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1.
While many reports indicate that voluntary modification of skin temperature is possible and may be useful in the treatment of Raynaud's phenomenon, little attention has been paid to the ecological validity of training skin temperature increases when a considerable amount of vasodilation of digital vessels may already exist (room temperature, 22-24 degrees C). Patients with Raynaud's vasospastic attacks may benefit from learning to avoid attacks when they are impending by voluntarily vasodilating the vessels of their digits under conditions when vasoconstriction has begun. The results in 14 patients with primary and secondary Raynaud's phenomenon indicated that (a) patients learned to voluntarily increase digital skin temperatures in a "cooling" environment during documented vasoconstriction, and (b) there was a 31% decrease in the occurrence of vasospastic attacks following such learning. These data suggest that a new methodology may be useful in the biofeedback treatment of Raynaud's phenomenon, but further research is needed to determine the specific mechanism(s) involved, and the limits to its usefulness.  相似文献   

2.
While many reports indicate that voluntary modification of skin temperature is possible and may be useful in the treatment of Raynaud's phenomenon, little attention has been paid to the ecological validity of training skin temperature increases when a considerable amount of vasodilation of digital vessels may already exist (room temperature, 22–24° C). Patients with Raynaud's vasospastic attacks may benefit from learning to avoid attacks when they are impending by voluntarily vasodilating the vessels of their digits under conditions when vasoconstriction has begun. The results in 14 patients with primary and secondary Raynaud's phenomenon indicated that (a) patients learned to voluntarily increase digital skin temperatures in a cooling environment during documented vasoconstriction, and (b) there was a 31% decrease in the occurrence of vasospastic attacks following such learning. These data suggest that a new methodology may be useful in the biofeedback treatment of Raynaud's phenomenon, but further research is needed to determine the specific mechanism(s) involved, and the limits to its usefulness.This research was supported by grants from the Manitoba Heart and St. Boniface General Hospital Research Foundations. We gratefully acknowledge John Arnett, Garry Hawryluk, and Charles Weinstein for their critical reading of a draft of this paper. Portions of this paper were presented at the Canadian Psychological Association meeting, Winnipeg, 1983.  相似文献   

3.
Raynaud's phenomenon is characterized by transient reduction in blood supply through the small arteries in the hands and feet. Severe Raynaud's phenomenon can cause digital necrosis. It has been hypothesized that nitric oxide may have a role in Raynaud's phenomenon. We report two cases in which oral L-arginine reversed digital necrosis in Raynaud's phenomenon and two additional cases in which the symptoms of severe Raynaud's phenomenon were improved with oral L-arginine. These reports suggest that a defect in nitric oxide synthesis or metabolism is present in Raynaud's phenomenon. They also suggest a potential role for oral L-arginine therapy in Raynaud's phenomenon, especially in Raynaud's phenomenon with digital necrosis.  相似文献   

4.
We studied reactive hyperemia after ischemia, after cold, and after cold plus ischemia, in normal subjects, in fingers with Raynaud's phenomenon, and in fingers without Raynaud's phenomenon in hands where other fingers were affected by Raynaud's phenomenon. The results obtained demonstrate the existence of a criohyperdysestesia both in fingers with Raynaud's phenomenon and in fingers without Raynaud's phenomenon in hands where other fingers are affected by it.  相似文献   

5.
Six Raynaud's disease and four Raynaud's phenomenon patients were treated with 12 sessions of finger temperature biofeedback. The mean frequency of vasospastic attacks was reduced to 7.5% of that reported during the pretreatment baseline and was maintained for a 1 year follow-up period. Significant control of digital temperature was demonstrated during laboratory training sessions. Raynaud's phenomenon patients showed significantly greater temperature increases during feedback periods than Raynaud's disease patients. Correlations between finger temperature and other physiological measures suggested that results could not be attributed to general physical relaxation. The role of imagery in self-control of digital temperature is considered.Portions of this paper were presented at the annual meeting of the Biofeedback Society of America, Albuquerque, March 1978.  相似文献   

6.

