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Biomedical subjects

D Cairns

Publications and source records attributed to D Cairns.

At least 37 records · Page 2Linked to original sources
PubMed1994

Selective effects of pentamidine on cytosolic and granule-associated enzyme release from zymosan-activated human neutrophilic granulocytes.

Therapeutic concentrations (0.3-1.5 mgL-1) of pentamidine isethionate, normally obtainable in-vivo after parenteral administration of the drug, did not affect the in-vitro activity of the enzymes lysozyme, beta-glucuronidase or myeloperoxidase released from zymosan-activated human neutrophilic granulocytes. At concentrations of 0.7, 1.1 and 1.5 mgL-1, activity of cytosolic enzymes lactate dehydrogenase and glucose-6-phosphate dehydrogenase were reduced relative to untreated cells (P < 0.001 and P < 0.01, respectively), but not in a dose-dependent fashion. Cell viability, as determined by dye-exclusion remained unaffected.

Adult↗
PubMed1994

Naphthalene black staining of granules of eosinophilic granulocytes: proposed mechanism of action using chemical blockade and computer graphics.

Histochemical staining of the granules of eosinophilic granulocytes and subsequent blockade of the reaction by alkaline benzyl was strongly suggestive that in its purified form, the diazo dye naphthalene black reacts with tissue sites containing high concentrations of arginine residues. Computer graphics modelling indicated that the sulfonate group of the dye reacts electrostatically with the guanidino functional group of arginine. This acid-base type reaction likely has a stoichiometric ratio of 2:1 in favor of the amino acid.

Amido Black↗
PubMed1993

Radiation pneumonitis: a possible lymphocyte-mediated hypersensitivity reaction.

OBJECTIVE: To determine if unilateral thoracic irradiation results in a lymphoid alveolitis in both irradiated and unirradiated lung fields. DESIGN: A prospective, nonrandomized study. PATIENTS: Women receiving postoperative radiotherapy for carcinoma of the breast were evaluated both before and 4 to 6 weeks after radiotherapy. Findings after radiotherapy in 15 asymptomatic patients were compared with findings in a group of patients with clinical radiation pneumonitis. MEASUREMENTS: History, physical examination, chest radiograph, quantitative gallium lung scanning, respiratory function tests, bronchoalveolar lavage, and lavage lymphocyte subset analysis. RESULTS: After irradiation, lavage lymphocytes increased significantly (34.5% versus 46.8%; P = 0.01) in the 17 patients studied prospectively. There was an associated reduction in vital capacity (102.5% versus 95.5%; P = 0.04). Comparison of results in patients before treatment, after treatment without clinical pneumonitis, and after treatment with clinical pneumonitis showed a dramatic increase in total lymphocytes after irradiation (6.3 versus 9.4 versus 35.2 million, respectively; P = 0.005), particularly in those with clinical pneumonitis. Only in those with clinical pneumonitis was this accompanied by an increase in the gallium index (3.7 versus 3.4 versus 9.0, respectively; P < 0.001). Vital capacity was also progressively reduced (102.5% versus 96.9% versus 76.7%, respectively; P = 0.04), as was diffusing capacity (98.6% versus 91.4% versus 72.6%, respectively; P = 0.003). No statistical differences existed between irradiated and unirradiated sides of the chest in either lavage or gallium lung scan studies. CONCLUSION: In most patients, a lymphocytic alveolitis develops in both lung fields after strictly unilateral thoracic irradiation; this is more pronounced in patients developing clinical pneumonitis. These findings suggest that radiotherapy may cause a generalized lymphocyte-mediated hypersensitivity reaction.

Adult↗
PubMed1993

Nailfold capillary circulation in osteoarthritis.

Nailfold capillaries in 28 patients with OA affecting the distal interphalangeal joints were compared to 23 age- and sex-matched controls without OA. Patients with OA showed a significantly lower density of capillaries in their nailfolds and significantly more capillary morphological abnormalities including haemorrhage, 'drop out', dilatation and irregularity. There was a trend for OA patients to have warmer fingers with reduced finger to brachial blood pressure ratios. There were significant correlations between nailfold capillary numbers and average joint tenderness and between capillary morphological changes and joint swelling. These results reveal a relationship between interphalangeal joint OA and nailfold capillary abnormalities and density. As changes in microcirculation may be pertinent to the pathogenesis of OA, further studies which could explore possible causal relationships are warranted.

Aged↗
PubMed1993

Changes in epithelial lining fluid albumin associated with smoking and interstitial lung disease.

