The effect of bacterial melanin on electrical activity of neurons of the substantia nigra under conditions of GABA generation

The changes in spike activity of single neurons of the compact part of the substantia nigra, evoked by nucleus caudatus stimulation under conditions of long-term registration of the single and multiple, isolated and combined actions of GABA, GABA-amide, glutamine, and ethanolamine-O-sulfate (EOS) were studied in albino rats. Inhibition of poststimulus activity under GABA action was recorded and the inhibitory effect of GABA-amide was revealed. Primary excitatory and subsequent inhibitory effects of glutamine in combination with EOS were shown. The subsequent administration of bacterial melanin, synthesized by a mutant culture of Bacillus thuringiensis (BT-M) evoked a clear-cut and prolonged excitatory reaction during all the combined actions of GABA, GABA-amide, glutamine, and EOS. Preliminary administration of BT-M abolished the inhibitory poststimulus effects of GABA, GABA-amide, and EOS, as well as glutamine-induced excitation.     

Arthroscopic Shoulder Stabilization: Is There Ever a Need to Open?

Recent studies show comparable results of arthroscopic shoulder stabilization techniques compared with the gold standard open Bankart reconstruction. Great technical advances and ever-increasing surgeon experience have rendered pathology once deemed an indication for open surgery as treatable by arthroscopic means. With this movement toward a more universal application of all-arthroscopic techniques, we might consider the following question: Is there ever a need to open? To answer this question, we must first consider normal anatomy and then appreciate the contribution of deranged pathoanatomy to recurrent instability in each individual case. The surgeon must then determine whether this is best addressed via an arthroscopic or open technique. Arthroscopy, as compared with open stabilization procedures, holds the potential benefits of decreased morbidity rates, early functional rehabilitation, and improved range of motion. Despite potential advantages, arthroscopic stabilization is clearly contraindicated when a significant pathologic lesion contributing to recurrent instability cannot be adequately addressed as a result of the limitations of current techniques or instrumentation. On the basis of this principle, we believe that sizable glenohumeral bone defects remain the only absolute contraindication to an all-arthroscopic approach. Many complicating issues, such as attenuated capsule, humeral avulsion of the glenohumeral ligament lesions, cases of revision surgery, and collision or contact athletes, exist and warrant close attention. We prefer to think of these situations as “challenges” for which both arthroscopic and open surgery should be considered, rather than as true contraindications to arthroscopic shoulder stabilization. We are, by no means, advocating arthroscopic treatment in all cases of shoulder instability, because this would represent a gross oversimplification of the issues at hand. However, we do acknowledge that the steadfast contraindications to arthroscopic shoulder stabilization are decreasing every day.     

ENDOSCOPIC MANAGEMENT OF A DIEULAFOY‐LIKE LESION IN A DUODENAL DIVERTICULUM

We present a 70‐year‐old man who had two episodes of melena during the preceding 8‐year period. He had a Dieulafoy‐like lesion in a diverticulum in the third portion of the duodenum. While emergency endoscopy revealed neither apparent blood nor clots around the diverticular orifice, there was a non‐bleeding vessel in the fundus of the diverticulum. The vessel ceased bleeding after argon plasma coagulation and, since then, the patient has not experienced bleeding. In cases of gastrointestinal bleeding of obscure origin, duodenal diverticulum should be considered as a possible source of bleeding, even when endoscopy discloses no apparent bleeding.     

