Changes In Functional Parameters Research Articles

Effects of replacing oxitropium with tiotropium on pulmonary function in patients with COPD: A randomized study

Inhaled bronchodilators are first line drugs in the treatment of chronic obstructive pulmonary disease (COPD). Tiotropium bromide is a recently introduced long-acting anticholinergic agent able to reduce dyspnoea and COPD exacerbations and to improve pulmonary function and quality of life. We designed a study to compare the short-term efficacy of tiotropium bromide with that of oxitropium bromide in improving pulmonary function in patients with COPD. Eighty patients were randomized either to continue oxitropium 800 mcg/day or to receive tiotropium 18 mcg/day. Seventy-six (39 in the tiotropium and 37 in the oxitropium group) completed the study. Plethysmography was performed at baseline and after 72 h in all patients. The changes in functional parameters in the two groups were compared by the Mann-Whitney U-test. There were no differences between the two groups regarding age (72.5 vs. 74.2 years), male/female ratio (25/14 vs. 23/14) and pulmonary function at baseline. The changes in spirometric parameters were significantly greater in tiotropium- than in oxitropium-treated patients: mean forced expiratory volume in 1s (FEV(1)) increased significantly by 15% vs. 3% (P=0.017), mean FVC by 10.5% vs. 2.2% (P=0.044), and FEF 25, 50, and 75 by 34% vs. 14% (P<0.05), 33% vs. 7% (P<0.05), and 50% vs. 6% (P<0.0001), respectively; mean FRC and RV decreased nonsignificantly by 7.5% and 10% with tiotropium vs. 4.3% and 6.5% with oxitropium, respectively. The replacement of oxitropium with tiotropium significantly increases pulmonary function in patients with COPD. The improvement involves also small airways that have not been investigated thus far.

Doppler echocardiography and Tissue Doppler Imaging in the healthy rabbit: Differences of cardiac function during awake and anaesthetised examination

Objective In the past years, Doppler echocardiography has evolved into a commonly used technique. More recent sophisticated advances in imaging quality have substantially improved spatial and temporal resolution allowing the adaptation of this technique to small animal models, particularly in rabbits but even in mice. Recently, parameters obtained by Tissue Doppler Imaging (TDI) have been shown to be more independent of pre- and afterload than classic hemodynamic Doppler measurements. Exploration of animal models may require anaesthesia but there is only very little information on the effect of anaesthesia on echocardiographic parameters in rabbits. Methods We therefore performed Doppler-echocardiographic examinations of 20 wild-type New Zealand White rabbits in awake state and under light ketamine–xylazine anaesthesia. Special focus was put on the evaluation of global and regional left ventricular systolic and diastolic function using TDI and the myocardial performance index (Tei-index). Results Doppler-echocardiographic measurements including TDI in rabbits were feasible to assess cardiac morphology and function within a short examination time. There were some distinct changes of functional parameters during anaesthesia. Exemplary for systolic function, fractional shortening, cardiac output and systolic TDI velocity of the lateral wall decreased distinctly. Global left ventricular function measured by the Tei-index deteriorated. Conclusions Doppler echocardiography and TDI can be performed easily, quickly and safely in the rabbit. Anaesthesia with the cardiodepressive ketamine–xylazine shows some distinct Doppler-echocardiographically measurable negative effects on cardiac function. Thus, echocardiography with less cardiodepressive anaesthetic regimes or even without anaesthesia after training of the animals should be considered as alternatives whenever possible.

