Neuromodulation in Psychiatric disorders: Experimental and Clinical evidence for reward and motivation network Deep Brain Stimulation: Focus on the medial forebrain bundle

Deep brain stimulation (DBS) in psychiatric illnesses has been clinically tested over the past 20 years. The clinical application of DBS to the superolateral branch of the medial forebrain bundle in treatment‐resistant depressed patients—one of several targets under investigation—has shown to be promising in a number of uncontrolled open label trials. However, there are remain numerous questions that need to be investigated to understand and optimize the clinical use of DBS in depression, including, for example, the relationship between the symptoms, the biological substrates/projections and the stimulation itself. In the context of precision and customized medicine, the current paper focuses on clinical and experimental research of medial forebrain bundle DBS in depression or in animal models of depression, demonstrating how clinical and scientific progress can work in tandem to test the therapeutic value and investigate the mechanisms of this experimental treatment. As one of the hypotheses is that depression engenders changes in the reward and motivational networks, the review looks at how stimulation of the medial forebrain bundle impacts the dopaminergic system.     

The expression of somatostatin receptors 1 and 2 in benign,pre‐malignant and malignant laryngeal lesions

The expression of somatostatin receptors 1 and 2 in benign, pre‐malignant and malignant laryngeal lesions The role of chemotherapy in squamous cell carcinoma of the larynx has not been clearly defined. Whilst toxic chemotherapy regimes may confer a marginal improvement in survival, surgery and radiotherapy remain the mainstay of treatment. Somatostatin is a naturally occurring peptide, which exerts antiproliferative and antiangiogenic effects via five membrane‐bound receptor subtypes. The expression of somatostatin receptor subtypes (SSTRs) 1 and 2 was studied in benign, pre‐malignant and malignant laryngeal specimens. Epithelial expression of SSTR1 was detected in 4/6 (67%) Reinke's oedema, 5/6 (83%) pre‐malignant and 8/12 (67%) malignant specimens, with virtually no stromal or vascular expression. High levels of epithelial SSTR2 expression were noted in all Reinke's oedema specimens, compared with low‐to‐moderate levels in only 2/6 (33%) pre‐malignant and 3/12 (25%) malignant specimens (P < 0.01). This ‘loss’ of epithelial SSTR2 expression may provide a growth advantage in pre‐malignant and malignant laryngeal lesions. Vascular expression of SSTR2 was ubiquitous in all groups, with scant stromal expression. Overall, most (>80%) pre‐malignant and malignant laryngeal specimens expressed at least one of the two SSTR subtypes studied. Somatostatin analogues may have a therapeutic role in squamous cell carcinoma of the larynx.     

基础医学教师课堂教学质量评价

为了了解本科教师的教学质量和教学效果 ,教学专家和学生评价了 14 7位基础医学教师。结果显示 ,讲师以上职称教师的教学质量明显好于初级职称教师 (P<0 .0 5 ) ,高级职称教师教学的科学性、艺术性和思想性明显好于讲师和助教 (P<0 .0 5 )。文章还对教学中存在的问题和对策进行了讨论。     

M细胞脊髓EPSP前电位的生理特性

直接刺激脊髓可在鲫鱼Ｍ细胞体诱发脊髓ＥＰＳＰ前电位（简称前电位）。前电位以较短的潜伏期〔（１．３３±０．２１）ｍｓ〕、较低的幅度〔（２．２２±１．０８）ｍＶ〕、较短的持续期间〔（２．６５±０．８３）ｍｓ〕和较低的刺激阈值〔（３．４９±０．７４）Ｖ〕区别于脊髓ＥＰＳＰ。前电位对Ｍ细胞的兴奋性具有调制作用，它可能由脊髓内直径较粗、传导速度较快、只经过一次混合突触接替的传入途径中介。     

Pre‐conditioning activates adenosine utilization in a cost‐effective way during myocardial ischaemia

During pre‐conditioning the interstitial concentration of adenosine, in contrast to lactate, presents a die‐away curve‐pattern for every successive episode of ischaemia. This die‐away pattern might not necessarily be attributed to diminished adenosine production. The present study was undertaken to investigate whether pre‐conditioning alters the metabolic turnover of adenosine as observed by the lactate production during ischaemia. Interstitial levels of metabolites in pre‐conditioned (n=21) and non‐preconditioned (n=21) porcine hearts were monitored with microdialysis probes inserted in both ischaemic and non‐ischaemic tissue in an open chest heart model. Three subgroups perturbated with either plain microdialysis buffer (control), buffer containing adenosine (375 μM ), or buffer containing deoxyadenosine (375 μM ) were studied. All animals were subjected to 90 min of equilibrium microdialysis before 40 min of regional myocardial ischaemia and 120 min of reperfusion. Pre‐conditioning consisted of four repetitive episodes of 10 min of ischaemia and 20 min of reperfusion. Significantly higher levels of inosine and lactate were found in the ischaemic tissue of the pre‐conditioned subgroup receiving adenosine (P < 0.05) compared with the other two subgroups receiving deoxyadenosine and plain buffer, respectively. This difference was only valid for pre‐conditioned ischaemic myocardium, and hence equal amounts of inosine and lactate were produced in the non‐preconditioned ischaemic myocardium regardless of the presence of adenosine or deoxyadenosine. In the non‐ischaemic myocardium baseline levels of metabolites were measured in all subgroups. Pre‐conditioning favoured degradation of exogenous adenosine to inosine successively ending up in enhanced lactate production. This was probably because of the involvement of the hexose monophosphate pathway in the pre‐conditioned ischaemic myocardium. This route may therefore be supplementary in energy metabolism as a metabolic flow can be started by adenosine ending up in lactate without initial adenosine 5′‐triphosphate (ATP) investment. Utilization of adenosine in this way may also explain the successive die‐away pattern of adenosine seen in consecutive pre‐conditioning cycles.     

