Age- and training-related changes in the collagen metabolism of rat skeletal muscle

Summary The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative proportion of type I collagen increased and that of type III collagen decreased with age, suggesting a more marked contribution by type I collagen to the agerelated accumulation of total muscular collagen. The results show that collagen biosynthesis decreases with maturation and that life-long endurance training maintains a higher level of biosynthesis in slow muscles.     

An association of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and common carotid atherosclerosis

Plasma homocysteine (Hcy) concentration has been shown to be influenced by a mutation in the gene coding methylenetetrahydrofolate reductase (MTHFR). Although plasma Hcy is related to atherosclerotic disorders, conflicting results have been reported about the association between MTHFR gene polymorphism and sclerotic lesions of the common carotid arteries. The effect of age–gene interaction on carotid arterial remodeling was investigated in elderly subjects with several risk factors for atherosclerosis. We evaluated sclerotic lesions of the common carotid arteries by ultrasonography in 326 patients (mean age ± standard deviation, 73 ± 12 years) and studied relations among the known risk factors for atherosclerosis, including MTHFR gene polymorphism and its interactions with age and sex. Of the 326 subjects studied, 136 had MTHFR genotype CC, 136 genotype CT, and 54 genotype TT. The three groups did not differ with respect to background factors such as age, history of cigarette smoking, blood pressure, lipids or uric acid, or in the incidence of atherosclerotic diseases. Spearman's rank correlation revealed a significant relationship between gender, age, Brinkman index, systolic blood pressure, triglycerides, HDL-cholesterol (HDL-C), uric acid, and MTHFR gene polymorphism. Multiple regression analysis using intima-media complex thickness (IMT) as a criterion variable and risk factors, including MTHFR gene polymorphism as explanatory variables showed that MTHFR gene polymorphism (P = 0.039) was a significant independent explanatory variable for IMT, along with gender (male) (P < 0.001), age (P < 0.001), systolic blood pressure (SBP) (P = 0.047), total cholesterol (T-C) (P < 0.001), and HDL-C (P < 0.001). Furthermore, a general linear model analysis revealed that interaction between age and MTHFR gene polymorphism was significantly associated with IMT, independently of age, SBP, T-C, and HDL-C in male subjects. However, age–gene interaction was not observed in female subjects. The findings of the present study confirm an association between MTHFR gene polymorphism and common carotid atherosclerosis in the Japanese population and further support the role of risk factor–gene interaction in common carotid atherosclerosis. Received: May 14, 2001 / Accepted: June 8, 2001     

Are there age induced morphologic variations of the superior glenoid labrum? About 100 shoulder arthroscopies

Different anterosuperior aspects of the glenoid labrum have already been described and are thought to be normal anatomical variations. The goals of this study were first to characterize these anterosuperior labral morphologies and then to analyze their variations in function of the patients’ age. One hundred shoulder arthroscopies were recorded to study the macroscopic characteristics of the anterosuperior labrum of the glenohumeral joint and its relationships with the proximal insertion of the tendon of the long head of the biceps. Then, patients were divided into two groups in function of their age (below and over 30 years old). Morphological modifications of the labrum were found in function of the age of the patient with an increase of the nonpathologic “mobile labrum” type after 30 years (P=0.0423). Therefore a mobile and loosely attached superior labrum should not always be considered as abnormal, especially in case of patient older than 30 years.     

Physical work capacity in dynamic exercise with differing muscle masses in healthy young and older men

Ten young (aged 23–30 years) and nine older (aged 54–59 years) healthy men with similar estimated limb muscle volumes performed, in random order, three different types of ergometer exercise tests (one-arm cranking, two-arm cranking, and two-leg cycling) up to the maximal level. Values for work load (WL), peak oxygen consumption , peak heart rate (HR), peak ventilation , respiratory gas exchange ratio (R), recovery blood lactate concentration [La^–], and rating of perceived exertion (RPE) were compared between the age-groups in the given exercise modes. No significant age-related differences in WL, peak , peak HR, R, [La^–], or RPE were found in one-arm or two-arm cranking. During one-arm cranking the mean peak was 1.65 (SD 0.26)1 · min^–1 among the young men and 1.63 (SD 0.10)1 · min^–1 among the older men. Corresponding mean peak during two-arm cranking was 2.19 (SD 0.32)1 · min-1 and 2.09 (SD 0.18)1 · min^–1, respectively. During one-arm cranking peak was higher (P < 0.05) among the older men compared to the young men. During two-leg cycling the young men showed higher values in WL (P < 0.001), peak (P < 0.001), and peak HR (P < 0.001). The mean peak was 3.54 (SD 0.24)1 · min^–1 among the young men and 3.02 (SD 0.20)1 · min^–1 among the older men. Corresponding mean peak HR was 182 (SD 5) beats · min^–1 and 170 (SD 8) beats · min^–1, respectively. During two-leg cycling, peak , R, [La^–], and RPE did not differ between the two age-groups. In summary, the older men with similar sizes of estimated arm and leg muscle volumes as the young men had a reduced physical work capacity in two-leg cycling. In one-arm or two-arm cranking, no significant difference in work capacity was found between the age-groups. These results indicate, that in healthy men, age, at least up to the 6th decade of life, is not necessarily associated with a decline in physical work capacity in exercises using relatively small muscle groups, in which the limiting factors are more peripheral than central.     

