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Biomedical subjects

P H Vooren

Publications and source records attributed to P H Vooren.

At least 19 recordsLinked to original sources
PubMed1989

Reference values of total respiratory resistance, determined with the "opening" interruption technique.

In a large epidemiological survey of lung function the subjects performed maximum expiratory flow volume (MEFV) manoeuvres. They were also interviewed by trained interviewers using a standardized questionnaire. In a random subset of the subjects the resistance of the respiratory system was measured with the "opening" interruption technique, in which the mouth pressure before the end of the interruption period is divided by the flow shortly after the end of it. The subset contained men and women, and smokers as well as nonsmokers, 229 of whom were considered to be healthy because they had no history of complaints and a "normal" flow-volume curve. In this group mean inspiratory and expiratory resistances did not differ significantly (0.27 and 0.29 for men and 0.39 and 0.38 kPa.l-1.s for women). The averages of in- and expiratory resistance were 0.28 +/- 0.10 kPa.l-1.s for men and 0.39 +/- 0.11 kPa.l-1.s for women. The resistance values were slightly but significantly correlated with body height, FEV1 and MEF50, but not with smoking habits. Due to the considerable variability the method does not permit sharp discrimination between normal and abnormal subjects. However, it appears to be useful in histamine challenge testing, to detect and monitor bronchial asthma, being not subjected to the disturbing effect of forced ins- and expirations.

Adult↗
PubMed1986

Respiratory allergy to laboratory fruit flies (Drosophila melanogaster).

Workers in a scientific laboratory, complaining of respiratory symptoms related to their contact with fruit flies, were tested to detect allergy to these insects. Seven of 22 of these individuals had respiratory symptoms, and six of these seven demonstrated both immediate-type skin reactions and positive RAST results. Nasobronchial challenge tests elicited responses also in six of the seven exposed workers with symptoms. Neither the majority of the exposed group without symptoms nor the nonexposed control group reacted to the skin test, RAST, or nasobronchial challenge. Specificity of the fruit-fly allergen and its presence in the dust of the laboratory cultivation room were confirmed by RAST-inhibition experiments. The present results reflect the high prevalence of occupational respiratory disease caused by an IgE-mediated allergy induced by the contact with laboratory fruit flies and fruit-fly cultures.

Adult↗
PubMed1983

Diagnostic relevance of the modified RAST using D epsilon 2 specific anti-IgE antibodies.

In 439 consecutive patients with reversible bronchial obstruction, commercial RAST and provocation inhalation tests were performed, resulting in 985 paired observations. In 405 of these, obtained before November 1977 when the old RAST technique was applied, RAST showed a high specificity (87%) but low sensitivity (29%) in predicting the result of provocation tests. However, in 580 subsequent paired observations RAST, using D epsilon 2 specific anti-IgE antibodies (modified technique), was both specific (78%) and sensitive (77%). In this way the mean of specificity and sensitivity, which was called "mean recognition", was better with the modified technique (78%) than with the old one (58%). RAST was equally indicative in patients showing either early, biphasic or late bronchial reactions after inhalation of the allergen. The predictive properties of the patients' histories, skin tests and RAST with respect to inhalation-provocation studies were compared. In general, histories were fairly specific but poorly sensitive, and skin tests were sensitive but not specific. RAST (modified version) was both specific and sensitive, but did not exceed a mean recognition of 78%.

Allergens↗
PubMed1981

Occupational asthma due to inhalation of chloramine-T. I. Clinical observations and inhalation-provocation studies.

Respiratory symptoms developed in 5 patients who were exposed to chloramine-T, a potent disinfectant used in cleaning butcheries, kitchens, and operating theaters. Skin tests, performed in 4 patients, showed an immediate type of wheal and flare reaction followed by a late-type infiltrative reaction. In 3 patients, inhalation tests with chloramine-T were done. 1 patient showed asthmatic bronchial obstruction, immediately after inhalation, followed by a late-type asthmatic reaction after some hours. 2 patients only exhibited late-type reactions, 4-8 h after challenge. The late bronchial response lasted for several hours or even days and was accompanied by leukocytosis in all 3 patients and a slight fever in 1 patient. No evidence of alveolar involvement appeared. Pre-challenge inhalation of cromoglycate in 1 patient ameliorated the late response considerably.

Administration, Intranasal↗
PubMed1981

Occupational asthma due to inhalation of chloramine-T. II. Demonstration of specific IgE antibodies.

In the sera of patients who developed asthmatic symptoms after exposure to chloramine-T, specific IgE antibodies are demonstrated by a polystyrene tube radioimmunoassay. These antibodies are directed against human serum albumin treated with chloramine-T. Specific antibodies of subclasses IgG1, IgG3 and IgG4 were not found. Histamine release in response to chloramine-T-treated human serum albumin was demonstrated using the peripheral blood leukocytes of one of the patients. To define the antigenic determinant to which the specific IgE antibodies are directed, radioimmunoassay and radioimmunoassay-inhibition studies were performed using several autologous and heterologous chloramine-T-treated proteins. Moreover, the inhibition capacities of chloramine-T and structurally related compounds were also determined. The results of these experiments indicate that the antigenic determinant is formed, at least in part, by the p-toluenesulfonyl group of the chloramine-T molecule.

Adult↗
PubMed1975

Comparative studies of six nebulizers with Congo Red millipore technique.

If the particle size is the important factor to be considered in case of droplet size spectrum then from our results it can be said that Gauchard with 6 1/min. flow and Bird Asmastik with 95 1/min. are producing the particle size classes which can reach most easily the lower respiratory passage. The nebulizers which are producing droplets of a mass median diameter bigger than 10 mu, send only an unpredictable portion of their liquid output into the lower respiratory system. Smaller particles are representing very little weight and carry only small quantities of liquid material unless present in vast majority in the aerosol. To recommend an ideal nebulizer is yet a long way to go but considering the very big quantitative influence of a few big droplets, a small mass median diameter (1-7 mu) is an important factor on the credit of any nebulizer.

Aerosols↗