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1.
Ana Vanson Arthur P. Arnold Barney A. Schlinger 《General and comparative endocrinology》1996,102(3):342-350
3β-hydroxysteroid dehydrogenase/Δ5−Δ4isomerase (3β-HSD) activity was measured in primary dissociated cell cultures prepared from telencephalons of developing zebra finches. 3β-HSD activity was confirmed after cultures were incubated with [7-3H]pregneno- lone (Preg) or (1,2,6,7-3H-) dehydroepiandrosterone (DHEA) and3H-progesterone (Prog) and3H-androstenedione (AE) were detected in the medium. Product identity was confirmed by recrystallizations and by HPLC analysis. When DHEA was used as substrate,3H-estradiol and3H-estrone were also detected in the culture medium, presumably derived from the aromatization of3H-AE or3H-T produced from3H-DHEA. To test this idea, cultures were incubated with3H-DHEA together with radioinert AE or with fadrozole HCl, a potent and specific aromatase inhibitor. In the presence of radioinert AE,3H-AE increased but metabolites of3H-AE decreased in the media; in the presence of fadrozole,3H-estrogens decreased but3H-AE and its androgenic metabolite3H-5β-androstanedione increased. These data demonstrate 3β-HSD activity in the songbird brain. The presence of Prog and estradiol in these cultures suggest that Preg and DHEA can potentially serve as substrates for the ultimate formation of active sex steroids in the songbird telencephalon. 相似文献
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We tested the effects of pre-treatment with dexamethasone on topically induced ocular anaphylaxis in the rat. Rats were immunized with dinitrophenylated Ascaris suum extract and challenged with di-DNP-lysine. Dexamethasone was administered topically once (24, 6, or 1 h before challenge) or three times (6, 4, and 2 h before challenge). A single pre-treatment given at 24 or 6 h had no significant effect. A single pre-treatment 1 h before challenge reduced the extent of edema assessed histologically but not clinically, and had no significant effect on the eosinophil count in conjunctival tissue examined 6 h after challenge. Eyes pre-treated with dexamethasone 6, 4, and 2 h before challenge showed a significant reduction in conjunctival edema assessed histologically and clinically 1 h after challenge. In addition, 6 h after challenge the number of eosinophils was significantly reduced. We conclude that repeated pre-treatment with dexamethasone can suppress both the immediate phase and the cellular late phase of topically induced ocular anaphylaxis. 相似文献
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For a quality management transformation to occur, a healthcare organization must focus on education and development, performance management, and recognition and reward systems during the first years of implementation. Education and development are perhaps the most important human resource management functions when implementing quality management principles and processes because behavioral changes will be required at all organizational levels. Specific programs that support an organization's quality management effort will vary but should include the conceptual, cultural, and technical aspects of quality management. The essence of quality management is to always satisfy the customer and to continuously improve the services and products the organization offers. The approach to performance management should therefore rely on customer feedback and satisfaction. An organization committed to quality management should base its performance management approach on customer orientation, process improvement, employee involvement, decision making with data, and continuous improvement. Managers and trustees are being challenged to provide innovative recognition and reward systems that reinforce the values and behaviors consistent with quality management. Such systems must also be aligned with the behaviors and outcomes that support the philosophy, mission, and values of the Catholic healthcare ministry. The following components should be considered for a recognition and reward system: base pay, incentives, benefits, and nonmonetary rewards. 相似文献
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Ma. Luisa Marván Joan C. Chrisler Jennifer A. Gorman Angela Barney 《Health care for women international》2017,38(9):971-982
The psychological meaning of menarche was explored in 102 college students from Mexico and the United States. The Natural Semantic Networks Technique was used and participants were asked to respond to the prompt “My first period was …” The strongest components of the Mexican women's semantic network were scary, confusing, and unexpected; the strongest components of the American women's semantic network were unexpected, annoying, and painful. Only the Americans listed positive words (i.e., nice). The Mexicans' network contained the most negative words (i.e., dirty). The results suggest a need for better education and greater social support, especially in Mexico. 相似文献
9.
Lukoyanov D Yang ZY Barney BM Dean DR Seefeldt LC Hoffman BM 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(15):5583-5587
Nitrogenase catalyzes the reduction of N2 and protons to yield two NH3 and one H2. Substrate binding occurs at a complex organo-metallocluster called FeMo-cofactor (FeMo-co). Each catalytic cycle involves the sequential delivery of eight electrons/protons to this cluster, and this process has been framed within a kinetic scheme developed by Lowe and Thorneley. Rapid freezing of a modified nitrogenase under turnover conditions using diazene, methyldiazene (HN = N-CH3), or hydrazine as substrate recently was shown to trap a common intermediate, designated I. It was further concluded that the two N-atoms of N2 are hydrogenated alternately (“Alternating” (A) pathway). In the present work, Q-band CW EPR and 95Mo ESEEM spectroscopy reveal such samples also contain a common intermediate with FeMo-co in an integer-spin state having a ground-state “non-Kramers” doublet. This species, designated H, has been characterized by ESEEM spectroscopy using a combination of 14,15N isotopologs plus 1,2H isotopologs of methyldiazene. It is concluded that: H has NH2 bound to FeMo-co and corresponds to the penultimate intermediate of N2 hydrogenation, the state formed after the accumulation of seven electrons/protons and the release of the first NH3; I corresponds to the final intermediate in N2 reduction, the state formed after accumulation of eight electrons/protons, with NH3 still bound to FeMo-co prior to release and regeneration of resting-state FeMo-co. A proposed unification of the Lowe-Thorneley kinetic model with the “prompt” alternating reaction pathway represents a draft mechanism for N2 reduction by nitrogenase. 相似文献
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