Biomedical subjects
Publications and source records attributed to C Ward.
We report a patient with coarctation of the aorta who presented with acute dissection of a large left subclavian artery aneurysm. The patient underwent successful reconstructive surgery.
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Methods for detecting recruitment patterns of the lumbar muscles during exercise in patients with chronic low back pain are limited. This article discusses the use of magnetic resonance imaging with Roman chair extension exercise to examine lumbar muscle usage in five normal volunteers, five chronic low back pain patients without surgery, and five chronic low back pain patients with surgery. Changes in signal intensities of psoas, multifidus, and longissimus/iliocostalis with graded exercise were measured at three lumbar disc levels. At rest, there was a difference between multifidus and longissimus/iliocostalis signal intensity in chronic low back pain subjects without surgery (P = 0.0162) and in chronic low back pain subjects with surgery (P = 0.0036), but not in normal subjects. At peak exercise, there was a difference in signal intensities between multifidus and longissimus/iliocostalis in all groups (normal volunteers, P = 0.0069; chronic low back pain patients without surgery, P = 0.0125; chronic low back pain patients with surgery, P = 0.0060). The exercise response was attenuated in chronic low back pain patients with surgery. Thus, MRI demonstrates static and dynamic differences in lumbar paraspinal musculature in chronic low back pain subjects compared to normal subjects.
Four Baluch siblings with mucolipidosis type III (pseudo-Hurler polydystrophy) are described. The patients had features commonly found in mucolipidosis III, including claw hands, joint stiffness, aortic valve involvement and radiological dysostosis multiplex. However, intelligence was normal, there were no eye abnormalities on slit-lamp examination and skin elasticity was normal. Many lysosomal enzymes were elevated in serum and diminished in cultured fibroblasts, although the findings for beta-galactosidase were atypical. Assays for the two enzymes involved in formation of the phosphomannose recognition marker revealed normal activity of the phosphotransferase with alpha-methylmannoside as an acceptor, and normal activity of the phosphodiester glycosidase. Metabolic labelling of fibroblasts with 32P followed by immunoprecipitation of cathepsin D, electrophoresis and fluorography showed that this enzyme was not labelled in the patients' cells, although some label was detected in the secreted precursor polypeptide. The data are consistent with the assumption that activity of the phosphotransferase is low towards lysosomal enzymes as substrates, and that the patients belong to complementation group C.
BACKGROUND: Standardised expression of results of bronchoalveolar lavage (BAL) is problematical in the absence of a validated "denominator" of epithelial lining fluid dilution. The suitability of albumin in BAL fluid has been investigated in groups of clinically stable asthmatic and control subjects. METHODS: Absolute levels of albumin in BAL fluid were measured in a preliminary study of 21 asthmatic and 10 control subjects. In a more complex study designed to investigate the origin of albumin sampled at BAL in nine asthmatic and seven control subjects, radiolabelled albumin was injected intravenously five minutes before BAL. RESULTS: In the preliminary study levels of albumin in BAL fluid were very similar, with a geometric mean value of 44 (95% CI 35-54) micrograms/ml BAL supernatant for the asthmatic subjects and 41 (95% CI 33-52) micrograms/ml for the controls. The majority of control and asthmatic subjects in the radiolabel study exhibited minimal flux of albumin from the circulation into the BAL aspirate. This finding was not uniform, however, and in a third of the asthmatic subjects an albumin flux equivalent to > 20% of the measurable albumin was found in two or more aliquots of a 3 x 60 ml lavage. CONCLUSIONS: The results of this investigation into the source of albumin sampled at BAL suggest that, in general, albumin would be a reasonable reference solute for normalising the degree of dilution of BAL fluid in the groups studied. The origin of albumin was not always restricted to the bronchopulmonary segment under investigation, however, with significant leakage from the blood compartment in some individuals despite the consistency of absolute levels observed in the preliminary study.
Sixteen patients with primary Sjögren's syndrome (1 degree SS) who complained of dyspnea were investigated with high resolution computerized tomography of the thorax, bronchoalveolar lavage, and transbronchial biopsy. Six patients had evidence of interstitial fibrosis, 5 had a peribronchiolar lymphocytic infiltration and 3 had pleural thickening. We conclude that significant pulmonary disease is not uncommon in patients with 1 degree SS.
