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81.
The autonomic nervous control of cardiac function during active orthostatic load has been studied by measuring the power spectrum of heart rate fluctuations in 16 insulin-dependent diabetic patients and 14 age-matched control subjects. The patients were subdivided into two groups: 8 with normal respiratory sinus dysrhythmia (RSA+) and 8 with reduced respiratory sinus dysrhythmia (RSA-). In RSA- patients the total power (0.01-0.50 Hz) was significantly reduced compared with control subjects (4.7 versus 15.5 min-2, 2p less than 0.05) and the pattern of heart rate fluctuations was characterized by a relative increase in the low-frequency component (0.01-0.05 Hz) as compared with RSA+ patients and control subjects (45% versus 24% and 27%, both 2p less than 0.01). There was also a significant reduction in the high-frequency component (0.15-0.50 Hz) as compared with RSA+ patients and control subjects (17% versus 36% and 33%, both 2p less than 0.05). During standing, a significant increase in total power was found only in control subjects (2p less than 0.01) and the difference between control subjects, and RSA+ and RSA- patients reached significance (32.2 versus 15.1 and 12.7 min-2, 2p less than 0.02 and 2p less than 0.01). The pattern of heart rate fluctuations in RSA- patients showed no significant change on standing. These results suggest that the reduced overall heart rate variability in diabetic patients with cardiac autonomic neuropathy is associated with a typical heart rate fluctuation pattern.  相似文献   
82.
We studied saccadic and smooth pursuit eye movements in 24 patients suffering from multiple sclerosis during disease worsening, before and after high-dose 6-methylprednisolone infusions. Quantitative evaluation of saccades was based on amplitude/duration and amplitude/peak velocity relationships, precision (i.e. the ratio of actual to desired saccade amplitude) and the latency, whereas smooth pursuit eye movements were studied using target velocity/performance index relationship. At basal recordings, 22/24 (91.7%) of the patients showed at lest one abnormality. Eleven of the 24 patients (45.8%) showed modification of one or several parameters: improvement in 6 patients, worsening in 2, coexistence of both trends in 3. Latency improvement was the only significant modification when patients were considered as a group. Neurophysiological modifications did not correspond to clinical changes.  相似文献   
83.
Recent studies of mortality from motor neurone disease (MND) in Sweden have demonstrated rising levels of mortality from the disease, especially amongst older age groups. Case-control investigations have suggested that certain environmental factors are significantly related to variations in mortality from the disease, and are associated with a probable individual susceptibility to MND. This study applies an innovative epidemiological technique to longitudinal and cohort analysis of Swedish mortality from MND during the period 1961 to 1990. Survival modelling shows that a subpopulation susceptible to MND exists in Sweden, as has been demonstrated in other countries. The increased life expectancy of the Swedish population since 1961 has resulted in more of that susceptible population living to the ages at which MND is expressed, explaining the majority of the increase in mortality from the disease. However, environmental factors may play a role in accelerating the course of MND and may affect the timing of death within the susceptible sub-population.  相似文献   
84.
An evaluation of the residual activity of quick-drying agents (alcoholic solutions) used for hygienic hand disinfection is described. We looked for residual efficacy following hand disinfection with soap and water alone or followed by one of two alcoholic handrub lotions supplied from an automatic hand washing machine. The bacterial counts on the hands obtained before and within 2 successive hours after disinfection showed that alcoholic chlorhexidine was the most effective for 10 minutes after contamination of the hands. WELPAS® (alcoholic chlorbenzarconium) followed this in its immediate effect and was better than soap and water alone. There were no significant differences after 30‘ or 120‘ between the three disinfecting methods.  相似文献   
85.
The recently developed method of total vertical projections is illustrated to estimate the total dendritic length of a human Substantia Nigra neuron. Next, the length of the different orders of dendritic branches, and the mean segment length for each order - commonly regarded as important parameters in neuron physiology - are also estimated. Finally, it is shown how to estimate the mean dendritic length in a population of neurons from vertical slices of arbitrary and unknown thickness. Being unbiased and highly efficient, the proposed methods offer interesting alternatives to current procedures used for the metric analysis of neuron arborizations.  相似文献   
86.
对我院1992年1月到1994年6月间应用KS—2A型特效癌症治疗仪治疗宫颈病变905例进行疗效分析,总的一次治愈率为97%,治疗宫颈糜烂858例,有效率100%,一次治愈率为97.4%,与冷冻治疗相比差异有显著性(P<0.001).治疗宫颈腺体囊肿34例,治愈率为84.5%.提示:与其它治疗方法相比,KS仅治疗具有治愈率高,副作用少,愈合时问短,操作简单,患者无痛苦等特点,具有推广和普及的价值.  相似文献   
87.
