Relationship between dyspnoea, pulmonry function and exercise capacity in patients with cystic fibrosis

AbstractThe median age of survival in patients with cystic fibrosis (CF) has improved considerably. Despite this improvement, deterioration of pulmonary function and decrease in exercise capacity are still the main problems for many patients. Although dyspnoea is a common complaint in CF patients, relatively little regard has been paid to this symptom. This study examined the relationship between dyspnoea, bicycle exercise capacity and pulmonary function in patients with CF.In 14 patients in a stable clinical condition, pulmonary function [forced expiratory volume in 1 s (FEV1), inspiratory vital capacity (IVC)], bicycle exercise capacity [maximum exercise capacity (Wmax)], subjective degree of dyspnoea during daily living [Medical Research Council (MRC) dyspnoea scale], and during exercise (Borg scale) were assessed.The mean (sd) age of the patients was 25 (6·8) years, FEV1 was 41 (19)% predicted, IVC was 63 (17)% predicted and FEV1IVC ratio was 47 (10)%; median (range) Wmax was 55 (0–79)% predicted. Bicycle exercise test performance appeared to be mainly determined by pulmonary function and MRC dyspnoea grade; multiple regression equation containing FEV1 and dyspnoea accounted for 76% of the variance in Wmax (% predicted) (Wmax= −7·9 dysp+1·1FEV1, +24). Exercise dyspnoea, assessed by the Borg scale, showed a significant linear correlation with minute ventilation. (V̇e), maximal voluntary ventilation (MVV) (%) (r=0·76; P<0·001). Medical Research Council dyspnoea score correlated relatively poorly with FEV1 (% predicted) (r= −0·17; n.s.) and IVC (% predicted) (r= −0·48; n.s.). Borg score at maximal exercise did not correlate with MRC dyspnoea score (r= −0·07). Borg50% score correlated significantly with MRC dyspnoea score (r= 0·61; P<0·05).These results show that dyspnoea has an influence on exercise capacity. Dyspnoea score showed a large inter-individual variation, not strongly related to pulmonary function. It is concluded that dyspnoea deserves more attention in CF patients and needs to be assessed in rehabilitation programmes and other intervention studies in these patients

The role of Comprehension in Requirements and Implications for Use Case Descriptions

Within requirements engineering it is generally accepted that in writing specifications (or indeed any requirements phase document), one attempts to produce an artefact which will be simple to comprehend for the user. That is, whether the document is intended for customers to validate requirements, or engineers to understand what the design must deliver, comprehension is an important goal for the author. Indeed, advice on producing ‘readable’ or ‘understandable’ documents is often included in courses on requirements engineering. However, few researchers, particularly within the software engineering domain, have attempted either to define or to understand the nature of comprehension and it’s implications for guidance on the production of quality requirements. Therefore, this paper examines thoroughly the nature of textual comprehension, drawing heavily from research in discourse process, and suggests some implications for requirements (and other) software documentation. In essence, we find that the guidance on writing requirements, often prevalent within software engineering, may be based upon assumptions which are an oversimplification of the nature of comprehension. Hence, the paper examines guidelines which have been proposed, in this case for use case descriptions, and the extent to which they agree with discourse process theory; before suggesting refinements to the guidelines which attempt to utilise lessons learned from our richer understanding of the underlying discourse process theory. For example, we suggest subtly different sets of writing guidelines for the different tasks of requirements, specification and design

Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin

<p>Abstract</p> <p>Background</p> <p>Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA). This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing.</p> <p>Results</p> <p>The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB) and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 μg) injected intrathecally produce thermal hyperalgesia. At higher doses (10 μg) peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons.</p> <p>Conclusion</p> <p>The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.</p

LUNG TRANSPLANTATION IN PATIENTS WITH CYSTIC-FIBROSIS

Worldwide more than 600 heart-lung or lung transplantations have been performed in patients with cystic fibrosis and end-stage respiratory disease. At the University Hospital in Groningen 10 patients with cystic fibrosis underwent bilateral sequential lung transplantation until April 1994. The 1-year survival was 76%, which is similar to that of lung transplant recipients with other diseases. Postoperative problems were mainly related to acute rejection, chronic graft dysfunction and infection. The main problem for further extension of the lung transplantation program is the persistent shortage of usable donor-organs for cystic fibrosis patients, especially of small-sized donors

SPONTANEOUS PNEUMOPERICARDIUM RELATED TO ACTIVE CYTOMEGALOVIRAL INFECTION IN A LUNG-TRANSPLANT RECIPIENT

Spontaneous pneumopericardium occurred in a patient almost 4 weeks after bilateral lung transplantation for cystic fibrosis. The patient had no specific complaints and was in stable haemodynamic condition. We suggest that this pneumopericardium was related to a concomitant active cytomegalovirus (CMV) infection. After treatment of the CMV infection, the pneumopericardium resolved spontaneously

LIPOSOMAL AMPHOTERICIN-B IN 3 LUNG-TRANSPLANT RECIPIENTS

Background: Opportunistic fungal infections are an important cause of morbidity and mortality in solid organ transplant recipients. Conventional therapy with amphotericin B is often restricted by toxicity. However, side effects and toxicity of liposomal amphotericin B are reported to be limited. Methods: Three lung transplant recipients with proven infections with Aspergillus fumigatus were treated with liposomal amphotericin B. Results: Therapy with liposomal amphotericin B in our patients showed more side effects and (nephro)toxicity than suggested by previous reports. However, it did not result in cessation of treatment prematurely, and patients were able to complete the antifungal therapy with good clinical success. Conclusions: Treatment with liposomal amphotericin B represents an advance from conventional amphotericin B therapy