对恶性肿瘤性别差异的再认识

恶性肿瘤性别差异表现在发病率、预后、治疗等多方面。生理结构、生活方式、工作、性格等流行病学因素是造成恶性肿瘤性别差异的外因,性激素及其受体研究在一定程度上解释了性别差异的本质,且为恶性肿瘤的内分泌治疗提供了理论依据。随着分子生物学技术发展,基因多态、分子突变等深入研究成果揭示更深层次的原因。     

d-Serine facilitates the effects of extinction to reduce cocaine-primed reinstatement of drug-seeking behavior

Male Sprague Dawley rats were allowed to self-administer cocaine (0.5 mg/kg) during 90 min sessions for a period of 15 days. On day 16, rats were either held abstinent in their home cage environment or experienced an extinction session in which the active lever had no programmed consequences. Facilitating N-methyl-d-aspartate (NMDA) receptor activity with the coagonist d-serine (100 mg/kg i.p.) before or following the extinction session significantly reduced the subsequent cocaine-primed reinstatement of drug-seeking behavior tested on day 17. d-Serine significantly reduced drug-primed reinstatement only when combined with extinction, and its effectiveness when administered following the training session suggested that an enhancement of consolidation of extinction learning had occurred. In contrast, d-serine treatment did not reduce sucrose-primed reinstatement, indicating that the beneficial effects of this adjunct pharmacotherapy with extinction training were specific to an addictive substance (cocaine) and did not generalize to a natural reward (sucrose).     

The relations among cry characteristics, demographic variables, and developmental test scores in infants prenatally exposed to methadone

This study examined the relations among developmental test scores, infants' demographic characteristics, and cry features. Cry features were strongly related to developmental test scores at all ages, suggesting that use of the infants' cry characteristics can help to identify those infants at greatest risk for later developmental problems.     

Activation of adenosine receptors in the posterior cingulate cortex impairs memory retrieval in the rat

Adenosine A1 and A2A receptor agonists and antagonists have been reported to alter learning and memory. The aim of our study was to investigate the involvement of adenosinergic system in memory retrieval into posterior cingulate cortex (PCC) of Wistar rats. To clarify this question, we tested specifics agonist and antagonists of adenosine A1 and A2A receptors in rats submitted to a one-trial inhibitory avoidance task. The stimulation of adenosine A1 and A2A receptors by CPA and CGS21680, respectively, impaired memory retrieval for inhibitory avoidance task, into PCC. These findings provide behavioral evidence for the role of adenosinergic system in the memory retrieval into PCC.     

Non-ligand activation of estrous behavior in rodents: cross-talk at the progesterone receptor

Estrous behavior in rodents is triggered by the binding of progesterone (P) to its intracellular receptor (PR). Non-steroidal agents (i.e., gonadotropin-releasing hormone, noradrenaline, dopamine and others), acting at the membrane, can facilitate estrous behavior in estrogen-primed rats. This action is mediated through the generation of second messengers (cyclic AMP, cyclic GMP, calcium) which, in turn, phosphorylate through diverse kinase systems (protein kinases A, G or C) either the PR or associated effector proteins linking the PR to the trans-activation machinery. P or its metabolites also activate cyclic AMP-signaling pathways by acting directly on the membrane or by modulating neurotransmitter release. Molecular processes resulting from second messenger signaling pathways and those from the progesterone-RP interaction synergize to elicit a full behavioral response.     

人是怎样与世界统一的——一个关于细胞信息跨膜传递特异性的假说

本文在讨论有限和无限的对立统一规律在抗原和抗体产生机制中的体现的基础上,提出关于细胞信息跨膜传递特异性机制的假说：第一信使可能由有限的基本单位构成,其信息的特异性可能通过有限的信息中介的组合来得以体现,效应部位也可能因具有特定的信息中介结合位点的组合而产生特异的细胞效应。本文最后为这一假说的证实提出展望。     

Eighteen-month-olds integrate verbal cues into their action processing: Evidence from ERPs and mu power

Behavioral research has shown that infants use both behavioral cues and verbal cues when processing the goals of others’ actions. For instance, 18-month-olds selectively imitate an observed goal-directed action depending on its (in)congruence with a model’s previous verbal announcement of a desired action goal. This EEG-study analyzed the electrophysiological underpinnings of these behavioral findings on the two functional levels of conceptual action processing and motor activation. Mid-latency mean negative ERP amplitude and mu-frequency band power were analyzed while 18-month-olds (N = 38) watched videos of an adult who performed one out of two potential actions on a novel object. In a within-subjects design, the action demonstration was preceded by either a congruent or an incongruent verbally announced action goal (e.g., “up” or “down” and upward movement). Overall, ERP negativity did not differ between conditions, but a closer inspection revealed that in two subgroups, about half of the infants showed a broadly distributed increased mid-latency ERP negativity (indicating enhanced conceptual action processing) for either the congruent or the incongruent stimuli, respectively. As expected, mu power at sensorimotor sites was reduced (indicating enhanced motor activation) for congruent relative to incongruent stimuli in the entire sample. Both EEG correlates were related to infants’ language skills. Hence, 18-month-olds integrate action-goal-related verbal cues into their processing of others’ actions, at the functional levels of both conceptual processing and motor activation. Further, cue integration when inferring others’ action goals is related to infants’ language proficiency.     

Differential Effect of TEA on Long-Term Synaptic Modification in Hippocampal CA1 and Dentate Gyrus in vitro

The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni²⁺ (50 μM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni²⁺ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 μM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni²⁺. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni²⁺. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus.     

公众对活体大器官移植的认知态度与对策

对河南地区公众关于活体大器官移植态度进行的抽样调查结果显示：（1）公众赞成开展活体大器官移植;（2）多数公众反对器官买卖,但赞成器官买卖的也有相当大的比例;（3）亲情是亲属活体器官捐献者愿意捐献的主要原因。针对调查结果,我们在比较分析的基础上,提出了相关对策,促使活体大器官移植技术更好地造福于人类。