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1.
The effects of whole body vibration on humans: dangerous or advantageous?   总被引:2,自引:0,他引:2  
The effects of whole body vibration (WBV) have been studied extensively in occupational medicine. In particular, it has been shown that when the body undergoes chronically to whole body vibrations spinal degeneration is likely to be one of the deleterious outcomes. Low back pain has been shown to be the leading major cause of industrial disability in the population under the age of 45 years and has been linked to whole body vibration exposure encountered in some industrial settings. Whole body vibration has been recently purposed as an exercise intervention suggesting its effectiveness in increasing force-generating capacity in lower limbs and low back. It has also been reported to be an effective non-pharmacological intervention for patients with low back pain. Relatively short exposure to whole body vibration has been also shown to increase the serum levels of testosterone and growth hormone. The combined effects on the neuromuscular system and endocrine system seem to suggest its effectiveness as a therapeutic approach for sarcopenia and possibly osteoporosis. Due to the danger of long-term exposure to whole body vibration, it is important to develop safe exercise protocols in order to determine exercise programs for different populations.  相似文献   

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Carnosine (Carn) occurs in high concentrations in skeletal muscle is a potent physico-chemical buffer of H+ over the physiological range. Recent research has demonstrated that 6.4 g.day−1 of β-alanine (β-ala) can significantly increase skeletal muscle Carn concentrations (M-[Carn]) whilst the resultant change in buffering capacity has been shown to be paralleled by significant improvements in anaerobic and aerobic measures of exercise performance. Muscle carnosine increase has also been linked to increased work done during resistance training. Prior research has suggested that strength training may also increase M-[Carn] although this is disputed by other studies. The aim of this investigation is to assess the effect of 10 weeks resistance training on M-[Carn], and, secondly, to investigate if increased M-[Carn] brought about through β-ala supplementation had a positive effect on training responses. Twenty-six Vietnamese sports science students completed the study. The subjects completed a 10-week resistance-training program whilst consuming 6.4 g.day−1 of β-ala (β-ALG) or a matched dose of a placebo (PLG). Subjects were assessed prior to and after training for whole body strength, isokinetic force production, muscular endurance, body composition. β-Alanine supplemented subjects increased M-[Carn] by 12.81 ± 7.97 mmol.kg−1 dry muscle whilst there was no change in PLG subjects. There was no significant effect of β-ala supplementation on any of the exercise parameters measured, mass or % body fat. In conclusion, 10 weeks of resistance training alone did not change M-[Carn].  相似文献   

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This study deals with the effects of post (12 or 18 months) whole body continuous (2 years) exposure of rabbits to 650 MHz electromagnetic fields (EMF) that are characteristic of those produced by broadcasting stations, on body weight and body mass, on the morphology of liver, spleen and brain, and on apoptosis rates and glycogen distribution in the liver. Two groups of rabbits were continuously exposed for 2 years to EMF of 650 MHz followed by 12 months (group 1) or 18 months (group 2) of post-exposure; a third group (group 3) was sham exposed. It was shown that the changes in apoptosis rates were conditional during the time of exposure, but not on a specific organ and that the whole body continuous exposure gave rise to modifications whose types and intensities were related to the time of post-exposure (12 or 18 months, respectively), the type of organ, and the individual animal. A number of effects were observed only in group 1, and not in group 2, which suggests some kind of adaptive response or of long-term recovery in the rabbits following continuous exposure to 650 MHz EMF.  相似文献   

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The blood pressure responses to an acute and long-term (three months) whole-body cryotherapy (WBC) were measured in men and women. Acute cold exposure (−10°C, −60°C, −110°C) increased both systolic and diastolic blood pressures temporarily. Neither significant gender differences nor adaptation in blood pressures were found during WBC. The variation of individual responses to the acute and long-term WBC was wide.  相似文献   

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Chronic treatment of rats with the 2-adrenergic agonists clenbuterol and fenoterol over 16–19 d raised energy intake, expenditure, and body weight gain but did not affect fat or energy deposition, and body protein gain was increased by 50 and 18%, respectively. Both drugs increased the protein content and mitochondrial GDP-binding capacity of brown adipose tissue. Clenbuterol did not affect plasma insulin, growth hormone, or triiodothyronine levels, although insulin levels were reduced by fenoterol. Both drugs caused hypertrophy of skeletal muscle (gastrocnemius), and muscle protein synthesis in vivo (fractional rate) was elevated by 34 and 26% in clenbuterol and fenoteroltreated rats, respectively.  相似文献   

