Optimal Cut-Off Points of 4-meter Gait Speed to Discriminate Functional Exercise Capacity and Health Status in Older patients with Chronic Obstructive Pulmonary Disease

Background: Gait speed, a vital sign of health and functional capacity, is commonly used to measure mobility. Although studies have assessed gait speed in older adults and individuals with chronic obstructive pulmonary disease (COPD) separately, few have evaluated gait speed in older adults with COPD. Therefore, the primary objective of our study was to determine the threshold point for the 4-meter gait speed test (4MGS) to better discriminate between functional exercise capacity and health status in older patients with COPD. The second objective was to determine possible predictors of gait speed. Methods: In this cross-sectional study, we assessed participants’ pulmonary function, dyspnea, health status (COPD Assessment Test [CAT]), gait speed (4MGS), functional exercise capacity (6-minute walk test [6MWT]), and physical activity. Results: For-ty-five older patients with COPD participated in this study. The predicted 6MWT and CAT scores were independent and significant determinants of the 4MGS score, explaining 54% of the vari-ance (p<0.001). We identified gait speeds of 0.96 m/s and 1.04 m/s as thresholds to predict abnormal functional exercise capacity (sensitivity 85% and specificity 56%) and impaired health status (sensitivity 90% and specificity 69%), respectively (p<0.05). Conclusion: Our findings demonstrated that gait speed can discriminate between abnormal functional exercise capacity and impaired health status in older patients with COPD. Moreover, functional exercise capacity and health status are predictors of gait speed. © 2022 by The Korean Geriatrics Society

Gait speed predictors and gait-speed cut-off score to discriminate asthma control status and physical activity in patients with asthma

Introduction: As a “vital sign” of health and functional capacity, gait speed is commonly used. However, there is insufficient evidence for possible determinants of gait speed in patients with asthma. The primary objective of the present study was to determine predictors of gait speed in patients with asthma. The second objective was to determine the cut-off point for the 4-minute Gait Speed (4MGS) to better discriminate asthma control status and physical activity in asthma. Material and methods: Fifty-seven patients with asthma were included in this cross-sectional study. Demographic and clinic characteristics, pulmonary function, asthma control status (ACT, Asthma Control Test), dyspnea, gait speed (4MGS), physical activity [International Physical Activity Questionnaire-Short Form (IPAQ-SF)] and activities of daily living were evaluated. Stepwise multiple linear regression analysis was used to investigate the possible predictors of gait speed. Receiver operating characteristic (ROC) curve analysis was used to determine whether usual gait speed had a discriminative value. Results: The stepwise multiple regression analysis revealed that the ACT score and the IPAQ-SF score were significant and independent predictors of the 4MGS in patients with asthma explaining 40% of the variance in 4MGS (p < 0.001). The ROC curve showed a cut-off point of 1.06 m/s for the 4MGS for poorly controlled asthma and physical inactivity (p < 0.05). Conclusions: Our findings indicate that asthma control status and physical activity can be independent predictors of gait speed in patients with asthma. In addition, gait speed may be discriminative to determine poorly controlled asthma and physical inactivity in patients with asthma. © 2022 PTChP

Cognitive and motor performances in dual task in patients with chronic obstructive pulmonary disease: a comparative study

Background Patients with chronic obstructive pulmonary disease (COPD) may display a motor and/or cognitive disadvantage during dual tasking. However, studies investigating dual task are quite limited in patients with COPD. Aims To compare cognitive and motor performances (i.e., muscle force production and functional balance/mobility together with a cognitive task) in dual task between patients with COPD and healthy controls. Methods Thirty-five clinically stable patients with COPD and 27 age- and sex-matched healthy controls participated in this cross-sectional controlled study. The muscle force production (knee extension muscle strength assessed with an isokinetic strength dynamometer) and functional balance/mobility (Timed Up and Go (TUG) test) were performed with and without a cognitive task. Dual-task interference (DTI) was assessed. Additionally, the rate of correct responses per second (RCR) was calculated to evaluate cognitive performance. Results The decrease in RCR(muscle force production)values was greater in the COPD group compared with the control group (p= 0.045). Similarly, the cognitive DTI in muscle force production test was higher in the control group than in the COPD group (p 0.05). Conclusion The study results indicate that in individuals with COPD, cognitive performance deteriorations are more pronounced than motor performance defects during dual tasking. Further studies are needed to investigate the effects of dual task taking into account this disadvantage in patients with COPD rather than focusing solely on motor performance

The Role of Oxygen Free Radicals in Acute Renal Failure Complicating Obstructive Jaundice: An Experimental Study