Introduction  

Laser Doppler imaging (LDI) is a relatively new method for assessing the functional aspect of superficial skin blood flow in systemic sclerosis (SSc) and Raynaud's phenomenon. The present study investigated the dynamic behavior of digital skin microvascular blood flow before and after cold stimulus (CS) in SSc patients and in healthy controls by means of a comprehensive approach of the functional (LDI), morphological (nailfold capillaroscopy (NFC)), and biochemical (fingertip lacticemy (FTL)) microcirculation components.  相似文献   

7.
Stipa breviflora, Agropyron oristatum and Artemisia frigida Association widely distributes in Qilian Mountain. The method of Fuzzy Mathematic was used to study the division of grazing retrogressive succession stage of the Stipa Steppe. The Degree of Fuzzy in different succession stages are L(AⅠ) =0.3675, L(AⅡ) = 0.55745, L(AⅢ)=0.5831, L(AⅣ) = 0.49175 respectively. The following preliminary conclusions can be drawn by the study: 1. It is confident that using the method of Fuzzy Mathematic to study the stages of grazing retrogressive succession of the Stipa Steppe, one may divide the stages of succession quantitatively and correctly. 2. The result of division shows that degree of fuzzy in the first and last stages is small, yet, in the middle stages is rather big (that means their delimitation is not quite clear). Such a phenomenon may be a common rule in this type of retrogressive succession. 3. The conclusion of this paper confirms that the terms "critical stages" and "critical indicative Species" which the authors have given in the paper of “Mathematical Models of Retrogression of Population” under Grazing Condition in the Stipa Steppe "are valuable for the purpose".  相似文献   

8.
黄浩  文蝶  黄汉晖 《古生物学报》2023,62(3):424-435
稀疏标准化是定量古生物工作中矫正多样性统计偏差的常用方法。相比基于样本大小的传统稀疏化,基于采样充分度的改进能更忠实反映多样性信息。然而一些案例对于稀疏化的适用性不够重视,尤其是改进的方法鲜有国内文献介绍。本文阐述了稀疏化的原理,强调了应用的注意事项和改进方法的优势。稀疏化的原理是从大小不同的样本中二次抽样出彼此“公平”的子样本,以比较其分类单元丰富度。传统方法据样本大小衡量公平,改进的方法据采样充分度评估公平,要求子样本在群落中代表的个体频率总和相等。两种思路均可通过计算机模拟多次重复二次抽样或公式推导来计算,已有PAST和iNext等软件可以实现。采样是否充分代表了古生物群落是有效应用该方法的首要前提。  相似文献   

9.
A novel method for real time, localized, flow measurements is applied to blood flow in human fingers. Results for arterial and venous flow in normal subjects and patients with abnormal blood circulation are presented. Effects of blood flow regulation by the autonomic nervous system have been observed. Stricture of the digital arteries could be clearly demonstrated in a patient with Raynaud's phenomenon. Experimental signals due to pulsatile flow in a model system can be simulated in a quantitative way. The calibration, however, depends on the actual spin-spin relaxation time and the shape of the pulsatile flow vs. time curve. Due to these limitations, the volume flow rate can be measured with a relative error of approximately +/- 25%.  相似文献   

10.
Long-term follow-up evidence for biofeedback treatment of headaches, Raynaud's disease, essential hypertension, and the irritable bowel syndrome was reviewed. Acknowledging the difficulties with cross-study comparisons, the following general success rate were determined: primary idiopathic Raynaud's disease—70%, or better; vascular headache—70%, or better; mixed headache—about 60%; and muscle contraction headache—50%, or less. With relatively fewer patients, successful outcomes with the irritable bowel syndrome and secondary Raynaud's phenomenon were roughly 60% and 40%, respectively. Few cases of clinically significant long-term decreases in diastolic blood pressure were demonstrated; however, the need for medication was reduced or eliminated in some patients. There were indications that biofeedback combined with psychotherapy resulted in highest success rates. No differences were found in effectiveness between biofeedback, other relaxation techniques, and biofeedback in combination with relaxation techniques—all had essentially comparable rates of success. No correlations between physiological and psychological measures of condition at follow-up were reported. Implications and interpretations of these findings are discussed.  相似文献   

