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1.
To identify relationships among hypertension, job and cardiovascular reactivity we studied 81 borderline hypertensives divided into labourers (L), white collars (W) and managers (M). After behavioral analysis, they underwent 4 tests: arithmetic, Sacks, acoustic, electric. Along the entire sitting, muscular contraction, skin conductance (SCL), peripheric temperature (THP), SBP, DBP and HR were taken, every 30". Depression, obsessive-compulsive, anxiety and neurotic traits were found in W. SBP, DBP and HR were not significantly different. Failed recovery curves of SCL were identified in M and W, but the presence of abnormal response profile, of both, SCL and THP, only in W. This autonomic dysreactivity, previously recognized as a possible characteristic of the prehypertensive condition, could uncover the role of certain work stressful condition to increase the sympathetic drive underlying hypertension.  相似文献   

2.
The present study was designed to explore whether changes occur in psychophysiological variables in healthy women not suffering from premenstrual tension. Variations in electroencephalogram frequencies, reaction time, somatosensory evoked potentials, and nerve conduction velocity were examined in a sample of 30 women, in relation to scores from the Hamilton Psychiatric Rating Scale for Depression and the State-Trait Anxiety Inventory. Trials and recordings were done weekly. EEG frequencies decreased before menstruation in all subjects. However, there were no significant changes for reaction time, nerve conduction velocity, HAMILTON nor State-Trait Anxiety scales associated with subperiods of the menstrual cycle. To explore the impact of anxiety, high and low anxiety groups were formed. The high anxiety group showed the highest scores in the A-Trait form, longer reaction time, enlarged latencies of the P100, but shorter nerve conduction velocity. Anxiety scores as well as reaction time increased during the premenstrual period only for the low anxiety group. The authors conclude that for some women premenstrual anxiety may be related to previous and continuous high levels of anxiety, which associated with some subtle neurological differences as compared with women who rated in low scores for anxiety.  相似文献   

3.
Increased HVR in pregnancy: relationship to hormonal and metabolic changes   总被引:1,自引:0,他引:1  
In prior studies at high altitude, we have found that pregnancy increases maternal hypoxic ventilatory response (HVR) but the factors responsible are unknown. Changes in metabolic rate and hormones that occur during pregnancy have previously been shown to influence HVR. We therefore sought to determine the contribution of metabolic rate and hormonal changes to the pregnancy-associated rise in HVR. Pregnancy increased HVR in each of 20 normal, low-altitude (1,600 m) residents. As measured by the shape parameter A, HVR at week 36 was 237 +/- 26 (SE) or twofold higher than the 124 +/- 13 value measured 3 mo postpartum (P less than 0.01) despite the presence of the potentially depressant effects of hypocapnia [change in alveolar partial pressure of CO2 (delta PACO2) = -4 +/- 1 mmHg] and alkalosis [change in arterial pH (delta pHa) = 0.02 +/- 0.01 U] during pregnancy. Sixty percent of the increase in HVR values had occurred by week 20 of gestation at which time O2 consumption (VO2) and CO2 production (VCO2) were unchanged relative to values measured postpartum. The remaining 40% rise in HVR paralleled increases in VO2 and VCO2, and further elevation in VO2 and VCO2 with moderate exercise produced an additional increase in HVR. Serum estradiol and progesterone levels increased with pregnancy, but levels did not correlate with HVR. The women reporting the greatest symptoms of dyspnea had higher HVR A values at week 36 than the least dyspneic women (285 +/- 28 vs. 178 +/- 34, respectively, P less than 0.05). We concluded that factors intrinsic to pregnancy in combination with increased metabolic rate raised HVR twofold with pregnancy and may have contributed to the often-reported symptoms of dyspnea in pregnant women.  相似文献   