Albumin is an important plasma protein which is useful in the assessment of in vivo membrane permeability in the lung. In subjects with interstitial lung disease (ILD) the relationship between albumin recovered from bronchoalveolar lavage (BAL) and other markers of inflammatory activity may provide useful information of the pathogenesis of the disease process. Unfortunately, its measurement is hampered by the variable dilution in BAL fluid. In this study, urea was used as a marker of epithelial lining fluid (ELF) dilution allowing the calculation of an apparent epithelial lining fluid volume and adjusted albumin content. We examined the relationship between ELF albumin content and BAL cell counts, immunoglobulin content, respiratory function tests and gallium lung scans in both smokers and nonsmokers with and without interstitial lung disease. Forty seven subjects with connective tissue disease and interstitial lung disease and 51 subjects with either connective tissue disease but no pulmonary involvement or non pulmonary malignancy (18 current smokers) underwent BAL, gallium lung scans and respiratory function tests. The subjects with ILD were further subdivided into those with active ILD or bronchiolitis using cluster analysis. In smokers without ILD an increased ELF volume and a decrease in ELF albumin were found. Increased ELF albumin was related to increased age. In subjects with ILD, increased albumin was strongly correlated with increased BAL lymphocyte absolute and differential counts, which overwhelmed any age or smoking effect. These findings suggest a possible causal relationship between lung vascular permeability and lymphocyte numbers in subjects with interstitial lung disease and reinforce the need to consider smoking and age as confounding factors in BAL analysis.

Biomarkers↗
PubMed1992

Smoking-induced changes in epithelial lining fluid volume, cell density and protein.

Bronchoalveolar lavage has proved a useful research technique for recovering cellular and molecular contents of the lower respiratory tract. Because the recovered fluid is variably diluted, an accurate estimation of molecular and cellular concentrations can only be made if the epithelial lining fluid volume recovered is also known. It has been suggested that smoking may alter epithelial lining fluid volume by reducing clearance or by stimulating production and, thus, affect the interpretation of bronchoalveolar lavage studies. In this study, urea was used as an endogenous marker of epithelial lining fluid volume in a comparison of 26 smokers and 31 nonsmokers. The mean epithelial lining fluid volume recovered from smokers was significantly greater than that of nonsmokers (2.4 +/- 1.40 ml vs 1.2 +/- 0.75 ml, p less than 0.005). The total cellular concentration in the bronchoalveolar lavage fluid in smokers was also greater (94.2 +/- 46 x 10(6) vs 33.9 +/- 21.5 x 10(6) cells per 300 ml lavage), even when corrected for bronchoalveolar lavage volume recovered (63.1 +/- 32.5 x 10(6) vs 24.9 +/- 13.3 x 10(6) cells per 100 ml recovered lavage fluid). This was true for macrophage, lymphocyte and neutrophil cell numbers. However, when corrected for the apparent epithelial lining fluid volume, only the macrophage count remained significantly higher in the smokers compared with nonsmokers (30.66 +/- 20.7 x 10(6) vs 18.21 +/- 8.6 x 10(6) macrophages.ml-1 ELF). In addition, concentrations of albumin and immunoglobulin M (IgM) were significantly lower in smokers after correction for epithelial lining fluid volume. These results highlight smoking as a confounding factor in the interpretation of bronchoalveolar lavage data.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchoalveolar Lavage Fluid↗
PubMed1992

The differing patterns of interstitial lung involvement in connective tissue diseases.

Connective tissue disorders (CTD) have a relatively high incidence of pulmonary complications but their delineation has been hampered by difficulties inherent in the diagnostic techniques. One fresh approach to this problem is based on a clustering method that uses data from 8 separate investigations to cluster the patients into 4 distinctly separate categories representing normal nonsmoker, normal smokers, those with active interstitial lung disease and those with bronchiolitis. Using this method, a large group of patients with CTD have been examined to assess the nature and extent of their pulmonary complications. Subjects in the first cluster had a normal test profile across all variables, and included no current active smokers. The normal smoking cluster contained only smokers who had a high total lavage cell number with a relative increase in macrophages and a decrease in lymphocytes. In this group, all respiratory variables were normal with the exception of a mildly depressed DLCO, also known to be associated with smoking. The general characteristics of the active interstitial lung disease cluster was a markedly depressed DLCO indicating impaired gas exchange, and elevated gallium index, bronchoalveolar lavage (BAL) cell number and neutrophil and lymphocyte percentages, all indicating an active inflammatory process. However more careful analysis of this group suggested the presence of 2 subgroups, one with a lymphocytic alveolitis, and another with a neutrophilic alveolitis. The bronchiolitis cluster characteristics were a markedly depressed maximal mid expiratory flow rate and raised BAL lymphocyte percentage and gallium index. The distribution of patients within the cluster groupings suggested that Sjögren's syndrome, often an accompaniment of other CTD, is most frequently associated with pulmonary disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Interstitial lung disease associated with connective tissue diseases. The use of statistical structure analysis in model development.

