Connectivity measures suggest a sub-cortical generator of myoclonus in Angelman syndrome

ObjectiveThe clinical and neurophysiological characteristics of myoclonus in Angelman syndrome (AS) have been evaluated in single case or small cohorts, with contrasting results. We evaluated the features of myoclonus in a wide cohort of AS patients.MethodsWe performed polygraphic EEG-EMG recording in 24 patients with genetically confirmed AS and myoclonus. Neurophysiological investigations included jerk-locked back-averaging (JLBA), cortico-muscular coherence (CMC) and generalised partial directed coherence (GPDC). CMC and GPDC analyses were compared to those obtained from 10 healthy controls (HC).ResultsTwenty-four patients (aged 3–35 years, median 20) were evaluated. Sequences of quasi-continuous rhythmic jerks mostly occurred at alpha frequency or just below (mean 8.4 ± 1.4 Hz), without EEG correlate. JLBA did not show any clear transient preceding the jerks. CMC showed bilateral over-threshold CMC in alpha band that was prominent on the contralateral hemisphere in the patient group as compared to HC group. GPDC showed a significantly higher alpha outflow from both hemispheres toward activated muscles in the patient group, and a significantly higher beta outflow from contralateral hemisphere in the HC group.ConclusionsThese neurophysiological findings suggest a subcortical generator of myoclonus in AS.SignificanceMyoclonus in AS has not a cortical origin as previously hypothesised.     

土壤环境基因组技术及其在新药发现中的应用

土壤是微生物最重要的生境，土壤微生物具有极大的多样性。然而传统培养技术只能得到约1％的微生物纯培养，其余都是未被纯培养微生物。利用土壤环境基因组技术，可以把未被纯培养微生物的基因克隆到载体中并在宿主中进行表达，获得比已培养微生物丰富的代谢产物多样性，这为我们发现新颖结构先导化合物以及新药开辟了新的道路。本文介绍应用环境基因组技术构建土壤DNA文库的思路和方法。     

Microvasculature of bone

The three dimensional vascular microarchitecture of mercox resin on the lateral surface of parietal bone in Wistar strain adult male rats (b. w. 260–350 g.) was studied in relation to bone formation by SEM observation of corrosion casts. The microarchitecture was a single layer of network composed of precapillary artery, capillary and postcapillary vein, which were serpigious, sometimes joined with the vein from the vascular foramen of bone. The meshes of this network, which were irregular and varied in size, existed apart from the bone surface. According to the report of Iwaku and Ozawa (1986), it was reported that the vascular microarchitecture of the bone surface was very changable during the process of bone remodeling and this network, which was shown on the flat bone surface in this study, was very similar to one in the resting phase and/or the period in which the bone formation further advanced. From these facts and the morphological features of the bone surface observed here by SEM, it is suggested that this vascular network was closely related with the resting stage and/or the period in which bone formation further advanced in bone remodeling.     

Hemiballismus from a parietal stroke in a Parkinson patient.

Stroke-induced hemiballismus (HB) has been reported to improve motor function in people with Parkinson's disease (PD). We report on a patient who developed HB from a parietal infarct. The HB was improved by very low-dose clozapine but the HB did not improve the parkinsonism. This suggests that HB itself, whether from a lesion in the subthalamic nucleus or elsewhere, is not what improves motor function in PD; instead, the physiological function of the damaged structure is the determining factor.     

Extracellular signal regulated kinases 1/2 signal pathway and responses of astrocytes after diffuse brain injury