4.
Adiponectin is an adipocyte-derived hormone involved in the regulation of carbohydrate and lipid metabolism. Its concentrations are decreased in patients with obesity, type 2 diabetes and atherosclerosis and are higher in females than in males. Gender differences of adiponectin levels raise the possibility that sex hormones directly regulate its serum concentrations, which may in turn influence insulin sensitivity in different phases of the menstrual cycle. To test this hypothesis we measured serum adiponectin, estradiol, progesterone, luteinizing hormone and follicle-stimulating hormone concentrations daily throughout the menstrual cycle in six healthy women. Mean adiponectin levels strongly positively correlated with serum cortisol concentrations [R=0.94286; p=0.0048 (Spearman correlation test)], but were not significantly related to other anthropometric, biochemical and hormonal characteristics of the subjects (BMI, blood glucose, insulin, testosterone, prolactin, cholesterol, HDL cholesterol, LDL cholesterol, triglycerides concentrations, or atherogenic index). Furthermore, no significant changes of serum adiponectin levels were found throughout the menstrual cycle. We conclude that changes in sex hormones during the menstrual cycle do not affect total circulating adiponectin levels in healthy women. Therefore, the differences in insulin sensitivity in various phases of the menstrual cycle are not due to changes of circulating adiponectin levels.  相似文献   

5.
6.
Clinical observations have suggested that limited hamstring flexibility may be associated with sagittal spinal curvatures in spine flexed postures. Thus, limited hamstring flexibility may be related to large amounts of spine flexion in “slumped” sitting postures which could contribute to low back pain and injury. The aim of this study was to determine if hamstring and pelvic flexibility are associated with flexed sitting postures using a backless office chair. Forty-one healthy female adults aged 18–69 years were recruited. Subjects performed the Sit-and-Reach test to determine maximum flexibility values and lumbar and pelvic angles were measured with accelerometers. Participants then completed a standardized typing task for a 10-minute sitting trial at an ergonomically adjusted workstation. The results showed no association between hamstring flexibility and seated lumbar spine and pelvic angles (p = 0.999, η2 = 0.000; p = 0.901, η2 = 0.006). Greater pelvic flexibility was associated with a more upright lumbar sitting posture (p = 0.023; η2 = 0.132) but with no specific pelvic sitting posture (p = 0.660; η2 = 0.005). Different movement strategies during the Sit-and-Reach test were detected: all participants moved through their lumbar spine; but only those with ‘excellent’ flexibility also used their pelvis. Individuals in the ‘excellent’ flexibility group were significantly shorter than those with ‘poor’ and ‘good’ flexibility (p = 0.020; η2 = 0.190). In conclusion, hamstring flexibility does not influence sitting posture but pelvic flexibility does. Other factors such as acetabulofemoral joint limitations, consciousness of posture, or the seat itself may also influence sitting posture. Different movement strategies as well as height appear to contribute to the Sit-and-Reach test which should be researched further.  相似文献   

7.
Objective: To examine the relationship between children's overweight status and other cardiovascular risk fitness factors and academic performance among fifth‐grade students. Research Methods and Procedures: Using a sample of 968 fifth‐grade students (50.7% boys; mean age = 10.6 years), children's cardiovascular risks (BMI, blood pressure, acanthosis nigricans) and fitness measures were compared with their mean group performance scores across four subscales (mathematics, reading/language arts, science, and social studies) of a statewide standardized academic performance test. Results: Of this sample, 39% were either at risk for being overweight or were already overweight; slightly over one half were of normal weight. Initial findings revealed a significant relationship between children's weight category and their reading/language arts, mathematics, and science test scores even after controlling for a proxy of socioeconomic status. When additional cardiovascular risk and fitness measures were included in the model, however, children's BMI status had no association. Instead, a composite fitness index, children's blood pressure, sex, and proxy of socioeconomic status were significantly associated with children's academic test scores. Discussion: This study expanded our understanding of the connection between children's overweight risks and academic performance by examining the impact of other cardiovascular risk factors such as high blood pressure and measures of fitness. These findings support the development and implementation of childhood cardiovascular risk surveillance programs that evaluate not only children's overweight risks but also their fitness, risk for type 2 diabetes, and/or high blood pressure by showing a relationship between some of these risks and children's academic test performance.  相似文献   