Hepatitis B virus DNA in serum of healthy black African adults positive for hepatitis B surface antibody alone: possible association with recombination between genotypes A and D

In some patients with chronic liver disease induced by hepatitis B virus, viral DNA is known to persist in low concentration in serum after seroconversion to hepatitis B surface antibody-positivity. This phenomenon has, however, not been documented in asymptomatic black African carriers of hepatitis B virus. Using nested amplification by the polymerase chain reaction, we detected low concentrations of hepatitis B virus DNA in the serum of 6 of 23 (26%) healthy black African adults with normal liver function and with hepatitis B virus surface antibody as the only serological marker of the virus. This finding offers one explanation for the earlier observation of integrated hepatitis B virus DNA in hepatocellular carcinomas in black Africans whose serum was positive for surface antibody alone. A number of genetic changes were found in the six isolates that might be responsible for evasion of the immune response and persistence of the virus. Isolated mutations were detected in the "a" determinant of the surface gene and in the encapsidation signal. In all five isolates sequenced in the core promoter, mutations were present in the upstream regulatory region. Recombination between genotypes A and D was present in three of the isolates, including both of those in which the entire genome was sequenced. This change in genotype also overlapped the amino end of the polymerase domain and may result in sufficiently low levels of replication to allow viral persistence. Topoisomerase 1 specific trinucleotides were concentrated in the vicinity of the recombination breakpoints.     

梗死前心绞痛对急性心肌梗死溶栓-再灌注的影响

目的 :探讨梗死前心绞痛与急性心肌梗死溶栓 再灌注的关系。方法 :对 2 7例梗死前 1周内有不稳定性心绞痛和 2 5例梗死前无心绞痛的患者进行比较。 2组基础临床情况相匹配。梗死范围大小根据血清酶和∑R、NQ来估计 ,冠脉再通时间以抬高最明显的ST段迅速下降达 5 0 %为准。结果 :溶栓后 30min内梗死前心绞痛组 33%冠脉再通 ,而梗死前无心绞痛组没有 1例再通 (P <0 0 0 5 ) ;6 0min内再通率分别为 5 9%和 36 % (P <0 0 0 5 ) ;再通时间分别为 (49± 16 )min和 (6 9± 19)min(P <0 0 5 )。在梗死前心绞痛组 ,反映梗死范围大小的血清酶均明显低 ,而∑R相对较高 ,NQ数目相对较少 (均P <0 0 5 )。结论 :梗死前心绞痛组溶栓效果较好 ,梗死范围较小 ,梗死前反复心绞痛可作为对溶栓治疗敏感的预测指标。     

全麻诱导前预注芬太尼“先发镇痛”效应临床研究

目的：探讨全麻预注芬太尼的先发镇痛效应。／方法：选择40例择期全麻病人,随机分成试验组与对照组（n=20例）,术前常规用药,试验组诱导前用芬太尼5ug/kg,对照组将芬太尼改切皮后静注,术中麻醉维持相同,手术结束后病人自然清醒。术后有镇痛药使用意愿者均使用哌替啶镇痛。结果：两组病人一般情况及芬太尼总用量无显著性差异（P＞0．05）,试验组初次使用镇痛药时间明显延长（P＜0．01）,用药次数及剂量也显著少于对照组（P＜0．01）,试验组术后仅7（35％）例使用派替啶,而对照组使用哌替啶者达15（75％）例,两组差异性显著（P＜0．05）,结论：全麻前预注芬太尼具有良好的先发镇痛效应。     

自发性高血压大鼠左心室肥厚与血压、心肌局部血管紧张素Ⅱ的关系

目的 研究自发性高血压大鼠(SHR)左心室肥厚与血压、心肌局部血管紧张素Ⅱ的关系。方法 取SHR(n=40)及正常对照组WKY(n=41),分为4周龄、8周龄、12周龄、24周龄及36周龄组．测收缩压、体重,左心室重量及用放免法测定心肌局部血管紧张素(AⅡ)含量,并进行两两线性相关分析。结果 通过对5个年龄段的SHR和WKY的收缩压、左心室重与体重比(LVM／BW)及心肌局部AⅡ含量的测定结果发现三者之间存在相关性,其中AⅡ与心肌肥厚有明显相关性。结论 血压与AⅡ在SHR大鼠的左心室肥厚中起着重要作用。