Using serial bronchoalveolar lavage (BAL), we have studied changes in the airway inflammatory cell populations in 20 asthmatic patients, before and after treatment with inhaled beclomethasone dipropionate (BDP), 2,000 micrograms daily in an uncontrolled study. There was a significant improvement in asthma severity, as measured by symptom score and airways responsiveness, and there were significant reductions in the total BAL eosinophil, epithelial cell and mast cell counts, with a significant increase in the percentage BAL lymphocyte count. No significant correlations were found between the changes in airway inflammatory cell numbers and the reduction in asthma severity. In contrast, the fall in ROS generation by the pulmonary macrophage and granulocyte populations was nonsignificant, but the improvement in airways responsiveness was positively correlated to the reduction in the unstimulated pulmonary macrophage activity. Although these data are uncontrolled, the results are compatible with previous studies in suggesting an effect of steroids on the eosinophil, mast cell and epithelial cell in asthmatic airways. They also highlight the probable importance of the luminal lymphocyte population and pulmonary macrophage activation within the asthmatic airway, the beneficial modulatory effect of inhaled BDP treatment upon them, and the relative steroid-resistance of pulmonary inflammatory cell activity.
Myeloma behaves differently to other osteolytic tumours which metastasize to bone, in that the latter usually provoke reactive bone formation in the host bone. A previous study showed that a myeloma cell line (GM1500) secreted an osteoblast-inhibiting factor(s). The present study was undertaken to determine whether other myeloma cells also secreted a factor(s) which inhibited both cell proliferation and DNA synthesis of osteoblast-like cells and whether the myeloma also affected the function of osteoblasts. The results showed that a second cell line (Karpas 707) as well as myeloma tissue taken from two patients had a similar effect. The myeloma cells did not affect total collagen or protein synthesis, and did not affect the overall degree of mineralization. A biphasic effect was seen on alkaline phosphatase activity. Thus, although the proliferation of the pre-osteoblast was affected, the synthetic functions of the osteoblasts were not.
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Bronchoalveolar lavage (BAL) urea has been advocated as a denominator that might allow for the dilution of the pulmonary epithelial lining fluid sampled at BAL, and so provide a meaningful method of expressing BAL data. We investigated the origin of water and urea sampled at BAL in five asthmatic and five control subjects using radiolabeled urea injected intravenously 5 min before BAL. Labeled BAL urea was found to be fully equilibrated with that in the bloodstream. A strong relationship was found between influx of radiolabeled water and radiolabeled urea from blood to BAL fluid, suggesting that urea sampled at BAL may be derived predominantly from an acute movement from the bloodstream into the BAL aspirate. We conclude that urea is an inappropriate denominator for the expression of BAL results, and that the fluid and solute dynamics that occur during BAL are both complex and variable.
A retrospective case record review was undertaken to determine the incidence of vancomycin-associated leucopenia in a cardiothoracic surgical unit. Forty-nine patients received 50 courses of vancomycin therapy. Nine patients (18%) developed reversible leucopenia (white cell count less than 4000 x 10(6)/l) or neutropenia (polymorphonuclear leucocyte count less than 1500 x 10(6)/l). Four patients (8%) had severe neutropenia (less than 1000 x 10(6)/l). The median total dosage associated with leucopenia and neutropenia was 30 g, range 22-56 g. The median duration of treatment in leucopenic and neutropenic patients was 22 days, range 6-28 days. The median recovery time to a normal white cell count was 4 days, range 1-11 days. Patients who developed leucopenia on vancomycin therapy did not differ from those who did not with respect to age, total vancomycin dose, length of therapy, underlying illness, incidence of cardiac surgery or use of concomitant medications. Vancomycin-associated leucopenia and neutropenia is common in patients with cardiothoracic infections, many of whom are on several other medications. White cell counts should be estimated regularly in such patients.
1. Fifty patients with symptoms due to chronic heart failure despite diuretic therapy were randomised to receive additional treatment with either hydralazine or captopril. The dose was titrated; 24 received hydralazine and 26 captopril up to a maximum daily dosage of 225 mg and 75 mg respectively. Forty-three patients had coronary heart disease and seven dilated cardiomyopathy. 2. Dyspnoea and tiredness were assessed using a visual analogue scale (0-100) before and during 12 weeks' treatment. Captopril produced a significantly greater reduction in breathlessness (F = 31.6, P less than 0.001) and tiredness (F = 65.8, P less than 0.001) compared with hydralazine. 3. There was an increase in treadmill exercise time during treatment with both hydralazine (from 5.5 (3.47-7.53) min to 6.9 (4.87-8.93) min), and captopril (from 5.0 (3.05-6.95) min to 7.8 (5.85-9.75) min), but the degree of improvement was significantly greater in the patients treated with captopril (F = 7.4, P less than 0.001). 4. There was no significant change in right ventricular ejection fraction (from 27.9 (19.3-36.5)% to 28.7 (20.1-37.3)%) or left ventricular ejection fraction (from 22.2 (14.2-30.2)% to 23.9 (15.9-31.9)%) during treatment with hydralazine. However, both right and left ventricular ejection fraction increased significantly during treatment with captopril (from 27.1 (18.9-35.3)% to 32.0 (23.8-40.2)%, P less than 0.05; and from 25.0 (17.2-32.8)% to 29.6 (21.8-37.4)%, P less than 0.05 respectively). 5. These results suggest that in patients with symptoms due to chronic heart failure despite diuretic therapy, treatment with captopril produces a greater symptomatic and haemodynamic improvement than treatment with hydralazine.
