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71.
《Biotechnic & histochemistry》2013,88(5):267-271
AbstractArgyrophilic nucleolar organizing region (AgNORs) associated proteins are important for cell proliferation and various diseases. We investigated AgNOR protein synthesis in hair root cells of males and females at different ages using two-dimensional image analysis. Experiments were performed on 58 healthy male and 24 healthy female volunteers in three groups according to age and sex. Hair root cells obtained from hair follicles were stained with silver. Total AgNOR number/total nuclear number (TAN/TNN) and total AgNOR area/nuclear area (TAA/NA) for each nucleus were analyzed. The only significant difference was observed in TAA/NA values for males and females from 6 to 12 years old. We suggest that the difference is due to high NOR activity caused by increased growth hormone production in hair root cells. 相似文献
72.
Some insect species are thought to grow quickly, even in low temperatures under natural conditions, presumably by conducting basking behaviors to use sunlight. However, whether basking behavior in fact enhances developmental speed and shortens the larval period in the field has not been determined. Moreover, few studies have examined whether basking is behavioral thermoregulation or simply the result of highly‐heterogeneous heat environments in the field. To examine these issues, we conducted field observations and laboratory experiments using larvae of Parnassius citrinarius Motschulsky, which mature within a short period after the thaw in early spring. First, body temperatures of larvae were measured under sunny and cloudy conditions. Second, larval preference for warmer locations was examined. Finally, we compared the developmental speed of larvae when they basked under field conditions and when did not bask in laboratory conditions under different air temperature regimes. Under sunny conditions, larval body temperature was substantially higher than either the temperature of the host plant or the air temperature, and was equivalent to the temperature of dead leaves, which the larvae used as basking sites. In contrast, no such tendency was observed under cloudy conditions. Larvae exhibited an exclusive preference for warmer locations. Moreover, in the field, despite the low ambient temperature, larvae grew much faster than those reared in the laboratory. These results imply that the basking behavior of P. citrinarius larvae is active thermoregulation to maintain high body temperatures in the cold season. 相似文献
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74.
《Epigenetics》2013,8(11):1473-1484
In utero smoke exposure has been shown to have detrimental effects on lung function and to be associated with persistent wheezing and asthma in children. One potential mechanism of IUS effects could be alterations in DNA methylation, which may have life-long implications. The goal of this study was to examine the association between DNA methylation and nicotine exposure in fetal lung and placental tissue in early development; nicotine exposure in this analysis represents a likely surrogate for in-utero smoke. We performed an epigenome-wide analysis of DNA methylation in fetal lung tissue (n = 85, 41 smoke exposed (48%), 44 controls) and the corresponding placental tissue samples (n = 80, 39 smoke exposed (49%), 41 controls) using the Illumina HumanMethylation450 BeadChip array. Differential methylation analyses were conducted to evaluate the variation associated with nicotine exposure. The most significant CpG sites in the fetal lung analysis mapped to the PKP3 (P = 2.94 × 10?03), ANKRD33B (P = 3.12 × 10?03), CNTD2 (P = 4.9 × 10?03) and DPP10 (P = 5.43 × 10?03) genes. In the placental methylome, the most significant CpG sites mapped to the GTF2H2C and GTF2H2D genes (P = 2.87 × 10?06 ? 3.48 × 10?05). One hundred and one unique CpG sites with P-values < 0.05 were concordant between lung and placental tissue analyses. Gene Set Enrichment Analysis demonstrated enrichment of specific disorders, such as asthma and immune disorders. Our findings demonstrate an association between in utero nicotine exposure and variable DNA methylation in fetal lung and placental tissues, suggesting a role for DNA methylation variation in the fetal origins of chronic diseases. 相似文献
75.
