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Biomedical subjects

J Dolovich

Publications and source records attributed to J Dolovich.

At least 55 records · Page 3Linked to original sources
PubMed1995

Eosinophils as a potential source of platelet-derived growth factor B-chain (PDGF-B) in nasal polyposis and bronchial asthma.

Tissue remodeling in bronchial tissues from asthmatics as well as in nasal polyp (NP) tissues includes sub-basement membrane deposition of collagen, stromal deposition of extracellular matrix protein, and hypertrophy/hyperplasia of airway smooth muscle cells, which are relevant to the cellular and molecular events induced by platelet-derived growth factor (PDGF). Therefore, we investigated the localization of mRNA and protein of PDGF-B chain (PDGF-B) in NP tissues and bronchial tissues from mild and severe asthmatics by in situ hybridization and immunohistochemistry, respectively. Cells expressing PDGF-B mRNA were found in all nine NP tissues and in bronchial tissues from 2 of 6 normal subjects, 2 of 5 mild asthmatics, and all of 6 severe asthmatics examined. The vast majority of cells expressing PDGF-B mRNA were eosinophils in NP (99.7 +/- 0.2%, mean +/- SD) and asthmatic bronchial tissues (75.0 and 77.8% in mild asthma, and 92.7 +/- 8.1% in severe asthma), but no cells expressing PDGF-B mRNA were eosinophils in normal bronchial tissues. The number of cells expressing the gene in severe asthma tissues (122.3 +/- 32.2/mm2) was similar to that in NP tissues (152.8 +/- 73.9/mm2) and greater than that in mild asthma tissues (4.7 +/- 7.6/mm2, P < 0.01), which was not significantly greater than that in normal bronchial tissues (3.4 +/- 5.2/mm2). Furthermore, we detected immunolocalization of PDGF-B in NP tissues and in asthmatic bronchial tissues. The eosinophils purified from peripheral blood were demonstrated to express PDGF-B gene transcript and immunoreactivity after stimulation with A23187.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Increased peak flow variability in children with asymptomatic hyperresponsiveness.

The relevance of increased methacholine airway responsiveness detected in children with no current or past symptoms of asthma is not known. We wished to determine whether the presence of airway hyperresponsiveness in asymptomatic children is also associated with abnormal variability of peak expiratory flow (PEF). In 12 asymptomatic children with methacholine hyperresponsiveness, we examined the diurnal variation of peak expiratory flow (PEF) and response to inhaled bronchodilator. Twelve asthmatic children with a comparable range of methacholine hyperresponsiveness, and 12 normal children without methacholine responsiveness, were used as positive and negative controls. The children were aged 11 (range 9-14) yrs. The mean diurnal variation of PEF in those children with asymptomatic hyperresponsiveness was increased at 9.3%, to a degree comparable to the symptomatic asthmatic children (10.7%), and greater than the normal children (5.7%). Methacholine stimulated airway constriction was associated with symptoms in subjects from each group, indicating that the children were capable of perceiving airway constriction. We conclude that asymptomatic children with methacholine airway hyperresponsiveness have other evidence of mild variable airflow obstruction with increased diurnal PEF variability, and can perceive airflow limitation. The lack of symptoms in the children with airway hyperresponsiveness could be due to an insufficient stimulus to cause symptomatic obstruction, or the absence of eosinophilic airway inflammation, which may be a requirement for the development of symptomatic airway hyperresponsiveness.

Adolescent↗
PubMed1995

Some technical factors influencing the induction of sputum for cell analysis.