It has been suggested that proteinase enzymes could play an important role in the pathogenesis of chronic bronchial infections including bronchiectasis and cystic fibrosis (CF). Because Pseudomonas aeruginosa frequently colonizes the respiratory tract in bronchiectasis and CF, we examined the in vitro effects of human neutrophil elastase (HNE) and proteinase enzymes produced by P. aeruginosa (elastase: PE; alkaline proteinase: PAP) on the ciliary beat frequency (CBF) and ultrastructure of human nasal ciliated respiratory epithelium. HNE (500 micrograms/ml) progressively reduced CBF and caused marked epithelial disruption; lower concentrations (100 and 20 micrograms/ml) also caused epithelial disruption but without slowing CBF. The effects of HNE (500 micrograms/ml) were completely abolished by adding alpha 1-antitrypsin (5 mg/ml). There was no synergy between HNE and pyocyanin, a product of P. aeruginosa which slows CBF. PE in phosphate-buffered saline also caused epithelial disruption without slowing CBF; however, PE in medium containing divalent metal ions caused CBF slowing as well as epithelial disruption at 100 micrograms/ml. PAP (500 micrograms/ml) had almost no effect on ciliated epithelium. The effects of HNE and PE on nasal and bronchial epithelium obtained from the same patient were similar. Light and transmission electron microscopy revealed that HNE and PE were cytotoxic and caused detachment of epithelial cells from neighboring cells and the basement membrane. There was cytoplasmic blebbing of the cell surface and mitochondrial damage; however, no increase of abnormalities in the ultrastructure of cilia on living cells was seen. These results support the hypothesis that HNE and PE contribute to the delayed mucociliary clearance and epithelial damage that is observed in patients with chronic bronchial infection.
Bone metastases in breast cancer may be osteolytic, osteosclerotic, or a mixture of the two. Although stimulation of bone resorption by breast cancer cells has attracted some interest, the formation of osteosclerotic secondary tumours and the influence of human mammary carcinoma cells on osteoblasts (bone forming cells), both important in understanding breast cancer--bone interactions, have been largely neglected. We therefore examined the effects of conditioned medium (CM) from two cultured human breast cancer cell lines (MCF7 and ZR-75) and from primary cultures of breast carcinomas from two patients, on osteoblasts and recruitment of bone-resorbing cells (osteoclasts) in vitro. Osteoblast-like cells (BDC) were cultured from human trabecular bone explants. Osteoclast maturation was studied in fetal rat calvaria cultured on collagen gels. CM from the MCF-7 line and cells derived from one patient each inhibited BDC DNA synthesis, but stimulated osteoclast recruitment. In contrast, CM from the second patient's cells or ZR-75 enhanced DNA synthesis in BDC, but blocked osteoclast maturation. This suggests that human breast carcinomas secrete soluble factors which influence both osteoclasts and osteoblasts. A further unexpected implication is that mammary carcinoma cells may cause local osteosclerosis by directly stimulating osteoblasts, rather than through raised bone turnover in metastases.
Genomic sequencing of two CG sites located in the 5'-flanking promoter region of the mouse beta-globin major gene shows these sites to be heavily methylated in the DNA from L929 mouse fibroblasts, a cell line that does not express the beta-globin gene. By contrast, the same CG sites in the DNA obtained from murine erythroleukemia cells, which can express the beta-globin gene, are unmethylated. The results suggest that either differentiation of progenitor cells to form the erythroid precursor murine erythroleukemia cell and/or transformation by the Friend virus group leads to demethylation of these CG sites. Final activation of the transcription process for the mouse beta-globin gene does not require demethylation in the 5'-promoter region of the DNA.
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