Comparison of the acute effect of tiotropium versus a combination therapy with single inhaler budesonide/formoterol on the degree of resting pulmonary hyperinflation

In 20 COPD patients (FEV(1) < or =65% predicted, IC<80% predicted), we evaluated changes in the degree of pulmonary hyperinflation after acute administration of tiotropium 18 microg or budesonide/formoterol 320/9 microg. The study consisted of a screening visit and two study days separated by at least one week. Functional parameters were measured before and 30, and 120 min after inhalation of single study drug. Both tiotropium and budesonide/formoterol induced significant changes in functional parameters after 30 and 120 min. However, the impact of tiotropium on the degree of pulmonary hyperinflation was larger than that of budesonide/formoterol, although only differences in IC and TGV between the two treatments were significant (P<0.05), at least after 120 min, whereas those in RV were not significant. The documentation that tiotropium is able to modify IC even after an acute administration indicates its capacity of influencing expiratory flow limitation in a very fast manner and this is an important finding. In fact, changes in IC after bronchodilators in patients with COPD with expiratory flow limitation at rest may represent an objective tool for prescribing these drugs to attain symptomatic improvement and better quality of life, even in the absence of a significant increase in FEV(1).

Zinc Chloride (Smoke Bomb) Inhalation Lung Injury: Clinical Presentations, High-Resolution CT Findings, and Pulmonary Function Test Results

Zinc chloride smoke inhalation injury (ZCSII) is uncommon and has been rarely described in previous studies. We hypothesized that structural changes of the lung might correlate with pulmonary function. To answer this question, we correlated findings from high-resolution CT (HRCT) scan and the results of pulmonary function tests (PFTs) in patients with ZCSII. Retrospective cohort study. University hospital. Twenty patients who had been hospitalized with ZCSII-related conditions. The study included HRCT scan scores (0 to 100), static and dynamic lung volumes, and diffusing capacity of the lung for carbon monoxide (D(LCO)). HRCT scans and PFTs were performed initially after injury (range, 3 to 21 days) in all patients and during the follow-up period (range, 27 to 66 days) in 10 patients. The predominant CT scan findings were patchy or diffuse ground-glass opacities with or without consolidation. The majority of patients showed a significant reduction of FVC, FEV1, total lung capacity, and D(LCO), but normal FEV1/FVC ratio values. Changes of functional parameters correlated well with HRCT scan scores. Substantial improvements in CT scan abnormalities and pulmonary function were observed at follow-up. The majority of our patients with ZCSII presented with a predominant parenchymal injury of the lung that was consistent with a restrictive type of functional impairment and a reduction in Dlco rather than with obstructive disease. Our results suggest that HRCT scanning and pulmonary function testing may reliably predict the severity of ZCSII.

Regression model based on Markov chain theory for composite fatigue curve approximation

Model of fatigue damage accumulation, which is founded on the bases of Markov chain theory, is used as nonlinear regression model for processing of S-N fatigue curve data of laminate. A simple method of approximate estimation of model parameters is suggested. A numerical example is given. Some parameters of this fatigue curve model can be considered as local static strength distribution parameters. This model can be used for prediction of fatigue curve changes as consequence of the static strength distribution function parameter changes and for prediction of the cumulative distribution function of fatigue life for arbitrary stress cycles consequence.

Combined radiofrequency surgery of the tongue base and soft palate in obstructive sleep apnoea

ObjectiveTo investigate the safety and efficacy of combined temperature-controlled radiofrequency volumetric tissue reduction of the tongue base and soft palate in obstructive sleep apnoea.Material and methodsA total of 20 patients with obstructive sleep apnoea and combined palatal and retrolingual obstruction were included in a non-randomized clinical trial and 51 combined treatments were performed under local anaesthesia. Postoperative pain was assessed using visual analogue scales. Functional parameters, daytime sleepiness and quality of life were assessed using questionnaires (Epworth Sleepiness Scale, Short Form-36) before and 12 weeks after the last treatment session. Concurrently, polysomnography was performed on two consecutive nights.ResultsThe mean postoperative pain score dropped from 5.6 at Day 1 to 0.6 at Day 7. Painkillers were taken for a mean of 3.3 days. There were no postoperative complications or changes in functional parameters. Daytime sleepiness improved significantly (p<0.05). The mean respiratory disturbance index was reduced from 25.3±11.4 to 16.7±15.3 (p<0.05). Six out of 18 (33%) patients were cured after a mean of 2.7 treatment sessions.ConclusionCombined radiofrequency volumetric tissue reduction of the tongue base and soft palate is a safe and effective treatment for obstructive sleep apnoea.