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Summary The ability of the generaEpidermophyton, Microsporon andTrichopyton to grow on some media at 4° C and 37° C was studied. It has been shown that specific differences exist among these fungi in the capability or rapidity of the growth at extreme temperatures.There is high positive correlation among perfect state production, isolation from the soil and growth at 4° C (group of characters A) and between pathogenicity and growth at 37° C (group of characters B). Between the groups A and B of characters exists a slighter negative correlation. Some prognosis about the five characters by certain species of dermatophytes may be given.  相似文献   

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Addition of amino acids to the DMSO buffer reduces the intracellular amino acid depletion of rat skin tissue frozen and stored at ?196 °C.Although prolonged exposure to DMSO progressively inhibits the [2-14C]glycine and l-[U-14C]leucine incorporation into the proteins, cortisol and amino acid additions to the buffer medium protect the protein-synthesizing activity. These factors also stimulate the incorporation of [6-3H]-thymidine into DNA. The stimulatory characteristics of cortisol and of amino acids separately are enhanced when both components are added together to the preserving buffer. These effects are noticeable in tissue only exposed to the DMSO buffer without freezing as well as in skin frozen and stored at ?196 °C and subsequently thawed at 40 °C.A stimulatory effect of cortisol and of a free amino acid, supplement to the medium on the α-amino-[1-14C]isobutyric acid uptake by the cells is only observed in skin exposed for a short period of time to the DMSO buffer, but it is not detectable after longer exposure and after freezing.  相似文献   

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Osipov  A. N.  Ryabchenko  N. I.  Ivannik  B. P.  Ryabchenko  V. I. 《Biophysics》2011,56(5):936-940
The effect of combined action of cadmium chloride at a dose of 0.5 mg/kg of body weight and γ-radiation of 1 Gy on induction of DNA damage in thymocytes and the total number of cells in the thymus of mice was studied. We found that injection of CdCl2 0.5 h prior to irradiation decreased the number of single-strand DNA breaks and the number of alkali-labile sites in thymocytes 48 h after irradiation as compared to the γ-radiation effect only. This effect was associated with a strong decrease in the total number of thymocytes in this organ as compared to the action of cadmium ions and γ radiation separately. This masked the general genotoxic effect of combined treatment and created an illusion of a radioprotective effect of cadmium ions. Injection of cadmium chloride into mice 24 h prior to irradiation was followed by an additive increase in the number of the single-strand DNA breaks and the number of alkali-labile sites in thymocytes as compared to the respective controls such as the separate effects of cadmium ions and irradiation. We revealed a simultaneous decrease in the part of DNA tightly bound to proteins, i.e., DNA-protein cross-links as compared to the effect of γ-radiation only. We did not observe any statistically significant changes in the total number of thymocytes as compared to the separate effects of cadmium ions and irradiation. Thus, our data show that exposure of murine thymocytes to combined action of cadmium ions and γ-radiation at the doses and with the methods of treatment used induced additive effects but not antagonistic effects or protection against radiation.  相似文献   

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Among colonies with different foraging distances, central-place-foraging seabirds may change their foraging and reproductive efforts. We compared the body condition, meal frequency, and diving behavior of male and female Adélie penguins at two locations: Dumont d'Urville, where there was little sea ice and they foraged in open waters far from the colony; and Syowa, where there was heavy, fast sea ice and they foraged in ice cracks close to the colony. The parental mass decrease rate during the chick-rearing period was similar between colonies and between sexes. A large individual variation in meal frequency positively affected the brood growth rate, but daily underwater time did not. A weak but significant positive effect of body condition on brood growth rate was found only in males at Syowa. It was suggested that males work with better body condition than females. We propose the hypothesis that the regional difference in the distance to the feeding sites and the sex difference in body energy reserve might constrain the capacity to regulate reproductive effort.  相似文献   

