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Biomedical subjects

U Pipkorn

Publications and source records attributed to U Pipkorn.

At least 55 records · Page 3Linked to original sources
PubMed1989

Prolonged treatment with topical glucocorticoids results in an inhibition of the allergen-induced weal-and-flare response and a reduction in skin mast cell numbers and histamine content.

The inhibitory effects of topical glucocorticosteroid treatment on the immediate dermal allergic reaction were studied in 10 patients in a double, randomized, placebo-controlled fashion. The aim was to study whether a prolongation of the treatment time would enhance the inhibitory effect beyond the 30-40% reduction previously reported after 1 week of treatment, and whether any changes in skin reactivity were accompanied by changes in the level of mast cells or histamine at the challenge site. Allergen and histamine skin-prick tests were performed on both forearms before the start of the study and after 2 and 4 weeks of treatment with placebo cream on one forearm and with 0.05% clobetasol-17-propionate cream on the other. Punch biopsies from the skin treated actively and with placebo were taken after 4 weeks in eight of the patients. The specimens were used for the light-microscopic evaluation of mast cell density and for the measurement of histamine and protein content. After 4 weeks of treatment we found a reduction in the allergen-induced weal (72%; P less than 0.001) and flare (62%; P less than 0.05) response. There was also a minor reduction in the histamine-induced weal (38%; P less than 0.05) but not the flare response, suggesting that the glucocorticoid treatment induced a reduced mediator release at allergen challenge. This could be partially explained by the finding of a reduction in the number of detectable skin mast cells (85%; from 0.78 to 0.11 mast cells per unit area) and in the histamine content of the skin as related to the tissue wet weight (36%; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The clinical efficacy of budesonide in hay fever treatment is dependent on topical nasal application.

During the last decade topical glucocorticoids have been established as the first hand choice for the treatment of allergic rhinitis. Although they are clinically effective, their precise mode of action has not been sufficiently clarified. In order to evaluate whether the clinical effect is dependent on the topical administration a randomized, double-blind, double-dummy study was performed. Ninety-eight patients with allergic rhinitis due to birch pollen were recruited at two centres in southern Sweden. The patients received one of the following three treatment alternatives: 200 micrograms of nasally applied budesonide twice daily, 250 micrograms of budesonide given orally twice daily or a placebo. The selection of the doses was based on previous pharmacokinetic studies giving almost equal plasma levels of the nasally and orally administered budesonide. To evaluate the possible clinical efficacy of the treatment, the patients kept a diary in order to register symptoms according to a 0-4 scale. After a run-in week with no treatment the patients entered the treatment period which lasted for 3 weeks. A total of 96 patients completed the study. The symptom data showed that topically applied budesonide was clinically effective with a pronounced reduction in all the nasal symptoms registered and compared with placebo treatment there was a statistically significant difference in favour of the budesonide treatment (P less than 0.001). The nasal symptoms of the patients receiving oral budesonide did not differ from those receiving placebo. Intranasally administered budesonide proved to be significantly more effective than orally applied budesonide (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1989

Blood flow in dermal allergen-induced immediate and late-phase reactions.

Changes in local skin blood flow after prick-tests with histamine and allergen challenge were evaluated using laser doppler flowmetry. Two series of measurements were performed; each included 11 subjects with seasonal allergic rhinitis. In the first series vascular reactions were registered intermittently for a period of 6 hr. This was then repeated with additional registrations after 14 and 24 hr. Registrations were made in the skin close to where the test substances were applied which was in the area of the initial weal reaction. Pre-loaded skin-prick test needles were used for the histamine and allergen tests. Controls using 'blank' needles were also set on the same occasion. The control induced a transient increase in blood flow which had disappeared after 1 hr. After histamine challenge, the initial rapid increase in blood flow was followed by a slow return to baseline within 1 hr, and no further changes were noticed during the registration period. A different blood flow response was seen after the application of allergen. After an initial increase, the blood flow remained at this higher level for more than 6 hr. Thereafter a slow decrease towards baseline was seen within 24 hr. The pronounced difference between the histamine- and allergen-induced responses in the later part of the registrations after similar initial peak responses indicates that actions other than an initial burst of released histamine are responsible for the changes in dermal blood flow observed after allergen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The effect of topical nasal anaesthesia on allergen-induced symptoms, obstruction and blood flow.

