Lateralization defects and ciliary dyskinesia: lessons from algae

Flagella and cilia are two very similar organelles that "beat" to move cells and to propel fluid over tissues. They are highly conserved, being found in organisms ranging from prokaryotes to plant and animal eukaryotes. In humans, cilia are present in almost every organ, and several human conditions involve dysfunctional cilia; for example, lateralization defects, where the positions of organs are reversed, and primary ciliary dyskinesia, a rare condition where patients suffer from recurrent respiratory infections. In this article, we will discuss how information gained from studies on algae has aided research into these human diseases. These studies found a variety of functions that was previously unsuspected, renewing interest in cilia.     

中国出生缺陷遗传学研究的回顾与展望

减少出生缺陷是我国“健康中国2030”规划中的重要组成部分。遗传因素单独或协同作用导致了超过80%的出生缺陷疾病。与出生缺陷相关的遗传学研究可为临床筛查、诊断和治疗提供精准的分子靶标。我国的出生缺陷遗传学研究自20世纪60年代以来取得了长足的发展。同时,随着相关研究成果的不断涌现,以遗传咨询和检测为核心的临床转化工作也在不断深化和完善。基础研究与临床应用的紧密结合,将为我国孕育“健康孩”提供可靠的技术保障。本文首先回顾了我国出生缺陷遗传学研究的历史,继而介绍当前国内外出生缺陷遗传学研究的现状和热点,最后对未来的研究方向及相关的临床应用趋势进行展望和讨论,旨在为读者提供了一个全局性的视角来认知我国的出生缺陷遗传学研究发展之路。     

The axr6 mutants of Arabidopsis thaliana define a gene involved in auxin response and early development

The indolic compound auxin regulates virtually every aspect of plant growth and development, but its role in embryogenesis and its molecular mechanism of action are not understood. We describe two mutants of Arabidopsis that define a novel gene called AUXIN-RESISTANT6 (AXR6) which maps to chromosome 4. Embryonic development of the homozygous axr6 mutants is disrupted by aberrant patterns of cell division, leading to defects in the cells of the suspensor, root and hypocotyl precursors, and provasculature. The homozygous axr6 mutants arrest growth soon after germination lacking a root and hypocotyl and with severe vascular pattern defects in their cotyledons. Whereas previously described mutants with similar developmental defects are completely recessive, axr6 heterozygotes display a variety of morphological and physiological alterations that are most consistent with a defect in auxin physiology or response. The AXR6 gene is likely to be important for auxin response throughout the plant, including early development.     

Reconstruction of proximal nasal defects with island composite nasal flaps

There are few local nasal flap options for repair of proximal nasal defects. Absence of suitable donor sites and the large dimensions of the defects limit the use of local nasal flaps in this region. Regional paranasal flaps may not be suitable in these cases because of color, texture, and donor-site scars. The composite procerus muscle and nasal skin flap, which is vascularized by the dorsal nasal branch of the angular artery, can be a useful treatment modality for proximal nasal reconstruction. Seven patients were successfully treated using the composite nasal flaps. The maximal size of the defects was 2.4 cm. In one case, the composite nasal flap was readvanced to close a new defect resulting from reexcision. The composite nasal flap has several advantages in reconstruction of proximal nasal defects. Reconstruction is performed with the same tissue and the donor defect is closed primarily. The composite nasal flap can be moved in multiple directions and has great mobility to reach every point of the proximal part of the nose with axial blood supply. Furthermore, it can be easily readvanced without additional morbidity in case of reexcision.     

Atlantoaxial dislocation and Down's syndrome.

The phenotypic features of Down''s syndrome are easily recognized and include characteristic facial features, hypotonia, ligament laxity, transverse palmar creases and mental subnormality. Associated manifestations and complications are also familiar and involve almost every organ system. Congenital heart defects, bowel malformations and a tendency to leukemia are common attendant problems. Less common, however, are defects of the skeletal system; in fact, the most recent edition of a standard pediatric textbook makes no mention of anomalies of the vertebral column. The purpose of this paper is to call attention to the association between Down''s syndrome and atlantoaxial dislocation, which in our patient resulted in quadriplegia and eventually death.     

Time trends in the prevalence of birth defects in Texas 1999–2007: Real or artifactual?

