Effects of psychogenic stress on oxidative stress and antioxidant capacity at different growth stages of rats: Experimental study.

This study examined the psychogenic stress (PS) effects on changes in oxidative stress and the antioxidant capacity of an organism at different growth stages. The experimental animals were male Wistar rats of five different ages from growth periods (GPs) to old age. The growth stages were randomly classified into control (C) and experimental (PS) groups. The PS was performed using restraint and water immersion once daily for 3 h for 4 weeks. Reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) were measured before and after the experiment. In addition, the liver and adrenal glands were removed, and the wet weight was measured. The d-ROM and BAP of all growth stages given PS increased significantly. The d-ROM in the C group without PS increased significantly in GPs while decreased significantly in old-aged rats. In addition, the BAP of the C group in GP and early adulthood were all significantly elevated. There were significant differences in organ weights between the C and PS groups at all growth stages. Oxidative stress and antioxidant capacity differed depending on the organism's developmental status and growth stage, and PS also showed different effects. In particular, the variability in oxidative stress was remarkable, suggesting that the effect of PS was more significant in the organism's immature organs.

Responses to oxidative stress and antioxidant capacity in rats at different growth stages.

[Purpose] Oxidative stress is regulated by antioxidant capacity in vivo. However, its impact on aging characteristics remains debatable. This study is first to report oxidative stress, antioxidant capacity, and their ratio in five age groups of rats, and aimed to provide basic data useful for disease prevention. [Materials and Methods] Sixty male Wistar rats of different ages were used as experimental animals, grouped as follows: weaned (three weeks), growth (eight weeks), adulthood (six months), middle-age (12 months), and old-age (24 months). To assess oxidative stress and antioxidant capacity, derivatives of reactive oxygen metabolites and biological antioxidant potential were measured. [Results] The lowest level of oxidative stress and the highest level of antioxidant capacity were observed during the weaning stage, and remarkable dynamic changes were observed until adulthood. The highest oxidative stress and lowest antioxidant capacity were observed in the old-age group. [Conclusion] In vivo oxidative stress and antioxidant capacity are largely reflected in the characteristics of aging, and this ratio is greatly influenced by the dynamics of oxidative stress and antioxidant capacity with age.

Observation of respiration-entrained brain oscillations with scalp EEG.

In animal models, oscillations of local field potentials are entrained by nasal respiration at the frequency of breathing cycle in olfactory brain regions, such as the olfactory bulb and piriform cortex, as well as in the other brain regions. Studies in humans also confirmed these respiration-entrained oscillations in several brain regions using intracranial electroencephalogram (EEG). Here we extend these findings by analyzing coherence between cortical activity and respiration using high-density scalp EEG in twenty-seven healthy human subjects. Results indicated the occurrence of significant coherence between scalp EEG and respiration signals, although the number and locations of electrodes showing significant coherence were different among subjects. These findings suggest that scalp EEG can detect respiration-entrained oscillations. It remained to be determined whether these oscillations are volume conducted from the olfactory brain regions or reflect the local cortical activity.

Impact of frailty and mild cognitive impairment on delirium after cardiac surgery in older patients.

BACKGROUND: Frailty and cognitive impairment are well-known risk factors of delirium after cardiac surgery. Frailty is closely associated with cognitive impairment. This study aimed to examine how frailty and cognitive impairment affect the incidence of delirium after cardiac surgery in older patients. METHODS: In total, 89 patients (aged ≥65 years) who underwent cardiac surgery between April 2016 and December 2017 were included (74.9 ± 5.5 years, male 64.1%). They were divided according to the combination of frailty and mild cognitive impairment (MCI): Group 1, non-frailty and non-MCI; Group 2, non-frailty and MCI; Group 3, frailty and non-MCI; and Group 4, frailty and MCI. Frailty was defined as a score of at least 3 points according to the Japanese version of the Cardiovascular Health Study criteria, and MCI was defined as a Montreal Cognitive Assessment score less than 26. Delirium was evaluated using the Intensive Care Delirium Screening Checklist, and a score of 4 or higher indicated delirium. Multivariate logistic regression analysis was performed to examine the influence of the combination of frailty and MCI on delirium after cardiac surgery. RESULTS: In total, 31 patients (34.8%) showed postoperative delirium. Multivariate analysis-adjusted baseline characteristics (reference, Group 1) showed that only Group 4 had a risk of delirium after cardiac surgery (odds ratio, 7.494; 95% confidence interval 1.539-36.494). CONCLUSION: Preoperative coexistence of frailty and MCI poses the greatest risk of delirium after cardiac surgery. Therefore, attention should be paid to both physical and cognitive function prior to surgery. Further studies are warranted to investigate the optimal intervention for high-risk patients.

