Detection of the interleukin 18 family in rat brain by RT-PCR

Interleukin 18, an inflammatory cytokine, mediates its effects by interaction with its receptor complex, consisting of the IL-18 receptor (IL-18R) and receptor accessory protein (AcPL). A functional inhibitor of IL-18, the IL-18 binding protein (IL-18BP), has been identified recently. This study reports the detection of IL-18, IL-18R, AcPL and IL-18BP mRNA expression in the brain of normal adult rats using RT-PCR.     

基于血氧水平依赖性的功能磁共振成像联合弥散张量成像技术纵向观察视觉通路病变中皮质功能和白质纤维结构的动态变化

目的：联合应用血氧依赖功能磁共振成像和弥散张量成像技术纵向观察视觉通路病变的皮质功能和白质纤维结构的动态变化,探讨病变后恢复期脑功能和结构重组的特点. 方法：病变组患者为2006-01/09解放军南京军区福州总医院收治,因视觉通路病变致单侧或双侧视觉障碍患者8例,采用美国GE公司Signa Excite HD 1.5T双梯度16通道磁共振成像系统,在病变早期和恢复期分别进行血氧依赖功能磁共振成像和弥散张量成像检查,对比治疗前后双眼刺激下脑激活区的体积以及视放射解剖结构、局部各向异性值,并与对照组12名正常被试比较. 结果：20例受试者均完成测试进入结果分析.①血氧依赖功能磁共振成像结果：正常被试采用黑白棋盘格刺激明显激活双侧枕叶距状回,平均激活皮质体素数为（9.12±2.47）万;病变组患者双眼刺激视皮质激活体积较对照组比较明显减少（P＜0.05）,治疗后复查,刺激的皮质激活像素数增多,激活区扩大.②弥散张量成像三维纤维束重建：对照组双侧视放射均能追踪至皮质下,12例被试视放射平均部分各项异性值为0.39±0.13.病变组中4例视觉通路病变患者视放射显示完整,与对照组间比较无明显差异,治疗前后纵向观察亦无显著变化;4例枕叶视中枢病变患者患侧视放射纤维部分中断、纤细,并可见移位,部分各项异性值均明显下降,治疗后视放射纤维束有一定程度恢复,部分各项异性值增加. 结论：血氧水平依赖功能磁共振成像联合弥散张量成像从皮质功能和纤维解剖方面诠释了病变的发展及康复过程,可帮助了解视觉通路病变后皮质功能区的重组.     

Effects of endogenous glucocorticoid secretion on the interleukin-6 response to bacterial endotoxin in pregnant and non-pregnant rats

Glucocorticoids (GCs) are released in response to immune activation by the bacterial endotoxin, lipopolysaccharide (LPS). However, GC secretion in response to immune activation and other stressors is attenuated at term of pregnancy. GCs are important modulators of the immune response, and both pro- and anti-inflammatory effects are described. Here, we examined whether GC secretion in response to LPS is maintained in earlier pregnancy before term, and investigated the role of endogenous GCs in modulating LPS-induced circulating cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), in pregnant compared to non-pregnant female rats. Plasma corticosterone (Cort) and ACTH responses to LPS were well maintained in pregnant rats at embryonic days 15/16 (E15/16) and E18/19 compared to non-pregnant rats. At E19, maternal LPS administration increased fetal plasma Cort and decreased testosterone in male fetuses. In non-pregnant animals, pretreatment with the GC synthesis inhibitor, metyrapone, inhibited the LPS-induced increase in IL-6, and the IL-6 response was restored by Cort replacement, indicating that LPS induction of IL-6 is Cort-dependent. In E15 pregnant animals, metyrapone had no effect on LPS-induced IL-6 levels, indicating that LPS-induction of IL-6 is not dependent on Cort. These contrasting patterns of IL-6 induction in non-pregnant and pregnant animals were reflected in levels of hypothalamic Socs3 mRNA, an indicator of IL-6 signaling pathway activation. In both non-pregnant and pregnant rats, LPS-induced plasma TNF-α responses were inhibited by metyrapone but not re-instated by Cort replacement. It is suggested that altered GC regulation of IL-6 may be required to sustain specialized functions of IL-6 during pregnancy.     