Changes in occlusal contact area and average bite pressure during treatment of anterior crossbite in primary dentition.

The purpose of this study was to examine changes in functional parameters of patients with anterior crossbite in primary dentition during orthodontic treatment. Occlusal contact area (OCA), average bite pressure (ABP) and integrated occlusal load (IOL) were measured. Data obtained before the start of treatment (period A), data obtained when crossbite had improved (period B) and data obtained when the appliance had been removed (period C) were compared. OCA showed the lowest value in period B, and then gradually increased. ABP increased until period B and then declined or became constant. OCA and IOL showed significant differences in periods A and B and periods B and C (p < 0.05). The results suggest that about 6 months is required for stability of the occlusion and acquisition of function in the new occlusion after improvement of crossbite.

From carcinoma in situ to testicular germ cell tumour.

The mechanisms of invasive tumour development from pre-invasive CIS are unknown. We examined changes in functional parameters of the tubular wall according to the increase in CIS cells and tubular size. Immunohistochemistry was performed on 37 testicular specimens from 25 patients with carcinoma in situ and/or malignant germ cell tumour for the detection of actin/myosin in myocytes, and laminin/integrin alpha 6 in the basement membrane of seminiferous tubules. Tumour cells were detected by PlAP, Sertoli cells by inhibin alpha and vimentin and by cytokeratin 18/connexin 26 immunoreactivity, which is selectively expressed together with CIS. Areas showing clusters of tumour cells surrounded by a fibrous sheet could be identified as enlarged tubules because of focal Sertoli cell-specific co-expression of inhibin alpha, vimentin, cytokeratin 18, and connexin 26 immunoreaction. These clusters exhibited an intact basement membrane shown by a persistent laminin/integrin alpha 6 immunoreactivity, but myocytes had lost their contractility indicated by the loss of myosin/actin immunoreactivity. They often showed septa originating from the fibrous sheet containing numerous capillaries. Focal areas of syncytiotrophoblastic cells within classical seminoma also expressing inhibin alpha, cytokeratin 18, and connexin 26 could be differentiated from single Sertoli cells within tumor cell clusters by typical hCG but absence of vimentin immunoreactivity. In contrast to the current concept of CIS cells passing the tubular wall, these data provide evidence for an additional theory, i.e. that the switch from pre-invasive CIS to invasive tumour takes place in situ by tubular enlargement due to tumour cell proliferation followed by Sertoli cell degeneration and conversion of the tubular wall into connective tissue.

Characterization of airway inflammation after repeated exposures to occupational agents

Background: Little is known about the comparative kinetics of eosinophil recruitment after exposure to low- and high-molecular-weight sensitizers in subjects with occupational asthma (OA). Objectives: The aims of the study were to investigate the kinetics of changes in inflammatory mediators associated with eosinophil infiltration (IL-5 and eotaxin) and to examine the nature of the airway inflammation induced in response to different types of occupational agents. Methods: We investigated 15 subjects with OA caused by high- and low-molecular-weight agents. The subjects were exposed to increasing doses of the relevant occupational agent over 3 to 4 days until a 20% fall in FEV1 occurred. Methacholine challenge and sputum induction were performed at the end of each day of exposure. Sputum samples were assessed for differential cell counts, including eosinophils, IL-5, and eotaxin messenger RNA. Results: There was an increase in sputum eosinophils, eotaxin, and IL-5 on the day preceding the occurrence of asthmatic reaction, although there was no change in functional parameters (FEV1 and PC20). Increase in sputum eosinophils was more prominent in subjects exposed to low-molecular-weight agents than to high-molecular-weight agents. Conclusion: Changes in eosinophils, IL-5, and eotaxin precede functional changes after exposure to occupational agents in subjects with OA. Eosinophil inflammation is a feature of exposure to both high- and low-molecular-weight agents. Induced sputum may be a useful tool in the early diagnosis of OA. (J Allergy Clin Immunol 2000;106:1163-70.)

