BACKGROUND:Skeletal muscle aging is associated with various chronic diseases.Exercise is considered an important means to delay this process,but the multimechanism regulation of exercise intervention strategies still requires in-depth exploration.OBJECTIVE:To systematically outline the main physiological changes in skeletal muscle aging and explore the multiple mechanisms by which exercise regulates these changes,thereby providing a theoretical basis for basic research and clinical applications.METHODS:By searching databases such as Web of Science,PubMed,Embase,CNKI,WanFang,and VIP,relevant literature from database inception to October 2024 was retrieved by the first author,including original research articles and reviews.The search terms were"skeletal muscle aging,sarcopenia,exercise regulation,physical activity,chronic inflammation,inflammaging,mitochondrial dysfunction,extracellular matrix fibrosis,lipid mediators,satellite cells"in English and Chinese.Literature was screened based on inclusion and exclusion criteria,and the included 95 articles underwent quality assessment and data extraction.RESULTS AND CONCLUSION:(1)The core manifestations of skeletal muscle aging are the decline in muscle mass,strength,and function,closely related to various physiological changes.The decreased protein synthesis capacity and accelerated degradation rate in muscles lead to muscle atrophy and functional decline.Additionally,dysfunction of satellite cells is considered a key factor in the reduced regenerative capacity of muscles.Mitochondrial dysfunction is another important factor leading to muscle fatigue and energy metabolism disorders,directly affecting the metabolic activity and endurance of skeletal muscles.Chronic inflammatory responses and extracellular matrix fibrosis further exacerbate muscle aging.These factors interact synergistically,collectively resulting in skeletal muscle degeneration.(2)Exercise is widely recognized as an important means to delay skeletal muscle aging.Exercise alleviates chronic low-grade inflammatory responses in skeletal muscle by regulating the immune system,increasing the secretion of anti-inflammatory factors,and inhibiting the expression of pro-inflammatory factors,thereby mitigating the damage of inflammation to muscles.Exercise also enhances mitochondrial biogenesis and function,improves the muscle's energy metabolism capacity,and consequently increases endurance and strength.Furthermore,exercise regulates lipid metabolism and the synthesis of lipid mediators,reduces fat accumulation and alleviates fat-induced inflammatory responses,thereby further protecting skeletal muscles.The mechanical stimulation from exercise promotes the remodeling of the extracellular matrix,reduces fibrosis occurrence,and improves muscle structure and function.Additionally,exercise activates satellite cells,enhancing the regenerative capacity of skeletal muscles,especially notable with strength training and high-intensity interval training.(3)Future research should include large-scale,multicenter clinical trials to evaluate the comprehensive effects of long-term exercise interventions on skeletal muscle aging.By analyzing data from genomics,metabolomics,and other fields,exploring individual differences in responses to exercise interventions can provide more precise theoretical bases for personalized exercise strategies.Besides exercise,the impacts of other interventions such as nutritional supplementation and pharmacological treatments on skeletal muscle aging should not be overlooked.Future studies can explore the combined use of exercise with these interventions to achieve more significant effects.

