N G-nitro-l-arginine antagonizes endothelium-dependent dilator responses by inhibiting endothelium-derived relaxing factor release in the isolated rabbit heart

The effects of a recently described inhibitor of endothelial NO synthesis, N ^G-nitro-l-arginine (l-NNA), on the vasomotor responses to endothelium-dependent and independent vasodilators, and on the release of endothelium-derived relaxing factor (EDRF), were studied in the isolated saline-perfused rabbit heart. Infusion of l-NNA (30 M) resulted in a 52±12% increase in basal coronary perfusion pressure. The vasomotor responses to 1 M acetylcholine (ACh) and serotonin after l-NNA became biphasic, showing a small transient dilation followed by a pronounced vasoconstriction. In contrast, the dilation observed with sodium nitroprusside was not affected by l-NNA. None of the above-mentioned effects was elicited by the Stereo-isomer d-NNA. Similarly, an increase in the basal coronary perfusion pressure by endothelin-1 (0.3 nM) to the same level as observed with l-NNA did not alter the vasomotor responses to ACh and sodium nitroprusside. The increase in cyclic GMP (cGMP) in platelets passing through the coronary vascular bed was used as an index of EDRF release. Platelet cGMP amounted to 0.50±0.10 pmol/mg protein after passage through the coronary bed of the unstimulated heart. When platelets were injected during an ACh infusion (1 M), a 2.7 fold increase in cGMP was observed (P<0.01). After a 30-min infusion with l-NNA, the cGMP content of platelets passing through the unstimulated heart was reduced by 62%. Likewise, the ACh-induced increase in platelet cGMP was totally blocked. These results show that l-NNA inhibits EDRF release, and is thus a potent and selective inhibitor of EDRF-mediated dilation in the isolated rabbit heart.     

The rheumatic patient''s early needs and expectations

During the last few years, studies have revealed that the need for psychosocial support and concrete social services are great in the early stages of the treatment of rheumatic diseases. The ability to keep a job, to do household chores, to participate in leisure activities and to maintain social relations is clearly impaired. Anxiety and depression are not unusual and often associated with weak support from relatives, loneliness and disturbed family relations. Nevertheless, the patients report resilience and determination to cope with the impacts of illness. Crisis intervention, vocational guidance and counselling about problems concerning the disease should be available and offered to the patients. As the patients seem to be unaccustomed to talking about their psychosocial problems, an empathetic and information-seeking attitude on the part of the health care staff is essential.     

高中学生自我价值感与应对方式、心理健康的相关研究

关于自我价值感的研究已经从概念、结构的探讨进入更为深入的自我价值感水平、发展特点以及与其他心理成分的关系的研究。国内关于自我价值感的相关研究 ,多数是借助国外的自尊量表作为测查工具 ,且仅仅从总体上考察了其他心理因素与自我价值感的相互关系[1-4] 。自我价值感作为应对的资源[5] ,不同自我价值感的人 ,在面对同一压力源时 ,可能有不同的应对反应 ,由此引起不同的情绪感受 ,因此 ,心理健康可能也存在差异。本研究将应用国内专家编制的有关量表 ,并将自我价值感视为一个较稳定的人格变量 ,考察自我价值感与应对方式、心理健康的…     

Contraluminal transport of hexoses in the proximal convolution of the rat kidney in situ

