Effects of Local Melatonin Application on Implant Osseointegration

Purpose: The aim of this study was to assess the effect of local melatonin administration on bone osseointegration around implants in rabbit tibiae. Material and Methods: Ten female, 6‐month‐old New Zealand rabbits were randomly divided into two groups: the experimental group, where five rabbits were treated with local application of melatonin (3 mg) to implant sites when placed into the rabbit tibia, and the control group, those who where without additive materials. Four weeks later, animals were sacrificed; tibiae were dissected from soft tissues and fixed in buffered formaldehyde, and then included in methacrylate. Histological sections were performed to be studied under light microscopy and analyzed morphometrically to evaluate the amount of bone to implant contact (BIC), trabecular area density, and cortical area density. One‐way analysis of variance test was used for statistical evaluation. p < .05 was considered to be significant. Results: Histological evaluation showed more trabecular reaction in the melatonin group. Morphometrical analysis showed a statistically significant increase in trabecular BIC in the melatonin group when compared with the control group (24.61% ± 2.87 vs 13.62% ± 1.44; p < .01). Cortical BIC was decreased in the melatonin group, without statistical significance (71.08 ± 3.63 vs 76.28 ± 2.57; p = 0.31). Trabecular area density was increased significantly in the melatonin group (8.68 ± 1.61 vs 4.02 ± 0.36; p < .05). Cortical area density was decreased significantly in the melatonin group (91.31 ± 1.6 vs 95.7 ± 0.5; p < .05). Conclusion: Within the limitation of this animal study, local melatonin application at the time of implant placement might induce more trabecular bone at implant contact and higher trabecular area density.     

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麻醉的历史就是人类控制疼痛的历史,口腔局部麻醉学作为麻醉学的一个分支,在解决口腔疼痛疾患以及各种口腔手术治疗中起到极其重要的作用。本文对口腔局部麻醉的发生、发展,局部麻醉药物和注射器械的发展以及口腔局部麻醉的未来展望等做一述评,为进一步推广口腔局部麻醉技术抛砖引玉。     

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口腔局部麻醉可以减轻患者口腔治疗带来的疼痛,降低不适感,缓解其对口腔治疗的恐惧感,已经在口腔临床中被广泛应用。随着牙科材料器械的不断革新,口腔治疗也呈现多样化的趋势,如何根据患者身心状况和治疗的需求选择适当的麻醉方法是牙科医生需要细心体会的问题。笔者通过学习国内外众多牙科医院的标准化操作,结合我国互联网时代医患关系变化的新形势,提出口腔医生应当思考的麻醉策略选择问题。希望能够帮助广大口腔医生对口腔麻醉策略进行梳理,在医患有效沟通的基础上,灵活选用麻醉技术,达成真正意义的无痛牙科治疗。     

Extracts from rabbit skin inflamed by the vaccinia virus attenuate bupivacaine-induced spinal neurotoxicity in pregnant rats

Extracts from rabbit skin inflamed by the vaccinia virus can relieve pain and promote repair of nerve injury. The present study intraperitoneally injected extracts from rabbit skin inflamed by the vaccinia virus for 3 and 4 days prior to and following intrathecal injection of bupivacaine into pregnant rats. The pain threshold test after bupivacaine injection showed that the maximum possible effect of tail-flick latency peaked 1 day after intrathecal injection of bupivacaine in the extract-pretreatment group, and gradually decreased, while the maximum possible effect in the bupivacaine group continued to increase after intrathecal injection of bupivacaine. Histological observation showed that after 4 days of intrathecal injection of bupivacaine, the number of shrunken, vacuolated, apoptotic and caspase-9-positive cells in the dorsal root ganglion in the extract-pretreatment group was significantly reduced compared with the bupivacaine group. These findings indicate that extracts from rabbit skin inflamed by the vaccinia virus can attenuate neurotoxicity induced by intrathecal injection of bupivacaine in pregnant rats, possibly by inhibiting caspase-9 protein expression and suppressing nerve cell apoptosis.     

Retention of Stem Cell Plasticity in Avian Primitive Streak Cells and the Effects of Local Microenvironment

Primitive streak (PS) is the first structure occurring in embryonic gastrulation, in which the epiblast cells undergo the epithelial‐mesenchymal transition to become the loose mesoderm cells subsequently. Because the mesoderm cells departing from different portions of PS are blessed with disparate migration trajectory and differentiation fate, one question is when the cell fate is determinated. To understand whether the cell fate and cell migration pattern will be alternated along with the microenvironment transformation, the traditional transplantation technology was used to replace the anterior PS cells in HH4 host embryo using posterior PS tissue labeled by green fluorescent protein (GFP) in the same stage donor embryo, and then, we tracked the migration trajectory of the GFP‐positive cells with fluorescence stereomicroscope after incubation, and eventually verified the cell contribution from the transplants with in situ hybridization and immunocytochemistry. The same experimental strategy applied for posterior PS site replacement in host embryo. We found that the transplanted posterior PS cells to anterior part of streak followed the anterior PS cell migration pattern rather than kept its posterior streak cell migration trajectory, and so did vice versa. In addition, the transplants were involved in the contribution to the subsequent organogenesis as the local PS tissues affirmed by specific expression of myocardial or hematopoietic markers. Therefore, our data strongly suggest that the PS cells still keep stem cell plasticity during gastrulation and the eventual cell fate will depend on the spatial gene expression within local microenvironment along with development. Anat Rec, 296:533–543, 2012. © 2012 Wiley Periodicals, Inc.     