BACKGROUND:Skeletal muscle aging is associated with various chronic diseases.Exercise is considered an important means to delay this process,but the multimechanism regulation of exercise intervention strategies still requires in-depth exploration.OBJECTIVE:To systematically outline the main physiological changes in skeletal muscle aging and explore the multiple mechanisms by which exercise regulates these changes,thereby providing a theoretical basis for basic research and clinical applications.METHODS:By searching databases such as Web of Science,PubMed,Embase,CNKI,WanFang,and VIP,relevant literature from database inception to October 2024 was retrieved by the first author,including original research articles and reviews.The search terms were"skeletal muscle aging,sarcopenia,exercise regulation,physical activity,chronic inflammation,inflammaging,mitochondrial dysfunction,extracellular matrix fibrosis,lipid mediators,satellite cells"in English and Chinese.Literature was screened based on inclusion and exclusion criteria,and the included 95 articles underwent quality assessment and data extraction.RESULTS AND CONCLUSION:(1)The core manifestations of skeletal muscle aging are the decline in muscle mass,strength,and function,closely related to various physiological changes.The decreased protein synthesis capacity and accelerated degradation rate in muscles lead to muscle atrophy and functional decline.Additionally,dysfunction of satellite cells is considered a key factor in the reduced regenerative capacity of muscles.Mitochondrial dysfunction is another important factor leading to muscle fatigue and energy metabolism disorders,directly affecting the metabolic activity and endurance of skeletal muscles.Chronic inflammatory responses and extracellular matrix fibrosis further exacerbate muscle aging.These factors interact synergistically,collectively resulting in skeletal muscle degeneration.(2)Exercise is widely recognized as an important means to delay skeletal muscle aging.Exercise alleviates chronic low-grade inflammatory responses in skeletal muscle by regulating the immune system,increasing the secretion of anti-inflammatory factors,and inhibiting the expression of pro-inflammatory factors,thereby mitigating the damage of inflammation to muscles.Exercise also enhances mitochondrial biogenesis and function,improves the muscle's energy metabolism capacity,and consequently increases endurance and strength.Furthermore,exercise regulates lipid metabolism and the synthesis of lipid mediators,reduces fat accumulation and alleviates fat-induced inflammatory responses,thereby further protecting skeletal muscles.The mechanical stimulation from exercise promotes the remodeling of the extracellular matrix,reduces fibrosis occurrence,and improves muscle structure and function.Additionally,exercise activates satellite cells,enhancing the regenerative capacity of skeletal muscles,especially notable with strength training and high-intensity interval training.(3)Future research should include large-scale,multicenter clinical trials to evaluate the comprehensive effects of long-term exercise interventions on skeletal muscle aging.By analyzing data from genomics,metabolomics,and other fields,exploring individual differences in responses to exercise interventions can provide more precise theoretical bases for personalized exercise strategies.Besides exercise,the impacts of other interventions such as nutritional supplementation and pharmacological treatments on skeletal muscle aging should not be overlooked.Future studies can explore the combined use of exercise with these interventions to achieve more significant effects.

Objective:To summarize the clinical and genetic characteristics of children with β-ketothiolase deficiency (BKTD).Methods:The clinical characteristics, biochemical, markers detected by tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC/MS), as well as the variants in ACAT1 gene among 5 children with BKTD in Children′s Hospital of Chongqing Medical University between October 2018 and December 2022 were retrospectively analyzed.Results:The onset age of the disease in 5 patients (4 males and 1 female) ranged from 9.7 to 28.0 months. During the acute phase, severe metabolic acidosis was observed with a pH of 6.9-7.1, as well as hypoglycaemia (2.3-3.4 mmol/L) and positive urinary ketone bodies (+-++++). Blood levels of methylcrotonyl carnitine, methylmalonyl carnitine and malonyl carnitine were 0.03-0.42, 0.34-1.43 and 0.83-3.53 μmol/L respectively and were significantly elevated. Urinary 2-methyl-3-hydroxybutyric acid was 22-202 and 3-hydroxybutyric acid was 4-6 066, both were higher than the normal levels. Methylcrotonylglycine was mild elevated (0-29). The metabolites detected by MS/MS and GC/MS were significantly reduced after treatment. Analysis of ACAT1 gene mutation was performed in 5 children. Most variants were missense (8/9). Four previously unreported variants were identified: c.678G>T (p.Trp226Cys), c.302A>G (p.Gln101Arg), c.627_629dupTGA (p.Asn209_Glu210insAsp) and c.316C>T (p.Gln106Ter), the first 2 variants were predicted to be damaging by SIFT, PolyPhen-2 and Mutation Taster software. c.316C>T (p.Gln106Ter) is a nonsense variant.Conclusions:β-ketothiolase deficiency is relatively rare, lacks specific clinical manifestations, however severe metabolic acidosis, hypoglycemia, and ketosis during the acute onset were consistent findings. Missense mutations in the ACAT1 gene are common genetic causes of β-ketothiolase deficiency.

Objective To assess the value of serum amyloid A(SAA)in patients with acute exacerbation of chronic pulmonary diseases. Methods Seventy AECOPD patients were randomly chosen. The AECOPD patients were divided into bacterial infection induced group and non-bacterial infection induced group by sputum bacteria culture. Thirty five SCOPD patients were chosen as control group. General data was collected. Lung function ,chest X ray,blood routine,CRP,SAA,IL6 and PCT were deteced and compared in the 3 groups. The diagnostic value of SAA to distinguish bacterial infection induced AECOPD was estimated. Results SAA of both AECOPD sub-groups were significantly higher than that of healthy controls. SAA in infection group is higher that that in exacerba-tion group. In terms of ROC curve,AUC was 0.8682 for SAA to distinguish merging bacterial infection,and the cut-off value was 72.10 mg/L with sensitivity of 94.29% and specificity of 65.71%. Conclusion SAA increases in AECOPD patients,and more obviously in AECOPD patients with bacterial infection. SAA may be used as a reliable biomarker not only to distinguish AECOPD patients from SCOPD patients ,but also distinguish merging bacterial infection during AECOPD.

