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991.
Van Leeuwen YD Düsman H Mol SS Pollemans MC Drop MJ Grol RP Van Der Vleuten CP 《Advances in health sciences education : theory and practice》1997,2(1):61-70
Objectives: The relation between the content of postgraduate training for general practice and the outcome in terms of the growth in knowledge of trainees was investigated. The training variables included were: (1) the number of patients seen per day, (2) the trainer, (3) the practice and (4) the theoretical curriculum.Methods: Subjects were 58 trainee-trainer pairs. Growth in knowledge was assessed by two written tests administered with eight months interval. Training variables were evaluated by means of questionnaires and logbook-registration. The correlation was explored between each of the training variables and the knowledge tests scores. To correct for interactional effects, a step-wise multiple regression analysis was performed with the second test as dependent variable and the first test as well as the training variables as independent variables.Results: Significant growth in knowledge was demonstrated. Non of all training variables investigated explained the variance in scores on the second test equally good or better than the scores on the entry test.Conclusions: The impact of the separate training-components on the growth in knowledge, remains unclear. We may speculate, that the sort of knowledge assessed with the written literature based true/false test is different from the sort of knowledge transferred during every day training: evidence based knowledge versus experience based knowledge. Equally valid is the conclusion that these findings fit into the theory that in adult learning the outcome is more learner than teacher dependent.This revised version was published online in September 2005 with corrections to the Cover Date. 相似文献
992.
- Modulation of presynaptic voltage-dependent calcium channels (VDCCs) by muscarinic receptors at the CA3–CA1 synapse of rat hippocampal slices was investigated by using the calcium indicator fura-2. Stimulation-evoked presynaptic calcium transients ([Capre]t) and field excitatory postsynaptic potentials (fe.p.s.ps) were simultaneously recorded. The relationship between presynaptic calcium influx and synaptic transmission was studied.
- Activation of muscarinic receptors inhibited [Capre]t, thereby reducing synaptic transmission. Carbachol (CCh, 10 μM) inhibited [Capre]t by 35% and reduced fe.p.s.p. by 85%. The inhibition was completely antagonized by 1 μM atropine. An approximate 4th power relationship was found between presynaptic calcium influx and postsynaptic responses.
- Application of the N-type VDCC-blocking peptide toxin ω-conotoxin GVIA (ω-CTx GVIA, 1 μM) inhibited [Capre]t and fe.p.s.ps by 21% and 49%, respectively, while the P/Q-type VDCC blocker ω-agatoxin IVA (ω-Aga IVA, 1 μM) reduced [Capre]t and fe.p.s.ps by 35% and 85%, respectively.
- Muscarinic receptor activation differentially inhibited distinct presynaptic VDCCs. ω-CTx GVIA-sensitive calcium channels were inhibited by muscarinic receptors, while ω-Aga IVA-sensitive channels were not. The percentage inhibition of ω-CTx GVIA-sensitive [Capre]t was about 63%.
- Muscarinic receptors inhibited presynaptic VDCCs in a way similar to adenosine (Ad) receptors. The percentage inhibition of ω-CTx GVIA-sensitive [Capre]t by Ad (100 μM) was about 59%. There was no significant inhibition of ω-Aga IVA-sensitive channels by Ad. The inhibitions of [Capre]t by CCh and Ad were mutually occlusive.
- These results indicate that inhibition of synaptic transmission by muscarinic receptors is mainly the consequence of a reduction of the [Capre]t due to inhibition of presynaptic VDCCs.
993.
Excess eicosanoid formation during inflammation has been attributed to the expression of the gene coding for the inducible
isoform of prostaglandin G/H synthase (PGHS-2). Human and murine PGHS-2 proteins differ in 73 out of the 604 amino acids.
When comparing the inhibitory effects of a panel of PGHS-inhibitors in a whole cell human and murine PGHS-2 assay carried
out under identical conditions, classical NSAIDs with the exception of aspirin and tenoxicam showed similar inhibitory effects
on both human and murine PGHS-2 enzymes. However, the PGHS-2 selective inhibitors nimesulide, flosulide and NS398 showed a
much greater inhibition of human PGHS-2. We suggest that these differences could be due to the genetic differences of human
and murine PGHS-2.
Formerly R&D Division of Hafslund Nycomed Pharma AG, Austria. 相似文献
994.
