Effect of endurance training on muscle fiber type composition and capillary supply in rat diaphragm

Summary Muscle fiber type composition and capillary supply in rat diaphragm were investigated after 14 weeks of endurance training: body weight and muscle fiber area were significantly decreased, the muscle fiber type composition, capillary to fiber ratio and number of capillaries around each fiber type were unchanged, and the capillary density and number of capillaries around each fiber relative to fiber type areas were significantly increased. These small fiber areas and increased capillary supplies in the trained rats would facilitate oxygen transport to all parts of the muscle fiber during exercise. It is concluded that the changes observed in the trained rat diaphragm appear to enhance the capacity for oxidative metabolism.     

Drug resistance in the fission yeast Schizosaccharomyces pombe: pleiotropic mutations affecting the oleic acid and sterol composition of cell membranes

Summary The whole cell lipid and sterol content of the drug resistant strains cyh1, cyh3 and cyh4 was compared with that of wild type by thin layer and gas liquid chromatography and by UV spectrophotometric analysis. The cyh3 and cyh4 strains had a decreased content of the unsaturated 18:1 fatty acid oleic acid, a decreased content of ergosterol and an increased content of 24,28 dehydroergosterol with respect to wild type. The cyh1 strain, however, only showed a decreased content of ergosterol and an increased content of 24,28 dehydro-ergosterol when compared to wild type.     

Differences in distribution of myofiber types between the supraspinatus and infraspinatus muscles of sheep

Background: The m. supraspinatus stabilizes the shoulder joint to bear the body weight, and the m. infraspinatus assists in extension and flexion of the joint in sheep. Postural muscles have many SO myofibers, whereas locomotory muscles have numerous fast-twitch myofibers. In sheep the distribution of myofiber types within the two muscles, necessary for a better understanding of postural function, remains to be clarified. Methods: Muscle samples were removed from the whole transverse sections of the dorsal, middle, and ventral compartments of the m. supraspinatus and m. infraspinatus of sheep. Myofibers were classified into FG, FOG, SO-1, and SO-2 myofibers by histochemical methods. Results: The distribution of SO myofibers changed more greatly in the m. supraspinatus (15.0–99.1%) than in the m. infraspinatus (24.5–62.3%). SO myofibers were concentrated markedly in the caudal and deep regions near the spine and fossa of the scapula in the m. supraspinatus and distributed more in the medial part than in the lateral part in the m. infraspinatus. Such changes were caused by increases in percentage of SO-2 myofibers and not SO-1 myofibers. The craniolateral regions of the m. supraspinatus and the caudolateral regions of the m. infraspinatus had many fast-twitch (FOG plus FG) myofibers suited for rapid extension and flexion of the shoulder joint. Conclusions: The m. supraspinatus has the compartmentalized, deep, and caudal regions occupied by SO myofibers, which seem to be specialized for maintenance of the joint extension. The medial region of the m. infraspinatus may assist in the joint stabilization. © 1995 Wiley-Liss, Inc.     

The effect of pentobarbital anaesthesia upon the extracellular fluid volume in the dog,studied by continuous infusion and single injection methods

The effect of pentobarbital anaesthesia on the volume and ionic composition of the extracellular space was studied in adult male mongrel dogs with permanent catheters in aorta and pulmonary artery. The extracellular fluid volume (Q ^ec ) was determined with: a) methods based on equilibration of the indicator throughoutQ ^ec by continuous infusion; b) methods based on the assumption that after a single injection of indicator the plasma indicator concentration equals extracellular indicator concentration as long as the log plasma indicator concentration-time curve is linear; c) a single injection method based on a closed flow system model with a single inflow and a single outflow orifice. The measurements were made before and 30 and 90 min after induction of anaesthesia. Thirty minutes after induction of anaesthesiaQ ^ec as determined with the method sub a, had decreased by about 10% and remained so during the following 60 min. The values ofQ ^ec as calculated by the method sub c fairly agreed withQ ^ec as determined with the method sub a and also showed a decrease ofQ ^ec during pentobarbital anaesthesia. The procedures sub b overestimatedQ ^ec and yielded a seemingly higherQ ^ec during anaesthesia, because the boundary conditions for these procedures do not apply. The haemoglobin concentration decreased by about 10% and the lactate concentration by about 50%. The phosphate concentration increased by about 25% while the other electrolyte concentrations (Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl^–, HCO ₃ ^– ) did not change. A respiratory acidosis developed during the first 30 min and almost disappeared in the following 60 min. Possible explanations for the pentobarbital-induced concentration ofQ ^ec are discussed.     

