Archive for the ‘COPD’ Category


IL-8We have used induced sputum samples and counted cells expressing HO-1, iNOS, and nitroty-rosine, and levels of soluble inflammatory mediators in patients with COPD who were hospitalized for severe exacerbation compared to stable state. The results showed significantly increased MPO, IL-8, nitrotyrosine, and HO-1 expression in patients during exacerbation relative to the stable state. These findings provide further insight into the pathogenesis of COPD exacerbations.

There are several limitations regarding our study. First, we did not examine them for evidence of acute viral infection, or for infection with chlamydia or mycoplasma, which are often detected during COPD exacerbations. Second, it was difficult to accurately differentiate between chronic bacterial colonization of the respiratory tract and acute infection. We tried to overcome this difficulty by comparing sputum samples obtained from patients during exacerbations with those obtained from the same patients in the stable state. Third, due to significant comorbidities in the majority of COPD patients who were admitted for severe exacerbations, we were only able to recruit a relatively limited number of patients. However, the power of our results was tested, and it was found to be > 80%. Therefore, a type 1 statistical error is unlikely. Fourth, the present study used sputum analysis to assess airway inflammation. It is known that dithiothreitol (DTT), a reducing agent that is regularly used to homogenize sputum, may affect the detection of inflammatory mediators in the sputum sol phase. However, other investigators have shown good recovery of sputum ECP, MPO, IL-8, and GM-CSF using commercial immunoassays, as well as no effect of DTT on their standard curves. Even if DTT affects any of these measurements, comparability between samples obtained from patients during exacerbations or while in the stable state was preserved.

(more…)

  • Comments Off on Canadian Health and Care Mall: Discussion of Airway Inflammation During Severe Exacerbations of COPD
  • The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: ConclusionThe fact that the findings with regard to the pulmonary function variables were inconsistent suggests several possible interpretations. The most likely explanation is that the pulmonary function variables assessed were not meaningful in the examination of the relationship. This could be true because the participants in this study were primarily only mildly to moderately impaired (95% of the sample). Therefore, the participants were not experiencing desaturation and were not limited in their oxygen delivery at submaximal levels of performance. It could also be that the measures that were taken in this study were not the ideal in terms of assessing limitations, which could influence the cerebral environment. For example, some researchers who have used Pa02 as their measure of oxygenation have found that there is a relationship between Pa02 and cognitive functioning. (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Conclusion
  • Surprisingly, once education and CESD were controlled for on the working memory span test, age did not contribute significantly to the prediction of the variance. This is in contrast to a wealth of research that has established that declines in working memory are associated with aging. There are several possible reasons for these contradictory findings. One possibility is that because only older adults were used in this study, there was not enough variance in performance or in age for age to be predictive; i.e., because the data were only examined at one end of the age and performance continuum, the relationship may not have been apparent. This possible explanation is further strengthened by the fact that the range of performance on the memory task was quite small. This task provides scores in a short range, from 2 to 6, and it is possible that this range is too small to make age-related differences apparent in a sample consisting of all older individuals. (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: CESD
  • The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Aerobic fitnessOn the speed-of-processing task, 6-min walk performance accounted for 20% of the variance in performance. The relationship was such that those who could walk further during the 6-min (and thus who had higher levels of aerobic fitness) had faster responses. Thus, aerobic fitness had a positive impact on performance of this task. Additionally, age was a significant predictor of performance. The nature of this relationship was such that older subjects had slower responses. These findings are of special interest because past research has shown that speed of processing may be one of two cognitive variables that are capable of explaining a large proportion of the age-related variance in cognitive functioning. In other words, aerobic fitness was found to be associated with the maintenance of speed of processing, which suggests the possibility that cardiovascular mechanisms may mediate the relationship between age and speed of processing and ultimately between age and performance on many cognitive tasks. read
    (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Aerobic fitness
  • The Culture Fair Intelligence Test is designed to assess fluid intelligence, and past evidence has shown that increasing age is associated with a decrease in performance on this task. The results of this study support this conclusion because age predicted a significant portion of the variance in performance and was negatively related to performance. Additionally, past cross-sectional research has provided support for the hypothesis that greater levels of aerobic fitness may be associated with a lessening of the normal age-related declines in cognitive functioning. (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Discussion
  • The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: SpeedSpeed
    Results of the regression analysis indicated that education and CESD did not predict a significant portion of the variance in speed of processing (F2,31 = 1. 24; p > 0.05). Distance on the 6-min walk test was stepped into the equation as a significant predictor of speed of processing (Fchange130 = 8.17; p < 0.01; r2change = 0.20, (3 = —1.18). Then, MVV was stepped into the equation and further contributed to the explanation of the variance (Fchange129 = 5.81; p < 0.03; r2change = 0.16; 3 = 9.17). Finally, age added further to the prediction of the variance (Fchange128 = 5.26; p < 0.03; r2change = 0.10; 3 = 25.43). Thus, 6-min walk distance, age, and MVV predicted 46% of the variance in speed of processing (F5,25 = 5. 45; p < 0.01). None of the other predictors reached the criterion required for entrance into the equation. (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Speed
  • Separate regressions were performed for each of the measures of cognitive functioning. Additionally, for the speed-of-process-ing task, performance was measured in terms of both accuracy of response and speed of response. A separate regression analysis was performed for each of these measures. To control for the potential confounding effects of education and depression on cognitive performance, CESD score and education level were forced into the first level of each regression. After controlling for these variables, age, the measures of pulmonary function (FVC, predicted FVC, FEV1, predicted FEV1, ratio of FEV1 to FVC, maximum voluntary ventilation [MVV], ratio of MVV to predicted MVV, and ratio of MVV to Ve), the measures of oxygen saturation (Spo2 during GXT, Spo2 immediately after 6-min walk), and the measures of aerobic fitness (Vo2peak, 6-min walk distance) were entered stepwise. For the stopping task, the time delay from the stimulus to the stopping signal was also entered as a predictor variable in the second level of the regression. (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Results
  • The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: ProcedureProcedure
    Program Entry: Participants completed three screening-day visits prior to their completion of the cognitive tests. The institutional review board for research with human subjects approved all procedures. During the first screening visit, informed consent forms were supplied, explained, and signed. Participants then completed a pulmonary function test and a series of questionnaires, including the CESD and a medical history questionnaire. During the second screening visit, participants underwent a medical examination conducted by a physician and completed a GXT. During the third screening visit, participants completed questionnaires that were not related to this study and then completed the 6-min walk test. Participants who met all the necessary criteria for participation were asked to return to the laboratory to complete the cognitive tests. canadian health&care mall
    (more…)

  • Comments Off on The Relationships Among Pulmonary Function, Aerobic Fitness, and Cognitive Functioning in Older COPD Patients: Procedure
  • Categories


    Advertising


    Most Popular

    • None found

    Recent Comments

    • None found