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Biomedical subjects

J V Collins

Publications and source records attributed to J V Collins.

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

Leukotrienes, LTC4 and LTB4, in bronchoalveolar lavage in bronchial asthma and other respiratory diseases.

Leukotrienes (LTs) C4 and B4 are potent proinflammatory mediators with a wide variety of biologic activities, including smooth muscle contraction, mucus hypersecretion, and leukocyte activation, which may be of particular relevance to the pathology of asthma and other respiratory diseases. We measured the concentrations of LTC4 and LTB4 in bronchoalveolar lavage fluid from 16 atopic subjects with asthma (eight symptomatic and eight asymptomatic) and from 14 control subjects without asthma (six with hay fever and eight nonatopic). The amounts detected in symptomatic subjects with asthma were significantly higher than in control subjects (LTB4, 0.58 +/- 0.06 versus 0.36 +/- 0.05 pmol/ml, p less than 0.05; LTC4, 0.36 +/- 0.1 versus 0.12 +/- 0.02 pmol/ml, p less than 0.01). LTC4 and LTB4 were also measured in 17 patients: nine with interstitial lung disease of varying etiology (cryptogenic fibrosing alveolitis [CFA] or idiopathic pulmonary fibrosis), three with sarcoidosis, one with extrinsic allergic alveolitis, one with sulphonamide-induced pneumonia, and one patient with eosinophilic granuloma. The concentrations of LTB4 (but not LTC4) were significantly greater in patients with CFA compared with normal control subjects (0.69 +/- 0.3 versus 0.36 +/- 0.05 pmol/ml, p less than 0.01). There was a significant correlation (p less than 0.05) between the percentage of neutrophils and the concentration of LTB4 in the bronchoalveolar lavage fluid) of the group with interstitial lung disease as a whole. This study provides evidence for a role for LTs in the airways of subjects with day-to-day asthma and suggests that LTB4 may also be involved in the recruitment of granulocytes into the lung in patients with CFA.

Adult↗
PubMed1989

Diagnosis, treatment and outcome of pneumonia in the acquired immune deficiency syndrome.

Fibreoptic bronchoscopy was performed in 43 of 52 consecutive patients with opportunistic pneumonia in the acquired immune deficiency syndrome (AIDS). The 15 patients in whom a likely pathogen was not found by bronchoscopy (including the nine not having the procedure) were treated for Pneumocystis carinii pneumonia (PCP) alone and all responded. In 11 of these a diagnosis of AIDS was confirmed because of an alternative opportunistic infection within 6 months. PCP was confirmed in 38 of the 52 patients and cytomegalovirus (CMV) was isolated from 15 patients. The lower the partial pressure of arterial oxygen (PaO2) on admission the more likely was a pathogen to be found by bronchoscopy. The admission PaO2 while the patient was breathing room air was the single most reliable prognostic indicator. The mean PaO2 for survivors was 9.6 kPa and 6.7 kPa for non-survivors (P less than 0.01 Student's t-test), with 50% mortality for patients with a PaO2 of less than 8 kPa on admission. Temperature and pulse rate were sensitive indicators of response to treatment, obviating the need for frequent arterial gas measurements and chest radiography. Our findings suggest that although fibreoptic bronchoscopy contributed little to the treatment and final outcome of the infection, it identified the causative pathogen in most patients.

Acquired Immunodeficiency Syndrome↗
PubMed1989

AIDS and the lung. 1--AIDS, aprons, and elbow grease: preventing the nosocomial spread of human immunodeficiency virus and associated organisms.

Epidemiological evidence indicates that transmission of human immunodeficiency virus (HIV) other than by direct inoculation or sexual contact is extremely rare. HIV has, however, been found on fibreoptic bronchoscopes used on patients with AIDS and there is a clear theoretical risk of transmission by bronchoscopy. Applied experiments have underlined the importance of cleaning equipment thoroughly and have shown the limitations of disinfection. Infection control policies should be revised to meet the following four basic requirements: (1) all precautions should apply to all patients alike--that is, whether infectious or not; (2) equipment should be cleaned thoroughly in detergent immediately after use to remove body secretions and reduce contamination; (3) staff who may be exposed to body secretions should wear simple barrier clothing routinely; and (4) contaminated bronchoscopes should be disinfected for 20 minutes in 2% alkaline glutaraldehyde after cleaning.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Bronchial biopsies in asthma. An ultrastructural, quantitative study and correlation with hyperreactivity.