Factors related to physical functioning decline after cardiac surgery in older patients: A multicenter retrospective study.

BACKGROUND: As few studies have examined physical functioning changes after cardiac surgery, the factors related to the decline in physical functioning remain unclear. This study aimed to investigate the factors related to physical functioning decline after cardiac surgery in older patients. METHODS: The final study sample consisted of 523 older (≥65 years) patients (age 74.2±6.1 years, 66% male) who underwent cardiac surgery at 8 Japanese institutions. We excluded patients who were unable to walk independently or had a slow gait speed (<0.8m/s) before surgery, and those who were unable to regain independent walking after surgery. We divided the patients into two groups, a decline-in-gait-speed group and a non-decline-in-gait-speed group, according to whether their gait speed was less than 0.8m/s at discharge. We analyzed patients' clinical characteristics to identify the factors that predicted the postoperative decline in gait speed. RESULTS: Eighty-nine patients (17.0%) showed a postoperative decline in gait speed. Multivariate logistic regression analysis showed that the following factors predicted a postoperative decline in gait speed: age [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.02-1.11]; estimated glomerular filtration rate (OR 0.98, CI 0.96-0.99); preoperative gait speed (OR 0.01, CI 0.00-0.08); and the postoperative day on which the patient could walk independently (OR 1.08, CI 1.02-1.14). CONCLUSIONS: Physical functioning declined in 17% of patients after surgery. The decline could be predicted by several clinical factors, including some that are modifiable. These results suggest that further interventional research on rehabilitation before and after cardiac surgery for older patients might help overcome the decline in physical functioning.

Impact of heart failure on functional recovery after hip fracture.

[Purpose] Heart failure has been identified as a risk factor for reduced physical function and falls; however, the impact of heart failure on functional recovery after a hip fracture is unclear. This study aimed to examine how heart failure and pre-fracture physical function affect recovery after a hip fracture. [Participants and Methods] The study population consisted of 122 patients with sub-acute hip fracture (mean age 81.7 ± 9.7 years, 18.9% male) who were divided into two groups: heart failure and non-heart failure. The outcome measurement was the functional independence measure effectiveness. A two-way analysis of variance was performed to investigate how heart failure and ambulatory ability prior to hip fracture were related to the functional independence measure effectiveness. [Results] Seventeen patients (13.9%) had a history of heart failure. The two-way analysis of variance showed the two independent variables (heart failure and ambulatory ability before fracture) had significant main effects; however, their interaction effect was not significant. [Conclusion] Heart failure affects functional recovery after hip fracture independent of the pre-fracture physical function, and vice versa. Further research on rehabilitation in hip fracture patients with heart failure is required to develop strategies to overcome poor functional recovery in such patients.

Combination of Low Body Mass Index and Low Serum Albumin Level Leads to Poor Functional Recovery in Stroke Patients.

BACKGROUND: Nutritional status is associated with the functional recovery of stroke patients. This study aimed to examine the influence of the combination of body mass index (BMI) and serum albumin level on functional recovery in subacute stroke patients. METHODS: This retrospective cohort study included 259 subacute stroke patients (mean age 68.9 ± 12.3 years). Patients were categorized into 4 groups according to their BMI and serum albumin level: group 1, low BMI (<18.5 kg/m2) and low serum albumin level (<3.5 g/dL); group 2, low BMI and high serum albumin level (≥3.5 g/dL); group 3, normal weight (≥18.5 kg/m2) and low serum albumin level; and group 4, normal weight and high serum albumin level. The outcome variable was the motor subscale of the Functional Independence Measure (M-FIM) effectiveness. We defined the first quartile of M-FIM effectiveness as poor functional recovery. Multivariate logistic regression analysis was performed to examine the influence of the combination of BMI and serum albumin level on poor functional recovery. RESULTS: Multivariate logistic regression analysis adjusted for baseline characteristics (reference, group 4) showed that group 1 was mostly associated with a significant risk of poor functional recovery (odds ratio, 4.13; 95% confidence interval, 1.53-11.15). CONCLUSIONS: Our results suggested that the combination of low BMI and low serum albumin level was more significantly associated with poor functional recovery in subacute stroke patients than either factor alone. The combination of BMI and serum albumin level should be taken into account when predicting functional recovery in subacute stroke patients.