The effect of topical anaesthesia on the nasal mucosa before and after allergen challenge was evaluated in 12 subjects with strictly seasonal allergic rhinitis. A single-blind randomized placebo-controlled design was used. The nasal challenge was carried out after pre-treatment of the nasal cavity with 52 mg of lidocaine/nasal cavity, or placebo applied topically in spray form. The number of sneezes was counted. The amount of nasal secretion was estimated by weighing used paper handkerchiefs. The capacitance and resistance vessel reactions were monitored by determining nasal peak flow and 133Xe wash-out respectively. After placebo pre-treatment the two doses of allergen induced moderate symptoms and vascular changes. Pre-treatment with local anaesthesia did not affect any of the symptoms nor did it affect the decrease in the tone of the capacitance vessels. It was found that topically applied lidocaine per se did not have any effect on nasal mucosal blood flow as measured using the 133Xe wash-out technique. However, the local anaesthesia did block the allergen-induced increase in the tone of the resistance vessels. In conclusion, a redundancy of systems appears to be involved in nasal allergic reactions. Although a reflex-induced mechanism may well play a significant role in the induction of the signs and symptoms of nasal allergic reactions, the redundancy of systems involved may well override any reduction in one single system, as appears to be the case in the present study. Lidocaine per se did not influence the nasal mucosal blood flow.

Administration, Topical↗
PubMed1989

Intranasally administered budesonide, a glucocorticoid, does not exert its clinical effect through vasoconstriction.

Dermally applied topical glucocorticoids induce a pallor of the skin. 'vasoconstriction', which has been used to grade the anti-inflammatory potency of such preparations. This study was performed in order to explore the possibility of a similar 'vasoconstrictor' phenomenon existing in the upper airway mucosa, which might thus offer one explanation for the clinically beneficial effect of topical glucocorticosteroid preparations in the treatment of allergic and non-allergic rhinitis. The possibility of a changed sensitivity to alpha and/or beta-adrenergic stimulation was also evaluated. Ten normal subjects participated in the present double-blind, randomized, crossover, placebo-controlled study. After establishing a baseline in nasal peak flow and nasal mucociliary clearance, the patients were treated for 8 days with either budesonide 100 micrograms/nasal cavity morning and evening, or a matching placebo. After a wash-out period of 2 weeks the treatment was repeated using the other treatment alternative. Nasal peak flow measurements were taken immediately before and 1 h after each application of treatment. After 1 week of treatment the nasal mucociliary transport was determined and the subjects were subjected to an intranasal challenge with 0.05 mg of oxymetazoline and 5.2 mg terbutaline on 2 different days in order to test for alpha and beta-adrenoceptor sensitivity. The response to these challenges was monitored by symptom scores and nasal peak flow measurements. Neither active treatment with budesonide aqueous suspension nor the placebo treatment induced any change in the mucociliary transport time nor in nasal airway as measured with the peak flow meters.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1989

Mucosal blood flow in the human nose following local challenge with histamine.

Nasal blood flow was measured using the 133Xe wash-out method in 10 non-allergic subjects and 13 asymptomatic hay fever patients. Determinations were made before and 15 min after challenge with diluent, 0.13 mg, 1.3 mg and 13 mg of histamine/nasal cavity. Nasal symptom scores were recorded. The nasal inspiratory peak flow was determined simultaneously in the hay fever patients. No differences in blood flow or symptom score recordings were found between the normal subjects and allergic patients under basal conditions or after histamine challenge. The nasal blood flow increased after challenge with the highest histamine dose. The increase was 34% (P less than 0.05) from baseline in normals and 47% (P less than 0.05) in allergics. There was a dose-dependent increase in nasal symptom scores following histamine challenge, again with no difference between normal and allergic subjects. The nasal peak flow decreased in a similar manner with a maximum decrease of 74% (P less than 0.001). The present study gives further support to the notion that histamine is not the only mediator involved in vascular reactions during allergic rhinitis.

Adult↗
PubMed1989

Eosinophils and eosinophil cationic protein in nasal lavages in allergen-induced hyperresponsiveness: effects of topical glucocorticosteroid treatment.

