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Biomedical subjects

I S Mackay

Publications and source records attributed to I S Mackay.

At least 37 records · Page 2Linked to original sources
PubMed1996

Grass pollen immunotherapy inhibits allergen-induced infiltration of CD4+ T lymphocytes and eosinophils in the nasal mucosa and increases the number of cells expressing messenger RNA for interferon-gamma.

BACKGROUND: Grass pollen injection immunotherapy is effective in patients with summer hay fever, although efficacy must be balanced against possible side effects. The mechanism of immunotherapy is unknown but may be related to its ability to inhibit allergen-induced late responses, which are known to be characterized by infiltration of T lymphocytes, eosinophils, and cells with messenger RNA for so-called TH2-type cytokines (IL-4 and IL-5). OBJECTIVE: This study was designed to observe the effect of grass pollen immunotherapy on late nasal responses and associated cellular infiltration and cytokine mRNA expression. METHODS: We performed local nasal provocation with grass pollen (and a control challenge) in 28 patients after a 12-month double-blind, placebo-controlled trial of immunotherapy. Nasal biopsy specimens were obtained at 24 hours and processed for immunohistology and in situ hybridization studies. RESULTS: Grass pollen immunotherapy inhibited allergen-induced immediate (0 to 60 minutes) increases in sneezing (p < 0.02) and nasal blocking (p < 0.01) and late (0 to 24 hours) nasal symptoms (p < 0.05). Immunotherapy also inhibited the associated infiltration of the nasal mucosa by CD4+ T lymphocytes and total (major basic protein-containing) and "activated" (cationic protein-secreting) eosinophils (all p = 0.03). There was a significant (p = 0.04) increase in cells expressing mRNA for interferon-gamma at 24 hours after allergen challenge, which correlated inversely with patients' seasonal symptoms (r = -0.65, p < 0.05) and medication requirements (r = -0.75, p < 0.02) during the pollen season. CONCLUSION: The results suggest that successful grass pollen immunotherapy for summer hay fever may act by inhibiting allergen-induced T lymphocyte and eosinophil recruitment and eosinophil activation in the target organ, possibly through a mechanism involving protective local increases in TH1-type cells.

Adult↗
PubMed1996

Snoring--a simple surgical solution.

In this paper a new palatal surgical technique for the treatment of snoring is described and evaluated. All 22 patients were severe snorers with no significant obstructive sleep apnoea, as confirmed by detailed sleep studies. The aim of the surgical technique was to eliminate the vibration of the soft palate and the posterior pillars which occurs during snoring. This was achieved under general anaesthetic by making a 1.5 cm vertical full thickness incision in the soft palate from the superior pole of the tonsil towards the pterygoid hamulus using monopolar cutting diathermy. Specifically designed daily pain questionnaires were completed by the patients during the first 2 post-operative weeks and the level of snoring was assessed by the patient's sleeping partner at 2, 6 and 12 weeks. The presence of any complications was also documented at these times. The results demonstrate that this surgical technique is effective, quick, simple and bloodless. The post-operative pain created is mild and quickly resolves. All patients experienced a dramatic diminution of their snoring and in 55% complete cessation was achieved.

Anesthesia, General↗
PubMed1996

Endoscopic sinus surgery in the treatment of cystic fibrosis with nasal polyposis.

We have performed endoscopic sinus surgery on 46 patients with chronic, polypoid rhinosinusitis since 1989. Follow-up ranged from 1 month to 6 years (mean, 28.2 months). Overall, our patients had a 50% chance either of their symptoms returning to preoperative severity or of undergoing a second endoscopic sinus procedure, by 18 to 24 months of postoperative follow-up. Patients with predominantly infective symptoms of mucopurulent rhinorrhea and pain had a significantly better outcome than those with predominantly nasal blockage. The chance of the former group of patients suffering symptom deterioration back to the preoperative state or undergoing a second endoscopic sinus operation was 37% of that of the latter group. The extent of disease on computed tomography scan had no relation to outcome.

Adult↗
PubMed1995

Endoscopic fenestration of choanal atresia.

We report two cases of unilateral choanal atresia and one of choanal stenosis treated successfully by endoscopic fenestration, with no recurrence at a mean follow-up of 18 months. Rigid endoscopy and axial CT scanning confirm the clinical diagnosis and this technique avoids the need for stenting or prolonged post-operative stay.

Adolescent↗
PubMed1994

Rhinitis, sinusitis and the yellow nail syndrome: a review of symptoms and response to treatment in 17 patients.

A total of 17 patients with yellow nail syndrome are described. Their symptoms, age of onset and severity are examined with particular reference to the presence of rhinosinusitis. Fourteen of the patients (83%) suffered severe rhinosinusitis, which pre-dated nail changes in four, coincided with yellow nails in six, and occurred later in the remaining patients. In general, patients responded poorly to conventional medical and surgical treatment, with the exception of functional endoscopic sinus surgery (FESS) which may be of value in these patients. The frequent association of rhinosinusitis with yellow nails may warrant its recognition as part of the syndrome. Careful inspection of the fingernails in all patients presenting with severe rhinosinusitis is warranted.

Adolescent↗
PubMed1994

Major complications of functional endoscopic sinus surgery.

The results of a postal questionnaire indicate an exponential rise in the practice of functional endoscopic sinus surgery (FESS) in the UK and a major complication rate of 0.23%. Cerebrospinal fluid leak was the most common serious complication accounting for 24 of the 36 reports.

Adult↗
PubMed1993

Pneumatization of the uncinate process.

We report one case of extensive and two of partial pneumatization of the uncinate process from a consecutive series of 250 CT scans of the paranasal sinuses. The CT findings are illustrated and the literature reviewed.

Air↗
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↗