Marttin Emmeline Verhoef J. Coos Cullander Christopher Romeijn Stefan G. Nagelkerke J. Fred Merkus Frans W. H. M. 《Pharmaceutical research》1997,14(5):631-637
Purpose. To visualize the transport pathway(s) of high molecular weight model compounds across rat nasal epithelium in vivousing confocal laser scanning microscopy. Furthermore, the influence of nasal absorption enhancers (randomly methylated -cyclodextrin and sodium taurodihydrofusidate) on this transport was studied.
Methods. Fluorescein isothiocyanate (FITC)-labelled dextrans with a molecular weight of 3,000 or 10,000 Da were administered intranasally to rats. Fifteen minutes after administration the tissue was fixed with Bouin. The nasal septum was surgically removed and stained with Evans Blue protein stain or DiIC18(5) lipid stain prior to visualization with the confocal laser scanning microscope.
Results. Transport of FITC-dextran 3,000 across nasal epithelium occurred via the paracellular pathway. Endocytosis of FITC-dextran 3,000 was also shown. In the presence of randomly methylated -cyclodextrin 2% (w/v) similar transport pathways for FITC-dextran 3,000 were observed. With sodium taurodihydrofusidate 1% (w/v) the transport route was also paracellular with endocytosis, but cells were swollen and mucus was extruded into the nasal cavity. For FITC-dextran 10,000 hardly any transport was observed without enhancer, or after co-administration with randomly methylated -cyclodextrin 2% (w/v). Co-administration with sodium taurodihydrofusidate 1% (w/v) resulted in paracellular transport of FITC-dextran 10,000, but morphological changes, i.e. swelling of cells and mucus extrusion, were observed.
Conclusions. Confocal laser scanning microscopy is a suitable approach to visualize the transport pathways of high molecular weight hydrophilic compounds across nasal epithelium, and to study the effects of absorption enhancers on drug transport and cell morphology. 相似文献
995.
Elbert T Dworkin BR Rau H Pauli P Birbaumer N Droste C Brunia CH 《International journal of behavioral medicine》1994,1(3):215-228
Activating the arterial baroreceptors in animals has been shown to blunt pain sensation and provide other forms of central
nervous system inhibition. This study tested the hypothesis that, among human subjects, a tonic increase in blood pressure
(BP) could be a learned response to environmental stressors among subjects in whom the baroreceptor inhibitory mechanism is
active. In a sample of 96 healthy, normotensive men and women, amount of pain-reduction produced by baroreceptor stimulation
predicted an increase in resting BP 20 months later: the increase was proportional to self-assessed daily life stress. Among
the subjects reporting the greatest amount of stress, the pain inhibition effect accounted for more than 80% of the BP variance.
These results support the hypothesis that the reduction in perceived stress produced by baroreceptor stimulation may reward
learned increases in BP.
This research was supported by Deutsche Forschungsgemeinshaft Grant EL 101/3 to Thomas Elbert and National Institutes of Health
Grant ROl HL40837 to B. R, Dworkin. 相似文献
996.
Serotonin (5-HT) nerve terminals innervate sympathetic preganglionic neurons of the intermediolateral cell column (IML); however, neither the depolarization-induced release of 5-HT nor the presence of presynaptic modulatory autoreceptors have been directly studied in this system. We used in vitro superfusion of the microdissected intermediate area (including the intermediolateral cell column, intercalated nucleus, and central autonomic nucleus) of the rat thoracic spinal cord to measure basal and stimulated release of preloaded [3H]5-HT. Elevated K+ evoked a concentration- and Ca2+ dependent release of [3H]5-HT. Exogenous 5-HT and the 5-HT1B agonist, CGS-12066B, both decreased the K+-stimulated release of [3H]5-HT. A 5-HT1B antagonist (methiothepin) blocked the 5-HT- and the CGS-12066B-induced inhibition of K+-evoked release of [3H]5-HT. A 5-HT1A antagonist (NAN-190) did not alter the inhibitory actions of exogenous 5-HT. Moreover, a 5-HT1A agonist (8-OH-DPAT), a 5-HT2A/2C agonist [(+/-)-DOI hydrochloride], and a 5-HT3 agonist (2-methyl-5-HT) did not alter the K+ evoked release of [3H]5-HT. These data demonstrate that 5-HT is released from the intermediate area of the rat thoracic spinal cord. The 5-HT receptor subtype involved in the inhibition of the evoked release of [3H]5-HT is of the 5-HT1B subtype. These findings may help clarify the complex role of 5-HT in spinal regulation of the sympathetic nervous system. © 1994 Wiley-Liss, Inc 1 This article is US Government work and, as such, is in the public domain in the United States of America. 相似文献
997.
998.