立体定向开放显微手术治疗脑内致痫小病灶

目的脑内致癫痫小病灶术前、术中的精确定位和病灶切除,是手术治疗效果的关键。探讨立体定向开放微创手术,皮层电极监测下切除脑内致痫小病灶的手术方法。方法53例症状性癫痫病例,CT、MR I检查有脑内小病灶(直径在0.5~3.0 cm),24 h视频脑电图确认致痫灶为脑内单发病灶。ASA 601S型立体定向仪CT引导辅助全麻环钻开颅,导针穿刺放置导管引导,显微镜下手术分离、切除病灶,皮层脑电图确认将致痫灶切除。结果病灶全切率达96.2%,术后50例得到随访,随访时间5~12个月,平均6.3个月,癫痫消失45例,脑电图检查记录到癫痫波11例,临床癫痫发作5例。因肺癌死亡3例。结论CT立体定向引导,显微手术切除颅内致痫小病灶,术中皮层电极确认将致痫灶切除,是一种定位精确、微创、安全、有效的治疗方法。     

脑干区占位病变的手术入路

本文报告了1990年5月以来脑干区大型、复杂占位病变15例.其中,位于脑干内3例,脚间窝2例,岩尖部4例,全岩骨区1例,全斜坡区2例,第四脑室内3例.本组采用以扩大了的岩骨入路为主的联合入路,行肿瘤全切除8例,次全切除5例.2例仅作了活检加减压术.除1例死亡外,均恢复良好.本文结合文献,对脑干区手术入路进行了讨论.     

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。     

rhGM-CSF对小鼠口腔粘膜损伤的防治作用

目的：探讨rhGM-CSF促进口腔腔溃愈合的作用机制。方法：取体外培养的胎儿口腔粘膜成纤维细胞，用rhGM-CSF刺激成纤维细胞后第2、4、6天用细胞计数及^3H－胸腺嘧啶掺入法（^3H-TdR）测定其增殖情况，结果rhGM-CSF对胎儿口腔粘膜成纤维细胞增殖及DNA合成有刺激作用，在80－100ng/ml时，细胞生长达到最佳状态，过高浓度rhGM-CSF的刺激作用反而下降。结论：rhGM-CSF可以通过刺激成纤维细胞增殖及DNA合成促进口腔溃疡愈合。     

103例流行性出血热患者的心电图及心肌酶学分析

目的了解流行性出血热病毒(EHFV)对心脏的损害情况。方法对103例流行性出血热(EHF)患者的心电图及心肌酶学检测结果进行分析。结果72例(69.9%)患者出现心电图异常,以窦性心动过缓(27.9%)及窦性心动过速(22.3%)最常见,明显高于其它类型的心电图改变(P分别<0.05和0.001)。103例流行性出血热(EHF)患者的CK、LDH及HBDH的升高者分别为43例(41.2%)、73例(70.9%)及46例(44.7%),以LDH异常最常见。轻型、中型、重型及危重型流行性出血热患者的LDH值分别为(346.3±155.6)IU/L、(330.7±130.7)IU/L、(1114.4±872.4)IU/L及(1227.1±936.7)IU/L,经统计学处理重型及危重型的值与轻型、中型比较均有显著性或高度显者性差异。结论EHF患者并发心肌损害较普遍,而且病情愈重者,心肌损害愈严重。     

Organization and physiology of thesubstantia nigra

Summary A comprehensive review of the literature on the anatomy, electrophysiology and pharmacology of thesubstantia nigra is presented. A diagram is developed taking into account the interneuronal interactions of neurotransmitters and receptors that control firing rates and neurotransmitter releases. The central features of the diagram are a positive dopaminergic feedforward process and a positive feedback mechanism mediated by extrasynaptic substance P diffusing from striatal terminals to dopaminergic dendrites of thezona compacta neurons. This loop can enhance the transmission of information from thestriatum through thepars reticulata output neurons. The loop is controlled at the level of zona compacta neurons by a negative feedback supported by the dendritic release of dopamine and boosted by pedunculopontine activation mediated by muscarinic receptors. The output of the loop is controlled by two negative feedforward processes, both involving GABAergic striatonigral afferents. Application of the model to pharmacological studies of diverse behaviors including seizures, turning, and conditioned behaviors reveals unforseen relationships and may offer insights into, and directions for, further analysis of the mechanisms and functions involved.