Causal links between long-term exposure to NO2 and the risk of cardiovascular hospitalization / 中华流行病学杂志

Objective: To determine the causal association between long-term Nitrogen dioxide (NO2) exposure and the risk of cardiovascular hospitalization. Methods: Based on a sub-cohort of a community-based prospective cohort study, a total of 36 271 participants were recruited from 35 communities randomly selected in Guangzhou in 2015. The annual average exposure of NO2, demographic characteristics, lifestyle factors, and information on the causes of hospitalization was collected. We applied marginal structural Cox models to investigate the effect of NO2 on cardiovascular hospitalization. Demographic and behavioral factors also stratified results. Results: The mean age of participants in the present study was (50.9±17.8) years, and the cardiovascular admission rate was 8.7%, with 203 822 person-years of follow-up. The annual mean NO2 concentration was 48.7 μg/m3 during 2015-2020. For each 10 μg/m3 increase in NO2 concentrations, the HRs (95%CIs) of total cardiovascular hospitalization, cardiovascular hospitalization, and cerebrovascular hospitalization were 1.33 (1.16-1.52), 1.36 (1.16-1.60) and 1.25 (1.00-1.55), respectively. Participants who were never married/married, with secondary education, high exercise frequency, or non-smokers/current smokers may be more susceptible than their counterparts. Conclusion: Long-term exposure to NO2 significantly increased hospitalization risk for cardiovascular disease.

Spatial distribution of cancer-related burden in Guangzhou from 2010 to 2013 / 中华流行病学杂志

Objective@#To evaluate the burden and to describe the characteristics of spatial distribution caused by malignant tumors among different administrative areas in Guangzhou from 2010- 2013.@*Methods@#Based on data from the Cancer Registry system and population in Guangzhou in 2010- 2013, disability-adjusted life year (DALY) was assessed on the disease burden of cancer, in accordance with the method used in the Global Burden of Disease study.@*Results@#The crude incidence rates of cancer appeared as 256.22/105 in 2010-2011 and 270.04/105 in 2012-2013, with the crude mortality rates as 143.17/105 and 148.01/105, respectively, in Guangzhou. Cancers caused 606 238.95 DALYs in 2010-2011 and 623 763.80 DALYs in 2012-2013 for both sexes and 37.63 and 37.81 person year per 1 000 persons, with the standardized DALY rates as 34.51‰, 34.00‰ respectively. Three administrative districts (Yuexiu, Haizhu and Liwan) were with the largest disease burden of cancers that accounted for 45% of the DALYs for the whole Conghua district, with liver cancer was the leading cancer on DALYs, and tracheal, bronchus and lung cancer ranked the first in the other districts.@*Conclusions@#In Guangzhou, disease burden caused by cancers was both prominently seen in the newly developed urban area and the old districts. It remains an arduous task to continue programs on control and prevention of cancers in this city.

Effect of Tuina on Autophagy-related Factor Beclin-1, Vacuolar Protein Sorting and Microtubule-associated Protein Light Chain 3 in Rats with Denervated Skeletal Muscle Atrophy / 中国康复理论与实践

Objective:To explore the effect and mechanism of Tuina on denervated skeletal muscle atrophy. Methods:A total of 77 male Sprague-Dawley rats were randomly divided into sham group (n = 7), model group (n = 35) and Tuina group (n = 35). The latter two groups were established skeletal muscle atrophy model by exposing and cutting off the common tibial nerve of rats. One day after modeling, the lower limbs of the surgical side received Tuina in Tuina group. Separately, the surgical side of gastrocnemius muscle were sampled on the 0th, 7th, 14th, 21st and 28thday after modeling, and measured the wet mass ratio. The cross-sectional area and diameter of muscle fiber were measured after HE staining. The mRNA expression of autophagy-realated factor Beclin-1, vacuolar protein sorting (Vps34) and microtubule-associated protein light chain 3 (LC3) were tested with reverse transcription real-time quantitative polymerase chain reaction. Results:There was no statistical difference in the ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber, and the mRNA expression of Beclin-1, Vps34 and LC3 among three groups on the 0th day (F < 1.321, P > 0.05). Compared with the sham group, the ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber decreased at different time points in the model group and Tuina group (P < 0.05), the ratio of gastrocnemius wet weight was higher, and the cross-sectional area and diameter of muscle fiber were bigger, both except on the 21st day, in Tuina group than in the model group (P < 0.05). Compared with the sham group, the mRNA expression of Beclin-1, Vps34 and LC3 increased at different points in the model group than in Tuina group (P < 0.05), and all the mRNA expression was higher, except on the 14th day, in Tuina group than in the model group (P < 0.05). The ratio of gastrocnemius wet weight, the cross-sectional area and diameter of muscle fiber showed a trend of progressive decrease with time in the model group and Tuina group (P < 0.05). The mRNA expression of Beclin-1 and Vps34 increased (P < 0.05), and the mRNA expression of LC3 increased in the model group 21 days after intervention (P < 0.05). The mRNA expression of Beclin-1, Vps34 and LC3 increased first and then decreased, except the mRNA expression on the 14th day in Tuina group (P < 0.05). Conclusion:Tuina may promote the activation of autophagy by up-regulating the expression of autophagy-realated factor Beclin-1, Vps34 and LC3, remove the damaged organelles and proteins, provide certain synthetic substrate and energy for muscle fiber regeneration, thereby reduce the loss of degree of denervated skeletal muscle atrophy.

