The contribution of AMPA and NMDA receptors to graded bursting activity in the hippocampal CA1 region in an acute in vitro model of epilepsy.

The AMPA/KA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the NMDA receptor antagonist 2-amino-5-phosphonovalerate (D-APV) were used to investigate the contribution of excitatory amino acid (EAA) receptors to graded bursting activity recorded in the CA1 region of the rat hippocampal slice following bath application of the convulsant drug bicuculline methiodide (BIC, 2-3 microM). CNQX (5-9 microM) significantly antagonised the burst in a reversible, concentration-dependent manner (n = 5). The effect involved a reduction in the amplitude but not the number of population spikes of the burst and also a depression of the underlying burst excitatory post-synaptic potential (EPSP). D-APV (5-25 microM), in contrast, reduced the amplitude and number of spikes in the burst but had no effect on the burst EPSP (n = 5). Following a single concentration of CNQX (5 microM), applied in the presence of bicuculline, it was observed that the components of epileptiform response which remained could be completely abolished with D-APV (10 microM; n = 10). It was also shown that, following elimination of synaptic transmission with CNQX (5 microM), application of bicuculline (2-3 microM) induced a small burst that could be reversibly antagonised with D-APV (10 microM). These results show that evoked epileptiform activity witnessed in the presence of bicuculline involves the activation of both AMPA and NMDA receptors, the AMPA receptor activation making the major contribution. The burst mediated by NMDA receptors is not dependent on prior activation of AMPA receptors.     

Records as a data source: the case for health visitor records

Health records as a source of research data are examined. A case study approach is adopted to evaluate the reliability of health visitor records as a data source. It is argued that such records may be a rich source of epidemiological data although their deficiencies should be acknowledged.     

Structure-activity studies on an excitatory receptor for glutamate on leech Retzius neurones.

1 Intracellular recordings were made from Retzius cells from the segmental ganglia of Hirudo medicinalis and Haemopis sanguisuga. Glutamate had a direct excitatory effect on the leech Retzius cells. 2 L-Glutamate was 25 times more potent than D-glutamate. 3 L-Glutamate was approximately equipotent with ibotenic acid and 11.2 times more potent than L-aspartic acid. 4 Quisqualic acid and kainic acid were both approximately 100 times more potent than L-glutamate. DL-1-Amino-cis-1-3-dicarboxyclyclopentane was approximately 5 times more potent than L-glutamate, while the trans isomer was 105 times less potent. 5 alpha-NH2-pimelic acid and beta-CH3-glutamic acid reduced the response to L-glutamate. 6 It is suggested that glutamic acid may interact with the Retzius cell glutamate receptor in an extended conformation.     

Pharmacological identification of acetylcholine and glutamate excitatory systems in the dentate gyrus of the rat

The responses of dentate granule cells to medial septum (MS) and perforant path (PP) stimulation were examined in urethane anaesthetized rats. MS and PP stimulation evoked an orthodromic activation of granule cells which was correlated with the negative transient of the characteristic field potential elicited from each site. The effects of electrophoretic application of acetylcholine (ACh) and glutamate (Glu) were examined on granule cells identified in this manner. The excitatory action of ACh but not that of Glu was antagonized by atropine. Glutamate diethylester (GDEE) blocked the excitation produced by Glu but not ACh. The synaptically evoked excitation elicited by MS was blocked by atropine but unaltered by GDEE whereas the PP excitatory response was blocked by GDEE and unaltered by atropine. The results of this study indicate that two discrete excitatory systems are present in the dentate gyrus of the rat: a cholinergic system originating in the medial septum and a glutamate mediated system originating in the entorhinal cortex.     

Shaping the trajectory of patients with venous ulceration in primary care

Objective  To explore the patient's experience of venous ulceration and how it is shaped within primary care.
Design  Qualitative grounded theory study.
Participants and setting  Thirty-nine patients, 33 nurses and 14 general practitioners in a major health district in England.
Results  The findings indicate that patients with the chronic condition of venous hypertension are handled in an anomalous way within primary care when they present with ulcers on their lower limbs. The trajectory projections for the patients are not developed from the usual basis of a medically defined condition-specific diagnosis but from a symptom-specific diagnosis. This leads to an unusual context of care where there is a serious but unrecognized conflict of focus between the nurses and their patients. The nurses in this study tended to set priorities related to the ulcer and to the underlying pathology, whereas the patients wanted help in pain management and in normalizing their lives. The patients eventually came to a position of 'guarded alliance' ² that in this study took one of three forms: adapting and enduring, emphasizing the positive, or negotiating for comfort.
Conclusion  The acute care approach applied to patients with this chronic condition led to a situation where the professionals usurped the self-care potential of the patients and navigated rather than piloted them through an acute phase of an underlying chronic illness. This in turn, led to poor quality of life for many of the patients and to frustration for the nurses who were failing to achieve the outcomes they desired. Both perspectives need to be encapsulated into the treatment approach for patients with this condition: healing the ulcer and normalizing the patients' lives can and should form the basis of care.     