Inhalation of hypertonic saline aerosol is a relatively noninvasive method to obtain sputum for examination of inflammatory processes in the airways. We investigated some technical factors which might influence the success of induction and sputum cell counts. In total, twenty six asthmatic and 13 healthy subjects, unable to raise sputum spontaneously, inhaled nebulized saline for three 7 min intervals. In three randomized, cross-over studies we repeated sputum induction on separate days with two ultrasonic nebulizers (De Vilbiss Ultraneb 99 and Fisoneb) and one jet nebulizer (Pari LL with Master Compressor) (Study 1, n = 15), with different saline concentrations (normal saline 0.9%; hypertonic saline 3% on 2 days; and hypertonic saline 3, 4 and 5%, sequentially) (Study 2, n = 14) and with pretreatment with either salbutamol or placebo (Study 3, n = 10). The latter two studies were double-blind. Sputum cells were dispersed with dithiothreitol, and the cell suspension was used to perform total cell counts and to prepare cytospins for differential cell counts. We compared success rate, cell counts, subject discomfort and percentage fall in forced expiratory volume in one second (FEV1) during the procedures. All sputum examinations were performed blind to the clinical procedures. The success rates and the cell counts of the specimens obtained with the two ultrasonic nebulizers were not different, whilst general discomfort was proportional to the saline output of the nebulizer. Induction of sputum by hypertonic saline was more successful than normal saline, but more disagreeable to the subjects. Induction with saline 3% on two days was only successful in 6 of 14 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1994

TNF-alpha production by eosinophils in upper airways inflammation (nasal polyposis).

TNF-alpha is a cytokine with a wide spectrum of proinflammatory activities. Nasal polyps (NP), which occur in association with allergic rhinitis and asthma, are characterized by a marked infiltration of activated eosinophils, epithelial damage, and varying degrees of stromal fibrosis. By using Southern blot analysis after a reverse transcription-PCR, we detected a signal specific for TNF-alpha mRNA in five of seven NP samples, but not in control nasal mucosal samples. With in situ hybridization, we detected cells expressing mRNA specific for TNF-alpha in eight of thirteen NP samples, but not in four control samples. Counterstaining with chromotrope 2R demonstrated that virtually all cells expressing TNF-alpha message were eosinophils. The ratio of eosinophils expressing TNF-alpha to the total number of eosinophils varied greatly among tissues; as an average, we observed 24% TNF-alpha-positive eosinophils. Using a mAb against human TNF-alpha, we demonstrated TNF-alpha localization in 12 NP tissues (48.8 +/- 16.5 positive cells/mm2) but not in three control samples. Morphologically, cells localizing TNF-alpha were both mononucleated and polynucleated with only a small number of eosinophils, as determined by aniline blue counterstaining. Studies of purified blood eosinophils from a patient with hypereosinophilic syndrome and from four healthy donors indicated that TNF-alpha is produced, but rapidly secreted, so that TNF-alpha mRNA-positive cells contain little detectable protein. Furthermore, cells that retain detectable TNF-alpha may not contain sufficient TNF-alpha mRNA to be detected by using the probe developed for our studies. Together, these findings identify a novel mechanism by which eosinophils may contribute to mucosal inflammation and provide an approach to future investigation.

Eosinophilia↗
PubMed1994

Interleukin 10 inhibits lipopolysaccharide-induced survival and cytokine production by human peripheral blood eosinophils.

In this study we have investigated the effects of interleukin 10 (IL-10) on human peripheral blood eosinophils stimulated with granulocyte/macrophage colony stimulating factor (GM-CSF) and lipopolysaccharide (LPS). We show that LPS was able to enhance eosinophil survival in a dose-dependent manner, as well as release of the cytokines GM-CSF, tumor necrosis factor alpha, and IL-8. LPS-induced eosinophil survival was largely inhibited by an anti-GM-CSF neutralizing antibody and completely blocked by polymyxin B, suggesting GM-CSF involvement in the survival enhancing mechanism and LPS specificity, respectively. IL-10 significantly inhibited survival of, and cytokine production from, eosinophils induced by LPS, but did not inhibit the survival induced by GM-CSF. These observations suggest a novel activation mechanism of eosinophils and, also, that IL-10 may participate in the regulation of diseases characterized by eosinophil infiltration.

Antibodies↗
PubMed1994

Assessment of quality of life in adolescents with allergic rhinoconjunctivitis: development and testing of a questionnaire for clinical trials.