Little is known of the structural changes in mild asthma. We have studied the light and electron microscopic structure of lobar bronchial biopsies taken at fiberoptic bronchoscopy from 11 atopic asthmatics, four of whom were symptomatic and seven of whom were asymptomatic. The former and three of the latter had bronchial hyperresponsiveness to methacholine (PC20 less than 4 mg/ml). Quantitative comparisons were made with biopsies from ten control subjects with normal airway reactivity; five had hay fever and five were nonatopic healthy volunteers. Complete absence of surface epithelium was found in three cases of symptomatic asthma, and stratified squamous epithelium was present in the fourth. A biopsy from one of the healthy control subjects had also lost its surface epithelium. The degree of epithelial loss in all subjects correlated with the degree of airway reactivity (rs = 0.67, p less than 0.001). The reticular lamina of the epithelial basement membrane showed a trend toward thickening in the seven hyperreactive asthmatics (p less than 0.001: median test). There was a tendency to high numbers of inflammatory cells in the lamina propria, but not in the submucosa, of asthmatics, but the differences between groups did not achieve statistical significance. There were significant alterations (px2 less than 0.001) in the proportions of each type of inflammatory cell found in the lamina propria and submucosa of symptomatic asthmatics: an increase of irregularly shaped lymphocytes contributed most to the observed alteration. Where surface epithelium was present, intraepithelial lymphocytes formed the major proportion of intraepithelial "migratory" cells: 64% in normal control subjects, 78% in subjects with hay fever, and 87% in asymptomatic asthmatics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Infection control revisited: dilemma facing today's bronchoscopists.

The emergence of the acquired immune deficiency syndrome has provoked a widespread review of policies for infection control. Incomplete knowledge about the human immunodeficiency virus (HIV), hepatitis B virus, and mycobacteria has until now been compensated for by adopting "overkill" precautions for patients who were thought to harbour these organisms. This policy is no longer tenable, given the difficulty in identifying infected patients. The control of infection in hospitals must instead be based on the routine use of high standards of hygiene that are adequate to contain all pathogens. Attempts by bronchoscopists to formulate such a policy have been frustrated by the lack of a suitable disinfectant and by ignorance of the susceptibility of microorganisms to cleaning and disinfection in a clinical environment.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Eosinophils and mast cells in bronchoalveolar lavage in subjects with mild asthma. Relationship to bronchial hyperreactivity.

We have performed bronchoalveolar lavage (BAL) on 17 subjects with mild atopic asthma (9 symptomatic, 8 asymptomatic) and 14 nonasthmatic control subjects (6 hay fever, 8 nonatopic). There was a significant increase in the percentage of mast cells in both groups of asthmatics although the counts were no different from those previously reported for a number of other respiratory diseases. Asthmatics with airway hyperreactivity (PC20 less than 4 mg/ml) had significant increases in spontaneous histamine release. There was a significant elevation in the eosinophil count and the concentration of major basic protein (MBP) in BAL fluid in the symptomatic asthmatics. Furthermore, there was a significant correlation between the amounts of MBP recovered and the percentage of eosinophils in the BAL. These changes were even more marked when asthmatics with airway hyperreactivity were compared with subjects with normoreactive airways. In addition, there was a significant increase in the percentage of epithelial cells in the hyperreactive asthmatics. There was an inverse correlation between the PC20 and the percentage of mast cells (p less than 0.01), eosinophils (p less than 0.05), and epithelial cells (p less than 0.05) and amount of MBP in BAL (p less than 0.01). This study supports the hypothesis that bronchial hyperresponsiveness is secondary to epithelial cell damage mediated through eosinophil-derived granule products.