8.
Long-term cooperation between individuals necessitates repairing damage arising from inevitable competing interests. How two members of a valuable relationship switch from competing to cooperating constitutes an important problem for any social species. Observations of non-human animals suggest that affiliative contact immediately following a contest facilitates continued cooperation. Behavioral studies further indicate that winners and losers frequently differ in hormonal changes following a competition. We tested the hypothesis that immediate contact with increases in cortisol (and testosterone for men) for winners following competition would facilitate subsequent cooperation between adult same-sex friends. Results show that contact (versus no contact) immediately following competition enhanced subsequent cooperation between female friends. During contact, increases in winner's cortisol for both sexes, and in testosterone for men, predicted future cooperation. Our results suggest two mechanisms that maintain social bonds following competition between established allies.  相似文献   

9.
Randomized controlled trials (RCTs) and observational and longitudinal studies provide positive, albeit, inconsistent evidence that estrogen might protect against cognitive decline in postmenopausal women. The fact that the Women's Health Initiative Memory Study (WHIMS), the largest RCT to date, failed to find that estrogen therapy (ET) had a protective effect against cognitive aging led to the formulation of the critical period hypothesis which holds that ET will effectively protect against memory decline when it is initiated around the time of menopause but not when considerable time has elapsed since the menopause. Evidence from basic neuroscience, and from rodent, nonhuman primate, and human studies that supports this theory is presented. Although much work remains to be done on the timing of initiation of treatment, on the most effective hormonal compounds and on their routes of administration, the hope is that, eventually, hormonal treatments may be able to attenuate or prevent the decline in aspects of cognition that occur with normal aging.  相似文献   

10.
The purpose of this study was to investigate the relationship between anaerobic threshold (Th(an)) and muscle fatigue threshold (EMGFT) as estimated from electromyographic (EMG) data taken from the quadriceps muscles (vastus lateralis) during exercise on a cycle ergometer. The subjects in this study were 20 female college students, including highly trained endurance athletes and untrained sedentary individuals, whose fitness levels derived from their maximal oxygen consumption ranged from 24.9 to 62.2 ml.kg-1.min-1. The rate of increase in integrated EMG (iEMG) activity as a function of time (iEMG slope) was calculated at each of four constant power outputs (350, 300, 250, 200 W), sufficiently high to bring about muscle fatigue. The iEMG slopes so obtained were plotted against the exercise intensities imposed, resulting in linear plots which were extrapolated to zero slope to give an intercept on the power axis which was in turn interpreted as the highest exercise intensity sustainable without electromyographic evidence of neuromuscular fatigue (EMGFT). The Th(an) was estimated from gas exchange parameters during an incremental exercise test on the same cycle ergometer. The mean results indicated that oxygen uptake (VO2) at Than was 1.39 l.min-1, SD 0.44 and VO2 at EMGFT was 1.33 l.min-1, SD 0.57. There was no significant difference between these mean values (P greater than 0.05) and there was a highly significant correlation between VO2 at Than and VO2 at EMGFT (r = 0.823, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
《Theriogenology》1996,45(8):1491-1503
Sixteen crossbred multiparous sows displaying estrus on Day 5 or 6 after weaning were used in this study. Jugular veins of sows were cannulated on Day 13 of the estrous cycle. Electrical resistance of the vaginal mucosa was measured twice daily on Days 17 to 19 of the cycle and at 4-h intervals (excluding 3 a.m.) during the periestrous period. Blood was sampled every 4 h beginning on Day 17 and continuing for 6 to 7 d. Blood samples were assayed for LH, P4, E2, androstenedione (A4) and testosterone (T) by radioimmunoassay. All data were standardized to maximum LH concentration (0 h). The mean LH surge lasted about 28 h and its mean amplitude was 6.5 + 0.8 ng/ml of plasma. Vaginal electrical resistance (VER) decreased 4 d before the LH peak, remained low for 3 d and gradually started to increase after 0 h. The first signs of estrus were observed 16.9 + 17.8 h prior to the LH peak. The range of the interval was −44 h to +8 h. The increase in VER followed peak LH by 6.2 + 4.5 h. Intervals from peak LH to the beginning of the VER increase ranged from 0 to 16 h. Variation of the interval from the onset of estrus to the LH peak was significantly higher than that of the interval from LH peak to the beginning of the increase in VER (P < 0.005). The decrease in the VER observed during the follicular phase coincided with low levels of P4 (<1 ng/ml) and increasing concentrations of E2. Profiles of E2 and both androgens (A4 and T) were similar; these hormones increased gradually during the follicular phase of the cycle. The highest values of E2, A4 and T were observed before and during the first hours of the preovulatory LH surge. Sows with ovarian cysts (n = 3) had atypical patterns of electrical resistance and aberrant plasma hormone concentrations. These results indicate that measurement of VER can be utilized for detection of LH surges during estrus in sows. Moreover, the monitoring of VER changes provides a more reliable indication of the LH surge than detection of estrus.  相似文献   