11.
A new method for the determination of adult skeletal age at death based upon chronological changes in the auricular surface of the ilium is presented. Formal stages have been constructed following extensive tests and refinements in observations made of such changes. Two completely "blind" tests were conducted to assess the accuracy and bias of the new method. Results show that the system is equally accurate to pubic symphyseal aging (although somewhat more difficult to apply), and also carries the advantages of a higher preservation rate for the auricular surface in archaeological populations and continued age-related change beyond the fifth decade.  相似文献   

12.
Systemic scleroderma (SSd) is a connective tissue disorder accompanied by generalized fibrosis. A disturbance of the synthesis and production of matrix glycoproteins, such as collagens, fibronectin, and proteoglycans, by connective tissue cells is typical for this disease. We previously demonstrated a decrease in the ganglioside content of cultured skin fibroblasts from patients with SSd. In this work the contents of sialoglycoproteins and sialoglycolipids in blood sera of patients with SSd were estimated. Simultaneously, the level of asialofetuin-sialyltransferase activity in blood plasma of three groups of patients--those with SSd, Raynaud's phenomenon, and with localized scleroderma--was investigated. CMP-5-acetamido-9-deoxy-9-fluoresceinylthioureidoneuraminic acid was used as a substrate for the enzyme assay. It was shown that the concentration of total sialic acid was increased and the concentration of lipid-bound sialic acid was slightly decreased in the blood sera of patients with SSd. A correlation between the lipid-bound sialic acid level and the severity of disease was observed; there was no correlation between severity of disease and total sialic acid. Sialyltransferase assay showed a decrease in the activity level in all three groups of patients. The greatest decrease (2-fold) of this activity was observed in patients with Raynaud's phenomenon. Our data suggest that in SSd and similar diseases the process of glycoconjugate sialylation is disturbed. These changes may considerably affect the mechanisms of regulation of metabolism and cellular interactions.  相似文献   

13.
Clinical evidence for the long-term effectiveness of biofeedback related relaxation training is accumulating. The purpose of this report is to describe the population, self-regulation procedure, outcome criteria, and final outcome for patients who received Quieting Response (QR) training. Data from 340 patients who completed at least the first follow-up at 3 months is presented. Primary presenting symptoms were headaches, 72%; primary and secondary Raynaud's, 14%; hypertension, 4%; irritable colon, 4%; and miscellaneous, 6%. QR training integrated EMG and thermal feedback with deep breathing, progressive relaxation, and autogenic exercises presented on cassette tapes. Eight 1-hour weekly sessions were given, with emphasis on daily home exercises. Follow-up evaluations were at 3 months, 6 months, 1 year, and 2 years. Outcome was based on change in frequency, severity, and duration of symptoms; changes in medication; and secondary benefits. Quieting Response training was found to be most beneficial for patients with primary Raynaud's disease (18 of 23 patients, or 78% successful), classic migraines (9 of 13, or 69%), and common migraines (20 of 32, or 62%), followed by mixed headaches (79 of 131, or 60%), Raynaud's plus other symptoms (9 of 15, or 60%), and the irritable colon syndrome (7 of 13, or 54%). Less successful were patients with headaches plus other symptoms (16 of 37, or 43%), muscle contraction headaches (13 of 33, or 39%), secondary Raynaud's phenomenon (4 of 10, or 40%), and essential hypertension (5 of 15, or 33%). Speculations about the differing outcomes across symptom groups were made.  相似文献   

14.
Vegetation surveys collect species-diversity information, a potentially valuable ecological indicator. However, the number of species recorded by vegetation surveys is influenced by several factors including inherent species-diversity, sampling method and sampling effort. The process of rarefaction is commonly used to control for variation in sampling effort. We aimed to use a combination of rarefaction and additive partitioning to control for sampling effort and extract vegetation α-, β- and γ-diversity respectively. The study focused on the Stony Plains region of the South Australian rangelands. Vegetation quadrat survey data were collected for land condition monitoring and species inventory by two government agencies. The analysis revealed a strong residual influence of sampling effort on β- and γ-diversity after rarefaction, a finding not previously reported in the literature. A method was developed to model then remove the residual influence of sampling effort on β- and γ-diversity. Thus the method outlined in this paper allows for the extraction from standard vegetation survey data of α-, β- and γ-diversity and the concurrent removal of sampling effort influence. This method is transferable to any other region for which there is vegetation survey data.  相似文献   

