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991.
Intracellular Viral RNA Species in Mouse Cells Nonproductively Transformed by the Murine Sarcoma Virus 下载免费PDF全文
The size and quantity of virus-specific RNA in five non-virus-producing mouse cells transformed by the Moloney isolate of murine sarcoma virus (MSV) was determined. Hybridization of RNA from transformed cells with the [(3)H]DNA product of the RNA-directed DNA polymerase of the murine sarcoma-leukemia virus was used to detect and quantitate virus-specific RNA. The amount of virus-specific RNA in non-virus-producing cells was less than one-sixth of that found in virus-producing cells. A striking correlation was found between the amount of intracellular virus-specific RNA and the degree of agglutination by conconavalin A previously reported for the four non-virus-producing NIH/3T3 cell lines (Salzberg and Green, 1974). A major RNA subunit sedimenting at 26 to 28S was detected in all five MSV-transformed non-virus-producing cells. This could represent the RNA genome of defective MSV. 相似文献
992.
A conditional mutant, referred to as RepR43, was isolated from Escherichia coli W2252 by N-methyl-N'-nitro-N-nitroso-guanidine mutagenesis. Although RepR43 does not permit growth of RNA phage beta at the restrictive temperature, 43 degrees C, cell growth and synthesis of macromolecules such as RNA and protein continue at a somewhat reduced rate. Several lines of evidence indicate that a RepR43 function is indispensable for normal phage RNA replication. In addition, this function appears to be involved in the maintenance of the perpetuated phage genome. The addition of 10% sucrose to the medium at the restrictive temperature resulted in the production of the phage, suggesting that the mutant cell might have an altered membrane organization which interferes with normal viral replication. 相似文献
993.
Setsuko Tohno Yoshiyuki Tohno Takeshi Minami Yuko Okazaki Masako Utsumi Fumio Nishiwaki Yumi Moriwake Masa-oki Yamada 《Biological trace element research》1998,62(1-2):17-23
To elucidate age-related changes of mineral contents in human veins, the relative contents (RCs) of elements in the human
internal jugular veins, superior and inferior venae cavae, and femoral veins from 27 subjects ranging from 40 to 98 yr old
were analyzed by inductively coupled plasma atomic emission spectrometry.
The average RCs of calcium in the 27 specimens were the highest in the internal jugular vein, followed in descending order
by the superior vena cava, femoral vein, and inferior vena cava.
The RCs of calcium and phosphorus in the internal jugular veins started to increase after the age of 50 yr, became the highest
in subjects in their 60s and thereafter decreased gradually. It is noted that such accumulations of minerals, similar to the
internal jugular vein, were also found in the veins, such as the superior and inferior venae cavae, and femoral vein. Accumulation
of minerals in the veins is different from that of arteries, which increase progressively by aging, but do not decrease. 相似文献
994.
Hirao K Natsuka Y Tamura T Wada I Morito D Natsuka S Romero P Sleno B Tremblay LO Herscovics A Nagata K Hosokawa N 《The Journal of biological chemistry》2006,281(14):9650-9658
Quality control in the endoplasmic reticulum ensures that only properly folded proteins are retained in the cell through mechanisms that recognize and discard misfolded or unassembled proteins in a process called endoplasmic reticulum-associated degradation (ERAD). We previously cloned EDEM (ER degradation-enhancing alpha-mannosidase-like protein) and showed that it accelerates ERAD of misfolded glycoproteins. We now cloned mouse EDEM3, a soluble homolog of EDEM. EDEM3 consists of 931 amino acids and has all the signature motifs of Class I alpha-mannosidases (glycosyl hydrolase family 47) in its N-terminal domain and a protease-associated motif in its C-terminal region. EDEM3 accelerates glycoprotein ERAD in transfected HEK293 cells, as shown by increased degradation of misfolded alpha1-antitrypsin variant (null (Hong Kong)) and of TCRalpha. Overexpression of EDEM3 also greatly stimulates mannose trimming not only from misfolded alpha1-AT null (Hong Kong) but also from total glycoproteins, in contrast to EDEM, which has no apparent alpha1,2-mannosidase activity. Furthermore, overexpression of the E147Q EDEM3 mutant, which has the mutation in one of the conserved acidic residues essential for enzyme activity of alpha1,2-mannosidases, abolishes the stimulation of mannose trimming and greatly decreases the stimulation of ERAD by EDEM3. These results show that EDEM3 has alpha1,2-mannosidase activity in vivo, suggesting that the mechanism whereby EDEM3 accelerates glycoprotein ERAD is different from that of EDEM. 相似文献
995.
PI4P-signaling pathway for the synthesis of a nascent membrane structure in selective autophagy 下载免费PDF全文
Phosphoinositides regulate a wide range of cellular activities, including membrane trafficking and biogenesis, via interaction with various effector proteins that contain phosphoinositide binding motifs. We show that in the yeast Pichia pastoris, phosphatidylinositol 4'-monophosphate (PI4P) initiates de novo membrane synthesis that is required for peroxisome degradation by selective autophagy and that this PI4P signaling is modulated by an ergosterol-converting PpAtg26 (autophagy-related) protein harboring a novel PI4P binding GRAM (glucosyltransferase, Rab-like GTPase activators, and myotubularins) domain. A phosphatidylinositol-4-OH kinase, PpPik1, is the primary source of PI4P. PI4P concentrated in a protein-lipid nucleation complex recruits PpAtg26 through an interaction with the GRAM domain. Sterol conversion by PpAtg26 at the nucleation complex is necessary for elongation and maturation of the membrane structure. This study reveals the role of the PI4P-signaling pathway in selective autophagy, a process comprising multistep molecular events that lead to the de novo membrane formation. 相似文献
996.