BACKGROUND: Few studies have reported time trends for total birth defects or for a comprehensive range of phenotypes. METHODS: We examined data from the Texas Birth Defects Registry (TBDR) from 1999 through 2007. Poisson regression was used to fit trend lines to birth prevalence over time for total birth defects (each infant/fetus counted once), for every birth defect collected by the TBDR, and for subsets of cases or defects grouped various ways. RESULTS: From 1999 through 2007, birth prevalence of total birth defects in Texas increased 3.6% per year. Increases were observed in all population groups, persisted after adjustment for demographic characteristics, and were strongest in regions of Texas that were more urban. There was a wide variety of different defects showing significant increases. The trends of several defects were driven by their mild cases. Perhaps the most compelling finding was that larger upward trends were observed in defects that had been rated as more susceptible to diagnostic variation. One notable exception to that was gastroschisis, which showed an average increase of over 5% per year, the total birth defects rate in TBDR increased at 3.6% per year, similar to 3.7% per year in birth certificate check boxes. CONCLUSIONS: In our opinion, the weight of evidence in our study suggests that the observed increase over time in total birth defects and in many specific birth defects is artifactual. This likely reflects increased awareness, referral, detection, or documentation in health care facilities visited by TBDR staff, resulting in more complete ascertainment by the registry, rather than a true change over time in the occurrence of most birth defects. Birth Defects Research (Part A), 2011. © 2011 Wiley‐Liss, Inc.     

CFC syndrome: a syndrome distinct from Noonan syndrome

We report two children with a common pattern of birth defects. Both have very sparse, curly hair, nystagmus and mental retardation. The first one has Noonan syndrome habitus associated with keratosis plantaris and nystagmus; the second one has a slightly Noonan-like face, macrocephaly, keratosis pilaris, and hypertrophic cardiomyopathy. They represent the extreme of a spectrum of congenital defects recently reported independently as CFC syndrome by Reynolds and as "Noonan-like short stature syndrome with sparse hair" by Baraitser and Patton. The clinical features are reviewed and the autonomy of the syndrome with regards to Noonan syndrome, is disputed, since every sign seems to occur independently in Noonan syndrome. The father of the second case probably has a minor syndrome expression, pointing to probable autosomal dominant inheritance.     

Finally,a sense of closure? Animal models of human ventral body wall defects

Malformations concerning the ventral body wall constitute one of the leading categories of human birth defects and are present in about one out of every 2000 live births. Although the occurrence of these defects is relatively common, few detailed experimental studies exist on the development and closure of the ventral body wall in mouse and human. This field is further complicated by the array of theories on the pathogenesis of body wall defects and the likelihood that there is no single cause for these abnormalities. In this review, we summarize what is known concerning the mechanisms of normal ventral body wall closure in humans and mice. We then outline the theories that have been proposed concerning human body wall closure abnormalities and examine the growing number of mouse mutations that impact normal ventral body wall closure. Finally, we speculate how studies in animal models such as mouse and Drosophila are beginning to provide a much-needed mechanistic framework with which to identify and characterize the genes and tissues required for this vital aspect of human embryogenesis.     

Role of geographic information systems in birth defects surveillance and research

BACKGROUND: With the significant advancement of geographic information systems (GIS), mapping and evaluating the spatial distribution of health events has become easier. We examine the role of GIS in birth defects surveillance and research. METHODS: We briefly describe the geocoding process and potential problems in accuracy of the obtained geocodes, and some of the capabilities and limitations of GIS. We illustrate how GIS has been applied using the Metropolitan Atlanta Congenital Defects Program geocoded dataset. We provide some comments on potential data quality and confidentiality issues with birth defects in relation to GIS. RESULTS: It is desirable to geocode addresses using a multistrategy approach to achieve a high-quality and accurate GIS dataset. Beyond the basic but important function of mapping, sophisticated statistical approaches and software are available to analyze the spatial or spatial-temporal occurrence of birth defects, alone or in association with environmental hazards, and to present this information without compromising the confidentiality of the subjects. CONCLUSIONS: We recommend a broad and systematic use of GIS in birth defects spatial surveillance and research.     

