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661.
Daniel S. Oh Alia Koch Sidney Eisig Sahng Gyoon Kim Yoon Hyuk Kim Do-Gyoon Kim Jae Hyuck Shim 《Journal of visualized experiments : JoVE》2015,(103)
Without an active, thriving cell population that is well-distributed and stably anchored to the inserted template, exceptional bone regeneration does not occur. With conventional templates, the absence of internal micro-channels results in the lack of cell infiltration, distribution, and inhabitance deep inside the templates. Hence, a highly porous and uniformly interconnected trabecular-bone-like template with micro-channels (biogenic microenvironment template; BMT) has been developed to address these obstacles. The novel BMT was created by innovative concepts (capillary action) and fabricated with a sponge-template coating technique. The BMT consists of several structural components: inter-connected primary-pores (300-400 µm) that mimic pores in trabecular bone, micro-channels (25-70 µm) within each trabecula, and nanopores (100-400 nm) on the surface to allow cells to anchor. Moreover, the BMT has been documented by mechanical test study to have similar mechanical strength properties to those of human trabecular bone (~3.8 MPa)12.The BMT exhibited high absorption, retention, and habitation of cells throughout the bridge-shaped (Π) templates (3 cm height and 4 cm length). The cells that were initially seeded into one end of the templates immediately mobilized to the other end (10 cm distance) by capillary action of the BMT on the cell media. After 4 hr, the cells homogenously occupied the entire BMT and exhibited normal cellular behavior. The capillary action accounted for the infiltration of the cells suspended in the media and the distribution (active migration) throughout the BMT. Having observed these capabilities of the BMT, we project that BMTs will absorb bone marrow cells, growth factors, and nutrients from the periphery under physiological conditions.The BMT may resolve current limitations via rapid infiltration, homogenous distribution and inhabitance of cells in large, volumetric templates to repair massive skeletal defects. 相似文献
662.
《Cancer epidemiology》2014,38(1):9-15
IntroductionThe incidence of gastric cancer declined over the past decades. Recently, unfavorable trend breaks (i.e. rise in incidence) were seen for non-cardia cancer in younger age groups in the US. It is unclear whether these also occur in other Western countries. We aimed to analyze the gastric cancer incidence trends by age, sex, subsite and stage in the Netherlands.MethodsData on all patients with gastric adenocarcinoma diagnosed from 1973 to 2011 (n = 9093) were obtained from the population-based Eindhoven cancer registry. Incidence time trends (European standardized rates per 100,000) were separately analyzed by sex, age group (<60, 60–74, and >75 years), subsite, and pathological stage. Joinpoint analyses were performed to discern trend breaks, age–period–cohort analyses to examine the influence of longitudinal and cross-sectional changes.ResultsThe incidence of non-cardia cancer declined annually by 3.5% (95% CI −3.8; −3.3). However, in males <60 years, the incidence flattened since 2006, and tended to rise in those >74 years. This pertained to corpus cancers. The incidence of cardia cancer peaked in 1985 and decreased subsequently by 2.4% (95% CI −3.2; −1.5) yearly. The absolute incidence of stage IV disease at first diagnosis initially decreased, but then remained stable over the past 15–20 years.ConclusionsThe incidence of non-cardia cancer declined over the past four decades in the Netherlands, but now seems to be stabilizing particularly in males. Unfavorable trend breaks are seen for corpus cancer in younger and older males. The trend breaks in the Netherlands are however not similar to those observed in the US. 相似文献
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664.
Limitations,depressive symptoms,and quality of life among a population‐based sample of young adults with congenital heart defects 下载免费PDF全文
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Birth order has been examined over a wide variety of dimensions in the context of modern populations. A consistent message
has been that it is better to be born first. The analysis of birth order in this paper is different in several ways from other
investigations into birth order effects. First, we examine the effect of birth order in an egalitarian, small-scale, kin-based
society, which has not been done before. Second, we use a different outcome measure, fertility, rather than outcome measures
of social, psychological, or economic success. We find, third, that being born late in an egalitarian, technologically simple
society rather than being born early has a positive outcome on fertility, and fourth, that number of older siblings and sibling
set size are even stronger predictors of fertility, especially for males.