Airway challenges with allergen are frequently followed by an increase in responsiveness to both specific and unspecific stimuli. This phenomenon in the lower airways has been linked to the presence of a late phase response to allergen challenge. One of the hallmarks of the late phase response is a tissue infiltration of granulocytes, specifically the eosinophils. A hypothesis for the increase in responsiveness has been that local activation of these eosinophils with subsequent release of the toxic granular constituents leads to a decrease in the barrier function of the airway epithelium. The aim of the present study was to further explore this hypothesis. Ten patients with previously demonstrated nasal allergen-induced hyperresponsiveness participated in a double-blind cross-over study involving pretreatment for various periods with topical glucocorticosteroids. The patients were challenged intranasally with allergen on one day, rechallenge 24 h later and the increase in responsiveness noted. In a nasal lavage performed immediately prior to challenge the number of eosinophilic granulocytes and the level of eosinophilic cationic protein (ECP) was determined. As expected, the placebo-treated patients demonstrated an increase in nasal responsiveness at rechallenge accompanied by a tendency for an increase in eosinophils as well as ECP in the lavage preceding the rechallenge compared with the initial allergen challenge 24 h previously. The amount of ECP found in the lavage on the second day correlated with the TAME-esterase activity, a marker of ongoing inflammatory activity (r = 0.64; P less than 0.05) in the same lavage, suggesting participation of the eosinophilic granulocyte in the inflammatory response to allergen.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Topical↗
PubMed1989

Effects of topical treatment with H1 and H2 antagonists on clinical symptoms and nasal vascular reactions in patients with allergic rhinitis.

Fifteen asymptomatic subjects with allergic rhinitis participated in a double-blind, randomized, crossover, placebo-controlled study. The subjects were pretreated intranasally with a single dose of a selective H1 receptor antagonist, levocabastine, and/or selective H2 receptor antagonist, ranitidine, prior to a nasal allergen challenge. The nasal symptoms obtained at the challenge were assessed using a scoring technique 15 min after the allergen exposure. The nasal airway resistance was determined twice prior to and once after the allergen challenge using anterior rhinomanometry. The nasal mucosal blood flow was determined before and 15 min after allergen challenge using the 133Xe wash-out technique. After pretreatment with the H1 antagonist there was a statistically significant reduction in the number of sneezes and rhinorrhea compared to pretreatment with placebo. Pretreatment with the H2 receptor significantly decreased the rhinorrhea but not the sneeze. The nasal blockage was unaffected by both the H1 and the H2 antagonists. Pretreatment with the H1 and/or the H2 antagonists inhibited the reduction in the nasal mucosal blood flow induced by the allergen challenge to a significant degree. The present findings suggest that topical treatment with the highly selective histamine antagonist, levocabastine, inhibits allergen-induced reflex-mediated symptoms. H1 and H2 receptors do not appear to be involved in the regulation of the tone of the capacitance vessels. This indicates that a more complex mechanism participates in the induction of nasal blockage than the direct effect of histamine on H1 and H2 receptors on the capacitance vessels of the nasal mucosa alone. Both H1 and H2 receptors are of importance for the regulation of nasal mucosal blood flow during the allergic reaction.

Administration, Topical↗
PubMed1989

Reversibility and reproducibility of histamine induced plasma leakage in nasal airways.

Plasma exudation is one cardinal factor in airways defence and inflammation. In inflammatory airway diseases such as rhinitis and asthma, however, plasma leakage may also have a pathogenetic role. Experimental data from animals indicate that highly sensitive, active, and reversible processes regulate the vascular and mucosal permeability to macromolecules. With the use of a nasal lavage model for the recovery of liquids on the mucosal surface the effect of histamine on the macromolecular permeability of the airway endothelial-epithelial barriers was studied in normal subjects. The concentrations of albumin, kinins, and N-alpha-beta-tosyl-L-arginine-methyl esterase (TAME) in nasal lavage fluid were measured and nasal symptoms assessed by a scoring technique. The reproducibility of three repeated challenges with 30 minute intervals on the same day was studied in 12 subjects and compared with the same procedure (three challenges) on a different day. Sneezing decreased significantly (p less than 0.05) after the first histamine challenge but was maintained thereafter. Otherwise, the mean values for symptoms and for markers of vascular leakage were very similar both for the three challenges in the same session and for the two challenge sessions on a different day. Sneezing, blockage, and secretions were associated with increased concentrations of TAME esterase (maximum 9000 cpm/ml), kinins (1.4 ng/ml), and albumin (0.3 g/l) in lavage fluid. Both the symptoms and the measures of plasma exudation were reversible and reproducible in the three repeat histamine challenges and at two challenge sessions on different days. These findings support the view that non-injurious, active processes regulate the inflammatory flow of macromolecules across airways endothelial-epithelial barriers. The present experimental approach would be suitable for studies of the modulatory effects of inflammatory stimulus induced plasma leakage and symptoms in human airways.

