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Nuclear reconstitution of demembranatedOrychophragmus violaceus sperm inXenopus laevis egg extracts
Ping Lu,Min Ren,Zhonghe Zhai
Science China Life Sciences , 2002, DOI: 10.1007/BF02879750
Abstract: The cell-free extracts from animalXenopus laevis egg could induce chromatin decondensation and pronuclear formation from demembranated plant (Orychophragmus violaceu) sperm. The demembranatedOrychophragmus violaceus sperm began to swell in 30 min incubation, and then were gradually decondensed. The reassembly of nuclear envelope in the reconstituted nuclei had been visualized by means of electron microscopy and fluorescent microscopy. Membrane vesicles fused to form the double envelope around the periphery of the decondensed chromatin. The morphology of the newly formed nucleus, with a double membrane, was similar to those nuclei after fertilization. Transmission electron microscope micrograph of the whole mount prepared nuclear matrix-lamina showed the reconstituted nucleus to be filled with a dense network.
Identification of a DNase activated inXenopus egg extracts undergoing apoptosis
Shan Zhu,Zhengfan Jiang,Bo Zhang,Zhigang Lu,Zhonghe Zhai
Chinese Science Bulletin , 1998, DOI: 10.1007/BF02883826
Abstract: A cell-free apoptosis system was established by adding dATP and cytochrome c toXenopus laevis egg extracts S-150. Accompanied by an incubation process, an apoptosis-specific DNase was activated in egg extracts which depended on Mg2+ and inhibited by Zn2+. Two nucleases existing in egg extracts were revealed by in-gel nuclease assay. Further experiments showed that 27 ku nuclease which was different from other Ca2+ /Mg2+ -dependent nucleases was a possible candidate involved in apoptosis.
The microtubule aster formation and its role in nuclear envelope assembly around the sperm chromatin inXenopus egg extracts
Ning Yang,Zhongcai Chen,Ping Lu,Chuanmao Zhang,Zhonghe Zhai,Xiaowei Tang
Chinese Science Bulletin , 2003, DOI: 10.1007/BF03183977
Abstract: Nuclear envelope is a dynamic structure in the cell cycle. At the beginning of mitosis, nuclear envelope breaks down and its components disperse into the cytoplasm. At the end of mitosis, nuclear envelope reassembles using the dispersed components. Searching for the mechanisms of the nuclear disassembly and reassembly has for a long time been one of the key projects for cell biologists. In this report we show that microtubules take a role in the nuclear envelope assembly around the sperm chromatin inXenopus egg extracts. Microtubule cytoskeleton has been demonstrated to take roles in the transport of intracellular membranes such as Golgi and ER vesicles. We found that the nuclear envelope assembly needs functional microtubules. At the beginning of the nuclear assembly, microtubules nucleated to form a microtubule aster around the centrosome at the base of the sperm head. Using the microtubule drug colchicine to disrupt the microtubule nucleation, nuclear envelope reassembly was seriously inhibited. If the microtubules were stabilized by taxol, another microtubule drug, the nuclear envelope reassembly was also interfered, although a significantly large aster formed around the chromatin. Based on these observations, we propose that microtubules play an important role in the nuclear envelope reassembly maybe by transporting the nuclear envelope precursors to the chromatin surfaces.
Immune reconstitution inflammatory syndrome  [cached]
Sharma Ajay,Makrandi Smita,Modi Megha,Sharma Archana
Indian Journal of Dermatology, Venereology and Leprology , 2008,
Abstract: Background: Immune reconstitution inflammatory syndrome (IRIS) is a paradoxical deterioration in clinical status in a patient on antiretroviral treatment (ART) despite satisfactory control of viral replication and improvement of CD4 count. Aim: To study development of IRIS as a part of ART. Methods: Hundred patients on antiretroviral treatment were studied prospectively in the Department of Skin and VD over a period of 2 years. Patients were asked to come if they developed any symptoms or on a monthly basis. They were screened clinically and investigated suitably for evidence of opportunistic infections. Results: Out of 100 patients, 10 patients did not come for follow-up. Twenty (22.2%) out of the 90 patients developed IRIS. Herpes zoster (HZ), herpes simplex virus (HSV), and tuberculosis (TB) were the cases of IRIS seen in the present study. Conclusions: IRIS in terms of HSV/TB is known to accelerate HIV disease progression. Hence early detection and prompt treatment, along with continuation of highly active ART, are of utmost importance.
Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae) fourth instar larvae
Albeny, Daniel S;Martins, Gustavo F;Andrade, Mateus R;Krüger, Rodrigo F;Vilela, Evaldo F;
Zoologia (Curitiba) , 2011, DOI: 10.1590/S1984-46702011000400017
Abstract: the mosquito aedes aegypti (linnaeus, 1762) is the main vector of dengue and yellow fever viruses. different methods have been used to control a. aegypti, including chemical and biological tools. however, chemical control can lead to a subsequent increase in the mosquitoes' insecticide resistance, and biological control represents an important method as an alternative to insecticide usage. larvae from the toxorhynchites genus (diptera: culicidae) are predators of other mosquitoes and represent a potential natural biocontrol agent of a. aegypti larvae. in the present work, a. aegypti larval survival was studied in the presence of the neotropical toxorhynchites violaceus (wiedemann, 1821) fourth instar larvae. toxorhynchites violaceus consumption of a. aegypti increased during the 192 hours of the experiment and was more marked in the intervals between 96 and 120 hours and between 168 and 192 hours, when the a. aegypti survival reached 0%. during the fourth instar, t. violaceus increased its predation on a. aegypti larvae, possibly in order to increase its nutrient storage prior to pupation. otherwise, low prey consumption can lead to a nutritional deficit for the larvae, delaying the adult's sexual development and reducing its egg production. here we show that a. aegypti survival can be reduced by the t. violaceus fourth larvae predation under laboratory conditions
无类囊体蓝藻Gloeobacter violaceus基于广宿主质粒的遗传转移系统
郭海涛,徐旭东
自然科学进展 , 2003,
Abstract: 无类囊体蓝藻Gloeobacter violaceus的细胞有厚胶质鞘包裹并形成群体,难以进行遗传操作.用注射器反复吸打的方法将胶质鞘剥落,得到大量单个细胞,通过接合转移将外源广宿主质粒pKT210转入G.violaceus.用斑点杂交方法以及对质粒进行酶切图谱分析,均证实外源质粒pKT210确已导入G.violaceus并稳定复制,未发生结构上的变化.从G.violaceus提取的pKT210可转化mcr和mrr基因缺陷的大肠杆菌DH10B却不能转化mcr+mrr+菌株DH5a,表明G.vio-laceus中可能存在甲基化酶系统.
Application of Xenopus laevis in ecotoxicology (I) —Introduction and quality control of laboratory animal
Zhanfen Qin,Xiaobai Xu
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-1273-3
Abstract: The aim of the series of papers is to discuss the application of Xenopus laevis, as model animal in biology, in ecotoxicology. X. laevis as model animal is wildly used in biological study and has provided a lot of relating data because of many advantages, such as living in water and being easily maintained, laying eggs in the whole year, and externally fertilizing and developing. Embryos and larvae of X. laevis like other amphibians are directly exposed in the aquatic environment and sensitive to pollutants. In addition, sex differentiation and sex organ development of X. laevis are sensitive to sex hormones and endocrine disruptors with sex hormone activities, which enable X. laevis to be used in studies on sex hormone disruption and reproductive toxicity of endocrine disruptors. Metamorphic development of X. laevis is very sensitive to thyroid hormones and thyroid disruptors, which enables X. laevis to be used for evaluating thyroid disruptors. Also, X. laevis ecotoxicology can be linked with amphibian population declines and malformed frog occurrence, being one of the hotspots in ecology. Thus, more and more laboratories have introduced X. laevis to ecotoxicological study. The quality of laboratory animals correlates with scientificity and reliability of results from animal experiments. It is especially important for toxicology. Quality control of X. laevis involving several factors such as water and food is discussed in this paper.
Immune reconstitution inflammatory syndrome in children
H Rabie, T Meyers, M Cotton
Southern African Journal of HIV Medicine , 2009,
Abstract: Paradoxical deterioration due to immune reconstitution inflammatory syndrome (IRIS) occurs in up to 21% of children initiating antiretroviral therapy. Mycobacterial diseases are the most common, with BCG-vaccine adenitis predominating in infants and Mycobacterium tuberculosis (TB) in older children. The difficulty of diagnosing TB in HIV-infected children and the increasing risk of drug-resistant TB complicate the diagnosis and management of both paradoxical IRIS and post-antiretroviral therapy TB. History and clinical assessment remain key strategies in the management of these infants and children. There are no prospective studies investigating diagnostic criteria and therapeutic strategies in children.
NUCLEAR RECONSTITUTION IN THE Xenopus laevis EGG EXTRACTS CELL-FREE SYSTEM

科学通报(英文版) , 1991,
Abstract:
Morfoanatomia e ontogênese da samara de Pterocarpus violaceus Vogel (Fabaceae: Faboideae)
Nakamura, Adriana Tiemi;Oliveira, Denise Maria Trombert;
Brazilian Journal of Botany , 2005, DOI: 10.1590/S0100-84042005000200016
Abstract: morphological, anatomical and developmental descriptions of p. violaceus fruits and seeds were made in order to verify the origin of the pericarpic wing and the occurrence of polyembryonic seeds, previously described for other dalbergieae genera. the fruit is a circular, glabrous samara. seeds show some typical characters of the faboideae specially in the hilar region. we describe six different fruit developmental stages. the pericarpic wing originates from the expansion of the ovary wall; the pericarp grows dorsiventrally, apically and basally, producing a flattened structure. in all material analysed, we do not find polyembryonic seeds. we also conclude that the pericarp of p. violaceus is unusual because of the fusion of its ventral vascular bundles, a feature that is considered phylogenetically derived for the group.
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