In order to study contraluminal hexose transport, concentration and time-dependent influx of³H-2-deoxy-d-glucose from the interstitium into cortical tubular cells has been measured. The influx curves fit to a two parameter kinetics (K _m 1.3±0.2 mmol/l,J _max 0.67±0.16 pmol/s · cm) plus an additional diffusion term (withP=6·10^–8 cm²/s) and a distribution ratio extracellular to intracellular amount of 2-deoxy-d-glucose of 10.6. Since the extracellular to intracellular free water space as estimated from morphological data was 12, one must conclude that glucose has only free access to 1/3 of the cell water. The intracellularly accessible space was augmented when the tubules were preperfused for 10 s with hypotonic saline. Thereby an increase of the compartment into which diffusion occurs was revealed and a final rupture of this intracellular compartment at 1/4 isotonic solutions was observed. Total replacement of ions in the peritubular perfusate by mannitol did not change 2-deoxy-d-glucose influx, indicating that it is Na⁺-independent. By adding isotonic concentrations of the respective sugars to the capillary perfusate, three degrees of inhibition of 2-deoxy-d-glucose influx could be revealed: strong inhibition byd-glucose, methyl--d-glucoside,d-mannose, 3-O-methyl-d-glucose, 2-deoxy-d-galactose, methyl--d-galactoside and 6-deoxy-d-glucose, moderate inhibition byd-galactose,l-glucose,l-mannose andd-fructose, no or borderline inhibition by methyl -d-glucoside, 2-deoxy-methyl--d-galactoside, 1-thio--d-glucose, 1-thio--d-galactose, 5-thio--d-glucose, myo-inositol and mannitol. The contraluminal 2-deoxy-d-glucose influx was also inhibited by phloretin, chlormerodrin and preperfusion with cytochalasin B. Starvation as well as streptozotocin diabetes has no influence on contraluminal 2-deoxy-d-glucose transport. Thus, in contrast to the luminal hexose transport system the contraluminal system is Na⁺-independent, does not require on OH-group at C-atom 2, acceptsl-glucose and fructose, but not an -methyl group at C-atom 1.     

父母教养方式对3～9岁儿童自尊的影响

目的:考察父母教养方式对3～9岁儿童自尊的影响。方法:采用3～9岁儿童自尊教师评定问卷和父母教养方式问卷对700名儿童进行调查。结果:(1)民主性教养方式与自尊总分呈显著正相关(r=0.687,P=0.000)。(2)父母在不一致性、溺爱性教养方式上的评分与儿童自尊总体(F=7.544,P=0.001;F=3.650,P=0.026)以及重要感(F=6.578,P=0.001;F=3.781,P=0.023)、外表感(F=4.418,P=0.012)、自我胜任感(F=6.132,P=0.002;F=4.989,P=0.007)维度存在显著差异。结论:民主性教养方式有助于儿童形成高自尊;相反,对儿童越溺爱、教育方式越不一致,则容易使儿童形成低自尊。     

Responses of calves to acute stress: individual consistency and relations between behavioral and physiological measures

The present study examined the consistency over time of individual differences in behavioral and physiological responsiveness of calves to intuitively alarming test situations as well as the relationships between behavioral and physiological measures. Twenty Holstein Friesian heifer calves were individually subjected to the same series of two behavioral and two hypothalamo-pituitary-adrenocortical (HPA) axis reactivity tests at 3, 13 and 26 weeks of age. Novel environment (open field, OF) and novel object (NO) tests involved measurement of behavioral, plasma cortisol and heart rate responses. Plasma ACTH and/or cortisol response profiles were determined after administration of exogenous CRH and ACTH, respectively, in the HPA axis reactivity tests. Principal component analysis (PCA) was used to condense correlated measures within ages into principal components reflecting independent dimensions underlying the calves' reactivity. Cortisol responses to the OF and NO tests were positively associated with the latency to contact and negatively related to the time spent in contact with the NO. Individual differences in scores of a principal component summarizing this pattern of inter-correlations, as well as differences in separate measures of adrenocortical and behavioral reactivity in the OF and NO tests proved highly consistent over time. The cardiac response to confinement in a start box prior to the OF test was positively associated with the cortisol responses to the OF and NO tests at 26 weeks of age. HPA axis reactivity to ACTH or CRH was unrelated to adrenocortical and behavioral responses to novelty. These findings strongly suggest that the responsiveness of calves was mediated by stable individual characteristics. Correlated adrenocortical and behavioral responses to novelty may reflect underlying fearfulness, defining the individual's susceptibility to the elicitation of fear. Other independent characteristics mediating reactivity may include activity or coping style (related to locomotion) and underlying sociality (associated with vocalization).     