We introduce an image processing method which reduces white noise and random artifacts in sets of high resolution, time resolved images. At each pixel, the processing consists of: (1) the isolation of a time intensity curve (TIC), (2) Fourier transformation of each TIC, (3) application of a threshold to remove low intensity coefficients, (4) inverse transformation to generate noise reduced TICS which are recombined to form images with improved signal-to-noise ratio (SNR). Noise filtering by Fourier thresholding is demonstrated on a set of cardiac images, resulting in a reduction of the noise energy by approximately 90%.  相似文献   
88.
An automated measurement of total and free hydroxyproline in serum or urine is presented that uses flow injection analysis. After exclusion of nonspecific substances, hydroxyproline was oxidized by chloramine- T and L-cysteine with Ehrlich's reagent. The linearity obtained was from 3.8μmole/ L to 1.22 mmole/L with good precision (CV <3%). Comparison of the proposed method with HPLC yielded r = 0.939 as the correlation coefficient. Reference intervals of free and total hydroxyproline are 1.4–9.7 μmole/L, 3.8–27.2 μmole/L for serum, and 10.0–72.5 μmole/L, 25.2–303.6 μmole/L for urine, respectively. Serum free and total hydroxyproline levels in renal osteodystrophy patients on maintenance hemodialysis (N = 71) were significantly higher than in controls (P<0.0001). This method is superior to the use of HPLC with regard to stability of the color reaction. The measurement of serum free and total hydroxyproline is a useful marker for therapeutic observation of renal osteodystrophy patients. © 1994 Wiley-Liss, Inc.  相似文献   
89.
Abstract Detection of peristalsis in the human small intestine has been limited in the past by both the available measurement techniques and the complexity of this activity. Recent developments in ambulant recording have provided a means of monitoring the occurrence of intestinal contractions at multiple sites in the small bowel, but the problem of complexity remains. Using digital data recorded from an intra-luminal strain-gauge transducer in the proximal gut, an algorithm was implemented to identify and classify contractile events within the small bowel. By modelling propagated activity the effect of varying transducer spacing and the number of transducers used was assessed. The question of variability of apparent velocity of peristaltic contractions was examined using successive cross-correlation calculations to extract underlying phase differences between samples of 512 minutes of manometric recording over 150 mm of human small bowel. The effective velocity was found to have a median value of 14 mm sec-1 and an inter quartile range of 12–18 mm see-1). It is proposed that, in dynamically tracking variations in phase difference between adjacent recording sites, cross-correlation techniques should be used to control the parameters used for the recognition of propagated contractile events and thereby improve the specificity of this process.  相似文献   
90.
The evolution of the dorsal thalamus in various vertebrate lineages of jawed vertebrates has been an enigma, partly due to two prevalent misconceptions: the belief that the multitude of nuclei in the dorsal thalamus of mammals could be meaningfully compared neither with the relatively few nuclei in the dorsal thalamus of anamniotes nor with the intermediate number of dorsal thalamic nuclei of other amniotes and a definition of the dorsal thalamus that too narrowly focused on the features of the dorsal thalamus of mammals. The cladistic analysis carried out here allows us to recognize which features are plesiomorphic and which apomorphic for the dorsal thalamus of jawed vertebrates and to then reconstruct the major changes that have occurred in the dorsal thalamus over evolution. Embryological data examined in the context of Von Baerian theory (embryos of later-descendant species resemble the embryos of earlier-descendant species to the point of their divergence) supports a new ‘Dual Elaboration Hypothesis’ of dorsal thalamic evolution generated from this cladistic analysis. From the morphotype for an early stage in the embryological development of the dorsal thalamus of jawed vertebrates, the divergent, sequential stages of the development of the dorsal thalamus are derived for each major radiation and compared. The new hypothesis holds that the dorsal thalamus comprises two basic divisions—the collothalamus and the lemnothalamus—that receive their predominant input from the midbrain roof and (plesiomorphically) from lemniscal pathways, including the optic tract, respectively. Where present, the collothalamic, midbrain-sensory relay nuclei are homologous to each other in all vertebrate radiations as discrete nuclei. Within the lemnothalamus, the dorsal lateral geniculate nucleus of mammals and the dorsal lateral optic nucleus of non-synapsid amniotes (diapsid reptiles, birds and turtles) are homologous as discrete nuclei; most or all of the ventral nuclear group of mammals is homologous as a field to the lemniscal somatosensory relay and motor feedback nuclei of non-synapsid amniotes; the anterior, intralaminar and medial nuclear groups of mammals are collectively homologous as a field to both the dorsomedial and dorsolateral (including perirotundal) nuclei of non-synapsid amniotes; the anterior, intralaminar, medial and ventral nuclear groups and the dorsal lateral geniculate nucleus of mammals are collectively homologous as a field to the nucleus anterior of anamniotes, as are their homologues in non-synapsid amniotes. In the captorhinomorph ancestors of extant land vertebrates, both divisions of the dorsal thalamus were elaborated to some extent due to an increase in proliferation and lateral migration of neurons during development. Mammals are unique in the degree to which their synapsid ancestors further elaborated the lemnothalamus, so that the identity of and previous experience with objects in their environment has become their most salient priority.  相似文献   
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