Objective:To investigate the changes in sympathetic nerve activity after lower limb immobilization and the role of sympathetic nerve in regulating disuse atrophy of skeletal muscles.Methods:The experiment was divided into the following 3 parts: ① Twelve 8-week-old male C57 mice were randomly divided into a blank control group and a hind limb fixation group ( n=6). The blank control group received no intervention while the hind limb fixation group received splint fixation of the hind limbs for 2 weeks before the musculoskeletal multi-dimensional characterization was completed at the behavioral, pathological and molecular levels. ② Thirty-six 8-week-old male C57 mice were selected and randomly divided into a control group and 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) ( n=6). The control group was fed normally until 14 days without any intervention while the 5 hind limb fixation groups were sampled after fixation for 1, 3, 5, 7 and 14 days, respectively. The level of norepinephrine in the serum and the expression level of tyrosine hydroxylase (TH), a marker of sympathetic nerve activity in the paraventricular nucleus of hypothalamus (PVN), were detected to observe the plasticity of sympathetic nerve activity. ③ Eighteen 8-week-old male C57 mice were selected and randomly divided into a blank control group, a hind limb fixation group and a hind limb fixation plus medication group ( n=6). The blank control group received no intervention while the 2 fixation groups were injected with phosphate buffer (PBS) and propranolol hydrochloride solution for 2 consecutive weeks, respectively. The parameters related to the skeletal muscles were compared between the 3 groups. Results:① Compared with the control group, the mass and function of skeletal muscles in the hind limb fixation group were statistically significantly decreased ( P<0.05). ② The levels of serum norepinephrine [(3.27±1.03) ng/mL, (9.21±1.05) ng/mL, (6.36±0.88) ng/mL, (3.84±1.00) ng/mL, and (3.91±0.75) ng/mL] and the PVN TH levels (42.00%±5.38%, 61.67%±5.57%, 55.82%±3.11%, 50.90%±2.53%, and 39.17%±9.07%) in the 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) were significantly higher than those in the control group [(1.81±0.72)] ng/mL and 23.33%±5.50%] ( P<0.05). ③ The wet weight of the gastrocnemius muscle [(93.50±4.32) mg] and the cross-section area of the tibial anterior muscle [(1,180.00±95.09) μm 2] in the hind limb fixation plus medication group were increased significantly compared with those in the hind limb fixation group [(80.83±9.99) mg and (907.80±121.00) μm 2] ( P<0.05). Conclusions:Overactivation of the sympathetic nervous system occurs in the mice model of skeletal muscle disuse atrophy after hind limb fixation. Inhibition of sympathetic nerve activity may reduce the severity of skeletal muscle atrophy at the lower limbs.

Objective:To investigate the changes in sympathetic nerve activity after lower limb immobilization and the role of sympathetic nerve in regulating disuse atrophy of skeletal muscles.Methods:The experiment was divided into the following 3 parts: ① Twelve 8-week-old male C57 mice were randomly divided into a blank control group and a hind limb fixation group ( n=6). The blank control group received no intervention while the hind limb fixation group received splint fixation of the hind limbs for 2 weeks before the musculoskeletal multi-dimensional characterization was completed at the behavioral, pathological and molecular levels. ② Thirty-six 8-week-old male C57 mice were selected and randomly divided into a control group and 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) ( n=6). The control group was fed normally until 14 days without any intervention while the 5 hind limb fixation groups were sampled after fixation for 1, 3, 5, 7 and 14 days, respectively. The level of norepinephrine in the serum and the expression level of tyrosine hydroxylase (TH), a marker of sympathetic nerve activity in the paraventricular nucleus of hypothalamus (PVN), were detected to observe the plasticity of sympathetic nerve activity. ③ Eighteen 8-week-old male C57 mice were selected and randomly divided into a blank control group, a hind limb fixation group and a hind limb fixation plus medication group ( n=6). The blank control group received no intervention while the 2 fixation groups were injected with phosphate buffer (PBS) and propranolol hydrochloride solution for 2 consecutive weeks, respectively. The parameters related to the skeletal muscles were compared between the 3 groups. Results:① Compared with the control group, the mass and function of skeletal muscles in the hind limb fixation group were statistically significantly decreased ( P<0.05). ② The levels of serum norepinephrine [(3.27±1.03) ng/mL, (9.21±1.05) ng/mL, (6.36±0.88) ng/mL, (3.84±1.00) ng/mL, and (3.91±0.75) ng/mL] and the PVN TH levels (42.00%±5.38%, 61.67%±5.57%, 55.82%±3.11%, 50.90%±2.53%, and 39.17%±9.07%) in the 5 hind limb fixation groups (for 1, 3, 5, 7 and 14 days) were significantly higher than those in the control group [(1.81±0.72)] ng/mL and 23.33%±5.50%] ( P<0.05). ③ The wet weight of the gastrocnemius muscle [(93.50±4.32) mg] and the cross-section area of the tibial anterior muscle [(1,180.00±95.09) μm 2] in the hind limb fixation plus medication group were increased significantly compared with those in the hind limb fixation group [(80.83±9.99) mg and (907.80±121.00) μm 2] ( P<0.05). Conclusions:Overactivation of the sympathetic nervous system occurs in the mice model of skeletal muscle disuse atrophy after hind limb fixation. Inhibition of sympathetic nerve activity may reduce the severity of skeletal muscle atrophy at the lower limbs.

Objective:To explore the effect of diet safety management based on swallowing function classification in perioperative period of elderly patients with hip fractures, so as to provide basis for improving perioperative food safety and shortening hospitalization time of patients with hip fracture.Methods:A total of 68 elderly patients with hip fractures in the First Medical Center of PLA General Hospital from December 2020 to August 2021 were selected and divided into experimental group and control group according to even and odd-number of admission number, each group contained 34 patients. The control group was given routine diet nursing and food safety education. The experimental group was given graded diet safety management according to the swallowing function evaluation results. The incidence of aspiration and length of hospital stay were compared between the two groups.Results:The incidence of chocking during hospitalization was 5.1% (78/1 517) in the control group and 1.2% (17/1 402) in the experimental group, and the difference was statistically significant ( χ2=35.73, P<0.01). The incidence of choking in the control group was 0.7% (11/1 517), and 0.4% (5/1 402) in the experimental group, and the difference was not statistically significant ( χ2=1.82, P>0.05). There was no significant difference in hospitalization time between the two groups, 10 (8,12) in the control group and 9 (8,11) in the experimental group ( Z=-1.33, P>0.05). Conclusions:The implementation of diet safety management based on swallowing function classification in elderly patients with hip fractures can reduce the incidence of coughing. Evaluation of swallowing function should be included in the evaluation of hip fractures in the elderly.

Fragile fracture has become a major health concern in our society and an important cause of death in elderly patients. Effective identification of risk factors and optimization of clinical nursing practice are helpful to improve the effect of treatment and nursing and reduce the medical burden of disease. This article reviews the literature on the risk factors and clinical practice of fragile fractures at home and abroad, determines the important risk factors of fragile fractures, provides the latest situation of fragile fracture nursing practice, and puts forward relevant suggestions for domestic brittle fracture nursing management research, which provides reference for optimizing the clinical practice of patients with fragile fractures.