Anesthesia Management and Recovery after Laparoscopic Colorectal Surgery

Open abdominal procedures are associated with high levels of postoperative surgical stress that can impede recovery of physiological functions. Trauma resulting from aggressive manipulation of organs, and especially the intestine, can increase postoperative complications and result in delay in normal recovery. In an attempt to minimize complications and overall duration of hospital stay, fast track strategies, called “early recovery after surgery” (ERAS) protocols, have been adopted. Laparoscopic surgery has recently been identified as a major component of rapid recovery. One of the key differences between the open and the laparoscopic approach is the use of pneumoperitoneum for organ exposure during laparoscopy. Prolonged increase in abdominal pressure in addition to patient positioning can have a profound effect on hemodynamic parameters such as central venous pressure (CVP), cardiac output and intracranial pressure. Modifications in fluid administration, the choice of anesthetic agent and the depth of neuromuscular blockade are indicated to accommodate to the conditions imposed by pneumoperitoneum. Postoperatively, laparoscopic surgery is usually associated with less aggressive analgesia management. Based on ERAS protocols, patients are encouraged to initiate early oral feeding and to resume physical activity as soon as possible after abdominal surgery. While laparoscopic abdominal surgery is associated with reduced needs for pain medication, there appear to be no significant differences in early enteral feeding and mobilization between laparoscopic procedures and open surgery. When all factors are taken into consideration, however, laparoscopic colorectal surgery is associated with significant reduction in the duration of the total hospital stay, and is therefore recommended whenever feasible.     

Alterations in cognitive function and behavioral response to amphetamine induced by prenatal inflammation are dependent on the stage of pregnancy

Maternal infection during human pregnancy has been associated with the development of schizophrenia in the adult offspring. The stage of development and the maternal inflammatory response to infection, which undergoes quantitative and qualitative changes throughout gestation, are thought to determine critical windows of vulnerability for the developing brain. In order to investigate how these two factors may contribute to the outcome in the offspring, we studied the inflammatory response to turpentine (TURP) injection (100 μl/dam) and its consequences in the adult offspring, in pregnant rats at gestational day (GD) 15 or 18, which correspond to late first and early second trimester of human pregnancy, respectively. Maternal inflammatory response to TURP was different between the two GDs, with fever and circulating levels of the pro-inflammatory interleukin (IL)-6 significantly attenuated at GD 18, compared to GD 15. In the adult offspring, TURP challenge at GD 15 induced a significant decrease in pre-pulse inhibition (PPI) of acoustic startle, increased latency in the cued task of the Morris-water maze, prolonged conditioned fear response and enhanced locomotor effect of amphetamine. In contrast, the same immune challenge at GD 18 induced only a prolonged conditioned fear response. These results suggest a window of vulnerability at GD 15, at which TURP seems to affect several behaviors that are strongly modulated by dopamine. This was supported by increased tyrosine hydroxylase expression in the nucleus accumbens of the adult offspring of mothers treated at GD 15.     

The role of the vagus nerve in mediating the long-term anorectic effects of leptin

Leptin, the product of the obese (ob) gene, is mainly known for its regulatory role of energy balance by direct activation of hypothalamic receptors. Recently, its function in the acute control of food intake was additionally attributed to activation of the vagus nerve to regulate meal termination. Whether vagal afferent neurones are involved in longer term effects of leptin on food intake, however, remains undetermined. Using vagotomised (VGX) rats, we sought to clarify the contributions of vagal afferents in mediating the long-lasting effect of leptin on appetite suppression. Intraperitoneal (i.p.) injection of leptin (3.5 mg/kg) attenuated food intake at 4, 6, 8 and 24 h and body weight at 24 h postinjection in SHAM-operated rats; however, this response was not abrogated by vagotomy. In a separate study using immunohistochemistry, we observed leptin-induced Fos expression in the nucleus tractus solitarii, a brain structure where vagal afferent fibres terminate. This signal was not attenuated in VGX animals compared to the SHAM group. Moreover, leptin treatment led to a similar level of nuclear STAT3 translocation, a marker of leptin signalling, in the hypothalami of SHAM and VGX animals. In addition to the effects of leptin, vagotomy surgery itself resulted in a decrease of 24 h food intake. Analyses of brains from saline-treated VGX animals revealed a significant induction of Fos in the nucleus tractus solitarii and changes in agouti-related peptide and pro-opiomelanocortin mRNA expression in the hypothalamus compared to their SHAM counterparts, indicating that the vagotomy surgery itself induced a modification of brain activity in areas involved in regulating appetite. Collectively, our data suggest that vagal afferents do not constitute a major route of mediating the regulatory effect of leptin on food intake over a period of several hours.