NR2A subunit expression shortens NMDA receptor synaptic currents in developing neocortex

NMDA receptors play important roles in learning and memory and in sculpting neural connections during development. After the period of peak cortical plasticity, NMDA receptor-mediated EPSCs (NMDAR EPSCs) decrease in duration. A likely mechanism for this change in NMDA receptor properties is the molecular alteration of NMDA receptor structure by regulation of NMDA receptor subunit gene expression. The four modulatory NMDAR2A-D (NR2A-D) NMDA receptor subunits are known to alter NMDA receptor properties, and the expression of these subunits is regulated developmentally. It is unclear, however, how the four NR2 subunits are expressed in individual neurons and which NR2 subunits are important to the regulation of NMDA receptor properties during development in vivo. Analysis of NR2 subunit gene expression in single characterized neurons of postnatal neocortex revealed that cells expressing NR2A subunit mRNA had faster NMDAR EPSCs than cells not expressing this subunit, regardless of postnatal age. Expression of NR2A subunit mRNA in cortical neurons at even low levels seemed sufficient to alter the NMDA receptor time course. The proportion of cells expressing NR2A and displaying fast NMDAR EPSCs increased developmentally, thus providing a molecular basis for the developmental change in mean NMDAR EPSC duration.     

女性掌握某些科技产品使用权

在某些科技产品的使用过程中，美国女性的主导权超过男人，比如观看电视节目、DVR使用、浏览社会类媒体网站，甚至是打游戏。这个调查结果是由Solution Research Group发布的一个新的、关于“女性和数字生活方式”报告发布的。     

The role of parathyroid hormone in the pathogenesis, prevention and treatment of postmenopausal osteoporosis

BACKGROUND: Nuclear deoxyribonucleic acid (DNA) content is a prognostic factor in several tumors, and decisions regarding treatment have been made using this parameter. Nevertheless, there is no agreement in head and neck cancer. The purpose of the present study was to ascertain whether tumor DNA content correlated with prognosis in cases of primary squamous cell carcinoma (SCC) of the oral cavity and tongue base. METHODS: A retrospective study of formalin-fixed, paraffin-embedded tissue from patients with histologically confirmed SCC of the oral cavity and tongue base was performed using flow cytometry. Tumor DNA content was studied in 109 sets of specimens from previously untreated patients. All of them underwent surgical resection at the University "Hospital de La Princesa" between 1982 and 1992. Clinical parameters (age, sex, site of primary tumor, clinical stage, adjuvant therapy received, and disease-free and overall survival) and histologic parameters (histopathologic stage, tumor differentiation, type of inflammatory infiltration, presence of perineural invasion) were recorded in all cases. An exhaustive statistical analysis was applied. RESULTS: Only the histograms of 93 patients were adequate for consideration. In flow cytometric analysis, DNA aneuploidy was observed in 51 tumors (55%). The proportion of aneuploid tumors was significantly higher in advanced-stage carcinomas (p < .05), tumors with perineural invasion (p < .05) and in men (p < .05). In the 24 patients with lymph node metastasis, the incidence of aneuploidy was 82% (19 of 24) (p < .05). The rate of metastasis and aneuploidy increased as the degree of differentiation decreased (p < .05 for both). Patients with aneuploid carcinomas in both early and advanced stages had shorter relapse-free and overall survival periods than did the patients with diploid tumors (p < .001 for both). A Cox regression analysis demonstrated that ploidy was the single most important prognostic factor in determining relapse and death (p < .001 for both). CONCLUSIONS: The results indicate that tumor DNA analysis by flow cytometry appears to be useful as a supplement to clinical and histologic evaluation in predicting the tendency of SCC of the oral cavity and tongue base to metastasize to regional lymph nodes and to predict the outcome of the disease.     

Middle fossa decompression of the trigeminal sensory root for trigeminal neuralgia--a re-appraisal and a modification of the technique

Twenty-three patients with intractable trigeminal neuralgia were treated by a modified technique of middle fossa extradural decompression of the trigeminal sensory root at the petrous ridge. After exposing the ganglion and the root at the petrous ridge, by an extradural Frazier's approach a thin layer of autogenous fat was interposed between the dura propria and the middle fossa dura anteriorly, and between the petrous ridge and the root posteriorly. The fat layers were used to prevent dural adhesions and to maintain a space between the petrous ridge and the root. The dura propria was preserved intact. All patients obtained immediate relief of pain following surgery. Twenty patients continue to remain pain free. Two patients have mild occasional pains and one has a persistent pain of moderate intensity. One patient developed a dense sensory loss and two had delayed facial weakness which recovered completely within a month. The mechanism of trigeminal neuralgia is discussed on the basis of anatomical, histopathological and electrophysiological findings and the rationale of middle fossa decompression of the root is stressed. This method is short, simple and safe and may serve as an alternative to the more recent methods of treating trigeminal neuralgia.     