Adult↗
PubMed1987

Mycobacterium chelonei and abscess formation in soft tissues.

Mycobacterium chelonei was isolated from a breast abscess in a healthy 46-year-old non-lactating Caucasian woman. In-vitro testing showed the organism to be resistant to conventional anti-tuberculosis agents but sensitive to tetracycline and erythromycin. Treatment with isoniazid, pyrazinamide and rifampicin initially produced a good response but the subsequent development of multiple abscesses required the addition of tetracycline and finally a change to erythromycin and trimethoprim, on which recovery was complete.

Abscess↗
PubMed1987

Fibreoptic bronchoscopy in diagnosis of bronchopulmonary Kaposi's sarcoma.

Kaposi's sarcoma of the lung patients with the acquired immune deficiency syndrome is often indistinguishable by clinical and radiographic criteria from opportunistic pneumonia. Pulmonary Kaposi's sarcoma and pneumonia may frequently be present in the same patient. Previous observers have commented on the repeated failure to establish a diagnosis of Kaposi's sarcoma of the lung by fibreoptic bronchoscopy. Thirteen fibreoptic bronchoscopies were performed in a series of 11 patients with thoracic manifestations of AIDS and Kaposi's sarcoma was identified in transbronchial or bronchial biopsy specimens in four patients. This diagnostic yield is comparable to that obtained only by open lung biopsy procedures in previous reports. Fibreoptic bronchoscopy may contribute to the correct management of the patient and facilitate an accurate prognosis by differentiating between opportunistic pneumonia and pulmonary Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Morphological and secretory properties of bronchoalveolar lavage mast cells in respiratory diseases.

We have studied various functional and morphological characteristics of mast cells obtained in bronchoalveolar lavage from fifty-two patients with several lung diseases. The percentage of mast cells ranged from 0.04 to 0.6% (bronchial carcinoma), 0.05-0.3% (sarcoidosis), 0.06-0.25% (asthma), 0.04-1.8% (miscellaneous) and 0.02-0.04% (normals). There were no significant differences in the mast cell counts between the disease groups. Lung mast cells exhibited heterogeneity of size, shape and intensity of staining. Cells from thirty-seven subjects were further studied for total histamine content and histamine release using various secretagogues. There was a significant correlation (P less than 0.001) between the histamine content of the total lavage cell population and mast cell counts. The calculated mean histamine content per mast cell was 6.35 pg. Histamine was released in a dose-dependent fashion after stimulation with anti-IgE, calcium ionophore and phorbol myristate acetate with a time course of histamine release characteristic of the mast cell. Unlike peripheral blood basophils, no release was observed following incubation with f-met-leu-phe (10(-6)-10(-8) M) and neither cell type released histamine following incubation with 48/80 (10 micrograms/ml). Inhibition of anti-IgE-induced histamine release was obtained following pre-incubation with salbutamol (10(-4)-10(-6) M). These studies indicate that bronchoalveolar lavage is a suitable model for the study of human lung mast cells.

Adult↗
PubMed1986

Value of serial peak expiratory flow measurements in assessing treatment response in chronic airflow limitation.

A double blind, randomised, placebo controlled, crossover trial of prednisolone (40 mg/day for 14 days) was carried out in 33 patients with chronic airflow limitation (mean age 62 years, mean FEV1 1.01 litres, mean FEV1/FVC ratio 44%), to assess the value of serial peak expiratory flow (PEF) measurements, taken five times daily in evaluating treatment response by comparison with other objective measurements and with measurements of symptoms. The mean serial PEF after a one week run in period was 189 1 min-1, during the second week of placebo 193 1 min-1, and during the second week on prednisolone 231 1 min-1. The difference in mean PEF values between placebo and prednisolone was significant (p less than 0.01). With regard to the response to steroids of the individual patients, 13 of the 33 had a detectable trend of improvement on visual inspection of serial PEF measurements during prednisolone treatment but only one during placebo administration. Of all the objective measurements made after the run in and after each treatment phase (12 minute walking distance, FEV1, forced vital capacity (FVC), serial PEF), the serial PEF chart provided the best discrimination between placebo and prednisolone treatment. There was no statistically significant association between steroid induced improvement in serial PEF measurements and in breathlessness, partly because of placebo improvements in symptoms in those who had no improvement in serial PEF values. This study indicates the importance of making objective measurements to identify a genuine steroid response rather than relying on symptomatic improvement alone. The best simple measurement to make is serial PEF during steroid trials. This is more sensitive in detecting a steroid response than are the 12 minute walking distance, FEV1, or FVC, and is also less likely than these measurements to show spurious placebo responses.