Objective To investigate the effect of oncolytic adenovirus vector SG600-IL24expressing human melanoma differentiation associated gene-7 (mda-7/IL-24) on hepatocellular carcinoma cell lines with different metastatic potential of HepG2, SMMC7721, MHCC97L and normal liver cell line LO2. Methods The oncolytic adenovirus SG600-IL24 which carrying mda-7/IL-24 gene was transfected into hepatocellular carcinoma cell lines and normal liver cell line. The mRNA and protein expression of mda7/IL-24 in HepG2, SMMC7721, MHCC97L and LO2 cell lines was confirmed by RT-PCR,ELISA assay and Western blot respectively. MTT assay and flow cytometry were used to study tumor cell proliferation and cell cycle in vitro. Hoechst33258 and flow cytometry were studied to indicate the apoptosis effects. Results It was confirmed by RT-PCR, ELISA assay and Western-blot that the exogenous mda-7/IL-24 gene was highly expressed in HepG2, SMMC7721, MHCC97L and LO2 cell lines. MTT and apoptosis detection indicated that MDA-7/IL-24 can induce the growth suppression (the inhibition rate was 75% ±2. 5% ,86% ±3. 5% ,and promotes apoptosis ( the apoptosis rate was 56. 5% ± 4. 0% , 34. 4% ± 2. 0% , 43. 3% ± 2. 5%cell lines at G2/M phase ( the blocking rate was 35. 4% ± 4. 2% , 40. 5% ± 5. 0% , 42. 0% ± 5. 0%metastatic potential hepatocellular carcinoma cell lines but not in normal liver cell line.Conclusions Oncolytic adenovirus vector SG600-IL24 can selectively induce growth suppression, promote apoptosis in hepatocellular carcinoma lines in vitro but not in normal liver cell LO2.

Objective To assess the value of blood perfusion of thyroid nodules using contrastenhanced ultrasonography(CEUS). Methods Blood perfusion parameters of 78 preoperative patients with thyroid nodule were examined using CEUS. Microvessel density(MVD) in the thyroid nodule specimens was calculated by immunohistochemical staining using anti-factor CD34. Results Compared to papillary thyroid carcinoma (PTC) and nodular goiter (NG), there was significant differences in peak value(PEAK),maximum value of video signal intensity(Slmax), and mean value of video signal intensity(SImean) in thyroid nodule with diameter ＜ 1 cm ( P ＜ 0. 05 ), the MVD of thyroid nodules was not statistically significant ( P ＞ 0.05). There were significant differences in regional blood volume and MVD in thyroid nodule with diameter ≥ 1 cm between two groups ( P ＜ 0.05). Conclusions The characteristics of blood perfusion are dissimilar for thyroid nodules with different sizes and properties. The quantitative analysis with CEUS can provide valuable information for clinical diagnosis.

There has been an ongoing search for clinically acceptable methods for the accurate, efficient and simple diagnosis and prognosis of hepatocellular carcinoma (HCC). Optical spectroscopy is a technique with potential clinical applications to diagnose cancer diseases. The purpose of this study was to obtain the optical properties of HCC tissues and non-tumorous hepatic tissues and identify the difference between them. A total of 55 tissue samples (HCC tissue, n=38; non-tumorous hepatic tissue, n=17) were surgically resected from patients with HCC. The optical parameters were measured in 10-nm steps using single-integrating-sphere system in the wavelength range of 400 to 1800 nm. It was found that the optical properties and their differences varied with the wavelength for the HCC tissue and the non-tumorous hepatic tissue in the entire wavelength range of research. The absorption coefficient of the HCC tissue (1.48±0.99, 1.46±0.88, 0.86±0.61, 2.15±0.53, 0.54±0.10, 0.79±0.15 mm(-1)) was significantly lower than that of the non-tumorous hepatic tissue (2.79±1.73, 3.13±1.47, 3.06±2.79, 2.57±0.55, 0.62±0.10, 0.93±0.16 mm(-1)) at wavelengths of 400, 410, 450, 1450, 1660 and 1800 nm, respectively (P<0.05). The reduced scattering coefficient of HCC tissue (5.28±1.70, 4.91±1.54, 1.26±0.35 mm(-1)) and non-tumorous hepatic tissue (8.14±3.70, 9.27±3.08, 2.55±0.57 mm(-1)) was significantly different at 460, 500 and 1800 nm respectively (P<0.05). These results show different pathologic liver tissues have different optical properties. It provides a better understanding of the relationship between optical parameters and physiological characteristics in human liver tissues. And it would be very useful for developing a non-invasive, real-time, simple and efficient way for medical management of HCC in the future.