The management of massive pneumocephalus and cerebrospinal fluid rhinorrhoea as a consequence of biopsy in a patient with inverted papilloma

Nasal polypectomy is a common ENT operation. Cerebrospinal fluid (CSF) rhinorrhoea and pneumocephalus are rare complications. We present a patient who developed both these complications after biopsy of nasal polyps which subsequently proved to be an inverted papilloma. He had a defect in the ethmoid roof, which was repaired. Whilst endoscopic repair of CSF leak is increasing in popularity, in this patient because of his pathology and difficulty of access a more traditional lateral rhinotomy approach was made with a successful outcome. An overview of the management of these complications is presented.     

美国脱水马铃薯粉在月饼中的应用研究

马铃薯是世界上优质的粮食种类之一。主要是直接用于食用。而在美国有20％的马铃薯用于制备脱水的马铃薯产品。美国的脱水马铃薯制品是采用优质的品种、大规模的机械化生产、严格的科学管理所得的马铃薯为原材料，经过去皮、切片、清洗、蒸煮、研磨、干燥和粉碎等工艺生产各种各样的脱水马铃薯产品。该脱水产品由于具有增稠、膨胀和持水、粘合、增量、成壳、透明等特点；且具有优良的产品质量、保质期长、运输费用低等经济上的效益，越来越广泛地应用在休闲食品、烘焙、面制品、沙司、肉类加工、餐饮等行业上。本文就以美国马铃薯粉（flour）为原材料，研究在广式月饼上应用，旨在拓宽应用的品种范围。     

美国脱水马铃薯产品在胚料上的应用

二次膨化技术，也称间接膨化技术，是指将混合，搅拌好的物料输送到挤出机，经过高压，低温挤出，经干燥后，在热风和沸油中膨化。我们研究了美国马铃薯粉在二次膨化中的应用，并探索了美国马铃薯在胚料生产中的作用以及其他辅料在胚料中的作用。     

Mapping brain networks engaged by, and changed by, learning

Major goals of research into the neurobiology of learning and memory are to identify (1) brain areas/circuitries that subserve different mnemonic functions and (2) chemistries that encode the memory trace. The discovery that activity modulates neuronal gene expression provided techniques attendant to the first goal and candidates for cellular changes pertinent to the second. Studies in our laboratories have exploited activity-regulated changes in c-fos gene expression to map regions engaged in two-odor discrimination learning, with particular interest in neuronal groups in hippocampus and amygdala. The results of these studies demonstrate that the subdivisions of hippocampus and amygdala do not act in concert across behaviors but are differentially activated depending on task demands. In hippocampus, preferential activation of field CA3 was uniquely associated with initial learning of an odor pair, whereas predominant activation of CA1 occurred with exploration of a novel field and with overtrained responding to odors. The reappearance of precisely the same balance of subfield activation within disparate behavioral contexts was taken to suggest that the hippocampus has basic modes of function that recur in different circumstances and make rather generalized contributions to behavior. Within the amygdala, the basolateral division was most prominently active during task acquisition but not during performance of the well-learned discrimination. Indeed, the amygdala appeared to play the dominant role relative to hippocampus in the early stages of associating positive and negative valences with discriminative cues. These results demonstrate that the balance of neuronal activity both within and between limbic structures changes across sequential stages of odor learning in a fashion that is likely to define behavioral output.     

Drug binding and nucleotide hydrolyzability are essential requirements in the vanadate-induced inhibition of the human P-glycoprotein ATPase

P-glycoprotein (Pgp) mediates drug transport utilizing the energy released from ATP hydrolysis. However, the mechanism by which Pgp couples these two reactions remains unclear. The present work is undertaken to describe kinetically the first step, which is the interdependence of nucleotide and drug binding to the Pgp by the use of vanadate. Preincubation of human Pgp expressed in Sf9 insect cells with vanadate in the presence of Mg2+, ATP, and verapamil resulted in nearly complete and stable inhibition of the drug-stimulated ATPase function. In contrast, the Pgp ATPase function was nearly unaffected when Mg2+, ATP, or verapamil was omitted. Inhibition was highly specific for divalent cations that support ATP hydrolysis, for nucleotides that serve as substrates of hydrolysis, and for those drugs/compounds that interact with the drug-binding/transport sites of the Pgp. Kinetic analysis indicated that vanadate inhibition was MgATP concentration-dependent with an apparent Ki value similar to the apparent Km, suggesting that MgATP was bound to a similar ATP-binding site in both the ATPase inhibition and activation reactions. In support of this conclusion, vanadate, in the presence of Mg2+ and verapamil, caused selective trapping of 8-azido [alpha-32P] ATP and covalent labeling of ATP-binding site in the Pgp. Differences were observed in the vanadate-induced inhibition of wild-type and Val185 mutant Pgp's with different drug/compounds. These results suggested that the affinity of the interacting drug/compound is a constant and influences the overall stability of the inhibited Pgp species. Possible implications of these observations for the coupling of ATP hydrolysis to drug transport are discussed.