BACKGROUND: The treatment of diffuse brain injury during an acute period is focused on relieving degrees of secondary brain injury. Generation and development of pathological changes of secondary brain injury depend on signal conduction, so down-regulating over response of astrocyte through interfering a key link of signal conduction pathway may bring a new thinking for the treatment of diffuse brain injury. OBJECTIVE: To observe the effect of over activity of extracellular signal regulated kinases 1/2 (ERK1/2) signal pathway on the response of astrocyte during an acute period of diffuse brain injury. DESIGN: Completely randomized grouping and controlled animal study. SETTINGS: Department of Neurosurgery, the Third Affiliated Hospital, Nanchang University; Department of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: A total of 158 healthy male SD rats, of 11 weeks old, weighing 320–370 g, were provided by Experimental Animal Faulty, Tongji Medical College, Huazhong University of Science and Technology. Rabbit-anti-phosphorylated ERK1/2 (pERK1/2) polyclonal antibody was provided by R&D Company; rabbit-anti-glial fibrillary acidic protein (GFAP) polyclonal antibody, SP immunohistochemical kit and horseradish peroxidase (HRP)-labeled goat-anti-rabbit IgG by Santa Cruz Company; specific inhibitor U0126 of ERK1/2 signal pathway by Alexis Company. METHODS: The experiment was carried out in the Laboratory of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from September 2004 to March 2006. ① Detection of pERK1/2 expression: A total of 110 rats were randomly divided into sham operation group (n =5), model group (n =35), high-dosage U0126 group (n =35) and low-dosage U0126 group (n =35). Rats in the sham operation group were only treated with incision of epicranium and fixation of backup plate, but not hit. Rats in the model group were used to establish diffuse brain injury models based on Marmarou free falling body without drug intervention. Rats in the high- and low-dosage U0126 groups were injected into caudal vein with 0.1 and 0.05 mg/kg U0126, respectively, and then, rats were hit to establish injured models. Every 5 rats were collected from model, high- and low-dosage U0126 groups at 5, 30 minutes, 3, 12, 24, 72 hours and 7 days after diffuse brain injury to detect pERK1/2 expression in cortex of parietal lobe based on Western blot technique. ② Distribution of pERK1/2 and positive GFAP cells in brain tissue: Another 48 rats were randomly divided into sham operation group (n =3), model group (n =15), high-dosage U0126 group (n =15) and low-dosage U0126 group (n =15). The intervention and administration were dealt as the same as those mentioned above. Every 3 rats were collected from model, high- and low-dosage U0126 groups at 30 minutes, 3, 12, 24 and 72 hours after model establishment to observe the distribution of pERK1/2 and postive GFAP cells in brain tissue which was cut from coronal section at Bregma –4.8 mm layer with immunohistochemical staining. MAIN OUTCOME MEASURES: pERK1/2 expression in cortex of parietal lobe and distribution of pERK1/2 and positive GFAP cells in brain tissues. RESULTS: ① pERK1/2 expression: After diffuse brain injury, pERK1/2 expression in cortex of parietal lobe was rapidly increased in the model group, reached at peak at 5 minutes and then decreased gradually. But the expression was still in a high level until the 72nd hour and fallen to the basic level on the 7th day. pERK1/2 level was lower in high- and low-dosage U0126 groups than that in model group at various time points (P < 0.01); meanwhile, pERK1/2 level was lower in high-dosage U0126 group than that in low-dosage U0126 group. The results showed that there was a certain dosage dependence on pERK1/2 expression. ② Distribution of pERK1/2 and positive GFAP cells in brain tissue: Positive expression of pERK1/2 lasted in brain tissue from 30 minutes to 72 hours after diffuse brain injury (P < 0.05). In addition, from 30 minutes to 3 hours, brown-yellow stained cells were mainly distributed in plasma, but rarely in nucleus. A lot of positive cells had tree-like apophysis, which was similar to neurons. With the time passing by, more and more nuclei manifested positive stains; moreover, nuclei mainly manifested positive staining until 24 hours after diffuse brain injury. Immune-positive pERK1/2 cells were widely distributed in brain tissue, especially mainly in binding site between deep cortex and cerebral white matter, and then in hippocampus. In addition, ependymal cell and vascular endothelial cells of choroids plexus also manifested strongly positive staining. As compared with model group, positive cells were decreased gradually in high- and low-dosage U0126 groups. However, number of positive cells was less in high-dosage U0126 group than that in low-dosage U0126 group. CONCLUSION: Diffuse brain injury strongly induces the activity of ERK1/2 signal pathway and response of astrocyte; in addition, U0126 can inhibit response of glial cells during an acute period, and the effect manifests dosage dependence.     