Adult↗
PubMed1989

Nasal mast cell response to natural allergen exposure.

A redistribution of mast cells into the epithelium and towards the mucosal surface was previously observed during the allergy season in individuals allergic to birch pollen. We have therefore attempted to investigate in greater detail the role of mast cells in mucosal allergy by the study of the morphological and biochemical changes that occur in the nasal mucosa of allergic individuals during natural allergen exposure. An activation of the intraepithelial mast cells was indicated by the observation of ultrastructural signs of a secretory activity. We also found that the normal strong correlation between mast cell numbers and histamine content in the nasal mucosa was absent in specimens taken during allergen exposure, which was interpreted as a result of a release of histamine from the mast cells with the appearance of a transient, non-mast cell pool of tissue histamine. Furthermore, the histamine content of the nasal mucosa during the pollen season was strongly correlated to the severity of symptoms experienced by the patients. These observations provide additional evidence that mucosal mast cells have a pathogenetic role in continuous allergic airway disease.

Allergens↗
PubMed1989

Natural allergen exposure does not influence the density of goblet cells in the nasal mucosa of patients with seasonal allergic rhinitis.

This double-blind, placebo-controlled group-comparative study in patients with seasonal allergic rhinitis was performed to investigate the possible influence of natural allergen exposure on the differentiation of goblet cells in the nasal mucosa. Furthermore, the effect of topical steroid treatment on such a putative influence was evaluated. Twenty adult patients with seasonal allergic rhinitis due to birch pollen were studied. Mucosal samples were obtained by scrapings before and during the pollen season and processed to evaluate the number of goblet cells/mm of intact epithelial lining. No statistically significant differences were found neither when comparing the number of goblet cells before and during the season nor when comparing the 2 treatment groups. In conclusion, the allergic inflammation could not be shown to accelerate the differentiation of goblet cells, and the beneficial effect of topical steroid treatment could not be explained by a prevention of increased goblet cell density.

Administration, Topical↗
PubMed1989

Objective monitoring of the allergic inflammatory response of the nasal mucosa in patients with hay fever during natural allergen exposure.

A method is presented for the objective monitoring of the inflammatory response of the nasal mucosa to natural allergen exposure through measurements of biochemical markers such as TAME-esterase activity in a daily nasal lavage. Nine patients with strictly seasonal allergic rhinitis caused by birch pollen and five healthy nonatopic control subjects participated in the present study, which started 1 wk before the birch pollen season and continued throughout the entire pollen season. A diary card was used to assess daily nasal symptoms, and a daily nasal lavage was performed once every afternoon. The degree of pollen exposure was assessed by daily pollen counts. The TAME-esterase activity in the lavage fluid from the allergic patients, but not in that from the nonallergic control subjects, increased significantly during pollen exposure despite low pollen counts and was found to correlate with daily nasal symptoms (r = 0.36; p less than 0.05) and the degree of pollen exposure (r = 0.45; p less than 0.01). The area under the curve for the daily TAME-esterase measurements thus differed significantly (p less than 0.02) between allergic patients (158 +/- 28) and control subjects (74 +/- 9). This approach for the monitoring of patients with hay fever during natural allergen exposure will make further objective studies on the pathophysiology and pharmacology of hay fever possible. We also provide support for the validity of previous findings obtained in allergen challenge situations utilizing the lavage approach.

Adult↗
PubMed1989

Nasal mucosal response to repeated challenges with pollen allergen.

In order to explore the dynamics of the cellular response of the airway mucosa to allergen exposure, controlled daily allergen challenges were performed for 7 days during the pollen-free winter months in nine patients with strictly seasonal allergic rhinitis caused by birch pollen allergen. Symptoms obtained after the challenge were related to morphologic changes within and on the surface of the nasal mucosa. Cell samples were obtained daily prior to challenge from the nasal mucosa using mucosal imprints on plastic strips, brush samplings from the nasal mucosa, and nasal lavage. For light microscopy, the cellular material obtained by brushing and nasal lavage were cytocentrifuged onto object slides. Histamine was measured in the cell pellets that were obtained using the lavage and brush procedures as well as in the lavage supernatant fluid. Four symptoms (sneezes, itching, secretion, and blockage) were recorded and expressed individually as well as in the form of a composite symptom score. Nasal blockage was measured using a nasal peak flow meter. The patients displayed an increase in nasal symptoms after the allergen challenge, which was further increased between Days 2 to 7 (p less than 0.05). The light microscopic evaluation of the lavage revealed an immediate increase in eosinophils from 2.3 to 13.1% and was maintained on the same level throughout the period of challenges. A similar increase was noted in the brush specimens, and a strong correlation was obtained between these two methods of sampling.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1988

A brush method to harvest cells from the nasal mucosa for microscopic and biochemical analysis.