Development of nocturia in relation to health, age and the menopause

Objectives:To analyse the relationship between nocturia, age, the menopausal transition, parturition and hormone replacement treatment (HRT) in women.Material and methods:A questionnaire study was carried out in 3669 randomly selected women (out of 6000 invited) in the County of Jämtland, Sweden. Questions were asked about health, the occurrence of somatic diseases and symptoms, habits, health care and medication.Results:In univariate analyses age, menopausal state and HRT, but not parturition, were associated with increased nocturia. In a multiple logistic regression analysis, independent correlates for two or more nocturnal micturition episodes versus no more than one episode were: health, poor versus good 2.9 (2.1–3.8); <5 years after the menopause versus before 1.8 (1.3–2.5); 5–9 years after the menopause versus before 2.1 (1.5–3.0); ≥10 years after the menopause versus before 3.1 (2.3–4.2). Age and HRT were deleted by the logistic regression model.Conclusion:The present data indicate that menopausal state, but not age, parturition and HRT are independent correlates of nocturia in 40–64-year-old women.     

German experimental hepatitis B vaccine — Influence of variation of dosage schedule,sex and age differences on immunogenicity in health care workers

Summary Of the medical staff of our hospital 217 members at high risk for hepatitis B were immunized with an experimental hepatitis B vaccine and anti-HBs titers used to study the influence of two dosage schedules, age, and sex on immunogenicity. Participants were 34 years of age (mean; range, 20–61); they were divided into two groups and vaccinated three times. Group A received 42 µg HBsAg for each vaccination. Group B received 84 µg for the first and 21 µg for the second and third vaccinations. The seroconversion rate was 32.7% after the first, 78.8% after the second, and 95.7% after the third vaccination. The participants who failed to produce anti-HBs titer (3 IU/l;n=9) or whose anti-HBs titers were below 50 IU/l (n=31) were vaccinated a fourth time. Only mild side effects of injections were observed in a third of all participants, usually in the form of a sore arm.Between groups A and B there were no significant differences as far as the seroconversion rate and anti-HBs titer were concerned. Nonresponders plus low-responders accounted for 19%. Female participants produced a markedly higher anti-HBs titer than males, and the female/male ratio among non- and low-responders was 1:2; among nonresponders, 1:2.5. There was a negative correlation of the anti-HBs titer with the age of the participants. These results not only have practical consequences for revaccination policy, but also offer the opportunity to further study the genetic regulation of the immune response to a complex peptide antigen in man.Abbreviations anti-HBc antibody to hepatitis B core antigen - anti-HBe antibody to hepatitis B e antigen - anti-HBs antibody to hepatitis B surface antigen - HBsAg hepatitis B surface antigen - IU/l international units per liter - MSD Merck, Sharp, and Dohme     

Effects of ouabain,age and K-depletion on K-uptake in rat soleus muscle

The relationship between the number of³H-ouabain binding sites and the Na, K-pump mediated K-uptake has been characterized in rat soleus muscle. By brief exposure to³H-ouabain (1×10^–6–1×10^–5mol/l) in vitro, it could be measured that 19–94% of the ouabain binding sites had been occupied. This was associated with a proportionate decrease in the ouabain suppressible K-uptake indicating that under strictly standardized conditions, measurements of³H-ouabain binding sites quantify functional Na,K-pumps.When 3 week old rats were K-depleted for a further week followed by K-repletion 2 h before measurements, the³H-ouabain binding site concentration was 61% lower than in age-matched control soleus muscles. However, the ouabain suppressible K-uptake was only reduced by 35% partly because intracellular Na remained higher in the muscles obtained from K-depleted rats.From the 1st to the 4th week of life, the³H-ouabain binding site concentration increased 2.9-fold. In contrast, the ouabain suppressible K-uptake decreased by a factor 3.5. Accordingly, in muscles from 1 week old rats, the ouabain suppressible K-uptake per³H-ouabain binding site was 10-fold higher than in muscles from 4 week old rats. This difference could not be accounted for by changes in intracellular Na, total or extracellular water. It may be related to differentiation and change in structure.On the basis of the present results and those reported in the literature for mouse and frog skeletal muscle it was calculated that under resting conditions at 30°C in vitro, isolated skeletal muscles only utilize between 3 and 25% of their total capacity for active Na, K-transport. Therefore, variations in the total Na, K-pump capacity may not readily be detected in measurements of the ouabain suppressible rate of K-uptake.     