应用反向被动血凝集抑制试验和血凝集抑制试验检测流行性出血热患者早期血清(7病日内)中病毒核蛋白、膜蛋白抗体。103例患者血清,仅核蛋白抗体出现者33例,病情转径及无变化者31例(93.94%).而转重者仅2例(6.06%),且其血清抗体主要为IgG型。仅膜蛋白抗体出现的患者9例,病情转重者8例(88.89%),其抗体主要为IgM.核蛋白、膜蛋白抗体均阳性的61例患者,病情转归介于上述二者之间.提示:核蛋白抗体先出现的患者,病情多转轻,而膜蛋白抗体先出现的患者,病情普遍转重,似与病毒的"一次性打击"有关。在仅核蛋白抗体出现的患者中,有2例病情转重,但其抗体球蛋白类型为IgG,故尚不能排除本病有"二次感染"的可能,这一现象在推行本病预防接种时值得重视,另对进一步探讨本病的发病机理及预测患者的病情转归亦具参考价值。 相似文献
999.
Borgonovi E Brovetto PR 《The International journal of health planning and management》1994,9(1):25-38
The scarcity of resources in healthcare systems has general causes and country-specific causes. Common to most healthcare systems is a strong emphasis on management and an increased attention to the role of the market. Management and market are concepts which need clarification: management applies not only to individual institutions but to systems of institutions. Market implies not only the pursuit of individual interests but also the assumption of responsibility. The design or redesign of healthcare systems must take into account the level of management skills which each system and its institutions can rely on. Cost patterns in a healthcare system develop around its institutional design. Different factors produce varying levels of costs in different healthcare systems. The same applies to the effort needed to reach a certain degree of effectiveness in output. An outline of strengths and weaknesses of options for the design of healthcare systems is presented in the final part of the article. These should always be considered together with the specific features of each country. 相似文献
1000.
M. Q. Paiva D. Moura M. J. Vaz-da-Silva S. Guimarães 《Naunyn-Schmiedeberg's archives of pharmacology》1994,350(1):28-33
The present study was undertaken to analyse the relationship between postnatal development of vascular 2-adrenoceptor-mediated responses and the content of adrenaline in the adrenal gland and its concentration in plasma. Dog saphenous vein tissue from newborn, two-weeks old and adult animals were either preloaded with 3H-noradrenaline (or 3H-adrenaline) to study prejunctional -adrenoceptor-mediated effects or mounted in organ baths to determine isoprenaline-induced relaxation of preparations contracted by phenylephrine to about 65010 of the maximum. The adrenal glands and samples of blood from the same animals were taken for estimation of adrenaline and noradrenaline.At birth, there were no -adrenoceptor-mediated effects pre- or postjunctionally. At two weeks, while the results at the prejunctional level were not significantly different from those obtained in newborns, at the postjunctional level there was a relaxant response to isoprenaline, which antagonised about 35010 of the previous contraction to 1.75 mol·l–1 phenylephrine. In adults, isoprenaline (50 nmol·l–1) increased by 24% tritium overflow evoked by electrical stimulation of tissues preloaded with 3H-noradrenaline but not that of tissues preloaded with 3H-adrenaline. On the other hand, propranolol (1 mol·l–1) reduced by 21% the overflow of tritium evoked by electrical stimulation of tissues preloaded with 3H-adrenaline but not that of tissues preloaded with 3H-noradrenaline; postjunctionally, the maximal response to isoprenaline antagonised 70% of the previous contraction to 1.75 mol·l–1 phenylephrine.At birth the catecholamine content of the adrenals was relatively low (2.9 ol·g–1) and the adrenaline/noradrenaline ratio was 0.26; two weeks later, the catecholamine content was 14.5 mol·g-1and the adrenaline/noradrenaline ratio was 0.74; in adults, the catecholamine content was 24.5 mol·g–1 and the adrenaline/noradrenaline ratio was 2.3. In plasma, the highest concentration of adrenaline was observed at birth (11.8 nmol·l–1); two weeks later it was 5.5 nmol·l–1 and in adulthood it fell to 3.1 nmol·l–1.On the basis of these results, it is concluded that some link between the postnatal increase in adrenaline adrenal content and the development of 2-adrenoceptor-mediated pre- and postjunctional effects may exist. Additionally it is suggested that circulating adrenaline may trigger the development of 2-adrenoceptor-mediated responses as well as some hypertensive states occurring as a consequence of an overreactivity of the sympathoadrenal system.
Correspondence to: S. Guimarães at the above address 相似文献