Immunolocalization of vascular endothelial growth factor on intramuscular ectopic osteoinduction by bone morphogenetic protein-2 总被引:7,自引:0,他引:7
When recombinant human bone morphogenetic protein-2 (rhBMP-2) is implanted in soft tissues, bony tissue is induced during the course of endochondral ossification. The relationship between endochondral ossification and vascularization is important in bone formation, and vascular endothelial growth factor (VEGF) is considered to play an important role in this process. In this study, the immunohistological localization of VEGF was investigated in rhBMP-2-induced ectopic endochondral ossification in the calf muscle of rats. In addition, the characteristics of anti-VEGF antibody-reactive cells were histologically investigated using electron microscopy to examine the cause of endochondral ossification induced by recombinant human bone morphogenetic protein-2. The role of VEGF in rhBMP-2-induced osteoinduction and vascular induction was studied by observing the relationship between the localizations of anti-VEGF antibody-reactive cells and vascularization. During the process of rhBMP-2-induced ectopic endochondral ossification, fibroblast-like cells, which were located at the margin of the implant and reactive to BMP-2 at 5 days, were positive for VEGF immunostaining. Hypertrophic chondrocytes appeared 9 days and osteoblasts appeared 14 to 21 days after implantation, and all these cells were reactive with anti-VEGF antibody. Bony trabeculae subsequently appeared in the muscle, and new blood vessels were formed alongside the trabeculae. When VEGF was added to rhBMP, more new blood vessels and bone were formed in the induced bone. These findings suggested that rhBMP-2 induced the differentiation of undifferentiated mesenchymal cells to chondrocytes and osteoblasts, and these differentiated cells expressed VEGF, creating an advantageous environment for vascularization in bony tissue. 相似文献
997.
998.
Hisao Oka Yoshitomo Ikai Yuko Ito Junko Hayakawa Ken-ichi Harada Makoto Suzuki Hiroko Odani Kenji Maeda 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,693(2):687
To reliably identify the residual tetracycline antibiotics (TCs), oxytetracycline (OTC), tetracycline, chlortetracycline (CTC) and doxycycline (DC), in bovine tissues, we have established a confirmation method using electrospray ionization liquid chromatography–tandem mass spectrometry (ESI LC–MS–MS) with daughter ion scan. All TCs gave [M+H−NH3]+ and [M+H−NH3−H2O]+ as the product ions, except for DC when [M+H]+ was selected as the precursor ion. The combination of C18 cartridge clean-up and the present ESI LC–MS–MS method can reliably identify TCs fortified at a concentration of 0.1 ppm in bovine tissues, including liver, kidney and muscle, and has been successfully applied to the identification of residual OTC in bovine liver and residual CTC in bovine muscle samples previously found at concentrations of 0.58 ppm and 0.38 ppm by LC, respectively. 相似文献
999.
Takeshi Nishijima Misao Takano Shoko Matsumoto Miki Koyama Yuko Sugino Miwa Ogane Kazuko Ikeda Yoshimi Kikuchi Shinichi Oka Hiroyuki Gatanaga 《PloS one》2015,10(11)
Background
Japan has not succeeded in reducing the annual number of new HIV-infected patients, although the prevalence of HIV infection is low (0.02%).Methods
A single-center observational study was conducted at the largest HIV clinic in Tokyo, which treats 15% of the total patients in Japan, to determine the reasons for having diagnostic tests in newly infected individuals. HIV-infected patients who visited our clinic for the first time between 2011 and 2014 were analyzed.Results
The 598 study patients comprised one-third of the total reported number of new patients in Tokyo during the study period. 76% were Japanese MSM. The reasons for being tested which led to the diagnosis was voluntary testing in 32%, existing diseases in 53% (AIDS-defining diseases in 22%, sexually transmitted infections (STI) in 8%, diseases other than AIDS or STIs in 23%) and routine pre-surgery or on admission screening in 15%. 52% and 74% of the study patients and patients presented with AIDS, respectively, had never been tested. The median CD4 count in patients with history of previous testing (315/μL) was significantly higher than that of patients who had never been tested (203/μL, p<0.001).Conclusions
Only 32% of the newly HIV diagnosed patients were diagnosed because of voluntary testing, and 53% were diagnosed due to presence of other diseases. These results remain unchanged from our previous report 10 years earlier (2000–2004) on newly diagnosed patients at the same clinic. HIV testing has not been widely used by newly diagnosed patients in the Tokyo metropolitan area. 相似文献1000.
Takahashi H Shinoyama M Komine T Nagao M Suzuki M Tsuchida H Katsuyama K 《Bioorganic & medicinal chemistry letters》2011,21(6):1758-1762
Synthesis, and structure-activity relationship (SAR) studies of the novel IKK-β inhibitors 2 and 3 characterized by a dihydrothieno[2,3-e]indazole core are presented. Compound 2t was efficacious in a mouse model of LPS-stimulated TNF-α production. 相似文献