Ca2+/calmodulin-dependent protein phosphorylation is not altered by amygdaloid kindling

Kindling is a process in which episodic electrical stimulation permanently increases seizure susceptibility. One mechanism to account for a change in seizure susceptibility is some alteration in signal transduction, possibly at the level of second messenger systems. In this study, male Long-Evans rats were kindled in the amygdala, and Ca2+/calmodulin (Ca2+/CaM)-dependent protein phosphorylation was assessed at the site of the primary kindled focus using one- and two-dimensional gel electrophoresis. In vitro phosphorylation of membrane and cytosol fractions in the presence of absence of Ca2+/CaM did not differentiate kindled from nonkindled amygdaloid tissue. These results suggest that changes in Ca2+/CaM-dependent phosphorylation are not related to the mechanism(s) underlying the establishment of an amygdaloid kindled focus.     

Improved quality of care and reduction of housestaff workload using trauma nurse practitioners

The University of California, Davis, Medical Center introduced the use of nurse practitioners (NPs) to the trauma service in fiscal year 1986-87 to alleviate the increasing burdens placed on the surgical housestaff in their attempt to accommodate the rising patient volume and acuity. The use of NPs was associated with a decrease in average length of stay for the seriously injured patients from 8.10 to 7.05 days while the length of stay for other patients in the hospital remained unchanged. Documentation of quality of care in the medical record increased substantially. For example, discharge summaries that were dictated by the NPs were judged complete in all aspects in at least 95% of sampled records compared with approximately 75% of records that were dictated by the residents. With introduction of the NPs, outpatient clinic waiting times decreased from 41 to 19 minutes. Patient complaints regarding the trauma team decreased from 16 to seven/year. Time saved for the housestaff averaged 352 minutes/day while the NPs were on duty. The NPs were well received by the hospital nurses, hospital quality assurance personnel, and ancillary services. They have proved to be of great value to the patients, the patients' families, the hospital, and the trauma team.     

Ganglioside treatment partially counteracts neurotoxic effects of trimethyltin but may itself cause neurotoxicity in rats: experimental results and a critical review.

We have demonstrated a deficit in working memory and/or consolidation of information in working memory into reference memory by a single oral dose of the neurotoxin trimethyltin(TMT). Moreover, TMT causes loss of hippocampal corticosterone receptors and increases brain glial fibrillary acidic protein(GFAP), an index of the astrocytic reaction to diverse types of CNS lesions. We tried to block the TMT-induced cognitive deficit and these biochemical markers by treating rats with purified mixed gangliosides (GS) for 21 days, starting 2 days before the TMT treatment. As expected, TMT decreased the number of corticosterone receptors in hippocampi and increased the GFAP concentration in hippocampi and to a lesser extent, in frontal cortices, measured more than 8 mon after treatment. The small increase in GFAP in frontal cortices was attenuated by GS but not in hippocampi. The pronounced learning deficits caused by TMT were attenuated to a small extent by GS in the TMT-GS group, when a learning criterion was used for the last session's performance of acquired lever-directed behavior. GS also delayed the appearance of significant performance differences between Controls and TMT-treated rats, when probed with a progressive fixed ratio schedule of reinforcement. However, most measures of learning and performance indicated that GS did not block the dysfunctional consequences of TMT treatment but instead caused similar functional decrements in rats treated with water instead of TMT. Corticosterone receptors in hippocampi were reduced to about 65% of Controls in the TMT-Water, TMT-GS, and Water-GS groups. A reduction in corticosterone receptors in hippocampi after TMT treatment probably reflects the loss of one or more cell types (e.g., pyramidal cells), which is supported by the increase in GFAP in this region. However, we did not observe a reciprocal relation between steroid receptors and GFAP after GS alone, indicating that GS did not cause detectable cell loss or cell damage, measured in this manner. Thus, reactive gliosis probably was not a pre-condition for the cognitive dysfunction. The fact that the cognitive deficits are probably related to hippocampal dysfunction supports the notion of a causal relationship between corticosterone receptor reduction and/or their altered function and cognitive impairment of this special type. The possibility that our results demonstrate potential neurobehavioral toxicity of GS is discussed in light of many reports which present data that can be similarly interpreted.     

INVOLVEMENT OF NON-NMDA AND NMDA RECEPTORS IN GLUTAMATE-INDUCED PRESSOR OR DEPRESSOR RESPONSES OF THE PONS AND MEDULLA

1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain.     

人体液中喷布洛尔及其代谢物的GC/MS分析

用气相色谱一质谱联用(GC-MSD)系统分析方法检出了人尿中喷布洛尔的6个羟化代谢物,用Scp-Pak柱提取的方法检出了人血浆中的原型药物。并从分子结构上对此药物的代谢途径进行了研究。尿中提取和血中提取的回收率分别为90.83.%和85.88%,Gc-MSD的检测限为5pg。本方法适用于运动员兴奋剂的系统检查。     

Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance

Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.