Search PubMed⌕ Search

Biomedical subjects

C M Roberts

Publications and source records attributed to C M Roberts.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1993

Value of pulse oximetry in screening for long-term oxygen therapy requirement.

Pulse oximetry, combined with spirometry, was evaluated as a method of selecting chronic obstructive pulmonary disease (COPD) out-patients requiring definitive arterial blood gas analysis for long-term oxygen therapy (LTOT) assessment. A relatively high screening arterial oxygen saturation by pulse oximetry (SaO2) level was set, in order to maximize sensitivity. All 113 COPD out-patients attending the hospital clinic over a 6 month period were screened. Sixty had a forced expiratory volume in one second < 1.5 l and 26 had an SaO2 < or = 92%. These 26 underwent arterial blood gas analysis. Nine had an arterial oxygen tension < 7.3 kPa all with an arterial carbon dioxide tension (PaCO2) > 6 kPa. A further eight had a PaO2 < 8 kPa. This produced a sensitivity of 100% and specificity of 69% for oximetry in the detection of PaO2 < 7.3 kPa determined by direct arterial puncture and 100% and 86% respectively for detecting a PaO2 < 8 kPa. Although the poor specificity of oximetry in the crucial PaO2 range makes it unsuitable, when used alone, for prescription of LTOT, it may prove valuable in selecting patients who require further definitive arterial blood gas analysis.

Aged↗
PubMed1993

Mission: Philippines 1992.

A volunteer mission to the Philippine island of Negros for Operation Smile International in February 1992 is retold. Two Virginia PACU nurses share experiences of the situations and circumstances on their first mission, which profoundly affected their personal and professional outlooks and nursing philosophies.

Humans↗
PubMed1992

The value of CT scanning and percutaneous fine needle aspiration of adrenal masses in biopsy-proven lung cancer.

Pre-operative CT scans of 546 patients with biopsy-proven primary bronchial carcinoma were reviewed. Twenty-two patients had a solid adrenal tumour (2 bilateral). Sixteen underwent percutaneous fine needle aspiration (FNA). Malignant cells were aspirated in five, eight revealed benign cells and in three cases there was insufficient material for diagnostic purposes. Six patients did not undergo FNA, four of these were considered to have benign adenomas on CT. This was confirmed by the unchanged CT image at more than 21 months follow-up. The five subjects with FNA-proven metastases died at a median of 14 months (range 3-24 months). All five would have been regarded as operable on their staging chest CT scan. Five patients with a negative biopsy underwent surgery, two died of metastases at 6 and 11 months respectively and one died of post-operative complications. The other two have unchanged adrenal lesions on CT at 9 months and 25 months. The CT appearances of these lesions were analysed. Well defined, low attenuation lesions which had a smooth attenuation rim or only involved part of the gland were benign and the survivors had unchanged CT appearances at follow-up (six lesions in five patients). Of these four lesions were less than or equal to 2 cm in diameter. Low attenuation lesions without a rim were malignant (n = 2). These latter both measured more than 2 cm in diameter. The CT appearances of many adrenal lesions were insufficiently distinctive to exclude malignancy and biopsy was necessary to establish a diagnosis.

Adrenal Gland Neoplasms↗
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 anatomy of radioisotope lung scanning.

An appreciation of the appearances of segmental and lobar defects on a lung scan is important for the diagnosis of pulmonary embolism. The appearances of segmental and lobar ventilation defects of known anatomical location have been examined on 81mKr ventilation scans in normal human subjects, utilizing fibreoptic bronchoscopy to place temporary occlusions under direct vision at the orifices of lobar and segmental bronchi. Scans were obtained in the posterior, posterior-oblique and lateral projections. Anterior views were included if the defects could not be adequately visualized on the other views. The completeness of the occlusion and the site and size of each defect could be confirmed by ventilating the segment itself with 81mKr via the balloon catheter while the occlusion was maintained. Segmental defects located anterior to the hilum of the lung tended to be optimally visualized on the lateral view and defects located posterior to the hilum tended to be optimally visualized on the posterior-oblique view. The size of segmental defects could be underestimated on the lung scan, especially those involving the anterior and lateral basal segments of both lower lobes. Defects involving the medial basal segment of the right lower lobe were undetectable on any view. By implication, the same conclusions apply to 99mTc perfusion scans.