A method is described for the sampling of epithelial cells and other effector cells from the human airway mucosa for structural and biochemical analysis. The cell samples are obtained from the nasal mucosa using a small nylon brush which is rotated over the epithelium and soaked and shaken in a small volume of a balanced salt solution. Morphological evaluation using light microscopy and transmission electron microscopy revealed excellently preserved cytological detail. In asymptomatic individuals the cells harvested were as follows: 45 +/- 5.9% (mean +/- SEM) epithelial cells, 38 +/- 7.1% granulocytes, 16 +/- 2.3% large mononuclear cells (monocytes), and 1.3 +/- 2.3% eosinophils. Repeated measurements in the same individual revealed a coefficient of variation of the order of 40% for the proportions of cells harvested. In comparison with nasal airway lavage, a higher proportion of epithelial cells and monocytes were obtained with the brush method. The cells harvested could also be used for biochemical analysis. The histamine content of the cell pellets was found to be strongly correlated with the mast cell count (r = 0.93) and was estimated to about 10 pg/cell, which is higher than previously reported for mast cells obtained from human lung tissue dispersed by an enzymatic method. The present method appears to be appropriate for the study of cellular events in the nasal mucosal epithelium.

Adult↗
PubMed1988

The effect of platelet activating factor on nasal hypersensitivity.

Platelet activating factor (PAF) is known to have a wide range of biological activities. In the lower airways PAF has been suggested as the biochemical mediator partly responsible for the bronchial hyperreactivity which is a feature of asthma. In order to study whether PAF has a similar effect in the upper airways, we carried out a double blind, placebo-controlled cross-over study in twelve patients with strictly seasonal allergic rhinitis. The study was performed in pollen-free winter months. 26 micrograms PAF or placebo was sprayed into each nasal cavity 8 h and 1 h before a nasal allergen challenge. The nasal response to PAF and the allergen challenge that followed was monitored by repeated measurements of nasal expiratory peak flow rate and symptom scores. PAF induced only minor changes in nasal patency and nasal symptoms as compared to placebo. However, pretreatment with PAF induced an increase in responsiveness of the nasal vasculature to the allergen challenge that followed. This was registered as a small, but statistically significant increase in the symptom scores for nasal blockage, from 1.7 (0.3; SEM) after placebo pretreatment to 2.4 (0.36; SEM) after PAF (p less than 0.05). A similar trend was also noted for the measurements of nasal peak flow. The other response parameters, sneezes and secretion, remained identical. These results suggest that PAF may play a role in human nasal hyperreactivity, but it appears that PAF is not a major mediator involved in the induction of this phenomenon.

Administration, Inhalation↗
PubMed1988

Phenotypic expression of proteoglycan in mast cells of the human nasal mucosa.

The phenotypic expression of the proteoglycan of human mast cells in the nasal mucosa and normal skin was analysed using histochemical techniques. Nasal mucosa was obtained from normal subjects, from patients with seasonal allergic rhinitis before and during the pollen season and from patients with nasal polyps. In the latter groups, specimens were taken from both polyp tissue and adjacent nasal mucosa. Formaldehyde treatment blocked the cationic dye binding in 75-84% of the mast cells located in the nasal mucosa, as compared to the optimum fixation with IFAA (iso-osmotic formaldehyde-acetic acid). A significantly lower degree of blocking of dye binding was obtained in the human skin where 45% of the mast cells were susceptible to formaldehyde treatment (P less than 0.01). The mast cells of the polyp tissue also showed a relatively low degree of blocking (54%), which was significantly lower than the blocking of mast cells of the nasal mucosa taken from the same individuals (P less than 0.05). Staining of serial tissue sections in Alcian Blue containing graded concentrations of MgCl2 was used to determine the critical electrolyte concentration (CEC) of the dye binding, defined as the salt concentration at which the staining of 50% of the mast cells is extinguished. The CEC of the skin mast cells was 0.64M MgCl2 which is significantly higher than that of the mast cells of the nasal mucosa of normal subjects [0.49M (P less than 0.05)], allergic subjects [0.52M (P less than 0.01)], patients with polyp disease [0.52M (P less than 0.01)] and the polyp tissue proper [0.57M (P less than 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