Postnatal histomorphogenesis of the mandible in the house mouse

The mandible of the house mouse, Mus musculus, is a model structure for the study of the development and evolution of complex morphological systems. This research describes the histomorphogenesis of the house mouse mandible and analyses its biological significance from the first to the eighth postnatal weeks. Histological data allowed us to test a hypothesis concerning modularity in this structure. We measured the bone growth rates by fluorescent labelling and identified the bone tissue types through microscopic analysis of histological cross-sections of the mandible during its postnatal development. The results provide evidence for a modular structure of the mouse mandible, as the alveolar region and the ascending ramus show histological differences throughout ontogeny. The alveolar region increases in length during the first two postnatal weeks by bone growth in the posterior region, while horizontally positioned incisors preclude bone growth in the anterior region. In the fourth postnatal week, growth dynamics shows a critical change. The alveolar region drifts laterally and the ramus becomes more vertical due to the medial growth direction of the coronoid region and the lateral growth of the ventral region of the ramus. Diet changes after weaning are probably involved in these morphological changes. In this way, the development of the masticatory muscles that insert on the ascending ramus may be particularly related to this shape modeling of the house mouse mandible.     

Apoptosis, metallothionein, and bioavailable metals in domestic mice (Mus musculus L.) from a human-inhabited volcanic area

The influence of extreme environments of volcanic origin over vertebrates and the cellular responses that these may give are almost unknown. The main objectives were to evaluate the exposure of mice to metals in the interior of houses of a small village settled inside a volcanic crater (Furnas, Azores), and the levels of apoptosis and metallothionein in the organs (lung, liver, and kidney) of those animals. Adult mice (Mus musculus) were captured in two areas, one with volcanic activity and the other without it over the last three centuries. In the excised organs, analysis of metals (Al, Cd, Pb, Zn), TUNEL assay for apoptosis, and immunohistochemistry for metallothionein were undertook. Mice from the area with volcanic activity presented higher levels of apoptosis and metallothionein than those from the area without volcanic activity. Such results were in agreement with the differences in metal burdens of the three organs, and interestingly these concentrations were similar to or higher than others found in heavily polluted areas outside the Azores. Thus, there may be a high risk of harmful effects for organisms, including humans, inhabiting areas with volcanism, where hazardous gases and metals in the air are very common during the entire day or even all year round.     

Housing conditions influence the expression of food-anticipatory activity in mice

If food is presented for a limited duration once every 24 h, rats will gradually develop increased activity in the hours preceding mealtime, even if this is during a time of day when they are normally inactive. This food-anticipatory activity (FAA) is mediated by the entrainment of an endogenous self-sustaining circadian pacemaker. Mice are increasingly being used for the molecular analysis of behavior because of the large number of genetically manipulated mouse models available, but little is known about food entrainment in this species. This study assessed the impact of different housing conditions on the expression of FAA in a temporally restricted feeding paradigm. Wheel-running activity rhythms were recorded from mice (Mus musculus) undergoing food restriction while housed under one of two conditions. The results demonstrated that mice housed on open shelves showed robust FAA while those housed in isolation boxes did not. These results indicate that differences in susceptibility to food entrainment among mice (e.g., those with different genotypes) should be interpreted cautiously, since at least one strain is strongly affected by a relatively minor procedural difference that was not anticipated to have a significant impact.     