髂骨皮瓣移植加外固定器固定修复胫骨缺损伴小腿软组织缺损

目的 探讨髂骨皮瓣移植加外固定器固定修复胫骨缺损伴小腿软组织缺损的方法和临床效果。方法1998年5月～2001年5月,应用Bastiani外固定器固定腔骨骨折及缺损端,同时行旋骼深血管为蒂的骼骨皮瓣移植,治疗腔骨缺损伴小腿软组织缺损共22例。男15例,女7例;年龄16～58岁,平均37岁。随访5～36个月,平均25.5个月。结果22例髂骨皮瓣均完全成活,胚骨及软组织缺损Ⅰ期修复,骨外固定器固定牢固,骨折愈合快,植骨与骨折端于术后2～4个月达临床愈合,术后3～6个月达骨性愈合。患肢功能恢复良好,无一例发生骨不连、骨坏死、关节僵直等并发症。结论 吻合旋骼深血管的髂骨皮瓣移植,可Ⅰ期修复胫骨缺损伴小腿软组织缺损。结合骨外固定器固定,可为植骨愈合创造便利条件,且固定牢靠,受区创伤小,可早期进行功能锻炼,避免应力遮挡,促进骨折愈合,是目前治疗胚骨缺损伴小腿软组织缺损的有效方法。     

A comparative histological and electrophysiological study of some neurotoxins in the rat hippocampus

Following dark incubation of isolated retinas of Xenopus laevis in Ringer solution supplemented with ³H-2 Deoxy-D-glucose (2DG), virtually all of the uptake of the label was by the inner segments and synaptic bases of the photoreceptor cells. Autoradiographs prepared from conventionally fixed tissue showed the same cellular distribution of label as those prepared from identically incubated, unfixed, freeze-dried retinas. However, fixation removed about 77% of the total counts. This fixation-labile, soluble fraction was identified as being primarily 2DG-6 phosphate by thin-layer chromatography. The remaining insoluble fraction corresponded in distribution to glycogen grains. In cones, glycogen is stored primarily in the paraboloid, whereas in rods it is distributed throughout the inner segment and synaptic base. EM autoradiographs illustrated that these were the sites over which fixationresistant 2DG label was localized. Measurements of radioactivity associated with extracts of retinal glycogen following 2DG incubation demonstrated that a disproportionately high fraction of total counts were associated with the glycogen fraction. We conclude that in the amphibian retina 2DG may be incorporated into glycogen.     

The use of qualitative methods in the study of parents' experiences of care on a children's surgical ward

User satisfaction with the care of hospitalized children is examined in this paper It is argued that parents are proxy consumers but that their status is conditional on the way in which they exercize choices Parents' involvement in the care of their children means that the term 'user' is more appropriate than 'consumer' Methodological problems in the assessment of user satisfaction are discussed A study of the experiences of parents of 24 children discharged from a surgical ward of a children's hospital is described and the implications for the assessment of user satisfaction reviewed The study demonstrates that qualitative methods have value in the assessment of user satisfaction with care A particular strength of qualitative methods of inquiry is that limitations of users' choice in care can be assessed     

Hypothalamic control of brown adipose tissue in Zucker lean and obese rats. Effect of electrical stimulation of the ventromedial nucleus and other hypothalamic centres

Electrophysiological stimulation of the hypothalamic ventromedial nucleus (VMN) resulted in an increase in interscapular brown adipose tissue (BAT) temperature in both lean and obese (fa/fa) rats. Graded stimulations resulted in progressively larger temperature increases in both lean and obese (fa/fa) groups. Both intraperitoneal injection of propranolol and surgical denervation (but not sham denervation) abolished the increase in BAT temperature following VMN stimulation, in both lean and obese (fa/fa) groups. Electrical stimulation of the supraoptic region, and certain anterior hypothalamic regions also resulted in increases in BAT temperature of lean and obese (fa/fa) rats, but stimulation of the dorsomedial nucleus and regions of the lateral hypothalamus did not affect BAT temperature. All hypothalamic regions capable of activating BAT gave a similar maximum rise in temperature for a given stimulus in lean and obese (fa/fa) rats. These results suggest that the efferent sympathetic pathway from the VMN and other hypothalamic regions of BAT is normal in the obese (fa/fa) rat.