Adult↗
PubMed1991

Melioidosis in a patient from Bangladesh.

A 54 year old Bangladeshi man presented with a history and chest X-ray appearances suggestive of pulmonary tuberculosis. Following deterioration 4 weeks later, he required ventilation. Although a blood culture isolate was subsequently found to be Pseudomonas pseudomallei, it was initially misidentified and dismissed as a contaminant. Further cultures demonstrated the organism, but the patient died, despite treatment with ceftazidime. The case illustrates the importance of taking a detailed travel history and having a high index of suspicion in patients from South East Asia and the Indian sub-continent, including Bangladesh, where the disease has not previously been considered endemic.

Bangladesh↗
PubMed1991

Reference values and prediction equations for normal lung function in a non-smoking white urban population.

Prediction equations for normal lung function have been derived from tests on 179 healthy, non-smoking, white urban dwellers. The subjects, 96 women (height 1.46-1.77 m) and 83 men (height 1.61-1.96 m) aged 18-86 years, underwent measurements of spirometric flow and volume, multi-breath helium dilution lung volumes, and single breath carbon monoxide transfer factor and the single breath nitrogen washout test. Regression analysis using height, age, and weight as independent variables was used to provide predicted values for both sexes. Correlation coefficients were similar to those found in previous studies but normal ranges for spirometic measurements were narrower than in many previous studies, and spirometric flow and volume measurements were higher than those obtained in studies that included cigarette smokers, reflecting our more stringent criteria for selecting subjects and the newer standardised technical methods adopted. Multi-breath helium dilution values for total lung capacity were similar to those found in previous studies but the inspiratory vital capacity was larger and the residual volume reduced. Values for carbon monoxide transfer factor and the single breath nitrogen washout did not differ significantly from existing values. A complete set of lung function reference values and prediction equations for both sexes has been derived from a single population. The exclusion of cigarette smokers and subjects with respiratory symptoms has produced values that should have a greater sensitivity in the detection of mild lung disease.

Adolescent↗
PubMed1990

An assay for the assessment of lipocortin 1 levels in human lung lavage fluid.

The physiological function of the lipocortins, proteins which are thought to be glucocorticoid-regulated, is unclear. An improved assay for lipocortins might help to elucidate their role. A rapid and specific sandwich enzyme-linked immunosorbent assay (ELISA) for lipocortin 1 with a working range of 1-2000 ng/ml and an interrun coefficient of variation of less than 10% is described and used in this pilot study to quantify human lipocortin 1 for the first time in acellular bronchoalveolar lavage fluid (BALF), and in media conditioned by BAL cells, from control patients and those with pulmonary sarcoidosis. Using this assay a statistically significant relationship, not previously observed in man, has been demonstrated between concentrations of lipocortin 1/ml of BALF and serum cortisol levels (n = 10, rs = 0.6939, P less than 0.05). Although lipocortin 1 levels in acellular BALF were the same in control and sarcoid patients, significantly more lipocortin 1 was released from sarcoid BAL cells in culture (median 21.6, range 8.1-45.4 ng lipocortin/10(6) cells/h in culture) than from control cells (2.5, 1.5-7.6 ng lipocortin/10(6) cells/h in culture). The possible clinical significance of these data is discussed, but remains to be established.

Annexins↗
PubMed1990

High-performance liquid chromatographic analysis of lung phospholipids and their precursors in the offspring of diabetic rats.

Pulmonary phospholipids and their precursors and metabolites were assayed in the offspring of streptozotocin-induced diabetic rats at 19 and 21 days gestation and at 2 days after birth by two unique methods that employ high performance liquid chromatography combined with automated phosphorus analysis. In general, lung phospholipids were not different between offspring of control versus diabetic mothers. Levels of phosphatidylglycerol, however, were decreased in the offspring of diabetics. Lysophosphatidylcholine appears to be increased in the lungs of offspring of diabetic mothers, suggesting that maternal diabetes is associated with alterations in the remodeling of phosphatidylcholine.

Animals↗
PubMed1990

The effect of nicardipine, a calcium channel blocker, on the sweat test in adult patients with cystic fibrosis.