Patricia Draper is a professor in the Department of Anthropology at the University of Nebraska. Her research interests are
in cross-cultural human development, evolutionary theory, hunter-gatherer society, and comparative family organization.
Raymond Hames is also a professor in the Department of Anthropology at the University of Nebraska. His research interests
are in behavioral and evolutionary ecology, exchange systems, and tropical forest peoples. 相似文献
668.
A key common feature of all but three known mammalian genera is the strict seven cervical vertebrae blueprint, suggesting the involvement of strong conserving selection forces during mammalian radiation. This is further supported by reports indicating that children with cervical ribs die before they reach reproductive age. Hypotheses were put up, associating cervical ribs (homeotic transformations) to embryonal cancer (e.g., neuroblastoma) or ascribing the constraint in cervical vertebral count to the development of the mammalian diaphragm. Here, we describe a spontaneous mutation c.196A > G in the Bos taurus T gene (also known as brachyury) associated with a cervical vertebral homeotic transformation that violates the fundamental mammalian cervical blueprint, but does not preclude reproduction of the affected individual. Genome-wide mapping, haplotype tracking within a large pedigree, resequencing of target genome regions, and bioinformatic analyses unambiguously confirmed the mutant c.196G allele as causal for this previously unknown defect termed vertebral and spinal dysplasia (VSD) by providing evidence for the mutation event. The nonsynonymous VSD mutation is located within the highly conserved T box of the T gene, which plays a fundamental role in eumetazoan body organization and vertebral development. To our knowledge, VSD is the first unequivocally approved spontaneous mutation decreasing cervical vertebrae number in a large mammal. The spontaneous VSD mutation in the bovine T gene is the first in vivo evidence for the hypothesis that the T protein is directly involved in the maintenance of the mammalian seven-cervical vertebra blueprint. It therefore furthers our knowledge of the T-protein function and early mammalian notochord development. 相似文献
669.
Heat shock proteins Hsp70-1 and Hsp70-3 Are necessary and sufficient to prevent arsenite-induced dysmorphology in mouse embryos. 总被引:2,自引:0,他引:2
Heat Shock Proteins (HSPs) represent a variety of protein families that are induced by stressors such as heat and toxicants, and the induction of HSPs in the organogenesis stage rodent embryo is well established. It has been proposed that thermotolerance and chemotolerance result from expression of the HSPs. However, whether these proteins function to prevent dysmorphogenesis and which family members serve this function are unknown. Therefore, we evaluated the specific ability of stress-inducible Hsp70-1 and Hsp70-3 to prevent arsenite-induced dysmorphology in the cultured mouse embryo using gain- and loss-of-function models. Loss of HSP function was accomplished by injecting antisense oligonucleotides directed against hsp70-1 and hsp 70-3 mRNAs into the amniotic cavity of cultured Day 9 mouse embryos. Suppression of hsp70-1 and hsp70-3 expression resulted in an up to six-fold increase in the incidence of arsenite-induced neural tube defects. Gain of HSP function was accomplished by microinjecting a transgene with a constitutive promotor driving expression of the hsp70-1 coding region, and resulted in a decreased incidence of arsenite-induced neural tube defects. These results indicate that Hsp70-1 and Hsp70-3 are both necessary and sufficient for preventing arsenite-induced dysmorphology in early-somite staged mouse embryos. Mol. Reprod. Dev. 59:285-293, 2001. 相似文献
670.
Andrea B. Gorzitze 《Primates; journal of primatology》1996,37(1):75-78
Two births of wild proboscis monkeys took place during a 1991/1992 field study at Tanjung Puting National Park, Indonesia.
After conception, both females continued copulating with their group’s male. One of the births took place during the night,
the other during mid-morning. In the latter case, the infant was born unassisted while the members of the group watched the
birthing process. After parturition, the mother consumed the placenta. 相似文献