Corticosterone and corticotropin‐releasing factor acutely facilitate gamma oscillations in the hippocampus in vitro

Stressful experiences do not only cause peripheral changes in stress hormone levels, but also affect central structures such as the hippocampus, implicated in spatial orientation, stress evaluation, and learning and memory. It has been suggested that formation of memory traces is dependent on hippocampal gamma oscillations observed during alert behaviour and rapid eye movement sleep. Furthermore, during quiescent behaviour, sharp wave‐ripple (SW‐R) activity emerges. These events provide a temporal window during which reactivation of memory ensembles occur. We hypothesized that stress‐responsive modulators, such as corticosterone (CORT), corticotropin‐releasing factor (CRF) and the neurosteroid 3α, 21‐dihydroxy‐5α‐pregnan‐20‐one (THDOC) are able to modulate gamma oscillations and SW‐Rs. Using in vitro hippocampal slices, we studied acute and subacute (2 h) impact of these agents on gamma oscillations in area cornu ammonis 3 of the ventral hippocampus induced by acetylcholine (10 μm ) combined with physostigmine (2 μm ). CORT increased the gamma oscillations in a dose‐dependent fashion. This effect was mediated by glucocorticoid receptors. Likewise, CRF augmented gamma oscillations via CRF type 1 receptor. Lastly, THDOC was found to diminish cholinergic gamma oscillations in a dose‐dependent manner. Neither CORT, CRF nor THDOC modulated gamma power when pre‐applied for 1 h, 2 h before the induction of gamma oscillations. Interestingly, stress‐related neuromodulators had rather mild effects on spontaneous SW‐R compared with their effects on gamma oscillations. These data suggest that the alteration of hippocampal gamma oscillation strength in vitro by stress‐related agents is an acute process, permitting fast adaptation to new attention‐requiring situations in vivo.     

Effect of Non‐Surgical Periodontal Treatment on Gingival Crevicular Fluid and Serum Endocan,Vascular Endothelial Growth Factor‐A,and Tumor Necrosis Factor‐Alpha Levels

Background: Periodontitis is a chronic inflammatory disease that occurs due to the interaction between pathogenic microorganisms and host defenses. Endocan is a proteoglycan secreted by endothelial cells under the control of inflammatory cytokines. Aims of the study are to determine serum and gingival crevicular fluid (GCF) endocan levels in the pathogenesis of periodontal diseases, supported with vascular endothelial growth factor (VEGF‐A) and tumor necrosis factor (TNF)‐alpha levels. This study additionally aims to evaluate correlation between GCF endocan levels, VEGF‐A, and TNF‐α levels with periodontal probing depth (PD). Methods: The study consists of two groups: group 1 (n = 20), healthy individuals; group 2 (n = 20), individuals with generalized chronic periodontitis (CP). Clinical measurements were recorded; GCF and serum samples were obtained from each participant before and 6 weeks after therapy. Levels of biomarkers were measured by enzyme‐linked immunosorbent assay. Intergroup comparisons of biochemical and clinical parameters were analyzed by Kruskal–Wallis/Bonferroni‐adjusted Mann–Whitney U test using statistical software. Results: Serum and GCF endocan, VEGF‐A, and TNF‐α levels were significantly higher in patients with CP than in healthy individuals (P <0.001) and decreased after treatment (P <0.03). A significant correlation was observed between GCF TNF‐α and PD (4 mm ≤ PD ≤5 mm and PD ≥6 mm). A significant relationship was found among GCF endocan and TNF‐α, VEGF‐A, CAL, and GI for all groups (P <0.05). Conclusions: Endocan and TNF‐α levels, both in GCF and serum, increased from health to periodontitis and decreased with non‐surgical periodontal treatment. Within the limits of the study, endocan may be considered as a potential inflammatory marker for periodontal disease.     

The feasibility of bipolar tissue sealer for appendix stump closure

Background: Appendiceal stump closure is a highly important step in laparoscopic appendectomy, especially for post-operative complications. The aim of this study is to compare the effects of suture ligation and bipolar tissue sealer techniques on burst pressure using flesh appendectomy specimens. Material and methods: Appendectomy specimens of 32 patients with grade I-II disease were included in the study. Perforated or necrotic appendices and specimens ineligible for pressure measurement were excluded from the study. Appendiceal stumps of 16 patients in group 1 were double-ligated with 2/0 polyglactin sutures, then appendectomy was performed between these sutures. In group 2, the management of the stump was performed through single ligation with polyglactin suture, followed by appendectomy using a bipolar tissue sealing device. Burst pressures were recorded for all specimens. Results: There were no differences between groups in terms of age and sex. There was no significant difference between the two groups in terms of burst pressure (p = 0.92). Also, no significant difference was found between groups in terms of localization of the perforation (p > 0.05). Conclusion: Bipolar tissue sealer achieves safe stump closure with satisfactory burst pressure values. Based on this, using bipolar tissue sealer for appendiceal stump closure in appendicitis may be safe and reliable.     

两种荧光波长CdSeS/ZnS-COOH合金量子点微核组学效应特征的比较研究

目的:比较两种荧光波长CdSeS/ZnS-COOH合金量子点对细胞微核组效应遗传毒作用的特征。方法:采用L5178Y细胞胞质分裂阻滞微核细胞组学试验,490和540 nm两种荧光波长的合金量子点CdSeS/ZnS-COOH受试浓度均为0.062 5、0.125、0.25、0.5和0.1 mg/mL,观察其微核组效应、剂量-效应和时间-效应关系。结果:与阴性对照组相比,两种波长的CdSeS/ZnS-COOH合金量子点在0.062 5 mg/mL剂量时均可诱导微核率增加(P<0.05);两者都能诱导Ⅰ型微核、Ⅱ型微核和核芽效应,但490 nm合金量子点不能诱导核质桥效应,而540 nm合金量子点能诱导核质桥效应。490 nm合金量子点在0.062 5 mg/mL可诱导产生总微核、Ⅰ型微核和核芽,而540 nm合金量子点在此浓度仅可诱导产生Ⅰ型微核;两者均随着剂量进一步增加诱导产生其他效应;各种微核组效应有明显的剂量-效应关系(P<0.05)。490 nm量子点在9 h首先出现核质桥,540 nm量子点在9 h首先出现总微核和Ⅱ型微核数增加;随时间延长进一步出现其他效应,27 h各效应值达到峰值,此后下降。结论:两种荧光波长CdSeS/ZnS-COOH合金量子点均可诱导微核组学效应,但在相同剂量的效应谱、剂量-效应和时间-效应方面均有差异,表明两者的遗传毒作用特点有差异。