Behavioral conditioning of endotoxin-induced plasma iron alterations

The cascade of physiologic mechanisms in response to infection, the acute-phase response, is recognized as playing a major role in host defence. One such response is the hypoferremia that is consistently reported to occur during bacterial infection. This study aimed to determine whether the alterations in plasma iron were conditionable using the conditioned taste aversion (CTA) paradigm. The regime involved the pairing of a novel-tasting saccharin solution with bacterial endotoxin. Seven days after the initial pairing of these stimuli (the test day), the saccharin solution was represented. Animals exposed to this condition displayed a significant reduction in the level of plasma iron. Animals treated with an intraperitoneal dose of 400 μg/Kg lipopolysaccharide (LPS) displayed lower conditioned iron levels than rats infused with 100 μg/Kg LPS; however, this difference was not significant. These results showed that in addition to other acute-phase responses (fever and anorexia), plasma iron alterations are able to be manipulated through behavioral manipulations.     

The influence of anaesthetic techniques and type of delivery on peripartum serum interleukin-6 concentrations

Background: Interleukin-6 is a pleiotropic cytokine with a wide range of physiological activities. It plays an important role in the immuno-neuro-humoral axis during stress and surgery.
Methods: Serum interleukin-6 in parturients was measured on hospital admission, immediately after birth and 12 and 24 hours later. All parturients had uncomplicated pregnancies, and delivered vaginally without (n=31) or with (n=20) epidural analgesia, or underwent Caesarean section under epidural (n=20) or general (n=10) anaesthesia.
Results: Serum interleukin-6 assayed immediately following Caesarean section was low, but peaked 12 hours later, irrespective of the anaesthetic technique or other foetomaternal characteristics. Patients who delivered vaginally showed the highest interleukin-6 levels immediately after delivery. These were positively correlated with serum interleukin-6 on admission and duration of labour. Serum interleukin-6 was significantly higher in parturients who had epidural analgesia, and was significantly lower in those receiving intravaginal prostaglandins compared to those without prostaglandins.
Conclusion: The interleukin-6 response after Caesarean section can be explained by a generalized acute phase response to surgery, with no anaesthetic, maternal or neonatal interference. The rapid increase in peripartum serum interleukin-6 levels after vaginal delivery reflects, in part, cervical ripening or labour, their physiological triggers and psychological or physical stress. Regional anaesthesia, duration of labour and exogenous prostaglandin administration can modulate the peripartum interleukin-6 response and subsequently the physiological effects of this cytokine.     

电刺激黑质对脑干伤害性单位放电的影响

本实验采用单细胞外记录神经元单位放电的方法，在Ｗｉｓｔａｒ大鼠上观察到网状巨细胞核。一区伤害性神经元５７个，其中伤害兴奋性神经元（ＮＥＮ）４２个，伤害抑制性神经元（ＮＩＮ）１５个。电刺激黑质对ＮＥＮ（２９）和ＮＩＮ（８的放电呈抑制作用，其反应百分率分别由刺激黑质第１分钟时的１．０±２．１％和－２０．４±６．２％，降到第５分钟时的－８３．６±１２．３％和－６５．４±１０．７％（Ｐ＜０．０１）。刺激黑质对少数ＮＥＮ（１３）和ＮＩＮ（７）的放电有兴奋作用，其值分别由第］分钟时的２０．５±７．３％和１．０±３．４％，升高到第５分钟时的７４．５±１０．７％和２１，５±８．６％（Ｐ＜０．０５）。氟哌啶醇注入ＰＡＧ腹外侧部可阻断刺激黑质的效应，这提示从黑质到网状巨细胞核α－区存在着一条痛调制通路，而且这种通路的递质是多巴胺能的。     

Staple penetration and staple histological response for attaching an epimysial electrode onto the abdominal surface of the diaphragm using a laparoscopic approach

Background: Laparoscopic stapling was found to be a viable option for attaching epimysial electrodes onto the abdominal surface of the diaphragm. Stapling was preferable to suturing due to its simplicity and speed. Methods: Of the two staplers tested in this study, the Ethicon Endopath was preferred over the Autosuture Endo Hernia because the staples did not penetrate the diaphragm when an electrode tab thickness greater than 0.75 mm was used. Results: The thickness of the electrode tab was an important factor in determining staple penetration but large variation in penetration depth indicated that other factors may also play a role. An electrode tab thickness of 1.0–1.25 mm was suggested to minimize the risk of diaphragm perforation. Conclusions: The histological reaction to staples implanted up to 14 months was unremarkable, reflecting the safety of laparoscopic staples for permanently anchoring electrodes on the diaphragm. Received: 2 April 1996/Accepted: 12 June 1996     

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.     

周围剂量当量仪的研制

周围剂量当量仪研制是根据国际辐射单位和测量委员会（ＩＣＲＵ）３９号报告推荐的周围剂量当量而设计的一种数字化智能型辐射防护仪。方法采用能量补偿对探测器进行能响校正。结果补偿结果使得探测器在４７～２３０ｋｅＶ与ＩＳＯ推荐的Ｈ＊（１０）／Ｋａ值误差在５％以内。本文重点描述了周围剂量当量仪探测器部分的工艺结构和剂量学性能以及电子学测量部分的主要功能。结论通过实际应用我们初步获得的结论是由于该仪器可直接测量周围剂量当量，稳定性好且具有自动取平均值特点，它可做为实验室校准用测量仪器，又由于该仪器体积小，电池供电，读数面板又有背光功能，它也可以做为现场仪器用于辐射防护实践的现场测量     

凝血机制紊乱在SIRS发展中的作用

凝血机制紊乱在全身炎症反应综合症(SIRS)发展、恶化过程中起重要作用．对SIRS时凝血系统紊乱的形成机制、在SIRS发生发展过程中的作用及其对病情危重程度的预测价值作一综述．     

猫延髓嘴侧腹外侧区微量注射内皮素－1对心血管和肾交感神经活动的影响

采用脑立体定向和脑内微量注射技术研究了猫延髓嘴侧腹外侧区（ｒＶＬＭ）微量注射内皮素－１（ＥＴ－１），对平均动脉压（ＭＡＰ）、心率（ＨＲ）和肾交感神经活动（ＲＮＡ）的影响。结果表明：ｒＶＬＭ内微量注射ＥＴ－１（２ｐｍｏｌ，０．５μｌ），可显著升高平均动脉压、增加心率和增强肾交感神经活动，并存在量－效间的正相关关系。双侧颈部迷走神经切断后，不影响上述结果。静脉预先给与α－受体阻断剂（Ｒｅｇｉｔｉｎｅ，５ｍｇ／ｋｇ），能显著抑制ＥＴ－１的上述升压作用。放射免疫观察到，ｒＶＬＭ内微量注射ＥＴ－１后，血浆精氨酸升压素（ＡＶＰ）含量显著升高，其变化与血压变化呈显著一致。以上结果提示，（１）ｒＶＬＭ内ＥＴ－１参与心血管活动的中枢调节，并显示有部位特异性；（２）该调节作用主要通过改变交感神经传出活动实现，而与迷走神经活动无关；（３）ｒＶＬＭ内ＥＴ－１还可能激动下丘脑室旁核及视上核的升压素能神经元，从而参与心血管活动的调节。     

Postsynaptic potentiation of end-plate currents in the rat diaphragm during variation in synaptic acetylcholinesterase activity

Leningrad University. (Presented by Academician of the Academy of Medical Sciences of the USSR S. N. Golikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 5, pp. 458–460, May, 1991.