Early Effects of Ionizing Radiation on the Microvascular Networks in Normal Tissue

Microvascular networks, which control the delivery of oxygen and nutrients and the removal of metabolic waste, are the most sensitive part of the vascular system to ionizing radiation. Structural and functional changes in microvascular networks were studied in locally irradiated (single 10-Gy dose) hamster cremaster muscles observed 3, 7 and 30 days post-irradiation. Networks were selected in reference to a well-defined location in the tissue to reduce heterogeneity due to spatial variations. Intravital microscopy was used to measure structural and functional parameters in vivo. A factorial design was used to examine the effects of radiation status, time postirradiation, and network vessel type on the structure and function of microvascular networks. While the diameter of microvessels in control animals increased significantly with age, vessel diameter in irradiated vessels decreased significantly with age. Red blood cell velocity in irradiated networks at 3 and 30 days postirradiation was significantly lower than in control networks. There was a significant decrease in capillary surface area and a significant increase in vessel hematocrit in irradiated animals. Blood flow in irradiated vessels was significantly lower than in control vessels. Changes in functional parameters were evident at 3 days postirradiation while changes in structural parameters occurred later. All vessel types were not damaged equally by radiation at every time examined.

Toxic effects of Erycibe obtusifolia, a Chinese medicinal herb, in mice

Extract of stem of Erycibe obtusifolia (EO) at doses of 10, 20 and 30 mg/kg was experimentally tested through oral and intraperitoneal administration. Toxic effects of EO were assessed through functional changes of the liver and kidneys. Mice died immediately following the i.p. injection at the dose of 10 mg/kg. However, no death occurred after the oral administration at the dose of 10, 20 or 30 mg/kg under close observations for at least 2 weeks. Changes of several functional parameters in both the liver and kidney appeared simultaneously after the oral administration. Although the higher dose increased the levels of serum glutamate-oxalate-transaminase (sGOT), serum glutamate-pyruvate-transaminase (sGPT), and blood urea nitrogen (BUN), and decreased the levels of hematocrit at 6 h after the treatment, no distinct dose-dependent relationship existed between the administered doses and the changes in functional parameters observed.

Transfer Function Parameter Changes Due to Structural Damage

A novel study of the transfer function parameter changes due to structural damage is presented in this paper. This study is based on a coherence approach, which uses the coherence between the parameter change of the transfer function of the tested system and the change due to structural damage for damage detection. Because only a few sensors are required in using the coherence approach for damage detection, the sensor placement is particularly important for this approach. This paper presents a technique of optimal sensor placement for structural damage detection. The results of a cantilevered Euler's beam will be used to demonstrate and verify the study and approach.

Impact of the hypothermic response in inhalation toxicology studies.

Previous studies from this laboratory showed that the decreases in Tco and associated functional parameters often observed in rodents following exposure to xenobiotic agents are capable of modulating the subsequent toxic response and that the magnitude of this induced hypothermic response may itself be modified by a number of experimental conditions. A moderate hypothermic response, characterized by a temperature drop of approximately 2 degrees C, appears to afford the optimal protection. Studies in which exposures occur through inhalation of harmful gases or particles present a special set of problems. In such studies, the dose of the toxic agent to which the animal is exposed is a function of the concentration of the agent in the atmosphere and the minute ventilation of the animal. Although ambient concentrations is generally held constant in laboratory studies, minute ventilation varies directly with metabolism, and both of these parameters may change significantly across experimental conditions. Thus, at low Tas, metabolism and minute ventilation are relatively high and uptake of inhalable toxic agents is increased. However, the development of the hypothermic response during the exposure entails a directly correlated reduction in these parameters and, presumably, in dose. For the most part, inhalation toxicological studies are conducted using resting animals or exercising humans. Animals are sometimes concurrently exposed to CO2 to simulate the increased ventilation of exercise and more closely mimic human studies. The experimental protocols employed in the above inhalation studies permitted examination of (1) the impact of species, size, handling stress, and changes in Ta on both the induced hypothermic response and the concomitant pulmonary toxicity; (2) the additive impact of exercise stress on O3 toxicity; and (3) the toxicity of ambient-derived particulate matter in normal rats and in rats with preexisting pulmonary inflammation. The results of these studies demonstrate that the magnitude of the induced hypothermic response is directly proportional to the uptake of the toxic agent by the lung and inversely proportional to the mass of the animal and the ambient temperature at which the exposure is conducted. The hypothermic response is sensitive to a number of experimental stresses including handling and changes in cage conditions. Exercise attenuates the hypothermic response, whereas CO2-stimulated increases in ventilation employed as an exercise surrogate may potentiate the response. Toxic exposures conducted in animals with lung disease or compromised pulmonary function may induce a severe hypothermic response while comparable exposures in normal animals produce only mild or moderate responses. In general, the development of the hypothermic response in the presence of ambient pollutants serves to decrease the minute ventilation of the animal and therefore limits the uptake and dose of the airborne toxicant. The results of these inhalation studies support our previous conclusions concerning the impact of the hypothermic response on toxicity and emphasize the need to monitor and incorporate these changes in functional parameters into analyses of toxicological data. Furthermore, because humans do not demonstrate a robust hypothermic response following exposure to toxic agents, extrapolation of the results obtained from animal studies and comparisons with data from human studies are considerably more complicated.

