Research advances in muscle stem cells and sarcopenia / 中华老年医学杂志

Sarcopenia is characterized by a loss of skeletal muscle mass and a decrease in muscle strength and function.The major etiological factors of sarcopenia include lack of exercise,decline of neuromuscular function,malnutrition and so on.Sarcopenia is associated with decreased numbers and function of muscle stem cells(also known as satellite cells).Muscle stem cells have a strong ability of self-renewal,with multi-potency,immune privilege,and antioxidant and anti-inflammatory properties, and are capable of promoting skeletal muscle regeneration.The mechanisms underlying cell proliferation,differentiation and self-renewal of satellite cells are not clear,but the number and activity of satellite cells are related to sarcopenia.Satellite cells work together with a variety of proliferation and differentiation factors to regulate muscle cell formation and muscle repair.Especially noteworthy is that p38α binds to a large number of myogenic gene promoters to regulate the proliferation and differentiation of satellite cells.In animal experiments,muscle stem cell therapy has shown regeneration and repair of muscle cells.Studies on changes at the molecular and gene levels in muscle fibers and their environment will be of great significance for the prevention and treatment of muscular disorders in the elderly.

Study on the changes in muscle mass in elderly people of different ages in Hangzhou / 中华老年医学杂志

Objective To investigate the changing characteristics of muscle mass by dual energy X-ray absorptiometry (DEXA) in middle aged and elderly people with different ages.Methods This study included 343 healthy people aged 50-89 years (178 males and 165 females).Subjects were divided into 4 groups:aged 50-59,60-69,70-79,and 80-89 years group.Fat-free body mass (FFM),the appendicular lean body mass (aLM),trunk lean mass (tLM) were measured by DEXA.The aLM/body weight (Wt％) and aLM index (ASMI) were calculated by DEXA.Results The tLM in both gender was decreased in aged 80-89 years group than in aged 50-59 years group [male (10.6± 1.8) kg vs.(18.4±2.9) kg,female (7.1±1.2) kg vs.(14.8±2.1) kg,F=5.7 and 7.8,P＜ 0.01].The average ASMI in both gender was decreased in aged 70-79 and 80-89 years groups than in aged 50-59 years groups [male (5.5±0.4) kg/m2,(4.9±0.7) kg/m2 vs.(6.1±0.5) kg/m2,female (4.3±0.4) kg/m2,(3.9±0.5) kg/m2 vs.(4.8±0.6) kg/m2,F=24.9 and 9.6,both P＜0.01].The quality of muscle mass was decreased with aging in the elderly.Conclusions Ageing is an important risk factor for sarcopenia in the elderly.DEXA can be used to evaluate the muscle mass in middle aged and the elderly,and ASMI can be used as a reliable measurement index.

Gliquidone versus metformin: differential effects on aorta in streptozotocin induced diabetic rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Diabetic cardiovascular complication is a major cause of mortality in type 2 diabetic patients. Hyperglycemia markedly increases the risk of cardiovascular disease. Endothelial dysfunction is common in type 2 diabetes mellitus (DM) and is an early indicator of diabetic vascular disease. Therefore, it is necessary to identify the effect of different hypoglycemic agents on vascular endothelium. The aim of the study was to examine and compare the effects of metformin and gliquidone on atherosclerotic lesions in streptozotocin-induced diabetic rats.</p><p><b>METHODS</b>Forty male Sprague-Dawley rats (age, 8 weeks; weight, 180-200 g) were included in this study and fed with a normal chow diet for 1 week. Rats (n = 10) served as the normal control group (NC group) were fed with a normal chow for another 2 weeks and received an injection of saline. The rest 30 rats fed with a high-fat diet for 2 weeks and injected streptozotocin were randomly assigned to three groups (n = 10 rats per group) as follow: type 2 DM group (DM group), DM + gliquidone group (GLI group) and DM + metformin group (MET group). Five weeks later, all rats were fasted overnight and taken tail blood samples for biochemical determinations. Then rats in the NC and DM groups were administrated with normal saline, while rats in the MET and GLI groups were administrated with metformin (100 mg/kg) or gliquidone (10 mg/kg), respectively. All medicines were given via intragastric administration for 8 weeks. After 16 weeks, plasma triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) were measured. The aortic arch was isolated from diabetic rats and was assessed by pathological sectioning using H&E staining.</p><p><b>RESULTS</b>Metformin treatment prevented weight gain ((315.80 ± 52.16) g vs. (318.70 ± 68.48) g, P = 0.773), improved plasma TG, HDL-C and LDL-C levels (P = 0.006, 0.003, 0.001, respectively, all P < 0.05). However, gliquidone showed no significant effects on plasma TG and TC levels (P = 0.819, 0.053, respectively). LDL-C and HDL-C in the GLI group changed ((0.46 ± 0.10) mmol/L vs. (0.36 ± 0.14) mmol/L, P = 0.007; (0.99 ± 0.27) mmol/L vs. (1.11 ± 0.18) mmol/L, P = 0.049). Both metformin and gliquidone treatment lowered blood glucose levels (P = 0.001, 0.004, respectively, P < 0.05). Under light microscopy, no changes were observed in the aortic wall structure of each layer; the intima was smooth and the membrane elastic fibers were normal in the NC group. In the DM group, the aortic wall structure was unclear, the intima was thickened with irregular intima, and membrane elastic fibers collapsed. The aortic intima in the MET and GLI groups was smoother compared with the DM group, but the endothelial structure of the MET group was closer to that of the NC group.</p><p><b>CONCLUSIONS</b>Both metformin and gliquidone have anti-atherosclerotic effects. But the endothelial structure of the MET group was closer to that of the NC group. Metformin and gliquidone therapy can reduce serum level of LDL-C and increase level of HDL-C, whereas gliquidone therapy did not lose weight and decrease serum level of TG. These data may have important implications for the treatment of patients with type 2 DM.</p>