表面改性双相陶瓷复合自体骨髓干细胞修复兔骨缺损的实验研究

目的:应用自体骨髓基质干细胞(Bone Marrow Stromal Cells,BMSCs)复合经低晶态羟基磷灰石(Low Crystalline Hydroxyap- atite,LcHA)涂层的双相陶瓷(Biphasic Calcium Phosphate,BCP)构建的组织工程化骨(LcBCP)修复兔桡骨节段性缺损。方法:体外分离培养、诱导扩增兔BMSCs,取第三代细胞复合LcBCP(实验组)后修复15只兔左侧桡骨15mm缺损;右侧桡骨缺损处植入复合BMSCs的BCP(对照组),于植入后4、8和12周处死动物,通过大体形态、组织学、影像学和扫描电镜检测骨缺损修复效果。结果:BMSCs-LcBCP复合物生长良好,随时间延长,X线显示实验组连接处骨痂形成,对照组连接处始终愈合稍差,12周大体观察实验组骨修复良好,髓腔再通;组织学显示板层骨形成,连接处骨性愈合,实验对照组连接处虽然也为骨性愈合,但尚有较多编织骨形成。结论:自体BMSCs复合LcBCP形成的组织工程化骨可修复兔桡骨节段性缺损,低晶态羟基磷灰石涂层能够增强双相陶瓷的早期成骨。     

fras1 shapes endodermal pouch 1 and stabilizes zebrafish pharyngeal skeletal development

Lesions in the epithelially expressed human gene FRAS1 cause Fraser syndrome, a complex disease with variable symptoms, including facial deformities and conductive hearing loss. The developmental basis of facial defects in Fraser syndrome has not been elucidated. Here we show that zebrafish fras1 mutants exhibit defects in facial epithelia and facial skeleton. Specifically, fras1 mutants fail to generate a late-forming portion of pharyngeal pouch 1 (termed late-p1) and skeletal elements adjacent to late-p1 are disrupted. Transplantation studies indicate that fras1 acts in endoderm to ensure normal morphology of both skeleton and endoderm, consistent with well-established epithelial expression of fras1. Late-p1 formation is concurrent with facial skeletal morphogenesis, and some skeletal defects in fras1 mutants arise during late-p1 morphogenesis, indicating a temporal connection between late-p1 and skeletal morphogenesis. Furthermore, fras1 mutants often show prominent second arch skeletal fusions through space occupied by late-p1 in wild type. Whereas every fras1 mutant shows defects in late-p1 formation, skeletal defects are less penetrant and often vary in severity, even between the left and right sides of the same individual. We interpret the fluctuating asymmetry in fras1 mutant skeleton and the changes in fras1 mutant skeletal defects through time as indicators that skeletal formation is destabilized. We propose a model wherein fras1 prompts late-p1 formation and thereby stabilizes skeletal formation during zebrafish facial development. Similar mechanisms of stochastic developmental instability might also account for the high phenotypic variation observed in human FRAS1 patients.     

Defects tracking matrix for mass customization production based on house of quality

The vision of mass customization has driven a movement toward low volume, high variety mass customization production (MCP) at low price. However, defect identification and defect tracking in such systems are extremely difficult because of the frequent reconfiguration needed by the number of different part types and the interruption of the information flow about quality with each reconfiguration of the system. It is important to quickly rebuild quality information flow with MCP system’s reconfiguration synchronously. This paper introduces a defect tracking method based on Quality Function Deployment for every MCP system module. A defects tracking matrix (DTM) based on the House of Quality directly connects manufacturing technologies with quality defects inside a MCP module. Each MCP reconfiguration requires the DTMs’ rearrangement and DTM-chain is proposed. A dynamic reconstructing algorithm synchronizes the DTM-chain with each MCP reconfiguration. A case study demonstrates the usefulness of the DTM and DTM-chain.     

A unique and universal molecular barcode array

Molecular barcode arrays allow the analysis of thousands of biological samples in parallel through the use of unique 20-base-pair (bp) DNA tags. Here we present a new barcode array, which is unique among microarrays in that it includes at least five replicates of every tag feature. The use of smaller dispersed replicate features dramatically improves performance versus a single larger feature and allows the correction of previously undetectable hybridization defects.     

Free fibula osteoseptocutaneous-pedicled pectoralis major myocutaneous flap combination in reconstruction of extensive composite mandibular defects

Lateral composite mandibular defects resulting from excision of advanced oral carcinoma often require mandible, intra-oral lining, external face, and soft-tissue bulk reconstruction. Ignorance of importance soft-tissue deficit in those patients may cause significant morbidity and functional loss. Such defects, therefore, can be reconstructed best with a double free flap technique. However, this procedure may not be feasible for every patient or surgeon. An alternative procedure is a free fibula osteoseptocutaneous flap combined with a pedicled pectoralis major myocutaneous flap. This combination was used in reconstruction of extensive composite mandibular defects in 14 patients with T3/T4 oral squamous cell carcinoma. All patients were men, and the average age was 54.3 years. The septocutaneous paddle of the fibula flap was used for the mucosal lining of the defects while the bony part established the rigid mandibular continuity. The pectoralis major flap then covered the external skin defect in the face and cheek, and the dead spaces left by the extirpated masticator muscles, buccal fat, and parotid gland. One free fibula flap failed totally, and one pectoralis major flap developed marginal necrosis. At the time of final evaluation, nine patients (64.3 percent) were alive, surviving an average of 25.7 months. All patients eventually regained their oral continence and an acceptable cosmetic appearance. In conclusion, the fibula osteoseptocutaneous flap plus regional myocutaneous flap choice is a successful and technically less demanding alternative to the double free flap procedures in reconstruction of extensive lateral mandibular defects.     