颞肌神经支配的研究及临床应用

目的了解颞肌的神经支配,以提高手术治疗麻痹性睑外翻的成功率。方法对１２具新鲜尸体解剖,观察颞深神经发出的部位并进行数据测量及统计学处理。结果测出数据表明,外眦至耳轮脚连线长（８７３３±１３１１）ｃｍ,颞深神经在（３８５２±０３５３）ｃｍ及（６３１７±０３３０）ｃｍ处与水平线呈６０°角,放射状分布至颞肌边缘。结论颞深神经二级分支在外眦至耳轮脚连线呈三等分放射状发出,与水平线各呈约６０°角。行颞肌瓣移转治疗麻痹性睑外翻手术时,于外眦至耳轮脚连线的中央１／３区作切口最为安全。临床应用３２例,３０例术后动态效果良好,占９３８％。     

Identification of Novel Rodent-Borne Orthohantaviruses in an Endemic Area of Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka

We reported the genetic evidence of circulating hantaviruses from small mammals captured in a chronic kidney disease of unknown etiology (CKDu) hotspot area of Sri Lanka. The high seroprevalence of anti-hantavirus antibodies against Thailand orthohantavirus (THAIV) has been reported among CKDu patients and rodents in Sri Lankan CKDu hotspots. We captured 116 small mammals from CKDu endemic regions in the Polonnaruwa District of Sri Lanka. Seven animals (five out of 11 Mus booduga and two out of 99 Rattus rattus) were PCR-positive for the hantavirus. A rat-borne sequence was grouped with a THAIV-like Anjozorobe virus. In contrast, Mus-borne sequences belonged to the THAIV lineage, suggesting a novel orthohantavirus species according to the phylogenetic analyses and whole-genome comparisons. Our genetic evidence indicates the presence of two THAIV-related viruses circulating in this CKDu endemic area, suggesting a basis for further investigations to identify the infectious virus in patients with CKDu and the CKDu induction mechanism of these viruses.     

小家鼠群体基因组连锁不平衡研究

模式动物小鼠是复杂性状相关疾病遗传研究的重要资源.连锁不平衡(linkage disequilib-rium,LD)是群体基因组遗传的重要信息.如果群体LD程度高,相关连锁区段大,有助于用少量遗传位标来对目标基因进行初步定位;反之,如果群体LD程度低,相关连锁区段小,则利用高密度的遗传位标可以对目标基因进行精细定位.本文介绍了实验小鼠群体和野生小鼠群体相关的LD、与LD相关的部分遗传参数以及利用LD进行相关基因定位研究.并提示实验小鼠和野生小鼠各具优势,都是复杂性状基因定位的重要遗传资源.     

维吾尔医成熟疗法和清除疗法治疗白癜风273例疗效观察

目的观察维吾尔医致病物质调理疗法(成熟疗法和清除疗法)治疗白癜风的疗效。方法对273例白癜风患者分别使用成熟和清除疗法后的白斑总面积和色素点总面积与入院时的情况进行客观比较。结果与入院时比较,使用成熟和清除疗法后白癜风患者的白斑平均总面积呈减小趋势,而色素点呈增生趋势(P均<0.001)。结论使用成熟和清除疗法对控制白癜风患者白斑扩散有显著作用。     

Functional evidence for Eme1 as a marker of cisplatin resistance

The ability to predict cisplatin sensitivity in tumors has been expected to greatly improve the outcome of cancer therapy, because the drug is frequently used in a variety of tumors. Although ERCC1 and other repair proteins have been investigated as markers of cisplatin resistance, reliable markers are still needed. Here, we demonstrate that Eme1 levels can predict cisplatin sensitivity more accurately than ERCC1 or Rad51 levels in a variety of human cancer cell lines. Eme1 forms a heterodimeric protein complex with Mus81 and functions as a structure‐specific endonuclease. Haploinsufficiency of Eme1 led to hypersensitivity to cisplatin in the colon cancer cell line HCT116. On the basis of this finding, we examined the relationships between levels of proteins involved in the repair of interstrand cross‐links and cisplatin sensitivity in human tumor cell lines with a variety of origins. Although ERCC1, Rad51 and Mus81 levels correlated with sensitivity to some extent, the clearest correlation was observed with Eme1. Tumors with low Eme1 levels were more sensitive to the drug than tumors with high levels. This suggests that the measurement of Eme1 in tumors may be more informative for cisplatin‐based chemotherapy than that of the currently available markers. © 2009 UICC