BACKGROUND: The objectives of the study were to evaluate impairment in quality of life in 12- to 17-year-old patients with seasonal allergic rhinoconjunctivitis and to develop and test a questionnaire suitable for evaluating change in quality of life during clinical trials. METHODS: Patients were asked to identify physical and emotional impairments associated with allergic rhinoconjunctivitis. The resultant questionnaire was tested for responsiveness and validity in a clinical trial in which fluticasone nasal spray and loratadine were compared for treatment of ragweed pollen-induced rhinoconjunctivitis. Eighty-three patients, 12 to 17 years of age, with grass- or ragweed-induced hayfever participated in the instrument development phase. They were recruited for the study from an allergy clinic and local schools and recreational organizations. Two hundred forty patients with ragweed hayfever participated in the clinical trial and provided quality of life data. RESULTS: The survey showed that in addition to local symptoms, patients experienced impairment of quality of life because of systemic symptoms, activity limitations, and emotional and practical problems. The resultant questionnaire has 25 items in six domains. In the clinical trial responsiveness was demonstrated by the questionnaire's ability to detect change over time and differences between treatments. Construct validity was demonstrated by moderate to strong relationships between changes in diary symptom scores and quality of life. CONCLUSIONS: The items identified by 12- to 17-year-old patients were not identical to those previously identified by adults. This suggests that impairment of quality of life may not be the same in the two groups and that it is appropriate to have a questionnaire specifically designed for adolescent rhinoconjunctivitis clinical trials.

Activities of Daily Living↗
PubMed1994

Nasal polyps: effects of seasonal allergen exposure.

Nasal polyps are characterized by chronic eosinophilic inflammation and often coexist with rhinitis and asthma. Many patients with polyps have no detectable allergy, and it is considered that allergy, at least in many cases, is not relevant to polyp to pathogenesis. To explore the association of nasal polyps with allergy, 16 patients with polyps and ragweed allergy (PRW +) and 16 patients with polyps who were not allergic to ragweed (PRW-) were compared with patients without polyps, 16 who were allergic to ragweed (NPRW +) and 16 who were not allergic to ragweed (NPRW-), before and during the ragweed season. The level of ragweed allergy was comparable in the PRW+ and NPRW+ populations as determined by ragweed skin test wheal diameter, ragweed IgE RAST percent binding, and total serum IgE. Symptom scores before the ragweed season recorded on visual analog scales for the symptoms of blockage, sneezing, decreased smell, itch, postnatal drip, and runny nose were high in patients in the PRW+ and PRW- groups and did not change during ragweed season. Mean symptom scores were low in the NPRW+ group before ragweed season and increased during the season to levels similar to those of patients in the PRW+ and PRW- groups. Preseason nasal lavage albumin concentration was higher in subjects with polyps than those without polyps (58.5, 98) versus (13.6, 15 micrograms/ml) (p = 0.02) and did not change significantly in any group with seasonal exposure. Data are presented as mean, 1 SD; comparisons are made with unpaired t tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The evaluation of a cell dispersion method of sputum examination.

In recent studies, sputum smear cell counts were found to be reproducible and usefully applied to research in asthma and other airway conditions. However, cell definition on the smears is poor, and the procedure is tedious and has limited utility. The objective of this study is to improve the methods of sputum examination. The subjects used in this study were people with bronchitis or asthma from whom sputum could be obtained. By inverted microscopy, portions of fresh sputum were selected to exclude salivary contamination. These portions were exposed to different volumes of dithiothreitol for varied time intervals. We used the resulting cell suspensions to perform total cell counts and prepare cytospins for differential cell counts and immunohistochemical stains for GM-CSF, EG2, TNF alpha and IL-8. Cytospins were compared with smears for differential cell counts on the same sputum specimens. Excellent cell dispersion and definition in cytospins could be observed. The time required for differential cell counting on cytospins was reduced and cytospin counts were more reproducible than smears. Greater duration of treatment of sputum with dithiothreitol tended to increase total cell counts and significantly decreased EG2 staining but had no effect on differential cell counts or the cytokine cell components. Therefore the proposed method of sputum examination involving cell dispersion and use of cytospins overcomes a number of the disadvantages of the examination of smears.

Cell Count↗
PubMed1994

Functional heterogeneity of mast cells isolated from different microenvironments within nasal polyp tissue.

