OBJECTIVETo observe the pathological changes in rabbits with spinal cord injury induced by decompression sickness (DCS), and to investigate the role of tumor necrosis factor-alpha (TNF-α) in spinal cord injury induced by DCS.

METHODSRabbits were randomly divided into normal control group, DCS group, and safe decompression group. The rabbit model of DCS was established. Light microscopy, real-time PCR, and immunohistochemical method were used to observe the pathomorphological changes in the thoracolumbar spinal cord and the mRNA and protein expression of TNF-α, respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to observe the apoptosis in the spinal cord.

RESULTSIn the DCS group, cavities formed in the white matter of spinal cord and gliosis occurred around necrotic areas. Moreover, the mRNA and protein expression of TNF-α was significantly higher in the DCS group than in the normal control group and the safe decompression group (P<0.01). The results of TUNEL showed that the number of positive apoptotic cells was significantly larger in the DCS group than in the normal control group and the safe decompression group (P<0.05).

CONCLUSIONApoptosis plays an important role in spinal cord injury induced by DCS. In the early stage of DCS, the massive release of TNF-α initiates apoptosis and contributes to the pathological changes in spinal cord injury induced by DCS.

Animals ; Apoptosis ; Decompression Sickness ; metabolism ; pathology ; Disease Models, Animal ; In Situ Nick-End Labeling ; RNA, Messenger ; Rabbits ; Spinal Cord ; pathology ; Spinal Cord Injuries ; metabolism ; pathology ; Tumor Necrosis Factor-alpha ; metabolism

Objective: An isochronous substitution model was established to explore the association and substitution effect between college students 24 hour activity behavior and physical health, so as to provide specific activity behavior suggestions for college students to improve their physical health. Methods: A stratified random cluster sampling method was used to conduct physical fitness tests and 24 hour activity behavior surveys among 2 794 college students in 12 colleges and universities in Tianjin.Time spent on sedentary behavior(SB), light intensity physical activity(LPA), moderate to vigorous physical activity(MVPA) and sleep(SLP) time. The isochronous method of components was used to explore the relationship between 24 h activity behavior and physical health. Results: Except for 50 m running, MVPA was negatively correlated with BMI Z ( β =-0.62, P <0.05), but positively correlated with other physical fitness indexes ( β =0.34~274.23, P <0.05). LPA was not associated with lung capacity, sitting forward flexion and 50 m running, and negatively correlated with other physical fitness indexes ( β =-14.30- -0.19, P <0.05). SB was negatively correlated with most physical fitness indexes ( β =-11.57- -0.33, P <0.05), but positively correlated with BMI Z ( β =0.45, P < 0.05 ). In addition to lung capacity, SLP was positively correlated with BMI Z , total physical fitness score,1 minute sit-ups, pull ups, 800/1 000 m running, sitting forward flexion, and 50 m running ( β =0.27-11.21, P <0.05), but negatively correlated with long jump ( β =-0.10, P <0.05）. Isochronous substitution showed that the adverse effects of 30 min/d SB and LPA substitution of MVPA were much greater than the beneficial effects of MVPA substitution for corresponding behaviors (total physical score: SB, -0.58 vs 0.47 points; LPA, -0.50 vs 0.38 points). Conclusion MVPA and SLP have been found to have a positive effect on physical fitness among college students. Therefore, in the process of improving the physical health of college students, ensuring adequate sleep, improving MVPA and reducing SB as much as possible may be one of the effective methods.

BACKGROUND:Sarcopenia refers to age-related progressive,systemic muscle mass reduction and/or muscle strength decline or muscle physiological function decline,which is related to the occurrence of a variety of adverse outcomes in older adults.Exercise is considered to be one of the main strategies for combating sarcopenia in older adults,but there is a lack of specific intervention methods of different exercise patterns to intervene in sarcopenia. OBJECTIVE:To elaborate the main influencing factors of sarcopenia and the research progress of different exercise methods to improve sarcopenia in older adults,providing reference and basis for combating sarcopenia in older adults. METHODS:Web of Science,PubMed,CNKI,VIP,WanFang databases were retrieved for relevant literature published from January 2000 to October 2023 using the keywords of"sarcopenia,sport,exercise intervention,resistant training,aerobic exercise,whole body vibration training,mixed training,physical performance,muscle strength,muscle mass"in Chinese and English,respectively.A total of 126 articles were included for review. RESULTS AND CONCLUSION:Resistance exercise is still the most effective way to prevent and treat senile sarcopenia,and the effect of high-intensity resistance exercise is more significant.However,in practical application,we should pay attention to the gradual increase of training load intensity.Aerobic exercise combined with resistance exercise is more effective to improve muscle mass and function in the elderly than a single exercise mode.It is suggested that older adults can carry out the transition of low-intensity aerobic exercise in the early stage and increase resistance exercise individually in the late stage.Whole body vibration training is a new treatment method for the prevention and treatment of senile sarcopenia,but particular attention should be paid to the effects of frequency,amplitude,and duration on patients during practical application.Multicomponent exercise combines different exercise modes,which can give full play to their respective advantages,so as to personalize exercise interventions.

OBJECTIVETo investigate the changes in expression of tumor necrosis factor-alpha (TNF-α) and glial fibrillary acidic protein (GFAP) in rabbits with decompression disease (DCS), and to investigate the functioning mechanism.

METHODSA total of 21 healthy adult rabbits were randomly divided into 3 groups: normal control group, DCS group, and safe relief group, with 7 rabbits in each group. A rabbit DCS model was established by quick decompression. The changes in pathological morphology and mRNA and protein expression of TNF-α and GFAP in the brain and spinal cord of rabbits with DCS were determined by light microscopy, real-time PCR, and immunohistochemistry, respectively.

RESULTSCavity formation was observed in the white matter of spinal cord in DCS group. The mRNA and protein expression of TNF-α and GFAP was significantly higher in the DCS group than in the normal control group and safe relief group (P < 0.01), while no significant differences were observed in the brain (P > 0.05).

CONCLUSIONSpinal cord is the main part of central nervous system injury in DCS. Activation of TNF-α and GFAP genes accompanied by increase in their protein expression can be observed at the early stage of DCS. The astrocytes and TNF-α play important roles in the process of spinal cord injury in DCS.

Animals ; Brain ; metabolism ; Decompression Sickness ; metabolism ; Disease Models, Animal ; Glial Fibrillary Acidic Protein ; metabolism ; Male ; Rabbits ; Spinal Cord ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism