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141.
Background
Physicians' awareness of their important role in defusing the obesity epidemic has increased. However, the number of family practitioners who treat obesity problems continues to be low. Self-efficacy refers to the belief in one's ability to organize and execute the courses of action required to produce given attainments. Thus, practitioners who judge themselves incapable of managing obesity do not even try. We hypothesized that practitioners' self-efficacy and motivation would be enhanced as a result of participating in an interactive course designed to enrich their knowledge of obesity management. 相似文献142.
Greger B Norris S 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2005,167(4):660-665
Evidence has been accumulating which supports a role for the cerebellum in motor learning. Motor learning is though to be
mediated by complex spikes acting as an error signal, which when firing in conjunction with simple spike activity modify synapses
between parallel fibers and Purkinje cells. We studied the activity of neurons in the posterior lateral cerebellar cortex
of macaques that were performing reaches to visual targets. We found that simple spike firing in many of these neurons was
modulated by whether the monkey successfully hit the target or not. The success–failure modulation was present for reaches
using either arm and could persist for several hundred milliseconds into a period when the monkey was constrained from moving
its arms. This temporally extended success–failure activity could interact with complex spike firing in order to enhance learning,
particularly when the motor command is temporally separated from sensory feedback. 相似文献
143.
Schwienbacher I Fendt M Schnitzler HU 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2005,160(4):538-544
The acoustic startle response is enhanced during states of fear and attenuated during pleasant ones. Our question was whether pharmacological stimulation of the reward system disrupts the learning and retrieval of conditioned fear as measured by fear-potentiated startle. We therefore injected the dopamine agonist amphetamine into the nucleus accumbens (NAC) immediately before either acquisition or expression of conditioned fear and measured the effect of these injections on fear-potentiated startle and baseline startle response. This study clearly showed that amphetamine injections into the NAC had no effect on baseline startle amplitude and acquisition/expression of conditioned fear. In contrast, amphetamine injections into the nucleus accumbens clearly enhanced spontaneous motor activity. These results suggest that dopamine within the NAC is not involved in modulation of fear-potentiated startle and baseline startle. 相似文献
144.
Carpenter MG Thorstensson A Cresswell AG 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2005,167(3):433-445
Understanding the physiological and psychological factors that contribute to healthy and pathological balance control in man
has been made difficult by the confounding effects of the perturbations used to test balance reactions. The present study
examined how postural responses were influenced by the acceleration–deceleration interval of an unexpected horizontal translation.
Twelve adult males maintained balance during unexpected forward and backward surface translations with two different acceleration–deceleration
intervals and presentation orders (serial or random). “SHORT” perturbations consisted of an initial acceleration (peak acceleration
1.3 m s−2; duration 300 ms) followed 100 ms later by a deceleration. “LONG” perturbations had the same acceleration as SHORT perturbations,
followed by a 2-s interval of constant velocity before deceleration. Surface and intra-muscular electromyography (EMG) from
the leg, trunk, and shoulder muscles were recorded along with motion and force plate data. LONG perturbations induced larger
trunk displacements compared to SHORT perturbations when presented randomly and larger EMG responses in proximal and distal
muscles during later (500–800 ms) response intervals. During SHORT perturbations, activity in some antagonist muscles was
found to be associated with deceleration and not the initial acceleration of the support surface. When predictable, SHORT
perturbations facilitated the use of anticipatory mechanisms to attenuate early (100–400 ms) EMG response amplitudes, ankle
torque change and trunk displacement. In contrast, LONG perturbations, without an early deceleration effect, did not facilitate
anticipatory changes when presented in a predictable order. Therefore, perturbations with a short acceleration–deceleration
interval can influence triggered postural responses through reactive effects and, when predictable with repeated exposure,
through anticipatory mechanisms. 相似文献
145.
Rajasekharan?Somasundaram Laura?Caputo DuPont?Guerry Dorothee?HerlynEmail author 《Journal of translational medicine》2005,3(1):41
A CD8+ cytotoxic T lymphocyte (CTL) line was derived from the peripheral blood mononuclear cells of a patient with primary melanoma.
The CD8+ CTL line specifically lysed the autologous primary melanoma cells and not the natural killer cell-sensitive K562 cells or
lymphokine activated killer cell-sensitive DAUDI cells. When a large panel of human leukocyte antigen (HLA)-matched and -unmatched
allogeneic melanoma, glioma, breast and colorectal carcinoma cells was tested as targets in cytolysis assays, 4 HLA-matched
and two HLA-unmatched allogeneic metastatic melanoma lines were lysed by the CD8+ CTL. Lysis of autologous and allogeneic melanoma cells was dependent on the effector-to-target cell ratio. Lysis of autologous
melanoma cells was not blocked by anti-HLA class I or class II antibodies, confirming that the cytolytic activity of the CD8+ CTL was HLA-unrestricted. CTL lysis of autologous melanoma cells was CD3 (T cell receptor) dependent and FAS-FAS-L, and CD1
independent. Identification of the melanoma-associated antigen recognized by the HLA-unrestricted CTL may provide a vaccine
for a broad population of melanoma patients. 相似文献
146.
