Modelling of diffusing capacity measurement results in lung microangiopathy patients: a novel pulmonary diagnostic support.

BACKGROUND: Lung microangiopathy is a little known negative influence of diabetes mellitus on the functioning of the lungs. In current medical practice lung microangiopathy is diagnosed by comparing two measurements of lung diffusing capacity - once with the subject standing and once with the subject lying down. The necessity to take two measurements is inconvenient. OBJECTIVES: The aim of this study is to design a supportive method for diagnosing lung microangiopathy. This will be based on routinely performed pulmonary measurements as well as on investigation of process modelling and data processing. METHODS: A model of the diffusion of oxygen from the alveoli to the blood has been described with a set of differential equations. The idea of the proposed model is based on the physiological analysis of the oxygen flow (caused by a concentration gradient) and on general knowledge regarding the kinetics of associating oxygen with haemoglobin. The model parameters are estimated using diffusing capacity and alveolar volume measurements - routinely performed in pulmonary tests. RESULTS: The model parameter estimates proved good candidates for the binary classification of the presence or absence of microangiopathy. The proposed classification procedure, based on parameter values and established diagnostic thresholds, gives sensitivity Sens = 79.34% and specificity Spec = 87.08%. The results of classification with the use of diffusing capacity measurement are worse: Sens = 62.12% and Spec = 79.89%. CONCLUSIONS: The proposed classification procedure is based on the model parameters. These have proved to be sensitive indicators of lung microangiopathy. Close to 80% of microangiopathy cases have been classified as such. Less than 20% were false alarms. The oxygen pathway model allows for simulations. Blood saturation and oxygen partial pressure have been simulated for the organism's various needs for oxygen, both for the normal and the impaired alveoli-capillary barrier.

Role of quantitative chest perfusion computed tomography in detecting diabetic pulmonary microangiopathy.

AIMS: Aim of the study was to determine the role of perfusion chest computed tomography (pCT) in evaluation of pulmonary diabetic angiopathy. METHODS: 18 never-smoking patients (10 diabetic patients and 8 healthy controls) underwent chest high resolution CT (HRCT) and then pCT scanning. In both groups, blood tests, biochemical analysis, fibrinogen, HbA(1c), spirometry, diffusion capacity for carbon monoxide (DLCO) and body pletysmography were performed.Following parameters of pulmonary perfusion have been analysed: blood volume (BV), blood flow (BF), mean transit time (MTT), time to peak (TTP) and permeability surface (PS). RESULTS: there were no statistically significant differences between groups in terms of age, sex, BMI, forced expiratory volume in one second (FEV(1)), DLCO. Chest HRCT revealed no pathologies. Significantly higher values of chest pCT for BF (p=0.05), BV (p=0.05) and PS (p=0.01) have been found in diabetics in comparison to controls. No differences were found in MTT. CONCLUSIONS: significant increase of perfusion parameters in diabetes seems to confirm pulmonary microangiopathy. The results indicate that further studies on application of pCT in diabetic patients may be beneficial for better understanding of lung microangiopathy, its diagnosing and monitoring.

[Lung manifestation of visceral larva migration syndrome due to Toxocara canis infection]. / Plucna postac zespolu wedrujacej larwy trzewnej wywolana przez Toxocara canis.

32 year-old patient was hospitalized because of disseminated lung lesions. 2 years earlier he manifested chorioditis. Exact disease history suggested suspicion of toxocare infection. The diagnosis was confirmed by serological tests with anti-Toxocara canis antibodies, bronchial lavage and chest CT scan. Administration of 450 mg of dietylokarbamasin (Hetrazan) resulted in complete resolution of pulmonary lesions.

[The use of leukotriene receptor antagonists and 5-lipoxygenase inhibitors in bronchial asthma treatment]. / Zastosowanie antagonistów receptorów leukotrienów i inhibitorów 5-lipoksygenazy w leczeniu astmy oskrzelowej.

Asthma is a chronic inflammatory disorder of airways. It is characterised by bronchoconstriction, oedema and airways mucus hypersecretion. The main clinical features of asthma are dyspnea, cough, wheezing and heaviness in the chest. The pathology of asthma is characterised by presence of many inflammatory mediators, where the most important are cysteinyl leukotriens. Leukotriens C4, D4 and E4 are 1000 times more potent than histamine in contracting airways smooth muscles. Inhibitors of arachidonic acid metabolism have been used in asthma treatment. They can block the 5-lipoxygenase enzyme and/or 5-lipoxygenase-activating-proteine (FLAP), or can block the cysteinyl leukotriene receptors on the cell surface. Many inhibitors of arachidonic acid metabolism have been found during experimental trials. But only two are used as a drugs: zafirlukast and montelukast (leukotriene receptor inhibitors) montelukast and zileuton (5-lipoxygenase inhibitors) having the best efficacy in asthma treatment. Chronic treatment with these drugs results in a decrease of asthmatic symptoms, improvement of lung function (FEV1, PEF) and decreased usage of other medications--beta-adrenergic agonists and inhaled steroids. It has been proved that zafirlukast and zileuton show the high efficacy in mild-to-moderate asthma, exercise-induced asthma, allergen-induced asthma and aspirin-induced asthma. These oral drugs have been shown to course only mild adverse effects (such as temporary elevation in liver function tests, gastrointestinel disturbances, headache). Clinical usage of zafirlukast, montelukast and zileuton is limited in our country, they are hardly approachable on the market and the cost of treatment is high.