Opposing influences of emotional and non-emotional distracters upon sustained prefrontal cortex activity during a delayed-response working memory task

Performance in delayed-response working memory (WM) tasks is typically associated with sustained activation in the dorsolateral prefrontal cortex (dlPFC) that spans the delay between the memoranda and the memory probe. Recent studies have demonstrated that novel distracters presented during the delay interval both affect sustained activation and impair WM performance. However, the effect of the performance-impairing distracters upon sustained dlPFC delay activity was related to the characteristics of the distracters: memoranda-confusable distracters increased delay activity, whereas memoranda-nonconfusable emotional distracters decreased delay activity. Because these different effects were observed in different studies, it is possible that different dlPFC regions were involved and the paradox is more apparent than real. To investigate this possibility, event-related fMRI data were recorded while subjects performed a WM task for faces with memoranda-confusable (novel faces) and memoranda-nonconfusable emotional (novel scenes) distracters presented during the delay interval. Consistent with previous findings, confusable face distracters increased dlPFC delay activity, while nonconfusable emotional distracters decreased dlPFC delay activity, and these opposing effects modulated activity in the same dlPFC regions. These results provide direct evidence that specific regions of the dlPFC are generally involved in mediating the effects of distraction, while showing sensitivity to the nature of distraction. These findings are relevant for understanding alterations in the neural mechanisms associated with both general impairment of cognitive control and with specific impairment in the ability to control emotional distraction, such as those observed in aging and affective disorders, respectively.     

注射式硫酸钙对山羊下颌骨牵张成骨促进作用的研究

目的建立山羊下颌骨牵张成骨实验动物模型,探讨注射式硫酸钙对牵张成骨的促进作用。方法手术截断14只山羊的单侧下颌骨并埋入骨牵张器后,随机分为A、B两组,A组山羊在牵张成骨的同时注射硫酸钙,B组山羊单纯牵张成骨,通过对比得出结论。结果14只山羊的下颌骨被成功牵张7mm,牵张间隙内新骨形成。X线、病理、生物力学检测结果显示A组山羊下颌骨的牵张间隙内有更多新骨形成,愈合后的抗压能力更强。结论注射式硫酸钙对牵张成骨有促进作用。即在相同的牵张成骨、骨骼愈合时间内,硫酸钙可以促进牵张间隙内更多的新骨形成,使愈合后骨骼的强度更大。     

Gradual detorsion of torsioned rat testis attenuates ischemia reperfusion injury

Aim

This study was designed to investigate effect of gradual detorsion on testicular ischemia reperfusion injury.

Materials and Methods

A total of 21 male rats were divided into 3 groups, each containing 7 rats. Torsion was created by rotating the left testis 720° in a clockwise direction. Group 1 underwent sham operation. Group 2 (sudden detorsion) served as a torsion/detorsion group, receiving 2 hours torsion and 2 hours detorsion. In group 3, 360° detorsion was done for 20 minutes after 720° torsion for 2 hours. Then, testis was done full detorsion for 100 minutes. At the end of the experiments (fourth hour), left orchiectomy was performed to measure the tissue levels of malondialdehyde (MDA), superoxide dismutase, and glutathione peroxidase and to perform histologic examination in testes.

Results

The MDA levels of testis tissues were significantly increased in the sudden detorsion group as compared with the sham group. We found decrease of the MDA level in gradual detorsion group, but it was not a statistically significant amount. Significant decrease was found in the superoxide dismutase and glutathione peroxidase activities in the sudden detorsion group as compared with the sham and gradual detorsion groups. Histologic examinations were in accordance with the testicular tissue MDA levels.

Conclusion

In the light of our biochemical and histopathologic findings, we can say that gradual detorsion has a trend to decrease the degree of testicular reperfusion injury in the rat torsion/detorsion model.     

Craniofacial surgery, from past pioneers to future promise

Objectives  

As a surgical subspecialty devoted to restoration of normal facial and calvarial anatomy, craniofacial surgeons must navigate the balance between pathologic states of bone excess and bone deficit. While current techniques employed take root in lessons learned from the success and failure of early pioneers, craniofacial surgery continues to evolve, and novel modalities will undoubtedly arise integrating past and present experiences with future promise to effectively treat craniofacial disorders.     