Aged↗
PubMed1986

Bronchoalveolar lavage in patients with interstitial lung diseases: side effects and factors affecting fluid recovery.

One hundred and seventy patients with interstitial lung diseases undergoing bronchoalveolar lavage (BAL), were contrasted with 51 patients undergoing fibreoptic bronchoscopy alone to define the factors which predispose to post-lavage side-effects. Transient post-bronchoscopy fall in the peak expired flow (PEF) greater than or equal to 20% occurred in both groups (24% and 23% respectively), and thus was probably related to the bronchoscopy procedure. Post-lavage pyrexia (greater than or equal to 1 degree C) occurred only in the patients undergoing BAL (26%), p less than 0.001. Only 4% with pyrexia required antibiotics, and only 2% with falls in PEF needed bronchodilator therapy. The only significant clinical association was more frequent pyrexia in patients on treatment with prednisolone, particularly in women (p less than 0.01). Pyrexia was also associated with higher lavage fluid introduction volumes (greater than 240 ml). Side effects did not relate to the percentages of lavage fluid recovered, although smokers had lower recoveries and, recoveries tended to be higher in sarcoidosis than cryptogenic fibrosing alveolitis. Serial lavages in 25 patients caused no significant increase in side effects.

Adult↗
PubMed1985

Is fibreoptic bronchoscopy in patients with lung cancer and hepatic metastases potentially dangerous?

Plasma lignocaine levels were measured in 18 patients with lung cancer undergoing fibreoptic bronchoscopy to determine whether those with hepatic metastases and disturbed hepatic function were at special risk from lignocaine toxicity. Peak plasma lignocaine levels were in fact lower in six patients with hepatic metastases and deranged hepatic function tests than in the nine patients with no evidence of hepatic metastases or dysfunction (mean +/- SEM 1.89 +/- 0.2 mg/litre and 2.60 +/- 0.3 mg/litre respectively, P not significant). The peak plasma lignocaine level did not correlate with tests of liver function but did correlate with age. Using a total dose of lignocaine of less than 400 mg, plasma lignocaine levels remained below the toxic range in all patients. The peak plasma lignocaine level correlated significantly with the amount of drug administered directly into the bronchial tree (P less than 0.05) rather than total dose administered. Patients with hepatic metastases from lung cancer do not appear to be at an increased risk from the toxic effects of lignocaine topical anaesthesia if moderate doses are used.

Administration, Topical↗
PubMed1984

Effects of prednisolone in chronic airflow limitation.

A double-blind, randomised, placebo-controlled, crossover trial of prednisolone (40 mg daily for 14 days) was carried out in 43 patients with chronic airflow limitation (mean age 60 years, mean FEV1 1.02 litres, FEV1/FVC ratio 43.7%). Several subjective and objective variables for response were measured. Significant improvements occurred with prednisolone in most variables measured, but improvements also occurred with placebo in some variables. The improvements with prednisolone in general wellbeing, 12 min walk distance, peak expiratory flow, FEV1, and relaxed vital capacity were significantly greater than those with placebo. Clinical assessment and assessment of atopic status did not reveal any feature of major predictive value for steroid responsiveness. A proportion of patients with chronic airflow limitation do improve on oral corticosteroids and the continued use of such trials in clinical practice is justified, though a placebo period should be included, and several variables for response should be measured.

Adult↗