Steffen Schneider Thomas Hofmann Stefan Stinchcombe Maria Cecilia Rey Moreno Ivana Fegert Volker Strauss Sibylle Gröters Eric Fabian Jutta Thiaener Karma C. Fussell Bennard van Ravenzwaay 《Birth defects research. Part B, Developmental and reproductive toxicology》2013,98(3):230-246
Epoxiconazole, a triazole‐based fungicide, was tested in toxicokinetic, prenatal and pre‐postnatal toxicity studies in guinea pigs, following oral (gavage) administration at several dose levels (high dose: 90 mg/kg body weight per day). Maternal toxicity was evidenced by slightly increased abortion rates and by histopathological changes in adrenal glands, suggesting maternal stress. No compound‐related increase in the incidence of malformations or variations was observed in the prenatal study. In the pre‐postnatal study, epoxiconazole did not adversely affect gestation length, parturition, or postnatal growth and development. Administration of epoxiconazole did not alter circulating estradiol levels. Histopathological examination of the placentas did not reveal compound‐related effects. The results in guinea pigs are strikingly different to those observed in pregnant rats, in which maternal estrogen depletion, pathological alteration of placentas, increased gestation length, late fetal death, and dystocia were observed after administration of epoxiconazole. In the studies reported here, analysis of maternal plasma concentrations and metabolism after administration of radiolabeled epoxiconazole demonstrated that the different results in rats and guinea pigs were not due to different exposures of the animals. A comprehensive comparison of hormonal regulation of pregnancy and birth in murid rodents and primates indicates that the effects on pregnancy and parturition observed in rats are not applicable to humans. In contrast, the pregnant guinea pig shares many similarities to pregnant humans regarding hormonal regulation and is therefore considered to be a suitable species for extrapolation of related effects to humans. Birth Defects Res (Part B) 98:230–246, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
76.
DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease. 相似文献
77.
Laren Narapareddy Derek E. Wildman Don L. Armstrong Amy Weckle Aleeca F. Bell Crystal L. Patil Suzette D. Tardif Corinna N. Ross Julienne N. Rutherford 《American journal of primatology》2020,82(3):e23101
Accumulating evidence suggests that dysregulation of placental DNA methylation (DNAm) is a mechanism linking maternal weight during pregnancy to metabolic programming outcomes. The common marmoset, Callithrix jaccus, is a platyrrhine primate species that has provided much insight into studies of the primate placenta, maternal condition, and metabolic programming, yet the relationships between maternal weight and placental DNAm are unknown. Here, we report genome-wide DNAm from term marmoset placentas using reduced representation bisulfite sequencing. We identified 74 genes whose DNAm pattern is associated with maternal weight during gestation. These genes are predominantly involved in energy metabolism and homeostasis, including the regulation of glycolytic and lipid metabolic processes pathways. 相似文献
78.
Ingrid Rosenburg Cordeiro Mikiko Tanaka 《BioEssays : news and reviews in molecular, cellular and developmental biology》2020,42(9):2000025
Oxygen is a key regulator of both development and homeostasis and a promising candidate to bridge the influence of the environment and the evolution of new traits. To clarify the various ways in which oxygen may modulate embryogenesis, its effects are reviewed at distinct organizational levels. First, the role of pathways that sense dioxygen levels and reactive oxygen species are reviewed. Then, the effects of microenvironmental oxygen on metabolism, stemness, and differentiation throughout embryogenesis are discussed. Last, the interplay between ecology and development are reexamined with a focus on the evolution of tetrapods, including during the emergence of a novel mechanism that shapes amniote limbs—interdigital cell death. Both genetic and environmental components work together during the formation of organisms, highlighting the importance of a multidisciplinary approach for understanding the evolution of new traits. 相似文献
79.
80.
Koichi Hirabayashi Masaaki Shiohara Kazuhiro Yamada Akane Sueki Yuichiro Ide Koichi Takeuchi Rokuro Hagimoto Tatsuya Kinoshita Akihiko Yabuhara S. Harvey Mudd Kenichi Koike 《Gene》2013