大鼠壁细胞的黏膜刮取式分离方法

采用黏膜刮取式方法，分离大鼠胃黏膜细胞。用相差显微镜、HE染色、电镜、荧光显微镜、免疫细胞化学染色等方法，对壁细胞进行观察和鉴定，并测定了壁细胞直径。结果成功地分离了大鼠胃黏膜细胞，同时证实，壁细胞在所分离的细胞中直径最大。     

大鼠壁胸膜通透性的电镜观察

目的观察大鼠壁胸膜的通透性，胸膜腔内物质的吸收途径。方法向大鼠胸膜腔内注射示踪剂，应用光镜、透射电镜方法观察壁胸膜的物质吸收途径以及壁胸膜间皮的形态变化。结果壁胸膜表面覆盖一层连续的间皮细胞，间皮细胞按形态可分为立方形和扁平形问皮细胞，立方形间皮细胞下的结缔组织内存在大量的毛细淋巴管。由毛细淋巴管内皮细胞突起穿过间皮下结缔组织与问皮细胞相连接而形成的间皮孔，是物质吸收的主要途径。结论壁胸膜通过三种途径吸收物质：①间皮孔的吸收作用；②问皮细胞的吞噬作用；③通过问皮细胞间裂隙吸收。     

Sequential Role of Hippocampus and Amygdala, Entorhinal Cortex and Parietal Cortex in Formation and Retrieval of Memory for Inhibitory Avoidance in Rats

The hippocampus and amygdala, the entorhinal cortex and the parietal cortex participate, in that sequence, both in the formation and in the expression of memory for a step-down inhibitory avoidance task in rats. Bilateral infusion of AP5 or muscimol caused retrograde amnesia when given O min after training into both hippocampus and amygdala, when given or 180 min after training into the entorhinal cortex, or when given 180 min after training into the parietal cortex. Therefore, memory formation requires the sequential and integrated activity of all these areas mediated by glutamate NMDA receptors in each case. Pre-test administration of CNQX 1 day after training into hippocampus and amygdala, 1 or 31 days after training in entorhinal cortex, or 1, 31 or 60 days after training in the parietal cortex temporarily blocked retention test performance. Therefore, 1 day after training, all these brain structures are necessary for retrieval; 1 month later, the hippocampus and amygdala are no longer necessary for retrieval but the entorhinal and parietal cortex still are; and 60 days after training only the parietal cortex is needed. In all cases the mechanisms of retrieval require intact glutamate AMPA receptors.     

Interaction of microorganisms with enterocytes after oral administration of pesticides

Intragastral administration of the pesticides Sumi-alpha and Omait to rats significantly increases the number of parietal microorganisms in the jejunum, ileum, and particularly in the cecum. Electron microscopy shows that parietal microorganisms invade goblet cells during secretion and then enter prismatic cells via the lateral plasma membrane. The number of parietal microorganisms entering enterocytes after Sumi-alpha is higher than after less toxic Omait, reaching the maximum 5 h after administration. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 4, pp. 467–470, April, 1997     

The prevalence of A. actinomycetemcomitans, P. gingivalis and P. intermedia in selected subjects with periodontitis

Abstract. The present study was carried out in a private periodontal practice. 8 clinical criteria were chosen to select patients for microbiological examination. These criteria characterize prominent features of disease which at the start, during, or in the maintenance phase of treatment suggest difficulties in the progress of the periodontal therapy. Based on these clinical characteristics, an inventory was made of the prevalence of the 3 putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia. Out of 320 referred patients 91 patients did meet 1 of the clinical criteria and consequently were selected for microbiological examination. Results showed that young patients (19–30 years) with periodontitis demonstrated the presence of A. actinomycetemcomitans more often (69%: p (0.005) compared to older age cohorts. A. actinomycetemcomitans was found more often when localized breakdown (in particular in the 1 st molar and incisor region) was observed and in patient who responded poorly to scaling and rootplaning. P. gingivalis and P. intermedia were most frequently recovered in patients showing primarily a bone loss pattern of angular defects of 5 mm. Retrospectively, these patients were further categorized, based on full mouth radiographs, in (1) patients with primarily horizontal bone loss and (2) patients with primarily angular bony defects. Results showed that A. actinomycetemcomitans occurred less frequently in patients showing horizontal bone loss ( p (0.05).