stings in an adult general population, 20-60 years old. The protocol included a standardized questionnaire, skin tests to venom in subjects reporting a history of systemic reaction, and in subjects reporting a history of severe local and systemic reactions, as well as in a control group, a radioallergosorbent test (RAST) to hymenoptera venoms. According to the questionnaire, 1.2% of the study population had a history of systemic reactions. Only 0.85% had both such a history and a positive skin test to venoms. RASTs were positive, for at least one venom, in 57% of subjects with a history of systemic reaction, 15.8% of subjects with a history of severe local reactions, and 6.0% of the control group. In conclusion, this study shows that systemic reactions are not uncommon in the general population. RASTs tests are not sensitive or specific enough to be considered, per se, for indications of allergy to venoms.

Comparative evaluation of the antitussive activity of butamirate citrate linctus versus clobutinol syrup.

In a double-blind randomized study 60 patients with either irritative cough due to seasonal respiratory disorders or chronic cough of any etiology were treated with either butamirate citrate linctus (Sinecod, Zyma) or with clobutinol syrup (Silomat, Boehringer, Ingelheim) for a period of 5 days at a dose regimen of 3 tablespoons daily. Efficacy was assessed based on the reduction of the severity as well as frequency of the cough and on the global opinion of the physician. Both groups showed highly significant improvements for the severity and frequency parameters (p less than 0.001), thus demonstrating the effectiveness of both treatments. No significant differences between groups were detected globally for the whole collective. For cough due to carcinomas (n = 14), however, a significantly better effect of butamirate on the frequency of cough (p = 0.026) was found which originated other significant differences in the global scores (p = 0.013) and in the physician's opinion (p = 0.026). Seven patients in both groups complained about side effects (mainly nausea and drowsiness).

French multicentre double-blind study to evaluate the efficacy and safety of acrivastine as compared with terfenadine in seasonal allergic rhinitis.

In this double-blind, multicentre study the antihistamine acrivastine was compared with terfenadine for the treatment of seasonal allergic rhinitis. The study was divided into three periods which together lasted 56 days. Patients (n = 83) were randomly assigned treatment with either 8 mg acrivastine three times daily or 60 mg terfenadine twice daily. Both agents were equally efficacious in reducing the severity of sneezing, itchy nose, blocked nose, running nose, itchy eyes, watery eyes and itchy throat as recorded daily by patients, and as rated by both the patients and their physicians at the end of each treatment period. Acrivastine and terfenadine were equally well tolerated with no serious side-effects. Both effectively controlled the symptoms of seasonal allergic rhinitis in otherwise healthy individuals.

[Respiratory allergy and domestic animals. Survey in a sample of the general population]. / Allergie respiratoire et animaux domestiques. Enquêtes réalisées en population générale.

To evaluate the role of exposure to furred pets on respiratory allergic disorders, we interviewed 10,338 adults, selected at random from communities of South-East France. All subjects answered a standardized questionnaire related to asthma and perennial rhinitis and to present or past exposure to furred pets and respiratory symptoms related to this exposure. Besides, a sample of the population had a blood analysis for detection of specific IgE directed against common aero-allergens (Phadiatop). Overall, more than half of the households had a pet, more often in rural than urban communities. Among asthmatics 9.3% acknowledged respiratory symptoms when exposed to pets and 5.9% had parted from their pets because of respiratory symptoms; among patients with chronic rhinitis, those figures were 5.1% and 2.6%, respectively. However, these subjects with respiratory symptoms had pets as often as the whole population. In atopic subjects (positive Phadiatop test), exposed to cats, the prevalence of perennial rhinitis was higher than in atopic subjects not exposed to cats and in non-atopic subjects. Thus furred pets have a deleterious influence on patients with asthma or rhinitis, especially in the atopic subgroup. Pet avoidance is an important factor in the management of these diseases.

[Suspicion on sulfites]. / Suspicion sur les sulfites.