犬下颌骨牵张成骨术后恒牙胚变化的实验研究

目的：研究犬下颌骨牵张成骨术后不同时期内恒牙胚的组织学改变。方法：对6只替牙期犬双侧下颌体部行骨皮质切开术，安置口内下颌牵张器，经5d延迟期后，以1mm／d的速率向前牵引延长7d(共7mm)，于牵张结束后0、1、2、4、6、8周各处死1只动物。对照组安置牵张器，但不加力牵引。对标本进行大体、X线和组织学观察。结果：实验组犬牙根部牙本质有吸收现象，髓腔形成血栓、充血，但牙齿仍可以正常萌出。结论：牵张使牙本质、牙髓和牙周膜等均产生了一定程度的病理学改变，但牙齿仍可以正常萌出。     

下颌骨牵引成骨与直接延长术的组织学比较

目的：通过对下颌骨牵引成骨与直接延长术组织学变化的对比研究分析，探讨牵引成骨的成骨机制。方法：24只狗随机分为牵引成骨组和直接延长组各12只，用HE染色光镜组织学检查方法分别观察牵引第6天、牵引后固定2、8周不同时期的两组组织学变化。结果：牵引组在牵引后固定第8周，牵引区几乎完全由新生的骨组织连接修复，成骨方式是以膜内成骨为主，伴有少量的软骨内成骨；而直接延长组仅早期在两骨断端附近可见活跃的膜内成骨，两周以后则以软骨内成骨为丰，中间区域仍为大量的纤维结缔组织，8周以后成骨量增加．但中央仍为软骨组织和纤维组织间隔。结论：牵引成骨以膜内成骨为主，达到良好的骨愈合，直接延长成骨效果不稳定，容易导致成骨不良。     

牵张成骨序列治疗颞下颌关节强直及继发畸形

目的:回顾我院应用牵张成骨序列治疗颞下颌关节强直及继发颌面部畸形的效果.方法:40例关节强直患者,平均年龄24.5岁(9～53岁),其中单侧强直11例,双侧29例,伴发OSAHS者27例.所有患者一期手术牵张成骨,二期手术拆除牵张器并同期行颞下颌关节成形术,同期或三期行正颌手术改善面部外形.通过术前术后最大张口度、面型及打鼾症状改善情况评估治疗效果.结果:关节成形术后40例患者张口度基本恢复正常,面型均得到显著改善,打鼾症状全部消失.经过4～72个月(平均20.5个月)的随访,4例患者关节强直复发.结论:应用一期牵张成骨二期关节成形治疗颞下颌关节强直及继发畸形能够精确控制面型和气道的改变.     

Adjustable selective maxillary expansion combined with one-stage maxillomandibular surgery: A prospective study of osseous widening in fifty-five consecutive patients

Objective

SARME is often considered to be the only available treatment for significant or severe maxillary transverse palatal deficiencies (MTD) in skeletally-mature patients. Despite this observation, the aim of our study was to assess a new type of maxilla distraction osteogenesis. Using two innovative tools, we performed selective expansion: the site to be widened and the amount of increase were both pre-selected. Patients were treated in a single maxillomandibular procedure. Our study focuses primarily on the extent of osseous widening.

Treatment of severe maxillary hypoplasia with oligodontia and complete bilateral cleft lip and palate by maxillary anterior segmental distraction osteogenesis

Effective maxillary advance treatment is difficult to achieve without impairing velopharyngeal function in patients with severe maxillary deficiency. We describe successful orthodontic treatment using maxillary anterior segmental distraction osteogenesis (MASDO) in a patient with cleft lip and palate. A 20-year-old woman with bilateral cleft lip and palate, multiple congenitally missing teeth, reduced maxilla, concave soft-tissue profile, and skeletal Class III jaw relationship was treated with a combination of orthodontic treatment and MASDO. After treatment, the anterior maxilla was displaced forward with new bone formation induced in the distraction gap for insertion of dental implants. Maxillary hypoplasia was successfully treated while preserving the velopharyngeal function with MASDO. We suggest that MASDO is useful for patients with severe maxillary hypoplasia.     

跨腕关节支撑钢板与外固定架治疗桡骨远端粉碎性骨折的临床研究

目的比较跨腕关节支撑钢板与外固定架治疗桡骨远端粉碎性骨折的临床疗效。方法对自2007年7月~2010年6月收治的57例闭合性桡骨远端粉碎骨折(AO C2、C3型)采用跨腕关节钢板和外固定架进行治疗。结果术后12个月随访,两组桡骨茎突长度无统计学差异(P>0.05),关节面台阶有统计学差异(P<0.05)。术后6、12个月随访时,两组间旋前、旋后、掌屈、背伸活动范围比较,无统计学差异(P>0.05)。根据Jakim评分标准,两组优良率差异无统计学意义(P>0.05)。外固定架组并发症发生率显著高于钢板组(P<0.05)。结论①跨腕关节钢板和外固定架治疗桡骨远端粉碎骨折,骨折复位情况和临床治疗效果相当;②跨腕关节钢板固定手术创伤较大,但稳定性好,并发症较少;③跨腕关节钢板和外固定架结合克氏针固定后,可减少术后碎骨块再移位的可能性;④跨腕关节钢板固定治疗桡骨远端粉碎性骨折,骨折复位好,能保持骨折部的撑开以维持桡骨长度,防止短缩,可以取得较好的疗效。