Nasal polyposis is a chronic inflammatory condition of the upper airways characterized by infiltration of activated inflammatory cells, including mast cells, both in the epithelium and in the stroma. The aim of this work was to study human mast cells derived from two different anatomical sites within the same nasal polyp tissue. To this end, we isolated two distinct mast cell populations, one from the epithelial and the other from the stromal layers of individual human nasal polyp tissues. We examined the mediator content of the two mast cell populations and found that stromal mast cells had a significantly higher content of tryptase compared with the epithelial mast cells from the same tissue. In addition, mast cells from the stromal compartment, but not those from the epithelium, released a significant amount of histamine after anti-IgE stimulation. By contrast, both populations released over 50% of the total histamine after non-specific stimuli (A23187 10(-6) M). The content of mediators and the response to immunological activation were not significantly altered in patients receiving topical steroid therapy. It remains to be determined if the observed differences are the result of an intrinsic characteristic of the mast cell populations localized to separate tissue compartments, or reflect a different in vivo exposure to stimuli such as antigens, or different surrounding structural or infiltrating cells. In conclusion, these data provide evidence of functional heterogeneity and differences in mediator content between mast cell subpopulations from a single human tissue. The failure of release of epithelial mast cell mediators from an immunologic stimulus may have implications concerning acute effects of antigen exposure in nasal polyposis.

Adult↗
PubMed1994

Nasal polyp inflammation. Effect of topical nasal steroid.

Topical nasal corticosteroid therapy produces clinical improvement in patients with nasal polyposis. To examine the mechanisms of steroid effect, we quantified the number of inflammatory cell types as well as the expression of relevant cell markers in nasal polyps from steroid treated patients (n = 11) and polyps from untreated patients (n = 10) judged to require polypectomy for symptomatic relief. We found that the majority of eosinophils in these tissues were in the stromal layers, and that the proportion of activated eosinophils (EG2+ versus total eosinophil count) was significantly lower in polyps from patients treated with the topical nasal steroid budesonide, 200 to 400 micrograms/d for 1 mo, than in polyps from untreated patients. We also found that in polyps from treated patients, the superficial stromal layer (SSL) and deep stromal layer (DSL) both contained a significantly lower tissue density of lymphocytes of CD3, CD4, and CD8 subsets. Treatment was also associated with a lower, albeit nonsignificant, expression of ICAM-1 and HLA-DR in the epithelium. The tissue density of CD14+ cells (monocyte/macrophage) and of tryptase+ cells (mast cells) was the same in the two groups. These findings demonstrate tissue effects of topical corticosteroid treatment which may point to the mechanisms of therapeutic benefit. In addition, these observations illustrate the value of markers that indicate cell functional activity rather than just cell numbers.

Administration, Intranasal↗
PubMed1994

Multicenter trial of fluticasone propionate aqueous nasal spray in ragweed allergic rhinitis.

A 4-week multicenter, double-blind, placebo-controlled, parallel-group trial was carried out with 416 adults with ragweed allergic rhinitis to compare 200 micrograms of fluticasone propionate once daily and 100 micrograms of fluticasone propionate twice daily with placebo. Compared with placebo, both groups receiving fluticasone propionate had greater number of symptom free days (P < .01), lower median symptom scores (P < .01), and greater number of days not requiring rescue medications (P < .001). No significant differences for individual symptoms were found between the two fluticasone propionate groups except that those taking the twice daily dosage used less antihistamine (P < .01) and had greater number of days free of rescue medications (P < .05). Adverse events were comparable between the three groups. These results indicate that topical intranasal fluticasone propionate 200 micrograms once daily and 100 micrograms twice daily are both efficacious and well tolerated.

Administration, Intranasal↗
PubMed1994

Efficacy of loratadine versus placebo in the prophylactic treatment of seasonal allergic rhinitis.