The sulfites have anti-oxygen and anti-microbial properties, which explain their great use in the food and drug industry. They may be responsible for anaphylactoid type episodes or more often asthmatic crises. 4 to 8% of asthmatics are sensitive to sulfites. The majority of asthmatics who are sensitive to sulfites are steroid dependent asthmatics. The pathophysiology is not clear: either a reaginic mechanism, reflex bronchoconstriction to SO2, a partial deficit in sulfite-oxidases. The diagnosis rests on oral provocation tests. These tests should be carried out according to a rigorous methodology, because there are frequent false positives (57 to 70%). Tests of alimentary provocation do not always correlate with the results from oral provocation tests to sulfites and pose the double question of sensitivity to the combined forms of sulfites which are present in food, and the reality of the risk of exposure of asthmatics to these foods. The prevention of any such mishaps rests on the eviction of such substances from the food which is often difficult and also of drugs. Vitamin B12, atropine, doxepin and sodium cromoglycate are capable of preventing totally or partially the bronchospasm induced by the absorption of sulfites.

[Heredity of asthma]. / Héridité de l'asthme.

To compare the heredity of asthma among families of intrinsic, extrinsic and control subjects, we have studied the siblings and offsprings of the 3 groups of subjects (using a standardized questionnaire). The results shown that asthma was genetically transmitted but the clinical manifestations appeared later among the relatives of intrinsic than among the relatives of extrinsic asthmatic patients.

Epidemiology of asthma in western Europe.

Asthma deaths are uncommon, but have recently increased in some countries due to problems in the management of the disease. Morbidity rates show large variations, which can be attributed to differences in defining the disease, but also to genuine variations, with a trend towards less asthma in northern Europe. It has been suggested that allergic diseases as a whole, and asthma in particular, may exhibit an upward secular trend. Risk factors include a genetic background and environmental triggering factors. The importance of genetic factors is illustrated by family studies and by extreme prevalence rates observed in some communities. Environmental factors include rapid air pollution variations which act as a trigger for asthma attacks. However, at levels currently prevailing in western Europe, air pollutants do not induce a higher incidence of asthma. Altitude generates a gradual decrease in Dermatophagoides, thus explaining both the clinical improvement in asthmatics living in altitude and a lower prevalence of asthma in populations born and living there. Among the other aero-allergens, grass pollens plays a major role in spring, elicitating asthma attacks. Some natural allergens transformed by man (castor bean, soja) can be responsible for asthma epidemics.

Atopy and anaphylactic reactions to suxamethonium.

Muscle relaxants are widely used for general anesthesia and may be responsible for IgE-dependent anaphylactic reactions (AR). A controversial issue in the field of drug allergy is whether ARs are more frequent or severe in atopic subjects. Thus, we performed a case-control study comparing the distribution of various clinical and biologic signs of atopy. The case group included 32 patients with a history of AR to suxamethonium, the most commonly used muscle relaxant. The control group included 128 subjects, matched to the case group according to age, gender, and socioeconomic status. The case group consisted mainly of young and middle-aged women. Distribution of symptoms suggestive of atopy and of skin tests and specific IgE to common aeroallergens was similar in both groups. In contrast, total serum IgE level was much higher in the case group, suggesting the presence of specific IgE against suxamethonium or other drugs. Thus, despite previous studies in the literature, atopy is not a risk factor for the occurrence of anaphylactic reactions to muscle relaxants. As AR to suxamethonium is a pure model of an IgE-dependent drug allergy, our data do not support a relationship between atopy and allergic drug reactions.

[Allergy to Hymenoptera. Incidence and degree of public knowledge]. / Allergie aux hyménoptères. Fréquence et degré d'information du public.

The prevalence of systemic reactions to hymenoptera stings in adults is unknown. To elucidate this point we interviewed 2.067 persons aged from 20 to 60 years who attended a medical screening centre. We asked them whether they had ever experienced a reaction this kind, what they knew about it and what they did, and we performed skin tests to hymenoptera venoms in those who gave a positive answer. The proportion of subjects who had had at least one type of systemic reaction after being stung was 1.2 per cent; 0.9 per cent of the subjects had both a history of reaction and a positive skin test. This figure is in keeping with those obtained in surveys carried out among children, but is does not tally with the mortality figures which probably are grossly under-estimated. The general population is not adequately informed of possible systemic reactions to hymenoptera stings, so that people often fail to consult, and the practitioners themselves do not advise their patients to see an allergologist for evaluation. Thus, adequate information of the general population and the physicians is badly needed.