Effects of tibolone on body composition in postmenopausal women: a 1-year follow up study

Objective: We investigated the effects of 1-year tibolone treatment on body weight, body composition and indices of android obesity in postmenopausal women.

Methods: Forty-four postmenopausal women participated in this open-label controlled study; mean age was 51.8 ± 2.21 years and all women were menopausal for 3.8 ± 1.40 years. Twenty-two of them started taking 2.5 mg tibolone (TIB) daily for 1 year, whereas the remaining 22 served as age-matched controls. All subjects underwent a structured interview, physical examination, body composition measurements performed by dual-energy X-ray absorptiometry (DXA) — Hologic QDR 4500 A, as well as bioelectrical body impedance analysis (BI) — Tanita TBF-215, Japan.

Results: The TIB group did not significantly increase their weight (+0.4 kg), while the non-treated controls increased their mean weight by 1.4 kg (p = 0.046). In the TIB group, DXA showed a non-significant body fat decrease by a mean of 0.5 kg and a non-significant lean mass increase by 0.8 kg, while in the control group, fat mass increased by 1.7 kg (p = 0.032) and lean mass did not change. BI revealed that the TIB group had lost some fat (≈0.6 kg, n.s.) and put some free-fat mass (≈1.0 kg, p = 0.048) without changes in total body water. The control group put on some fat (≈1.1 kg, p = 0.042) and lost some body water (≈0.4 kg, n.s.).

Conclusion: Results from both methods of measuring body composition show a similar trend: a decrease in fat mass and an increase in lean mass in TIB treated subjects. From the body composition perspective, tibolone may be regarded as a preferential alternative to conventional hormonal therapy (HT) in postmenopausal women.     

武警某部战士,学员体脂成分的研究

目的：评价武警阅队成员体脂成分现状,为科学选兵,合理制定训练计划和正确指导膳食营养提供资料,方法：以皮褶厚度测量法推算体脂指标。结果：武警甘部战士,学员在多项体脂指标方面都优于同龄地方大学生和通讯兵某部战士,对体脂百分率评价,男性均值尚属正常,肥胖占２．２％;女性均值超标了２．６６％,肥胖占１２．４％,结论：武警某部战士、学员体脂成分现尚好,但应注意严格选兵标准,科学调整膳食,加大耐力性训练力度。     

A comparison of skinfold anthropometry and dual-energy X-ray absorptiometry for the evaluation of body fat in cirrhotic patients

BACKGROUND AND AIMS: Skinfold anthropometry has been used to evaluate the nutritional status in cirrhosis. Such estimates are based on the calculations which derive from healthy subjects and may not apply to cirrhotic patients. We aimed to calculate the limits of agreement between Skinfold anthropometry (SA) and dual-energy X-ray absorptiometry (DXA) in estimating body fat in cirrhotics. METHODS: Forty cirrhotic patients were studied by both methods. The limits of agreement were estimated by the Bland and Altman method. RESULTS: Percentage body fat was similar when measured by DXA and SA (29.6 +/- 9.2 vs 28.9 +/- 7.5 %). Body fat mass was also similar (20.3 +/- 8.4 vs 20.3 +/- 7.7 kg). The limits of agreement between DXA and SA measurements were -7.04 (95%CI: -9.55 to -5.2) +8.56 (95%CI: +10.7 to +6.4.) in the assessment of percentage body fat and -5.32 (95%CI: -6.77 to -3.87) +5.24 (95%CI: +3.79 to +6.69) in the assessment of fat mass. CONCLUSION: Percentage body fat can be evaluated by SA or DXA with a difference of less then 5% in the majority of cirrhotic patients without overt fluid retention. This result is important when considering the large applicability of SA.