The efficacy of loratadine as prophylactic therapy for seasonal allergic rhinitis was evaluated in a randomized, double-blind, parallel group, placebo-controlled study. One hundred eighteen subjects received either loratadine, 10 mg once daily, or placebo for 6 weeks. Treatment was begun prior to the onset of grass pollen seasonal symptoms of allergic rhinitis. Total symptom-free days occurred more frequently in subjects receiving loratadine. More loratadine than placebo subjects (65% versus 49%) had no symptoms or mild rhinitis at the end of the study. In contrast, the differences between loratadine and placebo in symptom scores did not achieve significance. The incidence of sedation and anticholinergic effects were comparable between the groups. Prophylactic loratadine therapy was effective in suppressing symptoms of seasonal allergic rhinitis and providing patients with symptom-free days throughout the pollen season.

Adolescent↗
PubMed1994

Double-blind comparison of intranasal fluticasone propionate, 200 micrograms, once daily with 200 micrograms twice daily in the treatment of patients with severe seasonal allergic rhinitis to ragweed.

In a single-center, double-blind, crossover study of 90 subjects, fluticasone propionate aqueous nasal spray, 200 micrograms, once daily was compared with 200 micrograms twice daily in severe seasonal allergic rhinitis to ragweed. The mean percentage of days free of nasal itching and eye symptoms was significantly higher with twice daily fluticasone propionate (P = .004, P = .005, respectively). There were no significant differences between the two treatment groups for nasal blockage, rhinorrhea (runny nose), and sneezing. The median symptom scores for nasal itching were lower during twice daily treatment (P = .008) but there was no significant difference for the other symptoms. There were no significant differences between the groups in the use of rescue medication. Adverse events were infrequent, and similar in both groups. Most were considered unrelated to the treatment. Twice daily treatment with fluticasone propionate may be preferable for some patients with severe seasonal allergic rhinitis.

Administration, Intranasal↗
PubMed1993

Noninvasive methods to examine the anti-inflammatory effects of drugs.

The anti-inflammatory effects of drugs can be studied non invasively using sputum which has either been produced spontaneously or induced with hypertonic saline. We have developed an efficient semi-automated method to examine sputum which should be widely applicable. This approach is recommended to provide a direct sampling of the airway secretions to study the inflammatory process and to demonstrate drug effects. We have validated a method to prospectively induce a mild exacerbation of airway inflammation by controlled reduction of inhaled steroid in steroid-dependent asthmatics. This can be used to examine the ability of drugs to prevent or reverse airway inflammation.

Anti-Inflammatory Agents↗
PubMed1993

Intraepithelial mast cells in allergic and nonallergic asthma. Assessment using bronchial brushings.

Mast cell mediators are known to contribute to the pathogenesis of asthma. There is some disagreement concerning the numbers of mast cells in asthmatic mucosa. In this study a standardized bronchial brush technique was developed and used to assess intraepithelial mast cells and other inflammatory cells in allergic and nonallergic asthmatic and nonasthmatic subjects. A total of 10 nonasthmatic (5 allergic) and 13 asthmatic (8 allergic) subjects with stable controlled asthma treated with beta-agonist only were assessed by history, spirometry, allergy prick tests, and methacholine airway responsiveness. During fiberoptic bronchoscopy, bronchoalveolar lavage (BAL) was performed from the middle lobe and standardized bronchial brushings were taken from the lingula and left lower lobe bronchi. Quantitative cell counts were performed blind to the clinical characteristics of the subjects. The average total cell recovery from the brushings was 1.04 (SEM 0.09) x 10(6) ml, with a cell viability of 64% (5.3%). Reproducible total cell and mast cell counts were obtained from brushings taken from two lobar bronchi (ICC 0.86). Mast cells were significantly elevated in asthmatic compared with nonasthmatic subjects (1.5 +/- 0.34 versus 0.15 +/- 0.06%). Allergic asthmatic subjects had the greatest numbers of mast cells (1.86 +/- 0.48%); however, the numbers present in brushings from nonallergic asthmatic subjects were also increased (1.03 +/- 0.45%). The mast cells had the staining characteristics of mucosal mast cells, with formalin-blockable metachromatic staining and positive staining for tryptase. Both asthmatic groups also had elevated BAL eosinophils, and neutrophils were elevated in nonallergic asthmatic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