R. van Steenwijk

Interleukin-8 and eicosanoid production in the lung during moderate to severe Pneumocystis carinii pneumonia in AIDS: a role of interleukin-8 in the pathogenesis of P. carinii pneumonia

Pneumocystis carinii pneumonia (PCP) may cause severe respiratory distress. This is believed to be partly caused by the accumulation of neutrophils in the lung. Interleukin-8 (IL-8) and leukotriene B4 (LTB4) are potent neutrophil chemo-attractants and activators. Eicosanoids [i.e. prostaglandins (PG) and leukotrienes (LT)] are pro-inflammatory mediators released from arachidonic acid by action of phospholipase A2 (PLA2) and have been implicated in the host response to micro-organisms. Bronchoalveolar lavage (BAL) was performed on patients with PCP as part of a randomized study of adjuvant corticosteroids vs. placebo, in addition to standard antimicrobial therapy. Re-bronchoscopy was offered at day 10. BAL fluid was available for 26 patients who had follow-up bronchoscopy performed. At diagnosis, IL-8 levels were elevated in patients with PCP, compared to healthy controls, and correlated with relative BAL neutrophilia and P(A-a)O2. LTB4 was also elevated in PCP, but failed to correlate with either BAL neutrophilia or P(A-a)O2. PLA2 activity in patients correlated with IL-8 levels and BAL neutrophilia, but not with P(A-a)O2. A trend towards a decrease in IL-8 levels in BAL fluid was detected in the corticosteroid-treated patients from days 0-10, whereas no change was detected in the placebo group. No change in levels of LTB4, LTC4, PGE2, PGF2a and PLA2 were detected cover time in either treatment group. This study establishes a correlation between IL-8, BAL neutrophilia and P(A-a)O2, and suggests a role of IL-8 as a mediator in the pathogenesis of PCP, whereas the role of eicosanoids seems less clear.

Can the course of high dose cotrimoxazole for Pneumocystis carinii pneumonia in AIDS be shorter? A possible solution to the problem of cotrimoxazole toxicity

Abstract. Fifty consecutive patients with confirmed PCP received a high dose of cotrimoxazole for 14 d, or until development of intolerance, directly followed by reduced dose maintenance therapy. Seven individuals died during the high dose course. Twenty (47%) of the 43 survivors showed toxicity reactions that necessitated dose reduction to maintenance level on average after 9.6 d. Thirteen of these 20 individuals tolerated the reduced dose, and seven did not. No further cases of toxicity were observed. In 43 survivors only one early relapse (day 17) was observed in a patient who had received full dose treatment for 14 d.

Pneumocystis carinii pneumonia in HIV-negative patients with haematologic disease

SummarySince 1990,Pneumocystis carinii pneumonia (PCP) was diagnosed in 15 adult HIV-negative haematologic patients in our hospital. None of them had received PCP prophylaxis. All except one had been treated with prednisone. Symptoms usually started after stopping or tapering. In six patients the diagnosis of PCP was delayed because of confounding bacterial isolates from blood, sputum or urine leading to unsuccessful antibiotic treatment. PCP was diagnosed by demonstrating pneumocysts in bronchoalveolar lavage fluid. In four patients additional fungal or viral pathogens were identified. The infections were not clustered. The patients were treated with co-trimoxazole and, in case of a pO2<60 mmHg, with prednisone. Three patients died (20%); they all had a coinfection with cytomegalovirus and/or aspergillus. The others recovered completely. There were no relapses. Primary PCP prophylaxis should be considered in patients with lympho-proliferative disease and exposure to prednisone.

Concept of local resolution in the design of lead-off electrode systems

A new leading-off electrode system, a concentric bipolar electrode, with higher local resolution than other bipolar electrode systems has been developed. To achieve local resolution improvement, criteria for electrode design were demanded. A theoretical study, near-pass filtering, on the decline of the signal amplitude for increasing observation distances in relation to the size of leading-off surfaces of various unipolar and bipolar electrode systems was performed, and recommendations made for real systems.

Fast interactive computatinal setup for reconstruction and analysis of myocardial action potentials

An interactive computational setup for reconstruction of myocardial action potentials is described. System design is based on Beeler and Reuters myocardial model, and the calculation results are displayed during the computation on a timescale which approaches real-time presentation. Facilities are provided for use modification of model parameters and for display of parameters and internal variables during the computation. It is possible to use the setup for resolving measured action potential into fundemental currents and calculating their parameters in conformity with present-day theory of action potentials. The speed and accuracy of this computational setup, and the flexibility offered by the built-in interactive procedure, make this a very useful tool for studying the electrophysiology of the heart.

Recurrent acute pulmonary oedema after aortic and mitral valve surgery due to trachea malacia and obstructive sleep apnoea syndrome

In this report we describe a patient with recurrent episodes of acute pulmonary oedema after aortic and mitral valve surgery. The first episode of pulmonary oedema was caused by mitral valve dysfunction. The second episode of pulmonary oedema was not clearly associated with a mitral valve problem, but reoperation was performed in the absence of another explanation. After the third episode of acute pulmonary oedema occurred, the diagnosis of obstructive sleep apnoea syndrome (OSAS) was considered and confirmed. After starting treatment with continuous positive airway pressure (CPAP) during his sleep the patient had no further episodes of acute respiratory failure. Our case demonstrates that acute pulmonary oedema after cardiothoracic surgery can be caused or at least be precipitated by OSAS and should be suspected in patients with unexplained episodes of (recurrent) pulmonary oedema. (Neth Heart J 2008;16:310-2.)