Hutchinson-Gilford progeria syndrome: oral and craniofacial phenotypes

Objective:  Hutchinson-Gilford progeria syndrome (HGPS) is a rare early-onset accelerated senescence syndrome. In HGPS, a recently identified de novo dominant mutation of the lamin A gene ( LMNA ) produces abnormal lamin A, resulting in compromised nuclear membrane integrity. Clinical features include sclerotic skin, cardiovascular and bone abnormalities, and marked growth retardation. Craniofacial features include 'bird-like' facies, alopecia, craniofacial disproportion, and dental crowding. Our prospective study describes dental, oral soft tissue, and craniofacial bone features in HGPS.
Methods:  Fifteen patients with confirmed p.G608G LMNA mutation (1–17 years, seven males, eight females) received comprehensive oral evaluations. Anomalies of oral soft tissue, gnathic bones, and dentition were identified.
Results:  Radiographic findings included hypodontia ( n  = 7), dysmorphic teeth ( n  = 5), steep mandibular angles ( n  = 11), and thin basal bone ( n  = 11). Soft tissue findings included ogival palatal arch ( n  = 8), median sagittal palatal fissure ( n  = 7), and ankyloglossia ( n  = 7). Calculated dental ages (9 months to 11 years 2 months) were significantly lower than chronological ages (1 year 6 months to 17 years 8 months) ( P  = 0.002). Eleven children manifested a shorter mandibular body, anterior/posterior cranial base and ramus, but a larger gonial angle, compared to age/gender/race norms.
Conclusion:  Novel oral-craniofacial phenotypes and quantification of previously reported features are presented. Our findings expand the HGPS phenotype and provide additional insight into the complex pathogenesis of HGPS.     

Weight Loss Trajectories and Adverse Childhood Experience among Obese Adolescents with Polycystic Ovary Syndrome

Study Objective

To examine the effect of childhood trauma and family history of psychiatric illness on weight loss trajectories of obese, female adolescents with polycystic ovary syndrome (PCOS).

Civil defence in a nuclear disaster

Any nuclear war would be horrific and our main aim should be universal abolition of nuclear weapons. Civil defence, with its medical attributes, could certainly increase the survival rate should a disaster occur. The effect of the explosion of a nuclear warhead is outlined, together with what could be done to reduce casualties. Nuclear winter is discussed and it is suggested that the results of computerization of doubtful surmises have been treated too much as proven facts. The possibility of its occurrence should not deter emergency planning. Civil defence can save lives, and the fact that medicine as we know it would cease to exist in an all‐out nuclear war does not excuse us from doing what we can to increase the survival rate, if the worst should happen. Action should therefore be taken now to plan decentralization of resources and to instruct the public in protection, first aid and self‐sufficiency.     

红细胞保存期影响早产儿疗效的随机对照试验:研究设计

尽管目前趋于逐渐降低输血阅值,并开发技术避免输注异体血液,但异体红细胞输注仍是罹患疾病和贫血的新生儿重症监护患者一个重要的支持和挽救生命的方法.     

Citrus auraptene suppresses cyclin D1 and significantly delays N-methyl nitrosourea induced mammary carcinogenesis in female Sprague-Dawley rats

Background  

Breast cancer is a major problem in the United States leading to tens of thousands of deaths each year. Although citrus auraptene suppresses cancer in numerous rodent models, its role in breast cancer prevention previously has not been reported. Thus, our goal was to determine the anticarcinogenic effects of auraptene against breast cancer.     

家兔失神经支配腓肠肌肌纤维退行性变与修复性再生的超微结构观察

目的:观察家兔腓肠肌失神经支配后肌纤维在退行性变与修复性再生过程中超微结构的变化,探讨失神经支配骨骼肌修复性再生障碍的机制。方法:实验于2005-04/2006-04在南方医科大学中心实验室完成。选择成年新西兰大白兔20只,切断一侧胫神经腓肠肌肌支,术后1,4,8,12,16周分别采用耳缘静脉注射空气处死4只。取实验侧和对照侧腓肠肌内侧头肌组织少许,用于制备超薄切片标本,透射电镜观察各时间点兔失神经腓肠肌肌纤维形态。结果:纳入动物20只,均进入结果分析。①正常家兔腓肠肌肌原纤维排列整齐,肌小节和Z线清晰,线粒体均匀分布在肌原纤维之间,排列规则,细胞核位于质膜周边,未见溶酶体。②失神经支配1周,肌原纤维排列基本整齐,线粒体增多,无明显肿胀。③失神经支配4周,线粒体明显增多肿胀,部分线粒体空泡样变,溶酶体增多,Z线模糊,肌原纤维间隙增大。④失神经支配8周,肌纤维明显萎缩退行性变,大部分肌原纤维消失,残留的肌原纤维变得模糊,间隙增大,肌小结丧失正常的结构,胞浆内含有大量空泡变性的细胞器,可发现畸形核,染色质浓缩、边集,肌细胞膜极度皱缩。镜下发现较多的位于基膜下活化的肌卫星细胞,细胞内含有发达的粗面内质网和丰富的胞浆。一些肌卫星细胞直接与肌纤维融合。同时在间质中可发现一些形态上很象成纤维细胞的细胞,不过这些细胞含有大量的粗面内质网,胞浆内有颗粒和微丝,少量的圆形的线粒体。在退行性变的肌纤维基膜下也可发现肌管样结构的再生肌细胞,在这些肌管内一些肌丝在一起聚集成束,没有组装成肌原纤维,没有正常的肌小结结构。在它们周围有细小的空肌管样结构,可能是以往再生的肌细胞退行性变后的残余体。在间质中可发现一些细小的肌纤维。⑤失神经支配12周,大部分肌纤维萎缩退行性变,但是仍可发现没有萎缩的肌纤维,这些肌纤维细胞核位于周边,有良好的收缩系统,纤维排列规则,Z线清晰,有完整的肌膜。⑥失神经支配16周,肌卫星细胞的数量明显减少,并可发现大量细小的肌纤维,多分布在较大的肌纤维附近,肌膜完整平滑,无皱褶。可发现核位于中央的肌纤维,胞浆内肌原纤维结构清楚,但是肌原纤维的排列远不如核位于周边的肌纤维整齐,说明其收缩系统发育不良。结论:失神经支配后肌细胞退行性变和修复性再生同时存在,再生的肌细胞不能,化发育为成熟的肌纤维,进而发生退行性变。长时间失神经支配,肌卫星细胞的耗竭是失神经支配骨骼肌晚期的主要超微结构变化。