碘酊棉球填塞法急诊治疗牙龈出血的效果评价

目的:评价碘酊棉球填塞法急诊治疗牙龈出血的疗效。方法 :应用饱和2.5%碘酊溶液的棉球,对108例牙龈出血的急诊病例,进行填塞和压迫止血,观察15～30min,评价止血效果。结果:15min控制出血72例,占66.67%;30min控制出血36例,占33.33%。有效率达100%。结论:碘酊棉球填塞法急诊治疗牙龈出血方法简便、疗效可靠、复发率低,是一种有效的急诊止血方法。     

Analysis of six heavy metals in Ortho mineral trioxide aggregate and ProRoot mineral trioxide aggregate by inductively coupled plasma–optical emission spectrometry

Ortho mineral trioxide aggregate (MTA) is a mineral aggregate newly developed for perforation repair, root end filling and pulp capping. The aim of this study was to investigate the levels of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) in Ortho MTA and ProRoot MTA. A total of 0.2 g of each MTA was digested using a mixture of hydrochloric and nitric acids and filtered. Six heavy metals in the resulting filtrates were analyzed by inductively coupled plasma–optical emission spectrometry (n = 5). The results were statistically analyzed using the Mann–Whitney U‐test. The concentrations of Cd, Cu, Fe, Mn, Ni and Zn in Ortho MTA were 0.10, 7.73, 49.51, 2.58, 0.82 and 10.09 p.p.m., respectively. The concentrations of Cd, Cu, Fe, Mn, Ni and Zn in ProRoot MTA were 0.16, 9.38, 1438.11, 74.51, 18.98 and 4.05 p.p.m., respectively. In conclusion, Ortho MTA had lower levels of Cd, Cu, Fe, Mn and Ni than ProRoot MTA.     

Clinical outcomes of endoscopic submucosal dissection and endoscopic mucosal resection for laterally spreading tumors larger than 20 mm

Background and Aims: Colorectal laterally spreading tumors (LST) > 20 mm are usually treated by endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR). Endoscopic piecemeal mucosal resection (EPMR) is sometimes required. The aim of our study was to compare the outcomes of ESD and EMR, including EPMR, for such LST. Methods: A total of 269 consecutive patients with a colorectal LST > 20 mm were treated endoscopically at our hospital from April 2006 to December 2009. We retrospectively evaluated the complications and local recurrence rates associated with ESD, hybrid ESD (ESD with EMR), EMR, and EPMR. Results: ESD and EMR were performed successfully for 89 and 178 LST, respectively: 61 by ESD; 28 by hybrid ESD; 70 by EMR; and 108 by EPMR. Between‐group differences in perforation rates were not significant. Local recurrence rates in cases with curative resection were as follows: 0% (0/56) in ESD; 0% (0/27) in hybrid ESD; 1.4% (1/69) in EMR; and 12.1% (13/107) in EPMR; that is, significantly higher in EPMR. No metastasis was seen at follow up. The recurrence rate for EPMR yielding ≥ three pieces was significantly high (P < 0.001). All 14 local recurrent lesions were adenomas that were cured endoscopically. Conclusions: As for safety, ESD/hybrid ESD is equivalent to EMR/EPMR. ESD/hybrid ESD is a feasible technique for en bloc resection and showed no local recurrence. Although local recurrences associated with EMR/EPMR were seen, which were conducted based on our indication criteria, all local recurrences could obtain complete cure by additional endoscopic treatment.     

The outcome of endometrial ablation in women with inherited bleeding disorders

There are currently limited data on the use of endometrial ablation in the treatment of heavy menstrual bleeding (HMB) in women with inherited bleeding disorders (IBDs). A retrospective review of prospectively collected data was performed. Twelve women with IBDs who had received endometrial ablation for the treatment of HMB were identified and their records reviewed. Details of their menstrual history; quality of life (QOL) and amount of menstrual blood loss [as assessed by pictorial blood-loss assessment chart (PBAC) and haemoglobin (Hb) concentration] pre and post-ablation were collected. Twelve women were included. The median duration of follow-up post-ablation was 32 months (range, 6-76). The median duration of menstruation decreased from 11 to 0 days after treatment (P = 0.004). Median PBAC scores decreased from 1208 preop to 0 post-ablation (P = 0.002).The median Hb concentrations (10.5-13.1 g dL(-1)) and QOL scores (median, 17-54) improved significantly after endometrial ablation (P < 0.01). Endometrial ablation appears to be a safe and effective long-term treatment for HMB in women with IDBs. It significantly decreases menstrual blood loss and improves QOL.