Interstitial lung disorders associated with the connective tissue diseases are thought to be quite common, but their precise analysis is fraught with difficulty because of the absence of a Gold Standard that, short of open lung biopsy, is not available. Analysis is hampered by the biologic variability in test results, large overlap between the normal and the disease population for individual tests, the confounding effect of smoking, and the complexities of viewing multidimensional data. In order to better define the pattern of the lung involvement, an entirely different approach has been adopted that is based on the use of graphic and clustering techniques to define the multivariate structure inherent in the data, then discriminant analysis to assign patients into distinct clusters. Using this approach it has been possible to group patients into four distinct clusters based on the result of respiratory function studies, gallium lung scan, bronchoalveolar lavage, and smoking status. These clusters are a normal smoking cluster and a normal nonsmoking cluster, a cluster of patients with active ILD, and a cluster with bronchiolitis. The validity of this method has been verified, and an algorithm has been developed that allows the assignment of any new patient entering the study into one of these clusters. This type of analysis offers a valuable new approach to the categorization of patients into distinct groups based on the results of multiple investigations.

Algorithms↗
PubMed1989

Synthesis of novel benzylimidazolines possessing antihypertensive and sedative activity.

In the course of a study to produce new long acting local anaesthetics, a number of novel benzylimidazoline derivatives were synthesised and tested for local anaesthetic activity, vasoconstrictor effect and ease of displacement of p-aminoclonidine. The synthesis is shown in Scheme 1.- The synthesised compounds do not exhibit a significant local anaesthetic effect, but display an antihypertensive action with considerable alpha-2 adrenoceptor binding affinity.

Animals↗
PubMed1989

Concentration-response relationships for salicylate-induced ototoxicity in normal volunteers.

1. Ototoxicity is a common and troublesome side-effect of high-dose aspirin treatment but there has been little previous study of the relationships between the degree of ototoxicity and the plasma concentrations of salicylate. 2. In order to investigate the relationships between aspirin dose, total and unbound plasma salicylate concentrations and ototoxicity, eight normal volunteers were dosed with aspirin 1.95, 3.25, 4.55 and 5.85 g day-1 for 1 week at each dose level, the doses being administered in random order and double-blind, 2 weeks apart. 3. Ototoxic effects measured were hearing loss in decibels (dB) over six frequencies and tinnitus intensity, estimated both by electronic matching and a fixed interval scale (FIS). Measurements were taken after steady-state concentrations of salicylate had been achieved. 4. Total and unbound plasma salicylate concentrations increased disproportionately with increasing daily doses of aspirin. The increase in the unbound salicylate was relatively greater since the percentage of salicylate unbound in plasma increased over the dose range investigated from a mean of 3.9% to 10.4%. 5. Hearing loss and tinnitus intensity increased progressively with the aspirin dosage and increasing concentrations of total and unbound plasma salicylate concentrations. These ototoxic symptoms were observed at lower concentrations of total salicylate than previously reported. 6. There was a linear relationship between hearing loss and unbound salicylate concentrations. 7. Further work is required to test the hypothesis that unbound plasma salicylate concentration is a better predictor of salicylate-induced ototoxicity than total plasma salicylate concentration.

Adult↗
PubMed1989

The presence of Sjögren's syndrome is a major determinant of the pattern of interstitial lung disease in scleroderma and other connective tissue diseases.

A number of patients with scleroderma, Sjögren's syndrome and other connective tissue diseases (CTD) were assessed to ascertain the prevalence of respiratory abnormalities as defined by bronchoalveolar lavage (BAL), standard respiratory function studies and gallium scan of the lung, and the relationship of these abnormalities to the presence or absence of dyspnea. These results suggest that respiratory symptoms are very common in CTD and in scleroderma, particularly if Sjögren's syndrome is also present. Our findings also suggest the presence of 2 patterns of interstitial lung involvement in scleroderma. In scleroderma alone this appears to be characterized by the presence of increased neutrophil proportions in the BAL, decreased DLCO, and no increase in gallium uptake within the lung. Where scleroderma is associated with Sjögren's syndrome, there is an increase in the proportion of lymphocytes in the BAL and respiratory symptoms are very prominent, the latter associated with an increase in gallium uptake within the lung. This suggests that Sjögren's is a major determinant of the pattern of interstitial lung disease seen in CTD.

Bronchoalveolar Lavage Fluid↗
PubMed1976

A system for evaluating and treating chronic back disability.

Five methods of personality assessment are evaluated to provide guidance for the psychological treatment of patients with chronic back pain. Patient pain drawings, pentothal pain studies, stress score index, psychological testing with the Minnesota Multiphasic Personality Inventory (MMPI) and response to treatment challenge are used as measurements for evaluation. This evaluation gives the treating staff guidelines for individual treatment programs utilizing operant conditioning techniques. Using this approach, three fourths of the severely disabled patients seen have been successfully treated.

Back Pain↗