Effect of hibernation and jejunal bypass on mucosal structure and function

Intestinal mucosal structure and function may be regulated by systemic factors associated with oral feeding, as well as local responses initiated by contact of the mucosa with food. This study compared the relative effects of these factors in an animal model that undergoes seasonal long-term fasting. Jejunal bypass operations or sham surgeries were performed on active fed ground squirrels or on squirrels that subsequently ceased feeding and hibernated. Mucosal wet weight, protein content, villus height, and surface area were reduced in jejunal segments that had minimal exposure to luminal contents (bypassed segments of active squirrels and all segments of hibernators) compared with segments exposed to the luminal stream (incontinuity and sham segments of active squirrels). When normalized to mucosal weight, transepithelial absorption of 3-O-methylglucose and alanine-dependent sodium flux were greater in jejunal segments with minimal exposure to luminal nutrients. Altered structure in bypassed segments of active and hibernating squirrels paralleled changes in functional parameters despite the presence of different systemic factors in the two groups. Thus, in this animal model, contact of the mucosa with food, and not systemic factors associated with oral feeding, is the primary factor maintaining mucosal mass. The absence of mucosal contact with nutrients enhances specific absorptive function by mechanisms that have yet to be determined.

Non-enzymatic glycation and altered renal structure and function in the diabetic rat

Renal functional parameters including creatinine clearance, urinary albumin excretion, basement membrane thickening, and levels of non-enzymatic glycation of glomerular basement membrane were studied in rats rendered diabetic with streptozotocin. Diabetic animals had elevated, glycated hemoglobin levels (P less than 0.05), increased creatinine clearance, and urinary albumin excretion rates (P less than 0.05) as compared to insulin treated diabetic (euglycemic), age-matched, and streptozotocin non-diabetic animals. The level of non-enzymatic glycation of glomerular basement membrane was significantly elevated (P less than 0.05) in the diabetic animals as well, with the level of non-enzymatic glycation of all animals, correlating (P less than 0.05) to the average blood glucose level of each animal. Despite changes in functional parameters, and increased levels of non-enzymatic glycation between the diabetic and euglycemic animals, there was no difference in glomerular basement membrane thickness between the two groups. However, there was a difference between all diabetic euglycemics and the age-matched control animals. We hypothesize that increased glycation of glomerular basement membrane may alter renal function, possibly by affecting the net charge of the glomerular filtration barrier. However, glomerular basement membrane thickening per se does not affect the functional changes which have been observed, thus casting doubt upon its role in the development of diabetic nephropathy.

Bronchus morphometry. Correlations between morphometric data and lung function parameters in obstructive airway disease.

It is not clear which morphological alterations cause changes of functional parameters in obstructive airway disease; therefore, samples from bronchi of 29 deceased patients who underwent lung functio