重点理工科高校大一新生焦虑状况及相关因素的研究

目的探讨重点理工科学校大一新生焦虑状况及相关因素,为进行针对性的干预提供依据。方法以广东某重点理工高校2007级的大一学生为研究对象,采用自行设计一般项目调查表、状态-特质焦虑量表（STAI）、匹兹堡睡眠质量指数量表（PSQI）、应付方式问卷进行测评。结果测查学生不论男女状态焦虑、特质焦虑分均显著高于地方常模;19.29%的学生睡眠质量较差;高状态焦虑组和高特质焦虑组解决问题、求助应付因子分均显著低于低状态焦虑组和低特质焦虑组,而自责、幻想、退避应付因子分则显著高于低状态焦虑组和低特质焦虑组;多元逐步回归分析说明,学生如常采用解决问题应付方式,在一定程度上可避免焦虑的产生,而睡眠质量差、采用自责应对方式则可加重焦虑水平。结论采取有效的认知应对策略其意义是使学生改变应激源,以使其变得威胁较小或变成挑战,把情绪基调训练成兴奋、期待和征服。     

老年糖调节受损者不同转归情况应对方式的比较研究

目的：探讨老年糖调节受损（IGR）者的应对方式特点,并比较不同转归情况的老年IGR者应对方式的差异.方法：对220例老年IGR者的空腹血浆葡萄糖（FPG）及口服葡萄糖试验2小时血浆葡萄糖（OGTT2hPG）进行测定,并用特质应对方式问卷（TCSQ）对其应对方式进行评定,对不同转归情况的老年IGR者应对方式的差异进行比较.结果：老年IGR者的应对方式总体上是比较积极的,积极应对得分高于国内常模（P＜0.001）;有27.73%～78.64%的老年IGR者采用不同形式的积极应对方式,而4.09%～18.18%采取消极应对方式;不同转归组的老年IGR者应对方式的差异无显著性（P＞0.05）.结论：在老年IGR者的心理干预中应多关注采用积极应对方式较少、消极应对方式较多的这些人群.     

单细胞凝胶电泳在遗传学损伤检测中的应用

单细胞凝胶电泳或彗星试验是在暴露人群中评价遗传学损伤的新式方法。这种分析可以快速的探测单一细胞中不同形式的DNA损伤，因此适于在暴露人群分析应用。本文将对彗星试验在临床研究及监测职业、环境、合理饮食、生活方式等对DNA损伤的危险性，以及在DNA损伤与修复研究中的应用等方面进行综述。     

An investigation of depotentiation of long-term potentiation in the CA1 region of the hippocampus

We have investigated long-term synaptic depression in the CA1 region of rat hippocampal slices. Prolonged low-frequency stimulation (LFS; 900 stimuli delivered at 2 Hz) of the Schaffer collateral-commissural pathway in naïve slices did not induce long-term depression (LTD) of synaptic transmission. However, if long-term potentiation (LTP) was firstly induced in the pathway then LFS generated an LTD-like effect (i.e. depotentiation of LTP). Depotentiation could be induced 2 h (the longest time studied) after the induction of LTP and was stable for the duration of the experiment (followed for up to 40 min). The induction of depotentiation was not blocked by the N-methyl-d-aspartate receptor antagonist d-2-amino-5-phosphonopentanoate, the L-type voltage-gated Ca²⁺ channel blocker nimodipine or the nitric oxide synthase inhibitor N-nitro-l-arginine. However, the magnitude of depotentiation was reversibly reduced, in a stereoselective manner, by the specific metabotropic glutamate receptor (mGluR) antagonist (+)--methyl-4-carboxyphenylglycine. These results show that prolonged low frequency stimulation can result in an mGluR-dependent depotentiation of LTP.