刺激家兔中脑导水管周围灰质抑制束旁核伤害性放电的脊髓上机制

本工作比较了家兔脊髓背侧1/2进行横切前后刺激中脑中央灰质对束旁核伤害性放电的抑制率的改变。实验表明中央灰质既可通过公认的脊髓下行纤维抑制脊髓水平的痛传递,减弱束旁核单位的痛敏放电,也可通过某种脊髓上机制实现对束旁核的抑制。我们对这两种机制的相对重要性作了分析。用直11个束旁核痛敏单位所作的计算表明,在脊髓切割前,刺激中央灰质可使束旁核痛敏放电抑制67.5%,脊髓背侧1/2横切后,同样的中脑刺激只能使痛敏放电抑制42.9%。如以切割前的抑制率作为直100%,则切割可使抑制减弱36.5%,这一部分抑制应当是由被切断的脊髓下行纤维实现的,其余63.5%则可能主要通过脊髓上机制来实现。考虑到脊髓背半部横切不可能全部切断下行纤维,故实际上脊髓上机制的重要性不会有上述数值表示的那么大。     

A light and electron microscope study of changes occurring at the cut ends following section of the dorsal roots of rat spinal nerves

Summary Rat dorsal spinal nerve roots were cut; 20 h later the axons in the vicinity of the cut were examined by light and electron microscopy. The changes in the cut tip distant from the ganglion were largely degenerative. On the ganglionic side of the cut a cap of free unmyelinated sprouts was formed. These sprouts contained clear and dense-core vesicles 40–150 nm in diameter, smooth endoplasmic reticulum and mitochondria. Some of the unmyelinated sprouts were extensions of myelinated axons, others arose from myelinated axons by lateral budding. In both myelinated and non-myelinated axons there was an accumulation of mitochondria, tubulo-vesicular smooth endoplasmic reticulum and large and small dense-core vesicles for a distance of approximately 500 m behind the tip. Dense-core vesicles were more common in nonmyelinated axons than in their myelinated counterparts. In areas of intense accumulation the non-myelinated fibres were grossly swollen and distorted. The myelinated axons and some of the sprouts contained an unusual type of mitochondrion. The similarity between these sprouts and pre-synaptic terminals is discussed.I.R.D. is supported by the Medical Research Council; P.K. thanks the Mental Health Trust for a project grant     

Abnormal dorsal light response in teleost fish after intraocular injection of 6-hydroxydopamine

Following unilateral intraocular injection with 6-hydroxydopamine to the right eye, Midas cichlids displayed an acute abnormal dorsal light response, in favour of the right eye. This condition was reversed immediately by dopamine or dopamine receptor agonists delivered by intraocular injection but this recovery was not sustained, Retinal dopamine production reappeared gradually from day 30 post-6-hydroxydopamine treatment, and coincided with the fish beginning to adopt a normal dorsal light reaction. Dopamine production recovered completely at day 45 post-6-hydroxydopamine injection and coincided with complete recovery of the normal dorsal light reaction. These observations suggest a role for intraocular dopamine in maintenance of the visual part of the normal dorsal light reaction.     

The spinal cord in vitro: What can it tell us about nociception?

The use of amphibian and mammalian in vitro spinal cord preparations, e.g., hemisected cord and transverse slices, has gained in popularity over the years due to the flexibility and ease of use of such preparations compared to classical in vivo approaches. When combined with modern experimental methodologies, such as patch clamping of visualized single cells or post-experimental neuroanatomy, this approach provides a powerful addition to the armamentarium available to study nociceptive processing in the dorsal horn. Some of these novel experimental approaches and the insight into nociception that they have provided are described below. Neirofiziologiya/Neurophysiology, Vol. 38, Nos. 5/6, pp. 481–491, September–December, 2006.     