Moriguchi M Yamada M Yanagisawa T 《Anatomical science international / Japanese Association of Anatomists》2004,79(3):145-151
Keratan sulfate proteoglycan and dermatan sulfate proteoglycan have been reported to inhibit collagen fibrillogenesis. We investigated their distribution in order to evaluate the role of proteoglycan in dentinogenesis. Specimens of porcine tooth-germ dentin and erupted teeth were the materials on which antibodies to keratin sulfate and dermatan sulfate proteoglycan were used. Predentin was found to be positive for both antibodies and the reaction ceased in the calcification front. Uniformly thick collagen fibrils (30-70 nm in diameter) were distributed in the predentin matrix, which would become intertubular dentin in the future. Both antibodies reacted positively along these fibrils. In contrast, along the surface layer of dentin in the tooth germ and that in erupted teeth, collagen fibrils of 10-300 nm in diameter were noted occasionally in dentinal tubules whose odontoblastic processes had disappeared and these heterogeneous fibrils were negative for both antibodies. Our findings suggest that keratan sulfate proteoglycan and dermatan sulfate proteoglycan distributed in the predentin inhibit calcification of collagen fibrils in the uncalcified matrix and disappear in the calcification front. It is further suggested that keratan sulfate proteoglycan and dermatan sulfate proteoglycan distributed along collagen fibrils in the predentin matrix maintain uniform thickness, whereas collagen fibrils in dentinal tubules varied in thickness because of the absence of involvement of both proteoglycans. Therefore, keratan sulfate proteoglycan and dermatan sulfate proteoglycan were thought to be involved in both calcification and matrix formation. 相似文献
147.
Kun?Guo Robert?G.?RobertsonEmail author Sasan?Mahmoodi Yoav?Tadmor Malcolm?P.?Young 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2003,150(3):363-374
Face perception plays a crucial role in primate social communication. We have investigated the pattern of eye movements produced
by rhesus monkeys (Macaca mulatta) as they viewed images of faces. Eye positions were recorded accurately using implanted eye coils, while neutral upright,
inverted and scrambled images of monkey and human faces were presented on a computer screen. The monkeys exhibited a similar
eye scan pattern while viewing familiar and unfamiliar monkey face images, or while viewing monkey and human face images.
No differences were observed in the distribution of viewing times, number of fixations, time into the trial of first saccade
to local facial features, and the temporal and spatial characteristics of viewing patterns across the facial images. However,
there was a greater probability of re-fixation of the eye region of unfamiliar faces during the first few seconds of the trial
suggesting that the eyes are important for the initial encoding of identity. Indeed, the highest fixation density was found
in the eye region of all the face images. The viewing duration and the number of fixations per image decreased when inverted
or scrambled faces were presented. The eye region in these modified images remained the primary area of fixation. However,
the number of fixations directed to the eyes decreased monotonically from the upright images through the inverted versions
to the scrambled face images. Nonetheless, the eyes remain the most salient facial substructure regardless of the arrangement
of other features, although the extent of salience which they attain may depend both on the low level properties of the eyes
and on the global arrangement of facial features.
Electronic Publication 相似文献
148.
Fernández EA Valtuille R Willshaw P Perazzo CA 《Medical & biological engineering & computing》2003,41(4):392-396
Determination of the adequacy of dialysis is a routine but crucial procedure in patient evaluation. The total dialysis dose,
expressed as Kt/V, has been widely recognised to be a major determinant of morbidity and mortality in haemodialysed patients.
Many different factors influence the correct determination of Kt/V, such as urea sequestration in different body compartments,
access and cardiopulmonary recirculation. These factors are responsible for urea rebound after the end of the haemodialysis
session, causing poor Kt/V estimation. There are many techniques that try to overcome this problem. Some of them use analysis
of blood-side urea samples, and in recent years, on-line urea monitors have become available to calculate haemodialysis dose
from dialysate-side urea kinetics. All these methods require waiting until the end of the session to calculate the Kt/V dose.
In this work, a neural network (NN) method is presented for early prediction of the Kt/V dose. Two different portions of the
dialysate urea concentration-time profile (provided by an on-line urea minitor) were analysed: the entire curve A and the
first half B, using an NN to predict the Kt/V and compare this with that provided by the monitor. The NN was able to predict
Kt/V is the middle of the 4h session (B data) without a significant increase in the percentage error (B data: 6.69%±2.46%;
A data: 5.58%±8.77%, mean±SD) compared with the monitor Kt/V. 相似文献
149.
150.
Iliescu R Campos LA Schlegel WP Morano I Baltatu O Bader M 《Journal of molecular medicine (Berlin, Germany)》2003,81(7):420-427
We have previously shown that flutamide (specific antagonist of the androgen receptor) has antihypertensive effects. In the present study we examined the mechanisms of flutamide action in the vasculature. The vascular effects of flutamide were assayed in aortae isolated from male or female Sprague-Dawley rats and from rats or mice lacking a functional androgen receptor ( tfm, testicular feminization mutation). The effect of flutamide on coronary flow was tested in isolated hearts. In addition, male hypertensive rats with tfm mutation were treated with flutamide, and blood pressure was monitored. Flutamide induced a relaxation of rat aortae from all the strains used (maximum relaxation at 10 microM: 51.3+/-5.2% of phenylephrine contraction) and increased the coronary flow. The aortic relaxation to flutamide was abolished by endothelium removal, or by inhibition of nitric oxide synthase, guanylyl cyclase, and tyrosine kinase but not by calmodulin inhibition. Flutamide treatment attenuated the development of hypertension in mouse renin transgenic rats with the tfm mutation. Flutamide produces direct vasodilation by inducing release of NO from the endothelium and causes subsequent activation of soluble guanylyl cyclase in an active androgen receptor independent manner. This response may contribute to the observed antihypertensive actions of flutamide. 相似文献