15.
A novel method is presented that greatly facilitates the determination of vessel segment number and density in both simple and complex microvascular networks. This approach was applied to microvascular networks represented by the Bra-Ket operator technique and accurately predicted the number of vessel segments in both tree-branched and loop-branched (arcade) networks. The method was then applied to the complex hexagonal array network described by Engelson et al. for gastrointestinal mucosa and accurately yielded an average vessel segment number of three around each hexagonal loop. This new method may be used for conveniently estimating tissue microvascular densities, such as vessel rarefaction or proliferation, and for the modelling of microvascular networks.  相似文献   

16.
Aims In ecology and conservation biology, the number of species counted in a biodiversity study is a key metric but is usually a biased underestimate of total species richness because many rare species are not detected. Moreover, comparing species richness among sites or samples is a statistical challenge because the observed number of species is sensitive to the number of individuals counted or the area sampled. For individual-based data, we treat a single, empirical sample of species abundances from an investigator-defined species assemblage or community as a reference point for two estimation objectives under two sampling models: estimating the expected number of species (and its unconditional variance) in a random sample of (i) a smaller number of individuals (multinomial model) or a smaller area sampled (Poisson model) and (ii) a larger number of individuals or a larger area sampled. For sample-based incidence (presence–absence) data, under a Bernoulli product model, we treat a single set of species incidence frequencies as the reference point to estimate richness for smaller and larger numbers of sampling units.Methods The first objective is a problem in interpolation that we address with classical rarefaction (multinomial model) and Coleman rarefaction (Poisson model) for individual-based data and with sample-based rarefaction (Bernoulli product model) for incidence frequencies. The second is a problem in extrapolation that we address with sampling-theoretic predictors for the number of species in a larger sample (multinomial model), a larger area (Poisson model) or a larger number of sampling units (Bernoulli product model), based on an estimate of asymptotic species richness. Although published methods exist for many of these objectives, we bring them together here with some new estimators under a unified statistical and notational framework. This novel integration of mathematically distinct approaches allowed us to link interpolated (rarefaction) curves and extrapolated curves to plot a unified species accumulation curve for empirical examples. We provide new, unconditional variance estimators for classical, individual-based rarefaction and for Coleman rarefaction, long missing from the toolkit of biodiversity measurement. We illustrate these methods with datasets for tropical beetles, tropical trees and tropical ants.Important findings Surprisingly, for all datasets we examined, the interpolation (rarefaction) curve and the extrapolation curve meet smoothly at the reference sample, yielding a single curve. Moreover, curves representing 95% confidence intervals for interpolated and extrapolated richness estimates also meet smoothly, allowing rigorous statistical comparison of samples not only for rarefaction but also for extrapolated richness values. The confidence intervals widen as the extrapolation moves further beyond the reference sample, but the method gives reasonable results for extrapolations up to about double or triple the original abundance or area of the reference sample. We found that the multinomial and Poisson models produced indistinguishable results, in units of estimated species, for all estimators and datasets. For sample-based abundance data, which allows the comparison of all three models, the Bernoulli product model generally yields lower richness estimates for rarefied data than either the multinomial or the Poisson models because of the ubiquity of non-random spatial distributions in nature.  相似文献   

17.
Analysis of cyclic enzyme reaction schemes by the graph-theoretic method   总被引:1,自引:0,他引:1  
The development of the graph-theoretic method is proposed particularly for the analysis of closed cycles of elementary stages in enzyme reaction schemes. Some simplifications of the graph structure may be based on the application of Kirchhoff's laws to enzyme reaction graphs in the steady-state. The importance of the cyclic processes for enzyme regulations and a principle non-equilibrium of this phenomenon are emphasized. As an example of the regulatory role of cycles "the liberation" from substrate inhibition by substrate analogues is considered. The modification of the graph-theoretic method in the pre-steady-state kinetics for arbitrary initial conditions (for pre-mixing procedures) is also discussed. The necessary and sufficient conditions for damped oscillations in the pre-steady state are formulated which are the equality conditions for some of the rate constants along the cycle (both for reversible and irreversible stages).  相似文献   