Comparison of changes of intestinal microecology between different age groups in the healthy people / 中华老年医学杂志

Objective To analyze the diversity of intestinal microecology in different healthy age groups and explore the relationship between age and the composition of intestinal microflora.MethodsFecal samples were collected from the children,adult and elderly groups.The main intestinal microflora were cultured and quantified,and the qualitative and quantitative changes in the level of category were determined by fluorescence quantitative PCR.The Bifidobacteria/Enterobacteriaceae (B/E) ratio reflexing intestinal colonization resistance was also calculated.Results The germiculture of fecal samples indicated that the counts of Bifidobacteria and Lactobacillus (P＜0.01 and P＜0.05,respectively) were significantly lower in the adult and aged groups than in children group.The number of Bacteriodes and Enterobacteriaceae in the elderly group were higher than in the children and the adult groups (all P＜0.01).The counts of Enterococcus were increased in the adult and the aged groups (P＜0.05 and P＜0.01) compared with the children group,and were higher in the aged group than in the adult group (P＜0.05).The B/E ratio was significantly decreased in the aged group (0.88-±-0.13) as compared with the children (1.15±0.15) and the adult groups ( 1.01± 0.20) ( both P ＜ 0.01).The diversities of Bifidobacteria,Bacteriodes,Enterobacteriaceae and B/E ratio by fluorescent quantification PCR were consistent with the results by germiculture technology.The diversity of Lactobacillus (P＜0.01) between the children and the aged groups as well as between the children group and the adult group significantly improved (P＜0.01 and P＜0.05 ) in PCR compared with the germiculture technology. ConclusionsThe numbers of intestinal Bifidobacterium and Lactobacillus are decreased with lower colonization resistance,while the numbers of Bacteriodes,Enterobacteriaceae and Enterococcus are increased with aging.

The effect of atorvastatin on lowering lipids in elderly patients with type 2 diabetic mellitus plus hyperlipidemia / 中华老年医学杂志

Objective To observe the effect of atorvastatin on lowering blood lipid in patients with type 2 diabetic mellitus plus hyperlipidemia. Methods All patients took 10 mg atorvastatin every night for 12 months. The levels of total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), serum alanine aminotransferase (ALT), aspartate aminotransferase fAST), fasting blood glucose (FBG), creatinine (Cr), intima media thickness (IMT) of carotid artery (CA), common lilac artery (CIA) and femoral artery (CFA) were examined before and 3, 6, 9, 12 months after the treatment. Results TC [(5.11±0.94) vs. (4.46±0.98) mmol/L, P<0.01] and LDL-C [(3.01±0.78) vs. (2.55± 0.83) mmol/L, P<0. 01] were significantly decreased one year after the treatment. At different detection time points, the levels of LDL-C all reached the therapy standard (<2.59 mmol/L). But TC reached the therapy standard (<4.04 mmol/L) only at nine months after the treatment. IMT of CA, CIA and CFA were at the decreased tendency (P>0. 05). No significant changes were observed in ALT, AST and Cr. Conclusions Atorvastatin may significantly decreased the level of blood lipid with little adverse effect in elderly patients with type 2 diabetic mellitus plus hyperlipidemia, and it also has the effect of protecting the vascular intima.

Relationship between vasoactive substance and blood pressure in old patients with hypertension / 中华急诊医学杂志

Objective To observe the relationship between vasoactive substances and blood pressure in old patients with hypertension.Method Venous blood was drawn from 35 old hypertension patients when blood pressure was normal and abnormal,respectively.Epinephrine(E),norepinephine(NE),endothelins(ET),angiotensin ll (Angll) and ealcitonin-gene-retated peptide were determined by radio-immunity.The above five cytokines were also determined in 33 old healthy people.The cytokines levels were compared between the normal and abnormal blood pressure in hypertension patients and also between the old hypertension patients and healthy persons.The correlation between blood pressure and cytokines were analyzed.Results The level of ET,Angll,E and NE were obviously increased in old hypertension patients when their blood pressure was abnormal,while CGRP obviously decreased.No difference was found in the five cytokines between two groups when the blood pressure were normal.The correlation analysis showed that systolic pressure had positive correlation with ET,AnglI and E(r=0.304,0.337,0.587,P=0.031,0.019,0.036)and negative correlation with CGRP(r=-0.416,P=0.028)in old hypertension patients when the blood pressure was abnormal.And the diastolic pressure had positive correlation with AnglI and E(r=0.357,0.333;P=0.039,0.028).ET had positive correlation with Angll and E(r=0.361,0.315;P=0.041,0.029).Conclusion The levels of vasoaetive substances significantly changed in old hypertension patients with the blood pressure change.Among those cytokines,the substances that contract blood vessel increased most obviously.The vasoactive substances played an important role in the progress of blood pressure rising.