Massage relieves inflammation and oxidative stress and promotes autophagy after contusion of skeletal muscles / 中华物理医学与康复杂志

Objective To observe the effects of massage on inflammation,oxidative stress and autophagy during the repair of acute contusion of skeletal muscles so as to explore its biological mechanisms.Methods Forty-two adult Sprague-Dawley rats were randomly divided into a control group (n =6),a model group (n =18),and a treatment group (n =18).Acute contusion of the gastrocnemius muscles of the rats in the model and treatment groups was inflicted using a home-made impactor.Beginning forty-eight hours later,15 minutes of massage was administered daily for two weeks.After one,7 and 14 days of the massage treatment,the injured gastrocnemius was resected from 6 rats of both the model and treatment groups.Morphological changes were observed using haematoxylin and eosin (HE) staining.The serum content of tumor necrosis factor alpha (TNF-α),interleukin1β (IL-1 β),C reactive protein (CRP) and prostaglandin E2 (PGE2) were detected using enzyme-linked immunosorbent assay (ELISA).The serum content of superoxide (SOD) and malondialdehyde (MDA) were detected using spectrophotometry.The expression of microtubule-associated protein 1 light chain 3 (LC3),Bcl-2 homeodomain protein Beclin1 and ubiquitin binding protein P62 were detected using Western blotting.Results The HE staining showed more significant collapse and swelling of cells in the model group than in the control group at each time point.New muscle cells were observed at days 7 and 14 in the model group.At each time point,significantly better recovery was observed in the treatment group compared to the model group,with more new muscle cells and better cell morphology.According to the ELISA results,a significant increase in serum pro-inflammatory factors occurred in the model group compared to the control group and compared to the treatment group after one day and 7 days of treatment.The average serum content of SOD and MDA in the model group was significantly higher than in the control group,while the average serum content of SOD in the treatment group was significantly higher than in the model group and that of MDA was significantly lower.Western blotting showed a significant decrease in LC3 (Ⅱ/Ⅰ) and Beclin1,as well as a significant increase in P62 in the model group at each time point compared with the treatment group and the controls.Conclusion Inflammation and oxidative stress increase significantly in a skeletal muscle after injury,but autophagy decreases significantly.Massage can effectively reduce the inflammatory response and oxidative stress and promote autophagy,which leads to quicker repair of skeletal muscles.

Changes in expression of autophagy-related factors during acute contusion repair of skeletal muscle / 中国应用生理学杂志

<p><b>OBJECTIVES</b>To explore the possible biological mechanism of skeletal muscle contusion repair through researching the changes in expression of autophagy-related genes and proteins in SD rats with acute skeletal muscle contusion.</p><p><b>METHODS</b>Six rats were randomly selected as the control group from 30 male SD rats, acute skeletal muscle contusion model were established in the remaining 24 rats with self-made hitter, then the model rats were randomly divided into 4 groups (3 d, 5 d, 7 d, 14 d groups, =6). On the 3, 5, 7 and 14 day after injury, injured gastrocnemius of each group was harvested. The morphological and the ultra-microstructure changes of gastrocnemius after injury were observed by HE staining and transmission electron microscope (TEM) respectively. The relative protein levels of (LC3-Ⅱ) and P62 of each group were observed by Western blot. The relative mRNA levels of atg7, atg10, atg12, atg16L1 of each group were observed by RTPCR.</p><p><b>RESULTS</b>The results of HE staining showed that compared with the control group, the inflammation reached its peak on the 5 day after injury, new muscle fibers were clearly observed in 7 d group. The results of TEM showed that, compared with the control group, oncotic mitochondria could be clearly seen in the 3 d, 5 d, 7 d groups. Also, the Z line changed from disappearing to drift thickening, sarcoplasmic reticulum dilatation gradually improved, there was no evident difference between the 14 d group and the control group, suggesting that the damage has preliminarily healed. The results of Western blot showed that the expressions of LC3-Ⅱand P62 were increased at first and then decreased. The expression of LC3-Ⅱwas markedly up-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0.01). Similarly, compared with the control group, the expression of P62 reached its peak on the 3 day after injury (<0. 01), and returned to normal level on the 14 day. The results of RT-PCR showed that the expression of atg10 mRNA in the natural recovery group of 3 d, 5 d, 7 d, 14 d was firstly decreased and then increased, the atg10 mRNA was markedly down-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0. 01). The expression of atg7, atg12, atg16L1 mRNA was generally increased at first and then decreased, it was markedly up-regulated in the 3 d, 5 d, 7 d groups compared with the control group and the 14 d group (<0.01, <0.05, <0.01).</p><p><b>CONCLUSIONS</b>The above results indicate that the autophagy is involved in repair of skeletal muscle injury by its autophagyrelated factors,regularly changes after contusion, and the rate of damage repair may be related to the level of autophagy.</p>

Experimental Research Progress on Acupuncture in Skeletal Muscle Atrophy (review) / 中国康复理论与实践

@# Irrespective of physiological or pathological skeletal muscle atrophy, the endocrine and motor functions of skeletal muscle are impaired. The mechanism of acupuncture to prevent and treat skeletal muscle atrophy is not only related to classical protein synthesis and decomposition, but also involves apoptosis, autophagy, muscle satellite cell proliferation and differentiation, muscle fiber type conversion, neuromuscular junction conduction, and cell energy metabolism conversion.

Effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor in rats with skeletal muscle contusion / 中国针灸

<p><b>OBJECTIVE</b>To observe the effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor (HGF) in rats with skeletal muscle contusion, and to explore the mechanism of acupuncture at opposite acupoints on skeletal muscle contusion.</p><p><b>METHODS</b>Fifty-four Sprague Dawley (SD) rats were randomly divided into a blank group (6 rats), a model group (24 rats) and an opposing needling group (24 rats). The model group and opposing needling group were further divided into 1-day subgroup, 3-day subgroup, 5-day subgroup and 7-day subgroup, 6 rats in each one. No intervention was given in the blank group, while the model of skeletal muscle contusion was established in the model group and opposing needling group by self-made contusion device. 24 hours after contusion, electroacupuncture (EA) was applied at "Zusanli" (ST 36) and the corresponding points ofpoints at health side for 15 min, once a day. The subgroups of opposing needling group were treated for 1 day, 3 days, 5 days and 7 days, respectively. No treatment was given in the model group. Samples were collected in the subgroups 1 day, 3 days, 5 days and 7 days after treatment. The morphological change of injured gastrocnemius muscle was observed by using microscope after HE staining. The positive cell rate of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. The expression levels of HGF protein and PCNA protein were observed by Western blot.</p><p><b>RESULTS</b>① The results of HE staining showed that, 1 day after contusion, the inflammatory cells of gastrocnemius muscle in the opposing needling group were less than those in the model group; 3 days and 5 days after contusion, myoblasts and myotubes in the opposing needling group were more than those in the model group; 7 days after contusion, the neonatal muscle cells in the opposing needling group were more than those in the model group. ② The results of immunohistochemistry showed that, 1 day, 3 days and 5 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly higher than that in the model group (all<0.001); 7 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly less than that in the model group (<0.001). ③ The results of Western blot showed that, 1 day, 3 days and 5 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly higher than that in the model group (all<0.05); 7 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly lower than that in the model group (all<0.05).</p><p><b>CONCLUSION</b>Acupuncture at opposite acupoints could regulate the expression of HGF and promote the activation, proliferation, migration and differentiation of muscle satellite cells in rats with skeletal muscle contusion, which could speed up the process of skeletal muscle injury repair.</p>

Effects of Electroacupuncture on Autophagy-related Gene Expression in Skeletal Muscle in Denervated Rats / 中国康复理论与实践

@#Objective To explore the effects and mechanism of electroacupuncture(EA)on denervation-induced atrophy. Methods A total of 21 male Sprague-Dawley rats were divided into sham group(n=7),model group(n=7)and EA group (n=7).The latter two groups were cut off their right sciatic nerve.Since one day after modeling,EA group accept-ed electroacupuncture at right Zusanli(ST36)and Huantiao(GB30)for eight weeks.Then,the gastrocnemius of all the rats were obtained,and measured the wet mass ratio.Cross-sectional area(CSA)and fiber diameter were measured after HE staining. The expression of autophagy-related gene ULK1, Atg13, Beclin1, Atg14, Atg7, Atg12,Atg5 and Atg16L1 were tested with reverse transcription real-time quantitative polymerase chain reaction. Results Compared with the sham group,the wet mass ratio,CSA and fiber diameter of gastrocnemius were lower signifi-cantly in the model group and EA group(P<0.001),and they were more in EA group than in the model group(P<0.05).Compared with the sham group,the mRNA expression of ULK1,Atg13,Beclin1,Atg14,Atg7,Atg12,Atg5 and Atg16L1 was more significantly in the model group (P<0.001), and they decreased in EA group compared with those of the model group(P<0.05). Conclusion Electroacupuncture can inhibit the overexpression of autophagy-related gene in denervated rats,which may steady skeletal muscle cells to delay atrophy.

Advance in Model Establishment for Denervated Skeletal Muscle Atrophy (review) / 中国康复理论与实践

The skeletal muscle atrophy could be induced by the injury of nerve. According to the source of denervated skeletal mus-cle atrophy, it could be divided into exogenous muscle atrophy and endogenous muscle atrophy. In recent years, the ex-ogenous muscle atrophy models are mainly established by operating, physically injuring or chemically injuring, while the endogenous muscle atrophy models are mainly established by the transgenic animals of amyotrophic lateral sclero-sis. The selection and optimazation of animal models are crucial for the basic studies of denervated skeletal muscle atro-phy.