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Biomedical subjects

I S Mackay

Publications and source records attributed to I S Mackay.

13 recordsLinked to original sources
PubMed1992

Cytokine messenger RNA expression for IL-3, IL-4, IL-5, and granulocyte/macrophage-colony-stimulating factor in the nasal mucosa after local allergen provocation: relationship to tissue eosinophilia.

Tissue eosinophilia is characteristic of human atopic allergic inflammation, although the mechanism is largely unknown. In this study we test the hypothesis that eosinophil infiltration during allergen-provoked rhinitis in hayfever sufferers may occur as a consequence of activation of a population of cells having a characteristic cytokine profile equivalent to the murine Th lymphocyte Th2 subset. Biopsies of the nasal inferior turbinate were obtained from 10 grass pollen-sensitive patients 24 h after local nasal provocation with allergen and after a control challenge with the allergen diluent. Biopsies were divided into two and subsequently processed for in situ hybridization using 35S-labeled RNA probes for selected cytokines and for immunohistology using an eosinophil granule mAb (EG2) which recognizes secreting eosinophils. At allergen-challenged sites compared with control sites there were significant increases in mRNA+ cells for IL-3 (p less than 0.04), IL-4 (p = 0.01), IL-5 (p = 0.02) and granulocyte/macrophage-CSF (p = 0.03). In contrast, only occasional hybridization signals were observed for IL-2 and IFN-gamma at both allergen and control sites. After allergen there was an increase (p = 0.01) in EG2+ eosinophils and significant correlations were observed between EG2+ cells and mRNA expression for "Th2-type" cytokines, particularly IL-5 (r = 0.90, p less than 0.0001). These results demonstrate that recruitment of eosinophils during human allergen-induced rhinitis is associated with cells expressing mRNA for IL-3, IL-4, IL-5, and granulocyte/macrophage-CSF.

Adult↗
PubMed1992

Extrapulmonary sites of Pseudomonas aeruginosa in adults with cystic fibrosis.

BACKGROUND: Pseudomonas aeruginosa infection is seldom eradicated in patients with cystic fibrosis despite intensive antipseudomonal treatment. Upper airway sites of infection may contribute to perpetuation of lower airways infection. This study was designed to find out which extrapulmonary sites are infected and whether the strains at these sites are identical to those in the lungs. METHODS: Sputum and upper airway samples from 42 patients were cultured for P aeruginosa and stool samples from 20 patients were also tested. Nineteen isolates from sputum and extrapulmonary sites from four patients were genotyped with the pCM tox probe. RESULTS: P aeruginosa was isolated from the sputum of 36 patients, 34 of whom had infection in the upper airways. Six of the 20 patients tested were positive for P aeruginosa in the stool. The nasopharynx was colonised in 30 patients, the oropharynx in 29, the middle meatus in 13, the external nares in six, and the inferior turbinate in four. Three of four patients tested had the same strain of P aeruginosa (a different one in each individual) in the sputum and the upper airways, and in two of the three the stool isolate was a different strain. CONCLUSION: Most adults with cystic fibrosis and P aeruginosa pulmonary infection have upper airway reservoirs of the organism and strains from these sites are identical to those in the lungs.

Adolescent↗
PubMed1992

Immunohistology of the nasal mucosa following allergen-induced rhinitis. Identification of activated T lymphocytes, eosinophils, and neutrophils.

We have studied the immunohistology of the nasal mucosa in allergen-induced rhinitis. Sixteen grass pollen-sensitive patients were challenged twice by randomly allocated allergen or control solutions applied on filter paper disks to the inferior turbinate. All had immediate nasal responses, but late-phase responses were equivocal and only evident as nostril blockage. When cell counts in the nasal submucosa were compared with control values 24 h after allergen, there were no changes in CD45+ (total leukocytes), CD3+, or CD8+ cells. Significant increases were found in the numbers of CD4+ T-helper cells (p less than 0.05) and CD25+ [interleukin-2 receptor (IL-2R+)] cells (p less than 0.02). Increases in eosinophils (anti-major basic protein, p less than 0.01) and neutrophils (antineutrophil elastase, p less than 0.01) were also observed. There were increases in tissue macrophages and HLA-DR-positive immunostaining and a reduction in mast cells (tryptase positive), but none of these changes was statistically significant. No significant changes in epithelial thickness, cross-sectional area, or integrity were observed. There was a significant correlation between CD4+ and CD25+ cells (r = 0.61, p less than 0.01) but not between macrophages and CD25+ cells (r = 0.18). The changes in the nasal submucosa were not merely a reflection of alterations in circulating cell populations since it was shown that a significant increase in the lymphocyte CD4/CD8 ratio (p less than 0.05) was observed in nasal biopsies but not in peripheral blood after allergen challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

An evaluation of the penetration of cefuroxime axetil into human paranasal sinus tissue.

Nineteen patients presenting for sinus surgery were studied to evaluate the percentage penetration from serum to paranasal sinus tissue of a single orally administered dose of cefuroxime axetil. The methods and results are presented. Cefuroxime penetrates well into human sinus mucosa following oral administration and the concentrations obtained exceed minimum inhibitory concentrations of cefuroxime for the most common pathogens in sinusitis.

Administration, Oral↗
PubMed1991

Endoscopic sinus surgery.

Many intranasal sinus surgical procedures can be undertaken using the endoscope which provides the surgeon with a clear and well illuminated field of vision, and the ability to inspect recesses with angled distal lenses. Functional Endoscopic Sinus Surgery (FESS) distinguishes the Messerklinger technique, which aims at restoring the natural mucociliary clearance mechanism, drainage and aeration of the sinuses by a minimally invasive anterior-to-posterior technique, from more conventional and radical posterior-to-anterior endoscopic sinus surgery. Hopkins improved the endoscope by replacing lenses with solid rods and fibreoptic illumination, and aided by improved techniques in computer assisted tomography, this has allowed more precise preoperative diagnosis. Meticulous postoperative management, may be the key to the success of endoscopic sinus surgery. Very encouraging results have been reported by many authors. With adequate training and cadaver dissection, endoscopic procedures should not be associated with a higher incidence of complications than ethmoidal surgery by other routes.

Endoscopy↗
PubMed1990

Long-term safety and efficacy study of intranasal ipratropium bromide.

Forty patients presenting with watery rhinorrhoea as their main complaint were entered in an open trial of long-term intranasal ipratropium bromide. Fourteen of these (35 per cent) found it to be beneficial and completed one year of treatment. Side-effects were seen in 28 patients (70 per cent) but these were local and mild in nature. All resolved during the trial as patients adjusted the dosage to individual severity and frequency of symptoms. No significant systemic effects were noted during the course of therapy. Ipratropium is a useful drug in the treatment of watery rhinorrhoea and appears safe for long-term use.

Administration, Intranasal↗
PubMed1990

Multiple submucosal out-fractures of interior turbinates.

Nasal obstruction caused by the inferior turbinate is a common clinical problem. There are many surgical procedures which attempt to relieve it, but all of them have associated difficulties. We describe, for the first time, a new method, namely multiple submucosal out-fractures of the inferior turbinates, which is both effective and free from serious complication.

Humans↗
PubMed1977

Pre- and post-operative brainstem responses in a case of acoustic neuroma, sparing the VIII nerve.

A case is reported of a patient with an acoustic neuroma presenting with a 2 month history of tinnitus and a 25dB hearing loss with evidence of recruitment. The neuroma was removed via a posterior fossa approach with preservation of hearing. Preoperative and postoperative brainstem electric response (BSER) studies are compared. The preoperative results demonstrated a marked reduction in amplitude and increase in latency on the affected side which returned to normal after removal of the neuroma.

Action Potentials↗
PubMed1976

The treatment of pharyngeal pouch.

A case of carcinoma occurring in a pouch following a Dohlman's operation is reported. The management and complications of ninety-two patients with pharyngeal diverticula are discussed. The average length of hospitalization for patients undergoing diverticulectomy was sixteen days compared with eleven days for those treated by Dohlman's technique. The risk of carcinoma subsequently occurring in a retrained pouch should be considered and external diverticulectomy should be the treatment of choice whenever possible.

Adult↗
PubMed1976

The aetiology of otitis externa--a new concept.

This paper reports the results of middle ear pressure measurements on 33 patients with recurrent otitis externa and compares the results with those of 21 normal subjects. The maximum negative pressure in the control group was -50 mm. of water, while 17 patients (52%) with recurrent otitis externa recorded measurements of -100 mm. of water or more. It is postulated that chronic Eustachian tube dysfunction may interfere with the normal migration of epithelium from the tympanic membrane along the external auditory meatus leading to irritation and chronic infection. The treatment in these cases should be directed at the underlying cause of the Eustachian tube dysfunction.

Adult↗