There has been an ongoing search for clinically acceptable methods for the accurate,efficient and simple diagnosis and prognosis of hepatocellular carcinoma (HCC).Optical spectroscopy is a technique with potential clinical applications to diagnose cancer diseases.The purpose of this study was to obtain the optical properties of HCC tissues and non-tumorous hepatic tissues and identify the difference between them.A total of 55 tissue samples (HCC tissue,n=38; non-tumorous hepatic tissue,n=17)were surgically resected from patients with HCC.The optical parameters were measured in 10-nm steps using single-integrating-sphere system in the wavelength range of 400 to 1800 nm.It was found that the optical properties and their differences varied with the wavelength for the HCC tissue and the non-tumorous hepatic tissue in the entire wavelength range of research.The absorption coefficient of the HCC tissue (1.48±0.99,1.46±0.88,0.86±0.61,2.15±0.53,0.54±0.10,0.79±0.15 mm-1) was significantly lower than that of the non-tumorous hepatic tissue (2.79±1.73,3.13±1.47,3.06±2.79,2.57±0.55,0.62±0.10,0.93±0.16 mm-1) at wavelengths of 400,410,450,1450,1660 and 1800 nm,respectively (P＜0.05).The reduced scattering coefficient of HCC tissue (5.28±1.70,4.91±1.54,1.26±0.35 mm-1) and non-tumorous hepatic tissue (8.14±3.70,9.27±3.08,2.55±0.57 mm-1) was significantly different at 460,500 and 1800 nm respectively (P＜0.05).These results show different pathologic liver tissues have different optical properties.It provides a better understanding of the relationship between optical parameters and physiological characteristics in human liver tissues.And it would be very useful for developing a non-invasive,real-time,simple and efficient way for medical management of HCC in the future.

Objective To explore the mechanism of melanoma differentiation associated gene-7(mda-7) in combination with adriamycin(ADM) killing the HCC HepG2 cells and reversing their multidrug resistance (MDR). Methods The experiment was conducted in three groups including the combined group, ADM group and mda-7 group. MTT assay and FCM were used to determine the differences among the 3 groups and clarify the reversing effect of combined treatment on multidrug resistance of the tumor cells. Expression levels of MDR-1, STAT-3, BCL-2, BAXmRNA were determined with real-time PCR. Western blotting was performed to observe the changes of proteins gp-l70, stat3,P-stat3, PKB, bcl-2,bax in all 3 groups. Result After transfection with 100VP/cell Ad. mda-7,the growth suppression rate of HepG2 treated by ADM (1.5 mg/L) rose from 17.46% to 79. 5%.According to the changes, killed HepG2 cells were increased by a factor of 4.55. times. MDR-1 mRNA was decreased from (16.49 ± 0. 11) to (5.48±0.05) and STAT-3 mRNA increased from (13.17±0. 08) to (21. 57±0. 11)(P＜0.05). Western blotting also showed that P-170 and PKB was decreased and the phosphorylation-stat-3 increased after the combined treatment. Conclusion Ad.mda-7 can reverse the multidrug resistance HepG2 cells. It inhibits the expression of MDR-1 mRNA,then arrests PKB protein and the signaling pathway of active stat-3 to induce apoptosis of HCC cells.

Objective To analyze the correlation of acute pancreatitis with hyperlipemia and C reactive pro-tein. Methods 42 patients with acute pancreatitis with hyperlipemia were divided into two groups of SAP group and MAP group under the diagnostic code. The blood fat and CRP were compared between the two groups, also the scores of APACHE Ⅱ , Ranson and CT were measured. Results The CRP and TG in group SAP compared with those in group MAP had significant difference(P<0.01),but the CHOL has no-difference;the scores of APACHEⅡ , Ranson and CT after control lipid in 42 patients were significantly' different( P < 0.05). Conclusion Hyperlipe-mia is one risk factors of the AP;combined with the CRP, it can be one evaluating index of the severity.