18.
We have developed a competitive enzyme-linked immunosorbent assay for solubilized kinetochore components, using human CREST (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, telangiectasia) scleroderma autoimmune antibodies specific for these kinetochore elements. Using this quantitative assay, we found interphase persistent or "pre-kinetochore" components in low- and moderately high-salt (375 mM salt) extracts of micrococcal nuclease-digested rat liver and chicken erythrocyte nuclei. The release of antigen activity from nuclei under these conditions has been correlated with loss of pre-kinetochore foci as determined by immunofluorescence microscopy. Combined biochemical and competition assay analysis of chicken erythrocyte nuclear extracts indicates that pre-kinetochore components are tightly bound to chromatin of mononucleosome size. The conclusions based on competition assay data are supported by a direct binding assay, which confirms that antigens recognized by CREST sera are present on chromatin. These results raise the possibility that the kinetochore-specific chromosomal antigen(s) we have detected substitutes for "standard" mononucleosome components, such as histone H1. Furthermore, they suggest approaches to the isolation of kinetochore-specific DNA sequences from higher eucaryotes.  相似文献   

19.
In 63 patients affected by Systemic Sclerosis (SSc) (limited subset., 40; diffuse subset: 23; early: 30; advanced: 33) the peroxidation product diene-conjugates (DC) and antibodies against oxidised low density lipoproteins (Ab oxLDL) were tested in serum by a spectrophotometer (absorbance 234 mn) and by a standard ELISA respectively. The data were compared with those obtained by 21 healthy subjects. DC was significantly higher in patients (73.3 ± 37.2 M/l; p < 0.0001) than in controls (48.4 ± 16.7) as well as in the limited (80 ± 48.8; p < 0.05) than in the diffuse subset (64.5 ± 36.4); and in early (84.1 ± 31.4; p < 0.05) than in advanced stage of the disease (67.9 ± 42.5). The levels Ab oxLDL were significantly higher in SSc patients (309.5 ± 367.2 mU/ml; p < 0.0001) in all its subsets (limited: 351.9 ± 351.1, p < 0.0001; diffuse: 207.7 ± 316. 1, p < 0.05; early: 428.9 ± 417.1, p < 0.001; advanced: 302.7 ± 89.9, p < 0.0001) than in controls (89.3 ± 29.1). These antibodies levels were higher in limited subset than in diffuse (p < 0.05) and in early SSc than in advanced SSc (p < 0.05). The highest values of parameters of oxidative stress are found in the early stages, when the episodes of reperfusion after ischemic episodes (Raynaud's phenomenon) are very ferequent. Moreover, the damage is higher in the early stages of SSc, with intact microvessels, than in late stages, when microvessels are very reduced in number, destroyed by the worsening of the disease. These radicals products works as well in other diseases such as myocardial ischemia and pulmonary fibrosis.These data show that the respiratory burst deduced their lipoperoxidation is higher in SSe than in controls, may be an important pathogenetic factors involved in tissue changes in SSe.  相似文献   

20.
Understanding the conditions under which the brain integrates the different sensory streams and the mechanisms supporting this phenomenon is now a question at the forefront of neuroscience. In this paper, we discuss the opportunities for investigating these multisensory processes using modern imaging techniques, the nature of the information obtainable from each method and their benefits and limitations. Despite considerable variability in terms of paradigm design and analysis, some consistent findings are beginning to emerge. The detection of brain activity in human neuroimaging studies that resembles multisensory integration responses at the cellular level in other species, suggests similar crossmodal binding mechanisms may be operational in the human brain. These mechanisms appear to be distributed across distinct neuronal networks that vary depending on the nature of the shared information between different sensory cues. For example, differing extents of correspondence in time, space or content seem to reliably bias the involvement of different integrative networks which code for these cues. A combination of data obtained from haemodynamic and electromagnetic methods, which offer high spatial or temporal resolution respectively, are providing converging evidence of multisensory interactions at both "early" and "late" stages of processing--suggesting a cascade of synergistic processes operating in parallel at different levels of the cortex.  相似文献   

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