桥本氏甲状腺炎患者年龄、性别分布及自身免疫抗体水平分析

目的:分析桥本氏甲状腺炎(HT)在不同年龄男女性患者分布差异及相关抗体水平变化特点。方法:2014-01-01—2018-12-31五年间本院收治的HT患者共2705例,先按年龄分为儿童组(n=32)、青春期组(n=135)和成人组(n=2538),再将成人组中女性分为≤50岁组(n=1645)及>50岁组(n=519)两组,比较不同年龄组HT男女性占比差异,分析不同年龄组以及50岁前后女性甲状腺过氧化物酶抗体(TPOAb)和甲状腺球蛋白抗体(TgAb)的水平变化。结果:在三年龄组中,HT总病例数以成人组最多,儿童组较少。各年龄组间男性、女性HT占比差异有统计学意义(P<0.01);各年龄组内女性占比均显著高于男性,尤以成人组女性占比最高(P<0.01)。三年龄组间TPOAb、TgAb水平有显著统计学意义(均P<0.01)。青春期组及成人组TPOAb水平均低于儿童组(P<0.01),成人组与青春期组TPOAb水平差异无统计学意义(P>0.05);青春期组TgAb水平低于儿童组(P<0.01),儿童组与成人组间、青春期组与成人组间TgAb水平的差异均无统计学意义(P>0.05)。≤50岁与>50岁女性的TPOAb和TgAb水平比较均无统计学差异(P>0.05)。结论:成年人(>18岁)HT明显多于非成年人,且女性占比显著高于男性。TPOAb下降可能是成人HT的内分泌影响因素之一。     

The effect of 2,3-dimercaptopropane sodium sulfonate on mercury retention in rats in relation to age

The effectiveness of DMPS (sodium 2,3-dimercaptopropane-1-sulfonate) in reducing inorganic mercury retention was studied in 2-, 6-, and 28-week-old albino rats. ²⁰³Hg was administered IP. The chelating agent DMPS was administered by IP injection at a dose of 250 mol/kg body weight three times, 1 day after ²⁰³Hg administration and at 24 h intervals thereafter. The whole body retention determined 1, 2, 3, and 6 days after ²⁰³Hg administration showed that DMPS decreased the body retention of mercury in all age groups, being about twice as effective in adult compared to suckling rats. The reduced effectiveness was due to the reduced efficacy of DMPS in reducing kidney retention in young animals. In other organs the effectiveness of DMPS was not age dependent. These and previous results obtained with different chelating agents and other metals indicate that age might be an important factor in chelation therapy in general.     

矮小儿童骨龄骨密度值与年龄身高体重的相关性

目的研究矮小儿童的骨龄、骨密度值与年龄、身高、体重的相关性。方法选取2016年1月至2018年10月于广州市越秀区妇幼保健院进行咨询与治疗的64例矮小儿童作为研究对象,记录入组儿童的年龄、性别、身高以及体重等一般资料,同时检测入组儿童的超声骨密度,并通过腕骨平片评估其骨龄,分析不同骨龄、骨密度值与年龄、身高、体重的关系。结果入组儿童的实际年龄与骨密度、骨龄呈正相关(男童r=0.658、0.919,女童r=0.641、0.906);入组儿童的身高与骨密度、骨龄呈正相关(男童r=0.561、0.326,女童r=0.586、0.349);入组儿童的体重与骨密度、骨龄呈正相关(男童r=0.340、0.314,女童r=0.395、0.282)。结论矮小儿童的骨龄、骨密度值与其年龄、身高、体重均呈正相关关系,在临床诊断和治疗中,利用骨龄及骨密度进行指导,能够产生较为显著的效果,可以为矮小儿童的评估和预测提供更加科学的指标。