Browsing by Author "Taivans, Immanuels"

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    Detection of lung cancer with electronic nose and logistic regression analysis
    (2019-01) Tirzīte, Madara; Bukovskis, Maris; Strazda, Gunta; Jurka, Normunds; Taivans, Immanuels
    Lung cancer is a very common malignancy with a low five-year survival rate. Artificial olfactory sensor (electronic nose) is a tool that recently has been studied as a probable optimal screening tool for early detection of lung cancer, but still no statistical method has been put forward as the preferable one. The aim of the study was to explore the use of logistic regression analysis (LRA) to analyse patients' exhaled breath samples with electronic nose in order to differentiate lung cancer patients (regardless of the stage of the cancer) from patients with other lung diseases and healthy individuals. Patients with histologically or cytologically verified, untreated lung cancer, patients with other lung diseases such as benign lung tumors, chronic obstructive pulmonary disease, asthma, pneumonia, etc, and healthy volunteers were enrolled in the study, in total 252 cancer patients and 223 patients without cancer. Breath sample collection and analysis were performed with Cyranose 320 sensor device and data further analysed using LRA. The LRA correctly differentiated lung cancer patients from no-cancer patients. The overall sensitivity in detecting patients having cancer was 95.8% for smokers and 96.2% for non-smokers and the overall specificity was 90.6% for non-smokers and 92.3% for smokers. Exhaled breath analysis by electronic nose using LRA is able to discriminate lung cancer patients from patients with other lung diseases and from healthy individuals.
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    H1-antihistamines suppress wheal-and-flare reaction and skin blood perfusion measured by laser dopppler flowmetry : Randomized, double-blind, placebo-controlled, crossover design study
    (2010-01) Bukovskis, Māris; Tirzīte, Madara; Strazda, Gunta; Jurka, Normunds; Ligere, Renāte; Isajevs, Sergejs; Taivans, Immanuels
    The aim of our study was to compare the influence of pre-treatment with H1-antihistamines (levocetirizine, desloratadine, clemastine, quifenadine, and sequifenadine) and a placebo on the histamine-induced weal and flare reaction, increase of skin blood perfusion and sedation. Thirty healthy volunteers were enrolled in the study. The study design was a prospective, randomised, double-blind, placebo-controlled, crossover, balanced clinical trial. Volunteers in randomised and double-blind order were treated with oral levocetirizine 5 mg, desloratadine 5 mg, clemastine 1 mg, quifenadine 50 mg, sequifenadine 50 mg or a placebo. Two hours after intake of medication, the histamine skin prick test was performed and skin blood perfusion was registered with further evaluation of sedative effect. We conclude that levocetirizine induced a significant and pronounced decrease of weal and flare reaction and skin blood perfusion compared to the placebo and the other H1-antihistamines. The effect of quifenadine and sequifenadine on weal reaction area was similar to desloratadine and clemastine. Regarding the sedative effect, we can conclude that second generation antihistamines appear to be not non-sedative but the least impairing, and the first generation antihistamines appear to be the most impairing on central nervous system function. There is a necessity to consider the sedating potential of antihistamines, along with other factors such as efficacy, when prescribing antihistamines to patients.
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    Regional Lung Blood Perfusion Measured with Laser Doppler Method During Body Position Change, Valsalva Manoeuvre and Cardiopulmonary Bypass
    (2008-01-01) Taivans, Immanuels; Strazda, Gunta; Porīte, Nora; Vanags, Indulis; Lejnieks, Juris; Lācis, Romans; Strīķe, Eva; Department of Anaesthesiology, Intensive Care and Clinical simulations
    Methodological approaches to investigate local regulatory mechanisms of lung blood supply in humans are restricted. We tried a new approach using laser Doppler technique. During bronchoscopy, an angled laser Doppler flow probe was introduced through a biopsy channel and wedged into small bronchus. Laser light penetrated the wall of small bronchus and was reflected from blood cells running through neighbouring capillaries. Regional blood perfusion changes were recorded during body position change from vertical to supine and back to vertical, while performing Valsalva maneuver and during cardiac bypass surgery. Body position change and Valsalva maneuver markedly influenced the blood perfusion signal. During cardiac bypass when lungs were supplied with blood only through bronchial arteries regional blood perfusion dropped substantially on average from 93 ± 42 to 7.3 ± 4.3 perfusion units. We conclude that blood perfusion measured with this method reflect mainly the pulmonary vascular bed and may be used for investigation of its local regulatory mechanisms.