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As recently announced by the American Society for Reproductive Medicine (ASRM), human ovarian tissue cryopreservation is an established option for fertility preservation in prepubertal girls and young women undergoing gonadotoxic treatments for cancer as well as some autoimmune diseases. Proper ovarian tissue assessment before and after cryopreservation is essential to increase success rates. Ovarian fragments from 16 patients were divided into small pieces in form of cortex with medulla, and randomly divided into the following two groups. Pieces of Group 1 (n?=?16) were frozen immediately after operation, thawed and just after thawing their quality was analyzed. Group 2 pieces (n?=?16) after operation were cooled to 5 °C for 24 h, then frozen after 24 h pre-cooling to 5 °C, thawed and just after thawing their quality was analyzed. The effectiveness of the pre-freezing cooling of tissue was evaluated by the development and viability of follicles (Calcein-AM and Propidium Iodide) using complex object parametric analyzer and sorter machine (COPAS). Positive effect of cooling of cells to low supra-zero temperatures on their future development after re-warming has been observed. New flow cytometry- technique is suitable for the evaluation and sorting of cryopreserved whole human whole intact ovarian fragments. Long time (24 h) cooling of ovarian tissue to 5 °C before cryopreservation has a trend of a cell viability increasing.

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The ligand bonding geometry of carboxy-and cyanomet-myoglobin (MbCO and MbCN) has been measured by the XANES method (X-ray Absorption Near Edge Structure). A comparison between the ligand bonding geometry of carboxy- and cyanomet-myoglobin and of chelated protoheme methyl ester shows that the bent Fe–C–O configuration is the same in both systems. Therefore, we suggest that this configuration is not associated with any steric contraint imposed by the side chains of the aminoacid residues at the distal side of the heme pocket.  相似文献   

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The mechanisms by which single cells are injured during freezing are relatively well understood, but it is likely that additional factors apply to tissues and organs, factors that may be responsible for the poor suecess of attempts to cryopreserve complex multicellular systems. One such factor may be the formation of extracellular ice.
This study was designed to discover whether ice formation as such is detrimental to the contractile recovery of pieces of mammalian smooth muscle after storage at subzero temperatures. Strips of taenia coli muscle were equilibrated with 2.56 M Me2SO in a buffered solution, cooled at either 0.3 or 2 °C/min to ?21 °C and then held at this temperature in the frozen state. Other muscle strips were bathed in a solution the composition of which mimicked that of the unfrozen phase of the previous solution at ?21 °C; it contained 4.49 M Me2SO and 1.75 times the normal concentration of salts, and muscles equilibrated with this solution were also cooled at either 0.3 or 2 °C/min to ?21 °C, and then held unfrozen for the same length of time.It was shown that exposure to ?21 °C and the increased concentration of solutes had little effect on the contractile recovery of the muscles, whereas ice formation was damaging. Furthermore, the rate of cooling had a marked effect upon functional recovery in the frozen muscles, and this could be correlated with the known effect of these cooling rates on the pattern of ice formation in the tissue. The effect was also seen in muscles frozen at ?60 °C. Improved buffering increased the functional recovery of all groups, but the effect of ice, and of cooling rate in the presence of ice, was confirmed. These findings may have significant implications for attempts to cryopreserve complex tissues and organs.  相似文献   

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BackgroundPeritoneal dialysis (PD) is an acknowledged treatment for patients with irreversible kidney failure. The treatment usually causes peritoneal dialysis–related peritonitis (PDRP), a common complication of PD that can lead to inadequate dialysis, gastrointestinal dysfunction, and even death. Recent studies indicated that Fushen Granule (FSG), a Chinese herbal formula, improves the treatment of PD. However, the mechanism of how FSG plays its role in the improvement is still unclear. Gut microbiota has been closely related to the development of various diseases. We carried out a randomized controlled trial to assess whether FSG can modulate the gut microbiota during PDRP treatment.MethodsForty-two PDRP patients were recruited into the clinical trial, and they were randomly divided into control(CON), probiotics(PRO) or Fushen granule group(FSG). To check whether FSG improve the PD treatment, we assessed the clinical parameters, including albumin(ALB), hemoglobin(HGB), blood urea nitrogen(BUN) and creatinine(CR). Fecal samples were collected before hospitalization and discharge, and stored at -80°C within 1 hour. And we assessed the microbial population and function by applying the 16S rRNA gene sequencing and functional enrichment analysis.ResultsCompared to control group, ALB is improved in both probiotics and FSG groups, while HGB is increased but BUN and CR is reduced in FSG group. Sequencing of 16S rRNA genes revealed that FSG and PRO affected the composition of the microbial community. FSG significantly increased a abundant represented by Bacteroides, Megamonas and Rothia, which was significantly correlated with the improvements in carbohydrate and amino acid metabolism.ConclusionsThis study demonstrates that FSG ameliorates the nutritional status and improves the quality of life by enriching beneficial bacteria associated with metabolism. These results indicate that FSG as alternative medicine is a promising treatment for patients with PDRP.  相似文献   

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