Oxydant injury is considered to be an important mechanism in the pathophysiology of acute renal failure. It has been thought that decrease in extracellular and intracellular fluid and endotoxemia seen in obstructive jaundice may cause an increase in production of oxygen free radicals and impairment in antioxydant defense mechanism. This study is designed to investigate the possible role of oxydant injury in renal failure seen in jaundiced patients. In this study, 28 rats were divided into four groups: Control(C) (N=7); Renal ischemia (RI) (N=7); Obstructive jaundice+renal ischemia (OJ+RI) (N=7); Obstructive jaundice (OJ) (N=7). All groups were compared with each other according to renal failure findings and enzyme activities, such as Xanthine oxidase (XOD), Superoxide Dismutase (SOD) and Catalase in renal cortex and Glutathione Peroxidase (GSH-Px), in blood at 3rd day after ischemia and reperfusion. Renal failure findings monitored by blood urea and creatinine levels, seemed more evident in OJ+RI than RI group (p <0.05). When compared with RI, in OJ+RI group, increase in XOD activity at 3rd day was statistically significant [0.259 ±0.01 U/g (tissue) and 0.362±0.03 U/g (tissue) respectively] (p <0.05). SOD and GSH-Px activities of each ischemic group at 3rd day were decreased compared to non-ischemic groups. This fall was significant (p <0.05). But there was no statistical difference between jaundiced and non-jaundiced groups. Alterations in catalase activities also had no statistical significance

Diagnostic value of Chest CT and Initial Real-Time RT-PCR in COVID-19 Infection

Objectives: To evaluate the diagnostic value of the rtRT-PCR test and CT in patients presenting with typical clinical symptoms of COVID-19. Methods: The study with the participation of four center in Turkey was performed retrospectively from 20 March-15 April 2020 in 203 patients confirmed for COVID-19. The initial rtRT-PCR test was positive in 142 (70.0%) of the patients (Group-I) and negative in 61 patients (Group-II). Results: The mean age of the patients in Group-I was 49.718.0 years and the time between the onset of symptoms and admission to the hospital was 3.6 +/- 2.0 days; whereas the same values for the patients in Group-II were 58.1 +/- 19.9 and 5.3 +/- 4.2, respectively (p=0.004; p=0.026). Initial rtRT-PCR was found positive with 83.5% sensitivity and 74.1% PPV in patients with symptom duration of less than five days. It was found that rtRT-PCR positivity correlated negatively with the presence of CT findings, age, comorbidity, shortness of breath, and symptom duration, while rtRT-PCR positivity correlated positively with headache. Presence of CT findings was positively correlated with age, comorbidity, shortness of breath, fever, and the symptom duration. Conclusions: It should be noted that a negative result in the rtRT-PCR test does not rule out the possibility of COVID-19 diagnosis in patients whose symptom duration is longer than five days, who are elderly with comorbidities and in particular who present with fever and shortness of breath. In these patients, typical CT findings are diagnostic for COVID-19. A normal chest CT is no reason to loosen up measures of isolation in patients with newly beginning symptoms until the results are obtained from the PCR test

Kaa ömür tahmini için basitleştirilmiş bir algılayıcı düğüm enerji tüketimi hesaplama yaklaşımı

Kullanılabilirlik süresi (ömür), ağın ne zamana kadar işlevsel olarak çalışabileceği temel bilgisini verdiği için KAAuygulama tasarımındaki en önemli konulardan birisidir. Literatürde bir KAA’nın ömrünü belirleme ile ilgili çok sayıdaaraştırma makalesi olmasına rağmen kesin ve kullanışlı bir tanım üzerinde tam bir uzlaşma yoktur. Sonuç olarak, hepsigerçekten en iyi tahmini KAA ömür değerini bulmayı amaçlayan bu çalışmalarda çeşitli matematiksel ifadelerverilmektedir. Bu makalede, literatürde yakın zamanda önerilmiş bir KAA ömür hesaplaması yöntemi için KAA ömürüst sınırı belirlemeyi nispeten daha basit ve kolay hale getiren önemli bir yaklaşım sunulmaktadır

Band-based interpretability with SHAP for hyperspectral classification

Hyperspectral data enable high classification accuracies due to the large amount of spectral information they contain. However, the complete black box or at least partially opaque nature of machine learning approaches often make classification processes challenging to interpret and low in explainability. In this work, SHAP, which is an explainable artificial intelligence (XAI) method, is used for the interpretability of hyperspectral classification. For each class, band-based SHAP values are obtained over the trained classification model, providing a quantitative evaluation of the contribution of the spectral bands to the classification process. Preliminary experimental results are provided in this paper, and shed light on the proposed method's potential