12.
《农业工程》2014,34(5):266-270
Because of the absence of natural records with high resolution, the study of environmental changes in arid and semi-arid desert regions, an important component of the global system, lags behind studies in other regions. In this paper, we summarize the literature on the evolution, forms, and profile features of nebkhas (coppice dunes), and discuss the environmental implications of their formation and development. Based on this review, we argue that future research should focus on the quantitative conversion of environmental proxies revealed by nebkha evolution into the corresponding environmental factors: quantitative definition of the stages of nebkha evolution, enhancing the precision of age-dating, strengthening of cross-disciplinary research, and the comparison of nebkha results with other natural records to provide stronger, more reliable conclusions.  相似文献   

13.
In the Welfare Quality® assessment protocol for broilers, the touch test is included to assess the human–animal relationship in the flock. The test is designed to measure the animals’ fear of humans, assuming that broilers will withdraw from the observer if they are fearful. However, many broilers close to slaughter age have impaired walking ability, and the results from the touch test may thus be biased by lameness and poor leg health. As the touch test is currently being used in several countries to assess human–animal relationship in broilers, there is an urgent need to examine this potential relationship for a further validation of the test. In the present study, fear of humans was assessed in 50 randomly selected Norwegian broiler flocks, using the touch test as described in the Welfare Quality® protocol for ty broilers. Leg health was assessed by examining the gait of 150 random birds in each of the flocks, using a six-point gait score scale from 0 to 5. The coefficient for the relationship between touch test score and gait score was 0.034 (P<0.001), indicating that the animals express less fear as assessed by the touch test when the gait scores increase. This implies that the touch test may be confounded by impaired walking ability and therefore might be a suboptimal method of assessing fear of humans and human–animal relationship in broilers. In conclusion, the results from this study suggests that the touch test must be further validated in broilers and perhaps be replaced with a fear test that doesn’t rely on walking ability.  相似文献   

14.
To induce multiple shoots from pumpkin (Cucurbita moschata Duch.), cotyledon explants excised from various ages of seedlings after in vitro germination were cultured on MS augmented with different concentrations of BA (0, 0.5, 1.0 or 2.0 mg l−1). The highest frequency of shoot regeneration (63.7%) was observed from seven-day-old cotyledon explants cultured on MS containing 0.5 mg l−1 BA. The frequency and duration of shoot formation showed close correlation with the donor seedling age. By contrast, BA supply was necessary to promote shoot formation but no differences were observed in relation to different concentrations. Multiple shoots elongated on MS supplemented with 0.1 mg l−1 BA and 5–7 shoots per regenerated explant were recovered. Elongated shoots were rooted on MS, which was easier than that on 2/3MS, 1/2MS, or MS supplemented with 0.1 mg l−1 NAA. The rooted shoots were then transferred to greenhouse where they grew and flowered normally. Quantitative analysis of endogenous auxin (IAA) and cytokinins (iPA and ZR) in initial cotyledon explants of different aged seedlings showed that the regeneration ability of cotyledon explants varied dependently on their endogenous iPA contents. This study therefore deduces that the various organogenic capabilities of cotyledon explants from pumpkin are the result of their endogenous hormonal contents.  相似文献   

