Publications by authors named "Orehek J"

Microbial biodegradation and biodeterioration of cellulose based thickeners is a serious problem in industry. A new tosylic ester of carboxymethyl cellulose (TsCMC) was prepared with anhydride of p-toluensulphonic acid. The TsCMC has improved rheological properties, higher viscosity and pseudoplasticity, superior emulsification properties and decreased wettability compared to parental CMC.

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Carboxymethyl cellulose (CMC) is one of the most widely used thickening agents in industry. The combination of small-angle X-ray scattering (SAXS), static and dynamic light scattering, as well as viscosity measurements and microscopy at different pH values was utilized to explore the physicochemical properties of CMC on a scale ranging from individual macromolecules to supramolecular assemblies. The supramolecular structure of CMC was represented as a set of characteristic sample subspaces based on SAXS data utilizing the string-of-beads model.

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Background: The ability to culture Mycobacterium tuberculosis from clinical specimens serves as the gold standard for the diagnosis of tuberculosis. However, a number of false-positive diagnoses may be due to cross-contamination of such specimens. We herein investigate such episode of cross-contamination by using a technique known as multispacer sequence typing (MST).

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The prevalence of an echocardiographically visible patent foramen ovale (PFO) is higher in patients with obstructive sleep apnoea syndrome (OSAS) than in normal controls. We report a patient who presented with OSAS and right-to-left shunting (RLS) through the PFO in whom the RLS disappeared after treatment for 1 week with nocturnal continuous positive airway pressure (CPAP). This case shows the role of OSA in generating an awake RLS through a PFO and its possible reversibility by CPAP.

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Introduction: Many asthmatics have few or no symptoms despite severe obstruction of the airways. Physicians confronted with this phenomenon may therefore underrate the severity of the asthma and treatment may be insufficient. We studied the capacity of a group of general practitioners to assess the bronchial obstruction of patients presenting with varying degrees of symptoms and obstruction.

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Background: Despite its high prevalence, epidemiological surveys on the diagnosis and severity of asthma in the elderly are seldom.

Objective: The objectives of our study were: (i) to describe the criteria, used by French lung physicians, for the diagnosis of asthma in the elderly (age > or = 65 years); (2) to investigate whether the age at the onset of asthma is related to the severity of asthma in the elderly.

Methods: 1,485 asthmatics (783 men and 702 women; mean age +/- SD = 73.

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Inhaled beta-adrenergic agonists can decrease arterial oxygen tension (PaO2). A decrease in PaO2 can also be observed with supine posture. We assessed the effect on PaO2 of supine posture following salbutamol nebulization inpatients with chronic airflow obstruction.

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Almitrine (A) and medroxyprogesterone acetate (MA) given separately improve arterial blood gases in some patients with chronic obstructive pulmonary disease (COPD); the aim of this study was to assess the effect of the two drugs given together. Forty-eight patients with irreversible COPD and hypoxaemia were prospectively enrolled into a 14-day run-in period and received single-blind oral treatment with double placebo. Patients whose PaO2 remained stable (less than 10% change; n = 29, 25 males, mean age 65.

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Abnormal left ventricular (LV) diastolic function has frequently been reported in patients with chronic obstructive pulmonary disease (COPD). In the present work, diastolic function was studied by a combined analysis of pulmonary venous and mitral blood flow velocities in 34 patients with COPD clinically stable and without history of heart disease, and 20 control subjects. We confirmed the increased contribution of the atrial contraction to the LV filling in COPD patients in comparison with control subjects; furthermore, a decreased left atrial (LA) filling during the ventricular systole was observed.

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Multiple pulmonary arteriovenous malformations (PAVM) constitute an uncommon cause of respiratory disability. They may lead to severe hypoxaemia via right-to-left shunts and are sources of substantial mortality and morbidity. Conservative surgical resection has been proposed as the treatment of choice.

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Unexplained weight loss is common in chronic obstructive pulmonary disease (COPD). Blood levels of tumor necrosis factor-alpha (TNF-alpha), a cytokine causing cachexia in laboratory animals, are elevated in various human diseases associated with weight loss. We therefore prospectively measured TNF-alpha serum levels (immunoradiometric assay) in patients with clinically stable COPD (n = 30; all male; mean age, 65 yr) whose weight was less (Group I; n = 16) or more (Group II; n = 14) than the lower limit of normal taken from Metropolitan Life Insurance Company tables.

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The chest radiograph of a woman with acute asthma showed signs of obstructive emphysema of the left lung. Fiberoptic bronchoscopy excluded obstruction of a large bronchus. The signs disappeared after antiasthmatic treatment, suggesting that they were caused by airway closure.

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In Western Europe medicine packages contain an insert prepared by the manufacturer which enumerates the drug side-effects. We investigated the influence of this insert on alleged theophylline side-effects. Forty literate adult asthmatics were randomly allocated into two groups (n = 20 each): theophylline packages contained the manufacturer's insert in group A but not in group B.

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We investigated the antitussive effect of fenoterol in 40 patients (34 males) undergoing bronchofiberscopy for diagnostic purposes. The patients were randomly allocated into two groups, one receiving two puffs (400 micrograms) of fenoterol and the other two puffs of placebo, from a metered-dose inhaler in a double-blind fashion. The following procedure was used: premedication with 0.

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To study the efficacy of etoposide in brain metastases of lung carcinoma, etoposide was given during 3 consecutive days. The total dose of 1500 mg/m2 was divided into six 1 h perfusions delivered over 3 days to 19 patients having squamous (7), large cell (3), small cell (5) or adenocarcinoma (4). Response to chemotherapy was assessed by means of computerized tomography (CT) before and 15-30 days after the last course of chemotherapy (course interval = 28 days, maximum of four courses).

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The effect of terfenadine, a selective H1-receptor antagonist devoid of central nervous system side effects, was evaluated on hyperventilation-induced bronchospasm in 11 adult subjects with asthma in a double-blind, placebo-controlled, crossover study. Increases in specific airway resistance (SRaw) were induced by isocapnic hyperventilation with dry air on two occasions, 7 days apart. Before the tests, the subjects received oral terfenadine (120 mg, twice daily) or placebo for 3 days with the last dose administered 3 hours before the test.

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To evaluate retrospectively health care in severe chronic respiratory failure, we interviewed 38 patients, admitted for the first time to a pulmonary intensive care unit for an acute episode. A standardised questionnaire was devoted to establishing if the patients were aware of chronic respiratory disease prior to admission, if they had visited a general practitioner or a chest clinic, and had undergone a lung function evaluation. Six patients were unaware of any respiratory disease prior to the acute episode.

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The airway and systemic arterial smooth muscle responsiveness to cholinergic agents of two strains of rats, Rat Albino (RA) and Brown Norway (BN), was compared in vivo and in vitro. In vivo, we measured the doses of carbachol that induced a 100% increase in lung resistance (PD100 RL), a 50% decrease in dynamic lung compliance (PD50 Cdyn), and the value of systolic blood pressure at the carbachol dose of 10 micrograms (Pa 10 micrograms). In vitro airway smooth muscle and systemic arterial smooth muscle responsiveness was assessed by measuring the maximal response to acetylcholine, the slope of the linear portion of the dose-response curve, and the negative logarithm of the molar concentration of acetylcholine producing 50% of the maximal response (pD2).

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