In vitro studies have suggested a potential role for calcium channel blockers in manipulating the basic ionic defect of cystic fibrosis. In 17 adult patients with cystic fibrosis nicardipine was administered either intravenously or topically using iontophoresis or occlusive dressings. Sweat tests were performed before and after drug administration and examined using two way analysis of variance. No statistically significant difference was observed. We conclude that nicardipine used in vivo does not exert the easily demonstrable effect on the chloride ion defect that has been observed with other agents in vitro.

Adult↗
PubMed1990

Multi-breath and single breath helium dilution lung volumes as a test of airway obstruction.

Total lung capacity (TLC) and residual volume (RV) measurements derived from multi-breath and single breath helium dilution methods were combined to produce four indices of gas mixing: single breath volume/multi-breath volume ratio (TLCr, RVr) or multi-breath volume minus single breath volume difference (TLCd, RVd). The reproducibility of these indices and their sensitivity and specificity in discriminating between normal subjects and those with mild asthma and severe chronic obstructive pulmonary disease (COPD) was assessed. The total lung capacity ratio (TLCr) was the superior variable overall, providing a single range for both sexes with a specificity and sensitivity similar to that of the forced expiratory volume in one second (FEV1) in the diagnosis of airflow obstruction. Despite the similar sensitivity, correlation between TLCr and FEV1 was only moderate (r = 0.56). This may reflect greater influence of peripheral rather than central airflow obstruction on TLCr. Combining both tests improved sensitivity in the detection of airways obstruction in the asthmatic and COPD groups studied.

Adult↗
PubMed1989

The effect of nicardipine, a calcium channel blocker, on the sweat test in adult patients with cystic fibrosis.

Impaired cell membrane chloride ion movement in cystic fibrosis results in reduced resorption of sodium and chloride from sweat gland ductules producing the high concentrations measured in the sweat as a diagnostic test. Normal chloride ion movement can be restored in vitro by blocking transepithelial calcium flux with lanthanum, suggesting a potential role for calcium channel blocking drugs in the management of cystic fibrosis. We studied the effect of nicardipine, a calcium channel blocker, on the sweat sodium in 17 adult patients with cystic fibrosis. Nicardipine was administered intravenously or topically using iontophoresis or occlusive dressing. No significant change in sweat sodium concentration was observed between pre- and post-drug administration. We conclude that nicardipine used in vivo does not exert the same effect as lanthanum demonstrates in vitro on transepithelial cell membrane chloride ion movement in cystic fibrosis.

Administration, Topical↗
PubMed1988

The role of fibreoptic bronchoscopy in the investigation of pleural effusion.

Published data on the role of fibreoptic bronchoscopy in the investigation of pleural effusions are sparse and conflicting. We have reviewed our experience from November 1980 to December 1986. Thirty-two patients were identified from bronchoscopy records as having undergone the procedure during the evaluation of an effusion. Fibreoptic bronchoscopy was diagnostic in 6 of the 32 cases, but less invasive procedures had given the diagnosis in 4, and in the other 2 cases radiological abnormalities other than the effusion suggested an underlying bronchial malignancy. We conclude that routine fibreoptic bronchoscopy is not justified in the evaluation of pleural effusions.

Bronchial Neoplasms↗
PubMed1987

Oral ciprofloxacin compared with conventional intravenous treatment for Pseudomonas aeruginosa infection in adults with cystic fibrosis.

40 adult patients with cystic fibrosis (CF) were admitted to hospital with acute exacerbations of infection associated with isolation of Pseudomonas aeruginosa from sputum. The patients were randomly allocated (20 per group) to receive intravenous azlocillin 5 g and gentamicin 80 mg, or oral ciprofloxacin 500 mg. Both treatments were given three times a day for 10 days. The patients were assessed on days 1 and 10, and at 6 weeks. There was a significant improvement in lung function between days 1 and 10 in both groups (p less than 0.001). Significant improvement was maintained at 6 weeks after ciprofloxacin but not in the intravenous group. Improvement after ciprofloxacin was superior at day 10. Sputum weight decreased in both groups (p less than 0.001). Patient-recorded symptoms also improved in both groups. There was no serious toxicity or side-effects. Drug resistant organisms were isolated no more frequently after ciprofloxacin than after intravenous therapy. 17 of the ciprofloxacin-treated patients said they preferred oral treatment to intravenous therapy. Oral ciprofloxacin is a useful short-term treatment for patients with CF who are infected with Ps aeruginosa.

Acute Disease↗