15.
Most research on birth weight and adult health status has reported adult measures at a single time point. This study examined the relationship of self‐reported birth weight to longitudinal changes in adult body composition in 587 women of the Michigan Bone Health and Metabolism Study, followed from 1992 to 2007 and aged 24–50 years at baseline. Linear mixed models were used to estimate the association between three birth weight categories and women's 15‐year changes in adult weight, height, BMI, waist and hip circumference, waist‐to‐hip ratio, and fat, lean, and skeletal muscle mass. Body composition measures increased in all women over the 15‐year study period. At their adult baseline, high birth weight women weighed 13% more and had waist circumference and lean mass measures that were 5.51 cm and 3.91 kg larger, respectively, than normal birth weight women. No differences were observed in adult body composition between low and normal birth weight women and rates of change in the adult measures did not vary across the birth weight groups. Women heavier at birth continued to be heavier through adulthood, corroborating previous reports based on single measures of adult body composition. Research to address whether higher adult body composition in high birth weight women increases the longitudinal risk for obesity‐related chronic diseases is needed.  相似文献   

16.
17.
MIANS, a sulfhydryl-reactive fluorescence, was used to label the cysteines of MRP1 (multidrug resistance protein), and the results indicated that an increase in fluorescence intensity and a large emission blue shift took place after two Cys residues of MRP1 reacted with MIANS, which demonstrated that labeled Cys residues in MRP1 reside in a relatively hydrophobic environment. The experimental results obtained from fluorescence resonance energy transfer further uncover that two Cys residues of MRP1 modified by MIANS located in the vicinity of its NBDs, of which one lies close to NBD1, and the other near NBD2. ATP, ADP and anticancer drugs can all reduce the rate of reaction of MRP1 with MIANS. The collisional quenchers, acrylamide, I-1, and Cs+ were used to assess local environments of MIANS bound to MRP1 and the results showed that the region around the MIANS-labeled cysteine is positively charged. Both MIANS and NEM, which are sulfhydryl-reactive reagents, inhibited MRP1 ATPase activity, whereas anticancer drugs activated it. These results demonstrated that all nucleotides and drugs could induce changes in conformation of the NBDs in MRP1. Nucleotides can bind directly to NBDs, but drugs may react first with TMDs, which in turn alters the accessibility of the two Cys residues bound by MIANS and affects MRP1 ATPase activity, which is coupled with the transport of its substrates. Taken together, the above experimental results provide direct evidence for further study on the coupling of translocation of the transported species to hydrolysis of ATP in MRP1.  相似文献   

18.
The relationship between MRP1 activities and its NBD conformational changes   总被引:2,自引:0,他引:2  
The term multidrug resistance (MDR) is classi-cally used to define a resistance phenotype where cells become resistant simultaneously to different drugs with no obvious structural resemblance and with dif-ferent cellular targets. For some time after P-gp, the first membrane protein related with MDR, was dis-covered in 1976[1], it was widely believed that P-gp was the exclusive cause of multidrug resistance. However, increasing evidence afterward suggested that this was not the case. Several…  相似文献   

19.
Skin colour was determined by reflectance spectrophotometry at 426, 550 and 685 nm wavelength. The data is interpreted by converting 426 and 685 nm into logarithmic and antilogarithmic values. The study indicates the existence of sexual diamorphism in colour. Further, the variability in pigmentation is also not similar in both sexes.  相似文献   

20.
目的研究女性终末期肾病月经异常患者性激素周期性改变与子宫内膜乳杆菌的相关性。方法选择2016年5月-2018年6月在本院诊治的126例ESRD女性患者为研究对象,其中月经失调患者66例。将ESRD患者中非月经异常患者设为月经正常组60例,月经周期延长患者为延长组36例,周期缩短患者为缩短组30例。收集患者临床资料,检测患者子宫内膜分泌物微生物组成。结果缩短组患者卵泡期、排卵期、黄体期E2水平明显低于正常组。延长组和缩短组卷曲乳杆菌(Lactobacillus crispatus)、惰性乳杆菌(Lactobacillus iners)、阴道乳杆菌(Lactobacillus vaginalis)检出率明显低于正常组,缩短组加氏乳杆菌(Lactobacillus gasseri)检出率明显低于正常组。卷曲乳杆菌(Lactobacillus crispatus)、惰性乳杆菌(Lactobacillus iners)、詹氏乳杆菌(Lactobacillus jensenii)、阴道乳杆菌(Lactobacillus vaginalis)与月经异常存在相关性。结论大部分ESRD女性患者存在月经失调和性激素水平异常,同时伴随子宫内膜微生物的改变。  相似文献   

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