Direction of Temperature Control in the Thermal Biofeedback Treatment of Vascular Headache

In order to test for the specific therapeutic effects of thermal biofeedback (TBF) for hand warming on vascular headache (HA), 70 patients with chronic vascular HA were randomly assigned to TBF for hand warming, TBF for hand cooling, TBF for stabilization of hand temperature, or biofeedback to suppress alpha in the EEG. Patients in each condition initially had high levels of expectation of therapeutic benefit and found the treatment rationales highly credible. Participants in each condition received 12 treatment sessions on a twice-per-week basis. Based on daily HA diary data gathered for 4 weeks prior to treatment and 4 weeks after treatment, HA Index was significantly (p=.003) reduced as was HA medication consumption. There were no differential reducations in HA Index or Medication Index among the four conditions. Global self-reports of improvement gathered at the end of the post-treatment monitoring period also did not differ among the four conditions. We were unable to demonstrate a specific effect of TBF for hand warming on vascular HA activity.     

腹腔镜辅助胃癌D2根治术联合胃背侧系膜近胃端完整系膜切除术对进展期胃癌患者肠黏膜屏障功能和腹腔微转移的影响

摘要 目的：探讨腹腔镜辅助胃癌D2根治术联合胃背侧系膜近胃端完整系膜切除术对进展期胃癌（AGC）患者肠黏膜屏障功能和腹腔微转移的影响。方法：选取2016年12月～2018年12月我院收治的105例AGC患者,按随机数字表法分为对照组（n=52）和实验组（n=53）,分别施行腹腔镜辅助胃癌D2根治术、腹腔镜辅助胃癌D2根治术联合胃背侧系膜近胃端完整系膜切除术。观察两组手术情况（淋巴结清扫数量、手术时间、术中出血量、近切缘距离）、胃肠功能恢复指标（肛门排气时间、经口进食时间、肠鸣音恢复时间）、并发症、住院时间及术前、术后1 d、3 d、7 d肠黏膜屏障功能[尿乳果糖/甘露醇（L/M）、血清二胺氧化酶（DAO）]、气腹后、关腹前腹腔微转移指标[多巴胺脱羧酶（DDC）、癌胚抗原（CEA）],并于术后12个月随访两组复发率。结果：实验组术中出血量少于对照组（P＜0.05）;两组经口进食时间、肛门排气时间、住院时间、肠鸣音恢复时间比较无差异（P＞0.05）;术前、术后1 d、3 d、7 d两组血清DAO水平、尿L/M比较无差异（P＞0.05）;关腹前实验组腹腔冲洗液DDC、CEA水平低于对照组（P＜0.05）;两组并发症总发生率比较,差异无统计学意义（P＞0.05）;术后12个月随访,实验组和对照组各失访2例,实验组复发率3.92%（2/51）低于对照组20.00%（10/50）（P＜0.05）。结论：腹腔镜辅助胃癌D2根治术联合胃背侧系膜近胃端完整系膜切除术治疗AGC,能有效降低术中出血量,恢复胃肠功能,减少腹腔微转移及术后复发,且未增加肠黏膜屏障功能损伤,安全性高。     

Invasive legume management strategies differentially impact mutualist abundance and benefit to native and invasive hosts

Determining the best management practices for plant invasions is a critical, but often elusive goal. Invasive removals frequently involve complex and poorly understood biotic interactions. For example, invasive species can leave potent legacies that influence the success of native species restoration efforts, and positive plant‐microbial feedbacks may promote continued reinvasion by an exotic species following restoration. Removal methods can vary in their effects on plant–soil feedbacks, with consequences for restoration of native species. We determined the effects of invasion by a leguminous shrub (French broom; Genista monspessulana) on the density and community composition of, and benefit conferred by, its microbial mutualists in its invading range. Densities of soil‐dwelling rhizobia were much higher in areas invaded by G. monspessulana relative to uninvaded areas, and this increased density of rhizobia fed back to increase seedling growth of both the invader and native legumes. We further compared how three techniques for removing G. monspessulana affected the densities of rhizobia relative to areas where G. monspessulana was still present. Removal by hand‐pulling reduced soil rhizobial densities, and reduced growth of one native legume, while having no effect on the growth of the invader. Overall, our results show that the consequences of restoration techniques, both above‐ and belowground, could be critical for the successful removal of an invasive legume and restoration of native species.