夜蛾科(鳞翅目)卵分类性状的定量分析

本文用主成分分析法对夜蛾科卵的分类性状进行定量分析,用以说明各主成分的生物含义和各变量对分类的重要性．     

Review on genetic variants and maternal smoking in the etiology of oral clefts and other birth defects

A spectrum of adverse pregnancy outcomes, including preterm birth, low birth weight, and birth defects has been linked with maternal smoking during pregnancy. This article includes a review of studies investigating interactions between genetic variants and maternal smoking in contributing to birth defects using oral clefting as a model birth defect. The primary gene-smoking studies for other major birth defects are also summarized. Gene-environment interaction studies for birth defects are still at an early stage with several mixed results, but evolving research findings have begun to document clinically and developmentally important interactions. As samples and data become increasingly available, more effort is needed in designing innovative analytical methods to study gene-environment interactions.     

Applications of a mouse model of calvarial healing: differences in regenerative abilities of juveniles and adults

Young children are capable of healing large calvarial defects, whereas adults lack this endogenous osseous tissue-engineering capacity. Despite the important clinical implications, little is known about the molecular and cell biology underlying this differential ability. Traditionally, guinea pig, rabbit, and rat models have been used to study the orchestration of calvarial healing. To harness the research potential of knockout and transgenic mice, the authors developed a mouse model for calvarial healing. Nonsuture-associated parietal defects 3, 4, and 5 mm in diameter were made in both juvenile (6-day-old, n = 15) and adult (60-day-old, n = 15) mice. Calvariae were harvested after 8 weeks and analyzed radiographically and histologically. Percentage of healing was quantified using Scion Image software analysis of calvarial radiographs. A significant difference in the ability to heal calvarial defects was seen between 6-day-old and 60-day-old mice when 3-, 4-, or 5-mm defects were created. The authors' analysis revealed that juvenile mice healed a significantly greater percentage of their calvarial defects than adult mice (juvenile mean percentage of healing: 3-mm defects, 59 percent; 4-mm defects, 65 percent; 5-mm defects, 44 percent; adult mean percentage of healing: <5 percent in all groups; p < 0.05). All three defect sizes were found to be critical in the adult, whereas significant healing was seen regardless of the size of the defect in juvenile mice. The establishment of this model will facilitate further, detailed evaluation of the molecular biology underlying the different regenerative abilities of juvenile versus adult mice and enhance research into membranous bone induction by making available powerful tools such as knockout and transgenic animals.     

More folic acid, the five questions: why, who, when, how much, and how

In recent years, a number of studies have been performed to evaluate the possible health benefits of an increased intake of folic acid (FA) on human health. However, the only well-documented benefit emerging from randomized controlled trials, nonrandomized interventions trials, and observational studies is the risk reduction of neural tube defects (NTDs). NTDs are congenital malformations that include anencephaly, encephalocele, and spina bifida caused by the failure of fusion of the neural tube that normally closes between 22nd and 28th day since conception (on an average 40-42th day after the first day of last menstrual period). The occurrence of NTDs varies among population between 0.8 and 3 per 1,000, and it is estimated that 324,000 pregnancies are affected every year worldwide. More FA can decrease the NTDs risk up to 0.6 per 1,000 births. Other malformations as congenital heart defects, cleft lip, and limb deficiencies can be most probably also reduced. To decrease the NTDs risk, it is recommended that all women capable of becoming pregnant should have more FA. The goal is that every woman could start her pregnancy with an optimal folate status, estimated today to be as more than 906 nmol/L of red blood cell folate concentration. More FA can be obtained through a strict Mediterranean pattern of nutrition and healthy life style, fortified food, supplements. Women and health authorities can choose the most appropriate strategy. Monitoring folate status of women during the periconceptional period is an essential way to evaluate the success of the preferred strategy.